Isolation and Characterization of Three New Monoterpene Synthases from Artemisia annua

PubMed Central

Ruan, Ju-Xin; Li, Jian-Xu; Fang, Xin; Wang, Ling-Jian; Hu, Wen-Li; Chen, Xiao-Ya; Yang, Chang-Qing

2016-01-01

Artemisia annua, an annual herb used in traditional Chinese medicine, produces a wealth of monoterpenes and sesquiterpenes, including the well-known sesquiterpene lactone artemisinin, an active ingredient in the treatment for malaria. Here we report three new monoterpene synthases of A. annua. From a glandular trichome cDNA library, monoterpene synthases of AaTPS2, AaTPS5, and AaTPS6, were isolated and characterized. The recombinant proteins of AaTPS5 and AaTPS6 produced multiple products with camphene and 1,8-cineole as major products, respectively, and AaTPS2 produced a single product, β-myrcene. Although both Mg2+ and Mn2+ were able to support their catalytic activities, altered product spectrum was observed in the presence of Mn2+ for AaTPS2 and AaTPS5. Analysis of extracts of aerial tissues and root of A. annua with gas chromatography–mass spectrometry detected more than 20 monoterpenes, of which the three enzymes constituted more than 1/3 of the total. Mechanical wounding induced the expression of all three monoterpene synthase genes, and transcript levels of AaTPS5 and AaTPS6 were also elevated after treatments with phytohormones of methyl jasmonate, salicylic acid, and gibberellin, suggesting a role of these monoterpene synthases in plant–environment interactions. The three new monoterpene synthases reported here further our understanding of molecular basis of monoterpene biosynthesis and regulation in plant. PMID:27242840

Spruce budworm feeding and oviposition are stimulated by monoterpenes in white spruce epicuticular waxes.

PubMed

Ennis, Darragh; Despland, Emma; Chen, Fei; Forgione, Pat; Bauce, Eric

2017-02-01

Monoterpenes, source of the distinctive odor of conifers, are generally considered plant defensive compounds. However, they are also known to act as long-range insect attractants, as they are volatile and permeate forest airspaces. Moreover, they are lipid soluble and can be absorbed into plant epicuticular waxes. We test their role in short-range host plant choice by both adult females and larvae of a folivorous forest pest (Choristoneura fumiferana). We conducted laboratory assays testing the responses of Eastern spruce budworm to an artificial monoterpene mix (α-pinene, β-pinene, limonene, myrcene) and to white spruce (Picea glauca) epicuticular waxes in closed arenas. Ovipositing females preferred filter paper discs treated with P. glauca waxes to controls, and preferred the waxes + monoterpenes treatment to waxes alone. However, females showed no preference between the monoterpene-treated disc and the control when presented without waxes. Feeding larvae prefered wax discs to control discs. They also consumed discs treated with realistic monoterpene concentrations and wax preferentially over wax-only discs, but showed no preference between extremely high monoterpene concentrations and wax-only controls. In an insect-free assay, P. glauca epicuticular wax decreased monoterpene volatilization. These results suggest that P. glauca waxes and realistic concentrations of monoterpenes are stimulatory to both egg-laying females and feeding larvae, and that their effects are synergistic. © 2015 Institute of Zoology, Chinese Academy of Sciences.

Is forest management a significant source of monoterpenes into the boreal atmosphere?

NASA Astrophysics Data System (ADS)

Haapanala, S.; Hakola, H.; Hellén, H.; Vestenius, M.; Levula, J.; Rinne, J.

2012-04-01

Volatile organic compounds (VOCs) including terpenoids are emitted into the atmosphere from various natural sources. Damaging the plant tissue is known to strongly increase their monoterpene release. We measured the terpenoid emissions caused by timber felling, i.e. those from stumps and logging residue. The emissions from stumps were studied using enclosures and those from the whole felling area using an ecosystem-scale micrometeorological method, disjunct eddy accumulation (DEA). The compounds analyzed were isoprene, monoterpenes and sesquiterpenes. Strong emissions of monoterpenes were measured from both the stumps and from the whole felling area. The emission rate decreased rapidly within a few months after the logging. In addition to fresh logging residue, the results suggest also other strong monoterpene sources may be present in the felling area. These could include pre-existing litter, increased microbial activity and remaining undergrowth. In order to evaluate the possible importance of monoterpenes emitted annually from cut Scots pine forests in Finland, we conducted a rough upscaling calculation. The resulting monoterpene release was approximated to be on the order of 15 kilotonnes per year, which corresponds to about one tenth of the monoterpene release from intact forests in Finland.

Air-Sea exchange of biogenic volatile organic compounds and the impact on aerosol particle size distributions

NASA Astrophysics Data System (ADS)

Kim, Michelle J.; Novak, Gordon A.; Zoerb, Matthew C.; Yang, Mingxi; Blomquist, Byron W.; Huebert, Barry J.; Cappa, Christopher D.; Bertram, Timothy H.

2017-04-01

We report simultaneous, underway eddy covariance measurements of the vertical flux of isoprene, total monoterpenes, and dimethyl sulfide (DMS) over the Northern Atlantic Ocean during fall. Mean isoprene and monoterpene sea-to-air vertical fluxes were significantly lower than mean DMS fluxes. While rare, intense monoterpene sea-to-air fluxes were observed, coincident with elevated monoterpene mixing ratios. A statistically significant correlation between isoprene vertical flux and short wave radiation was not observed, suggesting that photochemical processes in the surface microlayer did not enhance isoprene emissions in this study region. Calculations of secondary organic aerosol production rates (PSOA) for mean isoprene and monoterpene emission rates sampled here indicate that PSOA is on average <0.1 μg m-3 d-1. Despite modest PSOA, low particle number concentrations permit a sizable role for condensational growth of monoterpene oxidation products in altering particle size distributions and the concentration of cloud condensation nuclei during episodic monoterpene emission events from the ocean.

Monoterpene persistence in the sapwood and heartwood of longleaf pine stumps: assessment of differences in composition and stability under field conditions

Treesearch

Thomas L. Eberhardt; Philip M. Sheridan; Jolie M. Mahfouz

2009-01-01

Monoterpenes in exudates, phloem and sapwood have received considerable attention relative to the active defenses of pine trees. However, little is known about the composition and function of the heartwood monoterpenes. To address this deficiency, monoterpene contents and relative compositions were determined for sapwood and heartwood samples from longleaf pine (Pinus...

Cloning and Characterizing Genes Involved in Monoterpene Induced Mammary Tumor Regression

DTIC Science & Technology

1998-05-01

Monoterpene -induced/repressed genes were identified in regressing rat mammary carcinomas treated with dietary limonene using a newly developed method...termed subtractive display. The subtractive display screen identified 42 monoterpene -induced genes comprising 9 known genes and 33 unidentified genes...as well as 58 monoterpene -repressed genes comprising 1 known gene and 57 unidentified genes. Several of the identified differentially expressed

Workplace concentrations and exposure assessment of monoterpenes in rosemary- and lavender-growing greenhouses.

PubMed

Tani, Akira; Nozoe, Susumu

2012-01-01

Monoterpenes can positively or negatively affect human health depending on their concentrations. To assess the atmospheric risk for greenhouse workers, monoterpene concentrations and personal exposure in herb-growing greenhouses were measured. Monoterpene concentrations in a commercial greenhouse, where rosemary (Rosmarinus officinalis L.) and lavender (Lavandula angustifolia L.) were grown in pots, were measured every 4 hours on 11 days spread across a year. In a small experimental greenhouse, typical horticultural tasks were conducted to determine the factors increasing monoterpene concentrations. Concentrations of α-pinene, camphene, β-pinene, limonene and cineole in the farmer's greenhouse were higher in winter than in summer because of longer ventilation periods of the greenhouse in summer. Further, the concentrations of these compounds were high (but <2 parts per billion in volume [ppbv]) when horticultural tasks were conducted inside the greenhouse. In a small experimental greenhouse, moving pots and cutting shoots increased ambient monoterpene concentrations to 10 ppbv. Spraying water also increased monoterpene concentrations but to a lesser extent. When performing tasks, greenhouse workers were exposed to monoterpene concentrations 2-3 times higher than the concentration in the ambient greenhouse air. Our measurement results reveal that monoterpene emissions are stimulated by horticultural tasks, even by spraying water. Our calculation result suggests that if ventilation is limited, the concentrations can reach levels high enough to cause sensory irritation in greenhouse workers. Greenhouse workers should be cautious when performing tasks for hours in tightly closed herb-growing greenhouses.

Cytosolic monoterpene biosynthesis is supported by plastid-generated geranyl diphosphate substrate in transgenic tomato fruits.

PubMed

Gutensohn, Michael; Orlova, Irina; Nguyen, Thuong T H; Davidovich-Rikanati, Rachel; Ferruzzi, Mario G; Sitrit, Yaron; Lewinsohn, Efraim; Pichersky, Eran; Dudareva, Natalia

2013-08-01

Geranyl diphosphate (GPP), the precursor of most monoterpenes, is synthesized in plastids from dimethylallyl diphosphate and isopentenyl diphosphate by GPP synthases (GPPSs). In heterodimeric GPPSs, a non-catalytic small subunit (GPPS-SSU) interacts with a catalytic large subunit, such as geranylgeranyl diphosphate synthase, and determines its product specificity. Here, snapdragon (Antirrhinum majus) GPPS-SSU was over-expressed in tomato fruits under the control of the fruit ripening-specific polygalacturonase promoter to divert the metabolic flux from carotenoid formation towards GPP and monoterpene biosynthesis. Transgenic tomato fruits produced monoterpenes, including geraniol, geranial, neral, citronellol and citronellal, while exhibiting reduced carotenoid content. Co-expression of the Ocimum basilicum geraniol synthase (GES) gene with snapdragon GPPS-SSU led to a more than threefold increase in monoterpene formation in tomato fruits relative to the parental GES line, indicating that the produced GPP can be used by plastidic monoterpene synthases. Co-expression of snapdragon GPPS-SSU with the O. basilicum α-zingiberene synthase (ZIS) gene encoding a cytosolic terpene synthase that has been shown to possess both sesqui- and monoterpene synthase activities resulted in increased levels of ZIS-derived monoterpene products compared to fruits expressing ZIS alone. These results suggest that re-direction of the metabolic flux towards GPP in plastids also increases the cytosolic pool of GPP available for monoterpene synthesis in this compartment via GPP export from plastids. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

Toxicity of Monoterpene Structure, Diversity and Concentration to Mountain Pine Beetles, Dendroctonus ponderosae: Beetle Traits Matter More.

PubMed

Reid, Mary L; Sekhon, Jagdeep K; LaFramboise, Lanielle M

2017-04-01

A high diversity of plant defenses may be a response to herbivore diversity or may be collectively more toxic than single compounds, either of which may be important for understanding insect-plant associations. Monoterpenes in conifers are particularly diverse. We tested the fumigant toxicity of four monoterpenes, alone and in combination, to mountain pine beetles, Dendroctonus ponderosae, in the context of the beetles' individual body traits. Chemical structures of tested monoterpene hydrocarbons had modest effects on beetle survival, mass loss, water content and fat content, with (R)-(+)-limonene tending to be more toxic than (-)-α-pinene, (-)-β-pinene, and (+)-3-carene. Monoterpene diversity (all qualitative combinations of one to four monoterpenes) did not affect toxicity. Concentration (0 to 1200 ppm) of individual monoterpenes was a strong determinant of toxicity. Beetle body size and body condition index strongly and positively affected survival during monoterpene treatments. Larger beetles in better condition lost proportionally less mass during exposure, where proportion mass loss negatively affected survivorship. Toxicity was much more associated with water loss than with fat loss, suggesting that a main cost of detoxification is excretion, a process that has received little attention. These results provide insight into the determinants of beetle success in historic and novel hosts that differ in monoterpene composition and concentration. We also suggest that water availability will affect beetle success directly through their ability to tolerate detoxification as well as indirectly through host responses to drought.

Co-expression of peppermint geranyl diphosphate synthase small subunit enhances monoterpene production in transgenic tobacco plants.

PubMed

Yin, Jun-Lin; Wong, Woon-Seng; Jang, In-Cheol; Chua, Nam-Hai

2017-02-01

Monoterpenes are important for plant survival and useful to humans. In addition to their function in plant defense, monoterpenes are also used as flavors, fragrances and medicines. Several metabolic engineering strategies have been explored to produce monoterpene in tobacco but only trace amounts of monoterpenes have been detected. We investigated the effects of Solanum lycopersicum 1-deoxy-d-xylulose-5-phosphate synthase (SlDXS), Arabidopsis thaliana geranyl diphosphate synthase 1 (AtGPS) and Mentha × piperita geranyl diphosphate synthase small subunit (MpGPS.SSU) on production of monoterpene and geranylgeranyl diphosphate (GGPP) diversities, and plant morphology by transient expression in Nicotiana benthamiana and overexpression in transgenic Nicotiana tabacum. We showed that MpGPS.SSU could enhance the production of various monoterpenes such as (-)-limonene, (-)-linalool, (-)-α-pinene/β-pinene or myrcene, in transgenic tobacco by elevating geranyl diphosphate synthase (GPS) activity. In addition, overexpression of MpGPS.SSU in tobacco caused early flowering phenotype and increased shoot branching by elevating contents of GA 3 and cytokinins due to upregulated transcript levels of several plastidic 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway genes, geranylgeranyl diphosphate synthases 3 (GGPPS3) and GGPPS4. Our method would allow the identification of new monoterpene synthase genes using transient expression in N. benthamiana and the improvement of monoterpene production in transgenic tobacco plants. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Influence of Light and Temperature on Monoterpene Emission Rates from Slash Pine

PubMed Central

Tingey, David T.; Manning, Marybeth; Grothaus, Louis C.; Burns, Walter F.

1980-01-01

There is a growing awareness of vegetation's role as a source of potentially reactive hydrocarbons that may serve as photochemical oxidant precursors. This study assessed the influence of light and temperature, independently, on monoterpene emissions from slash pine (Pinus elliottii Engelm.). Plants were preconditioned in a growth chamber, then transferred to an environmentally controlled gas exchange chamber. Samples of the chamber atmosphere were collected; the monoterpenes were concentrated cryogenically and measured by gas chromatography. Five monoterpenes (α-pinene, β-pinene, myrcene, limonene, and β-phellandrene) were present in the vapor phase surrounding the plants in sufficient quantity for reliable measurement. Light did not directly influence monoterpene emission rates since the emissions were similar in both the dark and at various light intensities. Monoterpene emission rates increased exponentially with temperature (i. e. emissions depend on temperature in a log-linear manner). The summed emissions of the five monoterpenes ranged from 3 to 21 micrograms C per gram dry weight per hour as temperature was increased from 20 to 46 C. Initially, emission rates from heat-stressed needles were similar to healthy needles, but rates decreased 11% per day. Daily carbon loss through monoterpene emissions accounted for approximately 0.4% of the carbon fixed during photosynthesis. PMID:16661285

Influence of light and temperature on monoterpene emission rates from slash pine.

PubMed

Tingey, D T; Manning, M; Grothaus, L C; Burns, W F

1980-05-01

There is a growing awareness of vegetation's role as a source of potentially reactive hydrocarbons that may serve as photochemical oxidant precursors. This study assessed the influence of light and temperature, independently, on monoterpene emissions from slash pine (Pinus elliottii Engelm.). Plants were preconditioned in a growth chamber, then transferred to an environmentally controlled gas exchange chamber. Samples of the chamber atmosphere were collected; the monoterpenes were concentrated cryogenically and measured by gas chromatography. Five monoterpenes (alpha-pinene, beta-pinene, myrcene, limonene, and beta-phellandrene) were present in the vapor phase surrounding the plants in sufficient quantity for reliable measurement. Light did not directly influence monoterpene emission rates since the emissions were similar in both the dark and at various light intensities. Monoterpene emission rates increased exponentially with temperature (i. e. emissions depend on temperature in a log-linear manner). The summed emissions of the five monoterpenes ranged from 3 to 21 micrograms C per gram dry weight per hour as temperature was increased from 20 to 46 C. Initially, emission rates from heat-stressed needles were similar to healthy needles, but rates decreased 11% per day. Daily carbon loss through monoterpene emissions accounted for approximately 0.4% of the carbon fixed during photosynthesis.

Monoterpene emissions from an understory species, Pteridium aquilinum

NASA Astrophysics Data System (ADS)

Madronich, Monica B.; Greenberg, James P.; Wessman, Carol A.; Guenther, Alex B.

2012-07-01

Monoterpene emissions from the dominant understory species Pteridium aquilinum (Bracken fern) in a mixed temperate forest were measured in the field during the summers of 2006, 2007 and 2008. The results showed that Bracken fern emitted monoterpenes at different rates depending if the plants were located in the understory or in open areas. Understory plants emitted monoterpene levels ranging from 0.002 to 13 μgC gdw-1 h-1. Open area plants emitted monoterpene levels ranging from 0.005 to 2.21 μgC gdw-1 h-1. During the summer of 2008 greenhouse studies were performed to complement the field studies. Only 3% of the greenhouse Bracken fern plants emitted substantial amounts of monoterpenes. The average emission, 0.15 μgC gdw-1 h-1 ± 0.9 μgC gdw-1 h-1, was much lower than that observed in the field. The factors controlling monoterpene emissions are not clear, but this study provides evidence of the potential importance of understory vegetation to ecosystem total hydrocarbon emissions and emphasizes the need for longer-term field studies.

Monoterpenes in the glandular trichomes of tomato are synthesized from a neryl diphosphate precursor rather than geranyl diphosphate.

PubMed

Schilmiller, Anthony L; Schauvinhold, Ines; Larson, Matthew; Xu, Richard; Charbonneau, Amanda L; Schmidt, Adam; Wilkerson, Curtis; Last, Robert L; Pichersky, Eran

2009-06-30

We identified a cis-prenyltransferase gene, neryl diphosphate synthase 1 (NDPS1), that is expressed in cultivated tomato (Solanum lycopersicum) cultivar M82 type VI glandular trichomes and encodes an enzyme that catalyzes the formation of neryl diphosphate from isopentenyl diphosphate and dimethylallyl diphosphate. mRNA for a terpene synthase gene, phellandrene synthase 1 (PHS1), was also identified in these glands. It encodes an enzyme that uses neryl diphosphate to produce beta-phellandrene as the major product as well as a variety of other monoterpenes. The profile of monoterpenes produced by PHS1 is identical with the monoterpenes found in type VI glands. PHS1 and NDPS1 map to chromosome 8, and the presence of a segment of chromosome 8 derived from Solanum pennellii LA0716 causes conversion from the M82 gland monoterpene pattern to that characteristic of LA0716 plants. The data indicate that, contrary to the textbook view of geranyl diphosphate as the "universal" substrate of monoterpene synthases, in tomato glands neryl diphosphate serves as a precursor for the synthesis of monoterpenes.

Monoterpenes in the glandular trichomes of tomato are synthesized from a neryl diphosphate precursor rather than geranyl diphosphate

PubMed Central

Schilmiller, Anthony L.; Schauvinhold, Ines; Larson, Matthew; Xu, Richard; Charbonneau, Amanda L.; Schmidt, Adam; Wilkerson, Curtis; Last, Robert L.; Pichersky, Eran

2009-01-01

We identified a cis-prenyltransferase gene, neryl diphosphate synthase 1 (NDPS1), that is expressed in cultivated tomato (Solanum lycopersicum) cultivar M82 type VI glandular trichomes and encodes an enzyme that catalyzes the formation of neryl diphosphate from isopentenyl diphosphate and dimethylallyl diphosphate. mRNA for a terpene synthase gene, phellandrene synthase 1 (PHS1), was also identified in these glands. It encodes an enzyme that uses neryl diphosphate to produce β-phellandrene as the major product as well as a variety of other monoterpenes. The profile of monoterpenes produced by PHS1 is identical with the monoterpenes found in type VI glands. PHS1 and NDPS1 map to chromosome 8, and the presence of a segment of chromosome 8 derived from Solanum pennellii LA0716 causes conversion from the M82 gland monoterpene pattern to that characteristic of LA0716 plants. The data indicate that, contrary to the textbook view of geranyl diphosphate as the “universal” substrate of monoterpene synthases, in tomato glands neryl diphosphate serves as a precursor for the synthesis of monoterpenes. PMID:19487664

Monoterpenes: Novel insights into their biological effects and roles on glucose uptake and lipid metabolism in 3T3-L1 adipocytes.

PubMed

Tan, X C; Chua, K H; Ravishankar Ram, M; Kuppusamy, U R

2016-04-01

Various strategies have been adopted to combat complications caused by Type 2 diabetes mellitus and controlled diet is one of them. Monoterpenes, major constituents of essential oils, are synthesized and widely used as artificial food flavors. A series of twelve monoterpenes were assessed in the present study. Monoterpenes, exhibited low 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity even at high concentrations. Some monoterpenes inhibited α-amylase and α-glucosidase activity and stimulated glucose uptake and lipolysis. Monoterpenes such as (R)-(+)-limonene stimulated both glucose uptake (17.4%) and lipolysis (17.7%); the mRNA expression of glucose transporter 1 (GLUT1) was upregulated but glucose transporter 4 (GLUT4) was unaffected, and adipose triglyceride lipase (ATGL) was suppressed. Taken together, the selected monoterpenes may not confer strong protection against free radicals but nevertheless, their positive influence on lipid and glucose metabolism may have potential in the control of obesity and Type 2 diabetes mellitus. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inhibition of methane consumption in forest soils by monoterpenes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amaral, J.A.; Knowles, R.

1998-04-01

Selected monoterpenes were tested for their ability to inhibit atmospheric methane consumption by three forest soils from different vegetation types and by the cultured methanotrophic strain, Methylosinus trichosporium OB3b. Subsurface soil from coniferous (Pinus banksiana), deciduous (Populus tremuloides), and mixed hardwood (Tsuga canadensis and Prunus pensylvanica) stands was used under field-moist and slurry conditions. Most of the hydrocarbon monoterpenes tested significantly inhibited methane consumption by soils at environmentally relevant levels, with ({minus})-{alpha}-pinene being the most effective. With the exception of {beta}-myrcene, monoterpenes also strongly inhibited methane oxidation by Methylosinus trichosporium OB3b. Carbon dioxide production was stimulated in all of themore » soils by the monoterpenes tested. In one case, methane production was stimulated by ({minus})-{alpha}-pinene in an intact, aerobic core. Oxide and alcohol monoterpenoids stimulated methane production. Thus, monoterpenes appear to be potentially important regulators of methane consumption and carbon metabolism in forest soils.« less

Conifer-Derived Monoterpenes and Forest Walking

PubMed Central

Sumitomo, Kazuhiro; Akutsu, Hiroaki; Fukuyama, Syusei; Minoshima, Akiho; Kukita, Shin; Yamamura, Yuji; Sato, Yoshiaki; Hayasaka, Taiki; Osanai, Shinobu; Funakoshi, Hiroshi; Hasebe, Naoyuki; Nakamura, Masao

2015-01-01

Conifer and broadleaf trees emit volatile organic compounds in the summer. The major components of these emissions are volatile monoterpenes. Using solid phase microextraction fiber as the adsorbant, monoterpenes were successfully detected and identified in forest air samples. Gas chromatography/mass chromatogram of monoterpenes in the atmosphere of a conifer forest and that of serum from subjects who were walking in a forest were found to be similar each other. The amounts of α-pinene in the subjects became several folds higher after forest walking. The results indicate that monoterpenes in the atmosphere of conifer forests are transferred to and accumulate in subjects by inhalation while they are exposed to this type of environment. PMID:26819913

De novo production of six key grape aroma monoterpenes by a geraniol synthase-engineered S. cerevisiae wine strain.

PubMed

Pardo, Ester; Rico, Juan; Gil, José Vicente; Orejas, Margarita

2015-09-16

Monoterpenes are important contributors to grape and wine aroma. Moreover, certain monoterpenes have been shown to display health benefits with antimicrobial, anti-inflammatory, anticancer or hypotensive properties amongst others. The aim of this study was to construct self-aromatizing wine yeasts to overproduce de novo these plant metabolites in wines. Expression of the Ocimum basilicum (sweet basil) geraniol synthase (GES) gene in a Saccharomyces cerevisiae wine strain substantially changed the terpene profile of wine produced from a non-aromatic grape variety. Under microvinification conditions, and without compromising other fermentative traits, the recombinant yeast excreted geraniol de novo at an amount (~750 μg/L) well exceeding (>10-fold) its threshold for olfactory perception and also exceeding the quantities present in wines obtained from highly aromatic Muscat grapes. Interestingly, geraniol was further metabolized by yeast enzymes to additional monoterpenes and esters: citronellol, linalool, nerol, citronellyl acetate and geranyl acetate, resulting in a total monoterpene concentration (~1,558 μg/L) 230-fold greater than that of the control. We also found that monoterpene profiles of wines derived from mixed fermentations were found to be determined by the composition of the initial yeast inocula suggesting the feasibility of producing 'à la carte' wines having predetermined monoterpene contents. Geraniol synthase-engineered yeasts demonstrate potential in the development of monoterpene enhanced wines.

α-Pinene, 3-carene and d-limonene in indoor air of Polish apartments: the impact on air quality and human exposure.

PubMed

Król, Sylwia; Namieśnik, Jacek; Zabiegała, Bożena

2014-01-15

Monoterpenes are among most ubiquitous volatile organic compounds (VOCs) to be detected in indoor air. Since the quality of indoor air is considered important for inhabitants' well-being, the present study aimed at investigating impact of human activity on levels of selected monoterpenes applying passive sampling technique followed by thermal desorption and gas chromatography coupled mass spectrometry. One of the objectives of the present work was to identify and characterize main emission sources as well as to investigate relationship between selected monoterpenes in indoor air. Concentration levels obtained for studied monoterpenes varied from 3 μg m(-3) for 3-carene to 1261 μg m(-3) for d-limonene. D-limonene was reported the most abundant of studied monoterpenes in indoor air. The strong correlation observed between monoterpenes suggests that studied compounds originate from same emission sources, while the I/O >1 proves the strong contribution of endogenous emission sources. The in-depth study of day-night fluctuations in concentrations of monoterpenes lead to the conclusion that human presence and specific pattern of behavior strongly influences presence and concentrations of VOCs in indoor environment. The evaluation of human exposure to selected monoterpenes via inhalation of air revealed that infants, toddlers and young children were the highly exposed individuals. © 2013.

Changes in monoterpene mixing ratios during summer storms in rural New Hampshire (USA)

USGS Publications Warehouse

Haase, K.B.; Jordan, C.; Mentis, E.; Cottrell, L.; Mayne, H.R.; Talbot, R.; Sive, B.C.

2011-01-01

Monoterpenes are an important class of biogenic hydrocarbons that influence ambient air quality and are a principle source of secondary organic aerosol (SOA). Emitted from vegetation, monoterpenes are a product of photosynthesis and act as a response to a variety of environmental factors. Most parameterizations of monoterpene emissions are based on clear weather models that do not take into account episodic conditions that can drastically change production and release rates into the atmosphere. Here, the ongoing monoterpene dataset from the rural Thompson Farm measurement site in Durham, New Hampshire is examined in the context of a set of known severe storm events. While some storm systems had a negligible influence on ambient monoterpene mixing ratios, the average storm event increased mixing ratios by 0.59 ?? 0.21 ppbv, a factor of 93 % above pre-storm levels. In some events, mixing ratios reached the 10's of ppbv range and persisted overnight. These mixing ratios correspond to increases in the monoterpene emission rate, ranging from 120 to 1240 g km-2 h -1 compared to an estimated clear weather rate of 116 to 193 g km-2 h-1. Considering the regularity of storm events over most forested areas, this could be an important factor to consider when modeling global monoterpene emissions and their resulting influence on the formation of organic aerosols. ?? 2011 Author(s).

Changes in monoterpene mixing ratios during summer storms in rural New Hampshire (USA)

USGS Publications Warehouse

Haase, Karl B.; Jordan, C.; Mentis, E.; Cottrell, L.; Mayne, H.R.; Talbot, R.; Sive, B.C.

2011-01-01

Monoterpenes are an important class of biogenic hydrocarbons that influence ambient air quality and are a principle source of secondary organic aerosol (SOA). Emitted from vegetation, monoterpenes are a product of photosynthesis and act as a response to a variety of environmental factors. Most parameterizations of monoterpene emissions are based on clear weather models that do not take into account episodic conditions that can drastically change production and release rates into the atmosphere. Here, the monoterpene dataset from the rural Thompson Farm measurement site in Durham, New Hampshire is examined in the context of a set of known severe storm events. While some storm systems had a negligible influence on ambient monoterpene mixing ratios, the average storm event increased mixing ratios by 0.59 ?? 0.21 ppbv, a factor of 93% above pre-storm levels. In some events, mixing ratios reached the 10's of ppbv range and persisted overnight. These mixing ratios correspond to increases in the monoterpene emission rate, ranging from 120 to 1240 g km-2 h -1 compared to an estimated clear weather rate of 116 to 193 g km-2 h-1. Considering the regularity of storm events over most forested areas, this could be an important factor to consider when modeling global monoterpene emissions and their resulting influence on the formation of organic aerosols.

Evaluation of sensory irritation of delta3-carene and turpentine, and acceptable levels of monoterpenes in occupational and indoor environment.

PubMed

Kasanen, J P; Pasanen, A L; Pasanen, P; Liesivuori, J; Kosma, V M; Alarie, Y

1999-05-28

The standard mouse bioassay was used for obtaining the RD50 (i.e., the concentration that causes a 50% decrease in respiratory frequency) and for estimating the irritation properties of d-delta3-carene (i.e., (+)-delta3-carene) and commercial turpentine. The chemicals studied possess mainly sensory irritation properties similar to the previously studied monoterpenes, pinenes. The irritation potency of d-delta3-carene (RD50 = 1345 ppm) was almost equal to that of d-pinenes. Thus, d-delta3-carene was about four times more potent as a sensory irritant than I-beta-pinene, whereas the difference with I-alpha-pinene was more marked; as a sensory irritant, I-alpha-pinene is almost inactive. Based on sensory irritation potency and physicochemical and structural properties of pinenes and delta3-carene, the potency of a closely related monoterpene, limonene, is discussed. For commercial turpentine, a mixture of monoterpenes (mainly d-delta3-carene, I-beta-pinene, alpha-pinenes, and limonenes), the RD50 (1173 ppm) was the same order of magnitude as those of d-pinenes and d-delta3-carene. Apparently, d-monoterpenes are responsible for the sensory irritation caused by turpentine. In the wood industry and in the indoor air of nonindustrial environments, monoterpenes are thought to be one of the causative agents for irritation symptoms. The occupational exposure limit (OEL) of turpentine (100 ppm in Finland and the United States) is also used for individual monoterpenes, excluding limonene. Using results from this and our previous study, proposed OELs and recommended indoor levels (RILs) for selected monoterpenes and turpentine were determined based on their RD50 values. According to our studies, the present OEL of turpentine (100 ppm; 560 mg/m3) in Finland and in the United States seems to be suitable only for I-pinenes. For d-monoterpenes and turpentine, an OEL about three times lower is suggested. Our results show that recommended indoor levels (RILs) for monoterpenes are high compared to the concentrations measured indoors in nonindustrial environments. Thus, it is very unlikely that monoterpenes alone can cause irritation symptoms in homes or offices under normal conditions.

Monoterpene glycosides from Paeonia veitchii.

PubMed

Fu, Qiang; Tan, Mao-Ling; Yuan, Hai-Mei; Chen, Jiang; Fu, Jia

2017-01-01

The EtOH extract of the roots of Paeonia veitchii afforded two new monoterpene glycosides paeonidanin I (1) and paeonidanin J (2), and a new dimeric monoterpene glycoside paeonidanin K (3). Their structures were elucidated on the basis of spectroscopic means and hydrolysis products.

The Capacity for Thermal Protection of Photosynthetic Electron Transport Varies for Different Monoterpenes in Quercus ilex1

PubMed Central

Copolovici, Lucian O.; Filella, Iolanda; Llusià, Joan; Niinemets, Ülo; Peñuelas, Josep

2005-01-01

Heat stress resistance of foliar photosynthetic apparatus was investigated in the Mediterranean monoterpene-emitting evergreen sclerophyll species Quercus ilex. Leaf feeding with fosmidomycin, which is a specific inhibitor of the chloroplastic isoprenoid synthesis pathway, essentially stopped monoterpene emission and resulted in the decrease of the optimum temperature of photosynthetic electron transport from approximately 38°C to approximately 30°C. The heat stress resistance was partly restored by fumigation with 4 to 5 nmol mol−1 air concentrations of monoterpene α-pinene but not with fumigations with monoterpene alcohol α-terpineol. Analyses of monoterpene physicochemical characteristics demonstrated that α-pinene was primarily distributed to leaf gas and lipid phases, while α-terpineol was primarily distributed to leaf aqueous phase. Thus, for a common monoterpene uptake rate, α-terpineol is less efficient in stabilizing membrane liquid-crystalline structure and as an antioxidant in plant membranes. Furthermore, α-terpineol uptake rate (U) strongly decreased with increasing temperature, while the uptake rates of α-pinene increased with increasing temperature, providing a further explanation of the lower efficiency of thermal protection by α-terpineol. The temperature-dependent decrease of α-terpineol uptake was both due to decreases in stomatal conductance, gw, and increased volatility of α-terpineol at higher temperature that decreased the monoterpene diffusion gradient between the ambient air (FA) and leaf (FI; U = gw[FA − FI]). Model analyses suggested that α-pinene reacted within the leaf at higher temperatures, possibly within the lipid phase, thereby avoiding the decrease in diffusion gradient, FA − FI. Thus, these data contribute to the hypothesis of the antioxidative protection of leaf membranes during heat stress by monoterpenes. These data further suggest that fumigation with the relatively low atmospheric concentrations of monoterpenes that are occasionally observed during warm windless days in the Mediterranean canopies may significantly improve the heat tolerance of nonemitting vegetation that grows intermixed with emitting species. PMID:16126854

Successful Colonization of Lodgepole Pine Trees by Mountain Pine Beetle Increased Monoterpene Production and Exhausted Carbohydrate Reserves.

PubMed

Roth, Marla; Hussain, Altaf; Cale, Jonathan A; Erbilgin, Nadir

2018-02-01

Lodgepole pine (Pinus contorta) forests have experienced severe mortality from mountain pine beetle (MPB) (Dendroctonus ponderosae Hopkins) in western North America for the last several years. Although the mechanisms by which beetles kill host trees are unclear, they are likely linked to pine defense monoterpenes that are synthesized from carbohydrate reserves. However, how carbohydrates and monoterpenes interact in response to MPB colonization is unknown. Understanding this relationship could help to elucidate how pines succumb to bark beetle attack. We compared concentrations of individual and total monoterpenes and carbohydrates in the phloem of healthy pine trees with those naturally colonized by MPB. Trees attacked by MPB had nearly 300% more monoterpenes and 40% less carbohydrates. Total monoterpene concentrations were most strongly associated with the concentration of sugars in the phloem. These results suggest that bark beetle colonization likely depletes carbohydrate reserves by increasing the production of carbon-rich monoterpenes, and other carbon-based secondary compounds. Bark beetle attacks also reduce water transport causing the disruption of carbon transport between tree foliage and roots, which restricts carbon assimilation. Reduction in carbohydrate reserves likely contributes to tree mortality.

Cyclic and Linear Monoterpenes in Phospholipid Membranes: Phase Behavior, Bilayer Structure, and Molecular Dynamics.

PubMed

Pham, Quoc Dat; Topgaard, Daniel; Sparr, Emma

2015-10-13

Monoterpenes are abundant in essential oils extracted from plants. These relatively small and hydrophobic molecules have shown important biological functions, including antimicrobial activity and membrane penetration enhancement. The interaction between the monoterpenes and lipid bilayers is considered important to the understanding of the biological functions of monoterpenes. In this study, we investigated the effect of cyclic and linear monoterpenes on the structure and dynamics of lipids in model membranes. We have studied the ternary system 1,2-dimyristoyl-sn-glycero-3-phosphocholine-monoterpene-water as a model with a focus on dehydrated conditions. By combining complementary techniques, including differential scanning calorimetry, solid-state nuclear magnetic resonance, and small- and wide-angle X-ray scattering, bilayer structure, phase transitions, and lipid molecular dynamics were investigated at different water contents. Monoterpenes cause pronounced melting point depression and phase segregation in lipid bilayers, and the extent of these effects depends on the hydration conditions. The addition of a small amount of thymol to the fluid bilayer (volume fraction of 0.03 in the bilayer) leads to an increased order in the acyl chain close to the bilayer interface. The findings are discussed in relation to biological systems and lipid formulations.

A systematic review of the wound-healing effects of monoterpenes and iridoid derivatives.

PubMed

Barreto, Rosana S S; Albuquerque-Júnior, Ricardo L C; Araújo, Adriano A S; Almeida, Jackson R G S; Santos, Márcio R V; Barreto, André S; DeSantana, Josimari M; Siqueira-Lima, Pollyana S; Quintans, Jullyana S S; Quintans-Júnior, Lucindo J

2014-01-13

The search for more effective and lower cost therapeutic approaches for wound healing remains a challenge for modern medicine. In the search for new therapeutic options, plants and their metabolites are a great source of novel biomolecules. Among their constituents, the monoterpenes represent 90% of essential oils, and have a variety of structures with several activities such as antimicrobial, anti-inflammatory, antioxidant and wound healing. Based on that, and also due to the lack of reviews concerning the wound-healing activity of monoterpenes, we performed this systematic review-which provides an overview of their characteristics and mechanisms of action. In this search, the terms "terpenes", "monoterpenes", "wound healing" and "wound closure techniques" were used to retrieve articles published in LILACS, PUBMED and EMBASE until May 2013. Seven papers were found concerning the potential wound healing effect of five compouds (three monoterpenes and two iridoid derivatives) in preclinical studies. Among the products used for wound care, the films were the most studied pharmaceutical form. Monoterpenes are a class of compounds of great diversity of biological activities and therapeutic potential. The data reviewed here suggest that monoterpenes, although poorly studied in this context, are promising compounds for the treatment of chronic wound conditions.

Monoterpenes as inhibitors of digestive enzymes and counter-adaptations in a specialist avian herbivore.

PubMed

Kohl, Kevin D; Pitman, Elizabeth; Robb, Brecken C; Connelly, John W; Dearing, M Denise; Forbey, Jennifer Sorensen

2015-05-01

Many plants produce plant secondary metabolites (PSM) that inhibit digestive enzymes of herbivores, thus limiting nutrient availability. In response, some specialist herbivores have evolved digestive enzymes that are resistant to inhibition. Monoterpenes, a class of PSMs, have not been investigated with respect to the interference of specific digestive enzymes, nor have such interactions been studied in avian herbivores. We investigated this interaction in the Greater Sage-Grouse (Phasianidae: Centrocercus urophasianus), which specializes on monoterpene-rich sagebrush species (Artemisia spp.). We first measured the monoterpene concentrations in gut contents of free-ranging sage-grouse. Next, we compared the ability of seven individual monoterpenes present in sagebrush to inhibit a protein-digesting enzyme, aminopeptidase-N. We also measured the inhibitory effects of PSM extracts from two sagebrush species. Inhibition of aminopeptidase-N in sage-grouse was compared to inhibition in chickens (Gallus gallus). We predicted that sage-grouse enzymes would retain higher activity when incubated with isolated monoterpenes or sagebrush extracts than chicken enzymes. We detected unchanged monoterpenes in the gut contents of free-ranging sage-grouse. We found that three isolated oxygenated monoterpenes (borneol, camphor, and 1,8-cineole) inhibited digestive enzymes of both bird species. Camphor and 1,8-cineole inhibited enzymes from chickens more than from sage-grouse. Extracts from both species of sagebrush had similar inhibition of chicken enzymes, but did not inhibit sage-grouse enzymes. These results suggest that specific monoterpenes may limit the protein digestibility of plant material by avian herbivores. Further, this work presents additional evidence that adaptations of digestive enzymes to plant defensive compounds may be a trait of specialist herbivores.

Temperature dependencies of Henry's law constants and octanol/water partition coefficients for key plant volatile monoterpenoids.

PubMed

Copolovici, Lucian O; Niinemets, Ulo

2005-12-01

To model the emission dynamics and changes in fractional composition of monoterpenoids from plant leaves, temperature dependencies of equilibrium coefficients must be known. Henry's law constants (H(pc), Pa m3 mol(-1) and octanol/water partition coefficients (K(OW), mol mol(-1)) were determined for 10 important plant monoterpenes at physiological temperature ranges (25-50 degrees C for H(pc) and 20-50 degrees C for K(OW)). A standard EPICS procedure was established to determine H(pc) and a shake flask method was used for the measurements of K(OW). The enthalpy of volatilization (deltaH(vol)) varied from 18.0 to 44.3 kJ mol(-1) among the monoterpenes, corresponding to a range of temperature-dependent increase in H(pc) between 1.3- and 1.8-fold per 10 degrees C rise in temperature. The enthalpy of water-octanol phase change varied from -11.0 to -23.8 kJ mol(-1), corresponding to a decrease of K(OW) between 1.15- and 1.32-fold per 10 degrees C increase in temperature. Correlations among physico-chemical characteristics of a wide range of monoterpenes were analyzed to seek the ways of derivation of H(pc) and K(OW) values from other monoterpene physico-chemical characteristics. H(pc) was strongly correlated with monoterpene saturated vapor pressure (P(v)), and for lipophilic monoterpenes, deltaH(vol) scaled positively with the enthalpy of vaporization that characterizes the temperature dependence of P(v) Thus, P(v) versus temperature relations may be employed to derive the temperature relations of H(pc) for these monoterpenes. These data collectively indicate that monoterpene differences in H(pc) and K(OW) temperature relations can importantly modify monoterpene emissions from and deposition on plant leaves.

Production of jet fuel precursor monoterpenoids from engineered Escherichia coli: Production of Jet Fuel Precursor Monoterpenoids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mendez-Perez, Daniel; Alonso-Gutierrez, Jorge; Hu, Qijun

Monoterpenes (C 10 isoprenoids) are the main components of essential oils and are possible precursors for many commodity chemicals and high energy density fuels. Monoterpenes are synthesized from geranyl diphosphate (GPP), which is also the precursor for the biosynthesis of farnesyl diphosphate (FPP). FPP biosynthesis diverts the carbon flux from monoterpene production to C 15 products and quinone biosynthesis. In this study, we tested a chromosomal mutation of Escherichia coli's native FPP synthase (IspA) to improve GPP availability for the production of monoterpenes using a heterologous mevalonate pathway. Monoterpene production at high levels required not only optimization of GPP productionmore » but also a basal level of FPP to maintain growth. The optimized strains produced two jet fuel precursor monoterpenoids 1,8-cineole and linalool at the titer of 653 mg/L and 505 mg/L, respectively, in batch cultures with 1% glucose. The engineered strains developed in this work provide useful resources for the production of high-value monoterpenes.« less

Repellence Produced by Monoterpenes on Rhodnius prolixus (Hemiptera: Reduviidae) Decreases After Continuous Exposure to These Compounds

PubMed Central

Lutz, Alejandra; Sfara, Valeria; Alzogaray, Raúl Adolfo

2014-01-01

Abstract Botanical monoterpenes are secondary metabolites present in essential oils produced by plants. Some of them are insect repellents. The bloodsucking bug Rhodnius prolixus Ståhl (Hemiptera: Reduviidae) is one of the main vectors of Chagas disease in the north of South America and some countries in Central America. In this study, we studied the repellence produced by two monoterpenes, menthyl acetate and geraniol, on fifth instar nymphs of R. prolixus . In the absence of other stimuli, both menthyl acetate and geraniol produced a repellent effect from 740 μg/cm 2 and 74 μg/cm 2 , respectively. Pre-exposure to each monoterpene reduced the repellent activity produced by the same substance. Additionally, pre-exposure to one monoterpene decreased the behavioral response of the nymphs to the other one. The repellent effect of both monoterpenes also decreased when nymphs’ antennae were previously treated with the nitric oxide donor S-nitroso-N-acetyl-cysteine. PMID:25525113

Production of jet fuel precursor monoterpenoids from engineered Escherichia coli: Production of Jet Fuel Precursor Monoterpenoids

DOE PAGES

Mendez-Perez, Daniel; Alonso-Gutierrez, Jorge; Hu, Qijun; ...

2017-05-18

Monoterpenes (C 10 isoprenoids) are the main components of essential oils and are possible precursors for many commodity chemicals and high energy density fuels. Monoterpenes are synthesized from geranyl diphosphate (GPP), which is also the precursor for the biosynthesis of farnesyl diphosphate (FPP). FPP biosynthesis diverts the carbon flux from monoterpene production to C 15 products and quinone biosynthesis. In this study, we tested a chromosomal mutation of Escherichia coli's native FPP synthase (IspA) to improve GPP availability for the production of monoterpenes using a heterologous mevalonate pathway. Monoterpene production at high levels required not only optimization of GPP productionmore » but also a basal level of FPP to maintain growth. The optimized strains produced two jet fuel precursor monoterpenoids 1,8-cineole and linalool at the titer of 653 mg/L and 505 mg/L, respectively, in batch cultures with 1% glucose. The engineered strains developed in this work provide useful resources for the production of high-value monoterpenes.« less

MONOTERPENE LEVELS IN NEEDLES OF DOUGLAS-FIR EXPOSED TO ELEVATED CO2 AND TEMPERATURE

EPA Science Inventory

Levels of monoterpenes in current year needles of douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were measured at the conclusion of four years of exposure to ambient or elevated CO2 (+ 179 mmol.mol-1), and ambient or elevated temperature (+ 3.5 C). Eleven monoterpen...

Quantitative and enantioselective analysis of monoterpenes from plant chambers and in ambient air using SPME

NASA Astrophysics Data System (ADS)

Yassaa, N.; Custer, T.; Song, W.; Pech, F.; Kesselmeier, J.; Williams, J.

2010-08-01

A solid-phase microextraction (HS-SPME) and gas chromatography/mass spectrometry (GC/MS) system has been developed for quantifying enantiomeric and nonenantiomeric monoterpenes in plant chamber studies and ambient air. Performance of this system was checked using a capillary diffusion system to produce monoterpene standards. The adsorption efficiency, competitive adsorption and chromatographic peak resolution of monoterpene enantiomer pairs were compared for three SPME fibre coatings: 75 μm Carboxen-PDMS (CAR-PDMS), 50/30 μm, divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS) and 65 μm divinylbenzene-polydimethyl-siloxane (DVB-PDMS). Key parameters such as the linearity and reproducibility of the SPME system have been investigated in this work. The best compromise between the enantiomeric separation of monoterpenes and competitive adsorption of the isoprenoids on the solid SPME fibre coating was found for DVB-PDMS fibres. The optimum conditions using DVB-PDMS fibres were applied to measure the exchange rates of monoterpenes in the emission of Quercus ilex using a laboratory whole plant enclosure under light and dark conditions, as well as in ambient air. With 592 and 223 ng m-2 s-1, respectively, β-myrcene and limonene were the predominant monoterpenes in the emission of Q. ilex. These values were closely comparable to those obtained using a zNose and cartridge GC-FID systems.

Quantitative and enantioselective analysis of monoterpenes from plant chambers and in ambient air using SPME

NASA Astrophysics Data System (ADS)

Yassaa, N.; Custer, T.; Song, W.; Pech, F.; Kesselmeier, J.; Williams, J.

2010-11-01

A headspace solid-phase microextraction (HS-SPME) and gas chromatography/mass spectrometry (GC/MS) system has been developed for quantifying enantiomeric and nonenantiomeric monoterpenes in plant chamber studies and ambient air. Performance of this system was checked using a capillary diffusion system to produce monoterpene standards. The adsorption efficiency, competitive adsorption and chromatographic peak resolution of monoterpene enantiomer pairs were compared for three SPME fibre coatings: 75 μm Carboxen-PDMS (CAR-PDMS), 50/30 μm divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS) and 65 μm divinylbenzene-polydimethylsiloxane (DVB-PDMS). Key parameters such as the linearity and reproducibility of the SPME system have been investigated in this work. The best compromise between the enantiomeric separation of monoterpenes and competitive adsorption of the isoprenoids on the solid SPME fibre coating was found for DVB-PDMS fibres. The optimum conditions using DVB-PDMS fibres were applied to measure the exchange rates of monoterpenes in the emission of Quercus ilex using a laboratory whole plant enclosure under light and dark conditions, as well as in ambient air. With 592 and 223 ng m-2 s-1 respectively, β-myrcene and limonene were the predominant monoterpenes in the emission of Q. ilex. These values were closely comparable to those obtained using a zNose and cartridge GC-FID systems.

Alleviating monoterpene toxicity using a two-phase extractive fermentation for the bioproduction of jet fuel mixtures in Saccharomyces cerevisiae.

PubMed

Brennan, Timothy C R; Turner, Christopher D; Krömer, Jens O; Nielsen, Lars K

2012-10-01

Monoterpenes are a diverse class of compounds with applications as flavors and fragrances, pharmaceuticals and more recently, jet fuels. Engineering biosynthetic pathways for monoterpene production in microbial hosts has received increasing attention. However, monoterpenes are highly toxic to many microorganisms including Saccharomyces cerevisiae, a widely used industrial biocatalyst. In this work, the minimum inhibitory concentration (MIC) for S. cerevisiae was determined for five monoterpenes: β-pinene, limonene, myrcene, γ-terpinene, and terpinolene (1.52, 0.44, 2.12, 0.70, 0.53 mM, respectively). Given the low MIC for all compounds tested, a liquid two-phase solvent extraction system to alleviate toxicity during fermentation was evaluated. Ten solvents were tested for biocompatibility, monoterpene distribution, phase separation, and price. The solvents dioctyl phthalate, dibutyl phthalate, isopropyl myristate, and farnesene showed greater than 100-fold increase in the MIC compared to the monoterpenes in a solvent-free system. In particular, the MIC for limonene in dibutyl phthalate showed a 702-fold (308 mM, 42.1 g L(-1) of limonene) improvement while cell viability was maintained above 90%, demonstrating that extractive fermentation is a suitable tool for the reduction of monoterpene toxicity. Finally, we estimated that a limonane to farnesane ratio of 1:9 has physicochemical properties similar to traditional Jet-A aviation fuel. Since farnesene is currently produced in S. cerevisiae, its use as a co-product and extractant for microbial terpene-based jet fuel production in a two-phase system offers an attractive bioprocessing option. Copyright © 2012 Wiley Periodicals, Inc.

Fate and transport of monoterpenes through soils. Part II: calculation of the effect of soil temperature, water saturation and organic carbon content.

PubMed

van Roon, André; Parsons, John R; Krap, Lenny; Govers, Harrie A J

2005-09-01

This theoretical study was performed to investigate the influence of soil temperature, soil water content and soil organic carbon fraction on the mobility of monoterpenes (C10HnOn') applied as pesticides to a top soil layer. This mobility was expressed as the amount volatilized and leached from the contaminated soil layer after a certain amount of time. For this, (slightly modified) published analytical solutions to a one dimensional, homogeneous medium, diffusion/advection/biodegradation mass balance equation were used. The required input-parameters were determined in a preceding study. Because the monoterpenes studied differ widely in the values for their physico-chemical properties, the relative importance of the various determinants also differed widely. Increasing soil water saturation reduced monoterpene vaporization and leaching losses although a modest increase was usually observed at high soil water contents. Organic matter served as the major retention domain, reducing volatilization and leaching losses. Increasing temperature resulted in higher volatilization and leaching losses. Monoterpene mobility was influenced by vertical water flow. Volatilization losses could be reduced by adding a clean soil layer on top of the contaminated soil. Detailed insight into the specific behaviour of different monoterpenes was obtained by discussing intermediate calculation results; the transport retardation factors and effective soil diffusion coefficients. One insight was that the air-water interface compartment is probably not an important partitioning domain for monoterpenes in most circumstances. The results further indicated that biodegradation is an important process for monoterpenes in soil.

Global isoprene and monoterpene emissions under changing climate, vegetation, CO2 and land use

NASA Astrophysics Data System (ADS)

Hantson, Stijn; Knorr, Wolfgang; Schurgers, Guy; Pugh, Thomas A. M.; Arneth, Almut

2017-04-01

Plants emit large quantities of isoprene and monoterpenes, the main components of global biogenic volatile organic compound (BVOC) emissions. BVOCs have an important impact on the atmospheric composition of methane, and of short-lived radiative forcing agents (e.g. ozone, aerosols etc.). It is therefore necessary to know how isoprene and monoterpene emissions have changed over the past and how future changes in climate, land-use and other factors will impact them. Here we present emission estimates of isoprene and monoterpenes over the period 1901-2 100 based on the dynamic global vegetation model LPJ-GUESS, including the effects of all known important drivers. We find that both isoprene and monoterpene emissions at the beginning of the 20th century were higher than at present. While anthropogenic land-use change largely drives the global decreasing trend for isoprene over the 20th century, changes in natural vegetation composition caused a decreasing trend for monoterpene emissions. Future global isoprene and monoterpene emissions depend strongly on the climate and land-use scenarios considered. Over the 21st century, global isoprene emissions are simulated to either remain stable (RCP 4.5), or decrease further (RCP 8.5), with important differences depending on the underlying land-use scenario. Future monoterpene emissions are expected to continue their present decreasing trend for all scenarios, possibly stabilizing from 2050 onwards (RCP 4.5). These results demonstrate the importance to take both natural vegetation dynamics and anthropogenic changes in land-use into account when estimating past and future BVOC emissions. They also indicate that a future global increase in BVOC emissions is improbable.

Lipoxygenase-inhibiting phenolic glycosides and monoterpene glycosides from Paeonia lactiflora.

PubMed

Zou, Liang; Hu, Lin-Feng; Guo, Yi-Dong; Song, Yu; Fu, Qiang

2015-01-01

The EtOH extract of the roots of Paeonia lactiflora afforded a new phenolic glycoside paenoside A (1) and a new monoterpene glycoside paeonin D (2), and five known monoterpene glycosides. Their structures were elucidated on the basis of spectroscopic means and hydrolysis products. All compounds displayed inhibitory potential against enzyme lipoxygenase.

Host-tree monoterpenes and biosynthesis of aggregation pheromones in the bark beetle ips paraconfusus

USDA-ARS?s Scientific Manuscript database

In the 1970-80s, vapors of the common conifer tree monoterpenes, myrcene and a-pinene, were shown to serve as precursors of ipsenol, ipsdienol and cis-verbenol, aggregation pheromone components of Ips paraconfusus. A paradigm developed that Ips bark beetles utilize pre-formed monoterpene precursors ...

Monoterpene oxidation in an oxidative flow reactor: SOA yields and the relationship between bulk gas-phase properties and organic aerosol growth

NASA Astrophysics Data System (ADS)

Friedman, B.; Link, M.; Farmer, D.

2016-12-01

We use an oxidative flow reactor (OFR) to determine the secondary organic aerosol (SOA) yields of five monoterpenes (alpha-pinene, beta-pinene, limonene, sabinene, and terpinolene) at a range of OH exposures. These OH exposures correspond to aging timescales of a few hours to seven days. We further determine how SOA yields of beta-pinene and alpha-pinene vary as a function of seed particle type (organic vs. inorganic) and seed particle mass concentration. We hypothesize that the monoterpene structure largely accounts for the observed variance in SOA yields for the different monoterpenes. We also use high-resolution time-of-flight chemical ionization mass spectrometry to calculate the bulk gas-phase properties (O:C and H:C) of the monoterpene oxidation systems as a function of oxidant concentrations. Bulk gas-phase properties can be compared to the SOA yields to assess the capability of the precursor gas-phase species to inform the SOA yields of each monoterpene oxidation system. We find that the extent of oxygenated precursor gas-phase species corresponds to SOA yield.

Repellence produced by monoterpenes on Rhodnius prolixus (Hemiptera: Reduviidae) decreases after continuous exposure to these compounds.

PubMed

Lutz, Alejandra; Sfara, Valeria; Alzogaray, Raúl Adolfo

2014-01-01

Botanical monoterpenes are secondary metabolites present in essential oils produced by plants. Some of them are insect repellents. The bloodsucking bug Rhodnius prolixus Ståhl (Hemiptera: Reduviidae) is one of the main vectors of Chagas disease in the north of South America and some countries in Central America. In this study, we studied the repellence produced by two monoterpenes, menthyl acetate and geraniol, on fifth instar nymphs of R. prolixus. In the absence of other stimuli, both menthyl acetate and geraniol produced a repellent effect from 740 μg/cm(2) and 74 μg/cm(2), respectively. Pre-exposure to each monoterpene reduced the repellent activity produced by the same substance. Additionally, pre-exposure to one monoterpene decreased the behavioral response of the nymphs to the other one. The repellent effect of both monoterpenes also decreased when nymphs' antennae were previously treated with the nitric oxide donor S-nitroso-N-acetyl-cysteine. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Production of jet fuel precursor monoterpenoids from engineered Escherichia coli.

PubMed

Mendez-Perez, Daniel; Alonso-Gutierrez, Jorge; Hu, Qijun; Molinas, Margaux; Baidoo, Edward E K; Wang, George; Chan, Leanne J G; Adams, Paul D; Petzold, Christopher J; Keasling, Jay D; Lee, Taek S

2017-08-01

Monoterpenes (C 10 isoprenoids) are the main components of essential oils and are possible precursors for many commodity chemicals and high energy density fuels. Monoterpenes are synthesized from geranyl diphosphate (GPP), which is also the precursor for the biosynthesis of farnesyl diphosphate (FPP). FPP biosynthesis diverts the carbon flux from monoterpene production to C 15 products and quinone biosynthesis. In this study, we tested a chromosomal mutation of Escherichia coli's native FPP synthase (IspA) to improve GPP availability for the production of monoterpenes using a heterologous mevalonate pathway. Monoterpene production at high levels required not only optimization of GPP production but also a basal level of FPP to maintain growth. The optimized strains produced two jet fuel precursor monoterpenoids 1,8-cineole and linalool at the titer of 653 mg/L and 505 mg/L, respectively, in batch cultures with 1% glucose. The engineered strains developed in this work provide useful resources for the production of high-value monoterpenes. Biotechnol. Bioeng. 2017;114: 1703-1712. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Ca²⁺ signal contributing to the synthesis and emission of monoterpenes regulated by light intensity in Lilium 'siberia'.

PubMed

Hu, Zenghui; Li, Tianjiao; Zheng, Jian; Yang, Kai; He, Xiangfeng; Leng, Pingsheng

2015-06-01

The floral scent is an important part of plant volatile compounds, and is influenced by environmental factors. The emission of monoterpenes of Lilium 'siberia' is regulated by light intensity, but the mechanism is large unknown. In this study, the expression of Li-mTPS, a monoterpene synthase gene in the tepals of Lilium 'siberia', and net Ca(2+) flux were investigated after exposure to different levels of light intensity (0, 100, 300, 600, 1000, and 1500 μmol m(-2) s(-1)). Moreover the effect of LaCl3 and ethylene glycol-bis-(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) on the Li-mTPS expression, monoterpene emission, and net Ca(2+) flux were examined at 600 μmol m(-2) s(-1). The results showed that along with the enhancement of light intensity, the expression level of Li-mTPS increased gradually, and the net Ca(2+) influx was also enhanced showing a similar pattern. It was found that LaCl3 and EGTA effectively inhibited the increase in expression of Li-mTPS and the net Ca(2+) influx induced by light treatment. Moreover, the release amounts of monoterpenes decreased significantly after treatment with LaCl3 and EGTA. So it can be concluded that Ca(2+) signal contributed to the biosynthesis and emission of monoterpenes regulated by light intensity in Lilium 'siberia' tepals. The increased light intensity firstly triggered the Ca(2+) influx to cytoplasm, and then the gene expression of monoterpene synthases downstream was activated to regulate the biosynthesis and emission of monoterpenes. But in the signaling pathway other mechanisms were thought to be involved in the emission of monoterpenes regulated by light intensity, which need to be investigated in future research. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Effect of water stress and fungal inoculation on monoterpene emission from an historical and a new pine host of the mountain pine beetle.

PubMed

Lusebrink, Inka; Evenden, Maya L; Blanchet, F Guillaume; Cooke, Janice E K; Erbilgin, Nadir

2011-09-01

The mountain pine beetle (Dendroctonus ponderosae, MPB) has killed millions of lodgepole pine (Pinus contorta) trees in Western Canada, and recent range expansion has resulted in attack of jack pine (Pinus banksiana) in Alberta. Establishment of MPB in the Boreal forest will require use of jack pine under a suite of environmental conditions different from those it typically encounters in its native range. Lodgepole and jack pine seedlings were grown under controlled environment conditions and subjected to either water deficit or well watered conditions and inoculated with Grosmannia clavigera, a MPB fungal associate. Soil water content, photosynthesis, stomatal conductance, and emission of volatile organic compounds (VOCs) were monitored over the duration of the six-week study. Monoterpene content of bark and needle tissue was measured at the end of the experiment. β-Phellandrene, the major monoterpene in lodgepole pine, was almost completely lacking in the volatile emission profile of jack pine. The major compound in jack pine was α-pinene. The emission of both compounds was positively correlated with stomatal conductance. 3-Carene was emitted at a high concentration from jack pine seedlings, which is in contrast to monoterpene profiles of jack pine from more southern and eastern parts of its range. Fungal inoculation caused a significant increase in total monoterpene emission in water deficit lodgepole pine seedlings right after its application. By 4 weeks into the experiment, water deficit seedlings of both species released significantly lower levels of total monoterpenes than well watered seedlings. Needle tissue contained lower total monoterpene content than bark. Generally, monoterpene tissue content increased over time independent from any treatment. The results suggest that monoterpenes that play a role in pine-MPB interactions differ between lodgepole and jack pine, and also that they are affected by water availability.

Airborne measurements of isoprene and monoterpene emissions from southeastern U.S. forests.

PubMed

Yu, Haofei; Guenther, Alex; Gu, Dasa; Warneke, Carsten; Geron, Chris; Goldstein, Allen; Graus, Martin; Karl, Thomas; Kaser, Lisa; Misztal, Pawel; Yuan, Bin

2017-10-01

Isoprene and monoterpene emission rates are essential inputs for atmospheric chemistry models that simulate atmospheric oxidant and particle distributions. Process studies of the biochemical and physiological mechanisms controlling these emissions are advancing our understanding and the accuracy of model predictions but efforts to quantify regional emissions have been limited by a lack of constraints on regional distributions of ecosystem emission capacities. We used an airborne wavelet-based eddy covariance measurement technique to characterize isoprene and monoterpene fluxes with high spatial resolution during the 2013 SAS (Southeast Atmosphere Study) in the southeastern United States. The fluxes measured by direct eddy covariance were comparable to emissions independently estimated using an indirect inverse modeling approach. Isoprene emission factors based on the aircraft wavelet flux estimates for high isoprene chemotypes (e.g., oaks) were similar to the MEGAN2.1 biogenic emission model estimates for landscapes dominated by oaks. Aircraft flux measurement estimates for landscapes with fewer isoprene emitting trees (e.g., pine plantations), were about a factor of two lower than MEGAN2.1 model estimates. The tendency for high isoprene emitters in these landscapes to occur in the shaded understory, where light dependent isoprene emissions are diminished, may explain the lower than expected emissions. This result demonstrates the importance of accurately representing the vertical profile of isoprene emitting biomass in biogenic emission models. Airborne measurement-based emission factors for high monoterpene chemotypes agreed with MEGAN2.1 in landscapes dominated by pine (high monoterpene chemotype) trees but were more than a factor of three higher than model estimates for landscapes dominated by oak (relatively low monoterpene emitting) trees. This results suggests that unaccounted processes, such as floral emissions or light dependent monoterpene emissions, or vegetation other than high monoterpene emitting trees may be an important source of monoterpene emissions in those landscapes and should be identified and included in biogenic emission models. Copyright © 2017 Elsevier B.V. All rights reserved.

Airborne measurements of isoprene and monoterpene emissions from southeastern U.S. forests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Haofei; Guenther, Alex; Gu, Dasa

Isoprene and monoterpene emission rates are essential inputs for atmospheric chemistry models that simulate atmospheric oxidant and particle distributions. Process studies of the biochemical and physiological mechanisms controlling these emissions are advancing our understanding and the accuracy of model predictions but efforts to quantify regional emissions have been limited by a lack of constraints on regional distributions of ecosystem emission capacities. We used an airborne wavelet-based eddy covariance measurement technique to characterize isoprene and monoterpene fluxes with high spatial resolution during the 2013 SAS (Southeast Atmosphere Study) in the southeastern United States. The fluxes measured by direct eddy covariance weremore » comparable to emissions independently estimated using an indirect inverse modeling approach. Isoprene emission factors based on the aircraft wavelet flux estimates for high isoprene chemotypes (e.g., oaks) were similar to the MEGAN2.1 biogenic emission model estimates for landscapes dominated by oaks. Aircraft flux measurement estimates for landscapes with fewer isoprene emitting trees (e.g., pine plantations), were about a factor of two lower than MEGAN2.1 model estimates. The tendency for high isoprene emitters in these landscapes to occur in the shaded understory, where light dependent isoprene emissions are diminished, may explain the lower than expected emissions. This result demonstrates the importance of accurately representing the vertical profile of isoprene emitting biomass in biogenic emission models. Airborne measurement-based emission factors for high monoterpene chemotypes agreed with MEGAN2.1 in landscapes dominated by pine (high monoterpene chemotype) trees but were more than a factor of three higher than model estimates for landscapes dominated by oak (relatively low monoterpene emitting) trees. This results suggests that unaccounted processes, such as floral emissions or light dependent monoterpene emissions, or vegetation other than high monoterpene emitting trees may be an important source of monoterpene emissions in those landscapes and should be identified and included in biogenic emission models.« less

Monoterpene ‘thermometer’ of tropical forest-atmosphere response to climate warming

DOE PAGES

Jardine, Kolby J.; Jardine, Angela B.; Holm, Jennifer A.; ...

2016-12-11

Tropical forests absorb large amounts of atmospheric CO 2 through photosynthesis but elevated temperatures suppress this absorption and promote monoterpene emissions. Using 13CO 2 labeling, in this paper we show that monoterpene emissions from tropical leaves derive from recent photosynthesis and demonstrate distinct temperature optima for five groups (Groups 1–5), potentially corresponding to different enzymatic temperature-dependent reaction mechanisms within β-ocimene synthases. As diurnal and seasonal leaf temperatures increased during the Amazonian 2015 El Niño event, leaf and landscape monoterpene emissions showed strong linear enrichments of β-ocimenes (+4.4% °C -1) at the expense of other monoterpene isomers. The observed inverse temperaturemore » response of α-pinene (-0.8% °C -1), typically assumed to be the dominant monoterpene with moderate reactivity, was not accurately simulated by current global emission models. Given that β-ocimenes are highly reactive with respect to both atmospheric and biological oxidants, the results suggest that highly reactive β-ocimenes may play important roles in the thermotolerance of photosynthesis by functioning as effective antioxidants within plants and as efficient atmospheric precursors of secondary organic aerosols. Monoterpene composition may represent a new sensitive ‘thermometer’ of leaf oxidative stress and atmospheric reactivity, and therefore a new tool in future studies of warming impacts on tropical biosphere-atmosphere carbon-cycle feedbacks.« less

Monoterpene 'thermometer' of tropical forest-atmosphere response to climate warming.

PubMed

Jardine, Kolby J; Jardine, Angela B; Holm, Jennifer A; Lombardozzi, Danica L; Negron-Juarez, Robinson I; Martin, Scot T; Beller, Harry R; Gimenez, Bruno O; Higuchi, Niro; Chambers, Jeffrey Q

2017-03-01

Tropical forests absorb large amounts of atmospheric CO 2 through photosynthesis but elevated temperatures suppress this absorption and promote monoterpene emissions. Using 13 CO 2 labeling, here we show that monoterpene emissions from tropical leaves derive from recent photosynthesis and demonstrate distinct temperature optima for five groups (Groups 1-5), potentially corresponding to different enzymatic temperature-dependent reaction mechanisms within β-ocimene synthases. As diurnal and seasonal leaf temperatures increased during the Amazonian 2015 El Niño event, leaf and landscape monoterpene emissions showed strong linear enrichments of β-ocimenes (+4.4% °C -1 ) at the expense of other monoterpene isomers. The observed inverse temperature response of α-pinene (-0.8% °C -1 ), typically assumed to be the dominant monoterpene with moderate reactivity, was not accurately simulated by current global emission models. Given that β-ocimenes are highly reactive with respect to both atmospheric and biological oxidants, the results suggest that highly reactive β-ocimenes may play important roles in the thermotolerance of photosynthesis by functioning as effective antioxidants within plants and as efficient atmospheric precursors of secondary organic aerosols. Thus, monoterpene composition may represent a new sensitive 'thermometer' of leaf oxidative stress and atmospheric reactivity, and therefore a new tool in future studies of warming impacts on tropical biosphere-atmosphere carbon-cycle feedbacks. © 2016 John Wiley & Sons Ltd.

Monoterpene ‘thermometer’ of tropical forest-atmosphere response to climate warming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jardine, Kolby J.; Jardine, Angela B.; Holm, Jennifer A.

Tropical forests absorb large amounts of atmospheric CO 2 through photosynthesis but elevated temperatures suppress this absorption and promote monoterpene emissions. Using 13CO 2 labeling, in this paper we show that monoterpene emissions from tropical leaves derive from recent photosynthesis and demonstrate distinct temperature optima for five groups (Groups 1–5), potentially corresponding to different enzymatic temperature-dependent reaction mechanisms within β-ocimene synthases. As diurnal and seasonal leaf temperatures increased during the Amazonian 2015 El Niño event, leaf and landscape monoterpene emissions showed strong linear enrichments of β-ocimenes (+4.4% °C -1) at the expense of other monoterpene isomers. The observed inverse temperaturemore » response of α-pinene (-0.8% °C -1), typically assumed to be the dominant monoterpene with moderate reactivity, was not accurately simulated by current global emission models. Given that β-ocimenes are highly reactive with respect to both atmospheric and biological oxidants, the results suggest that highly reactive β-ocimenes may play important roles in the thermotolerance of photosynthesis by functioning as effective antioxidants within plants and as efficient atmospheric precursors of secondary organic aerosols. Monoterpene composition may represent a new sensitive ‘thermometer’ of leaf oxidative stress and atmospheric reactivity, and therefore a new tool in future studies of warming impacts on tropical biosphere-atmosphere carbon-cycle feedbacks.« less

The Ratio and Concentration of Two Monoterpenes Mediate Fecundity of the Pinewood Nematode and Growth of Its Associated Fungi

PubMed Central

Niu, Hongtao; Zhao, Lilin; Lu, Min; Zhang, Shuai; Sun, Jianghua

2012-01-01

The pinewood nematode (PWN) Bursaphelenchus xylophilus, vectored primarily by the sawyer beetle, Monochamus alternatus, is an important invasive pest and causal agent of pine wilt disease of Chinese Masson pine, Pinus massoniana. Previous work demonstrated that the ratios and concentrations of α-pinene∶β-pinene differed between healthy trees and those trees containing blue-stain fungus (and M. alternatus pupae). However, the potential influence of the altered monoterpene ratios and concentrations on PWN and associated fungi remained unknown. Our current results show that low concentrations of the monoterpenes within petri dishes reduced PWN propagation, whereas the highest concentration of the monoterpenes increased PWN propagation. The propagation rate of PWN treated with the monoterpene ratio representative of blue-stain infected pine (α-pinene∶β-pinene = 1∶0.8, 137.6 mg/ml) was significantly higher than that (α-pinene∶β-pinene = 1∶0.1, 137.6 mg/ml) representative of healthy pines or those damaged by M. alternatus feeding, but without blue stain. Furthermore, inhibition of mycelial growth of associated fungi increased with the concentration of the monoterpenes α-pinene and β-pinene. Additionally, higher levels of β-pinene (α-pinene∶β-pinene = 1∶0.8) resulted in greater inhibition of the growth of the associated fungi Sporothrix sp.2 and Ophiostoma ips strains, but had no significant effects on the growth of Sporothrix sp.1, which is the best food resource for PWN. These results suggest that host monoterpenes generally reduce the reproduction of PWN. However, PWN utilizes high monoterpene concentrations and native blue-stain fungus Sporothrix sp.1 to improve its own propagation and overcome host resistance, which may provide clues to understanding the ecological mechanisms of PWN's successful invasion. PMID:22363713

Differential effects of plant ontogeny and damage type on phloem and foliage monoterpenes in jack pine (Pinus banksiana).

PubMed

Erbilgin, Nadir; Colgan, L Jessie

2012-08-01

Coniferous trees have both constitutive and inducible defences that deter or kill herbivores and pathogens. We investigated constitutive and induced monoterpene responses of jack pine (Pinus banksiana Lamb.) to a number of damage types: a fungal associate of the mountain pine beetle (Dendroctonus ponderosae Hopkins), Grosmannia clavigera (Robinson-Jeffrey & R.W. Davidson); two phytohormones, methyl jasmonate (MJ) and methyl salicylate (MS); simulated herbivory; and mechanical wounding. We only included the fungal, MJ and mechanical wounding treatments in the field experiments while all treatments were part of the greenhouse studies. We focused on both constitutive and induced responses between juvenile and mature jack pine trees and differences in defences between phloem and needles. We found that phytohormone applications and fungal inoculation resulted in the greatest increase in monoterpenes in both juvenile and mature trees. Additionally, damage types differentially affected the proportions of individual monoterpenes: MJ-treated mature trees had higher myrcene and β-pinene than fungal-inoculated mature trees, while needles of juveniles inoculated with the fungus contained higher limonene than MJ- or MS-treated juveniles. Although the constitutive monoterpenes were higher in the phloem of juveniles than mature jack pine trees, the phloem of mature trees had a much higher magnitude of induction. Further, induced monoterpene concentrations in juveniles were higher in phloem than in needles. There was no difference in monoterpene concentration between phytohormone applications and G. clavigera inoculation in mature trees, while in juvenile trees MJ was different from both G. clavigera and simulated herbivory in needle monoterpenes, but there was no difference between phytohormone applications and simulated herbivory in the phloem.

Local and regional variation in the monoterpenes of ponderosa pine wood oleoresin

Treesearch

R.H. Smith; R.L. Peloquin; P.C. Passof

1969-01-01

A gas chromatographic analysis of the mono-terpenes of 927 ponderosa pines, representing to some degree a major portion of the species' range, showed considerable local and regional diversity in composition. Five major monoterpenes— α-pinene, β-pinene, 3-carene, myrcene, and limonene—were analyzed. There is some evidence to support the...

PLANT VOLATILES. Biosynthesis of monoterpene scent compounds in roses.

PubMed

Magnard, Jean-Louis; Roccia, Aymeric; Caissard, Jean-Claude; Vergne, Philippe; Sun, Pulu; Hecquet, Romain; Dubois, Annick; Hibrand-Saint Oyant, Laurence; Jullien, Frédéric; Nicolè, Florence; Raymond, Olivier; Huguet, Stéphanie; Baltenweck, Raymonde; Meyer, Sophie; Claudel, Patricia; Jeauffre, Julien; Rohmer, Michel; Foucher, Fabrice; Hugueney, Philippe; Bendahmane, Mohammed; Baudino, Sylvie

2015-07-03

The scent of roses (Rosa x hybrida) is composed of hundreds of volatile molecules. Monoterpenes represent up to 70% percent of the scent content in some cultivars, such as the Papa Meilland rose. Monoterpene biosynthesis in plants relies on plastid-localized terpene synthases. Combining transcriptomic and genetic approaches, we show that the Nudix hydrolase RhNUDX1, localized in the cytoplasm, is part of a pathway for the biosynthesis of free monoterpene alcohols that contribute to fragrance in roses. The RhNUDX1 protein shows geranyl diphosphate diphosphohydrolase activity in vitro and supports geraniol biosynthesis in planta. Copyright © 2015, American Association for the Advancement of Science.

Biotransformation of (-)-α-pinene and geraniol to α-terpineol and p-menthane-3,8-diol by the white rot fungus, Polyporus brumalis.

PubMed

Lee, Su-Yeon; Kim, Seon-Hong; Hong, Chang-Young; Park, Se-Yeong; Choi, In-Gyu

2015-07-01

In this study, the monoterpenes, α-pinene and geraniol, were biotransformed to synthesize monoterpene alcohol compounds. Polyporus brumalis which is classified as a white rot fungus was used as a biocatalyst. Consequently α-terpineol was synthesized from α-pinene by P. brumalis mycelium, after three days. Moreover, another substrate, the acyclic monoterpenoids geraniol was transformed into the cyclic compound, p-menthane-3, 8-diol (PMD). The main metabolites, i.e., α-terpineol and PMD, are known to be bioactive monoterpene alcohol compounds. This study highlights the potential of fungal biocatalysts for monoterpene transformation.

The oxygen-independent metabolism of cyclic monoterpenes in Castellaniella defragrans 65Phen

PubMed Central

2014-01-01

Background The facultatively anaerobic betaproteobacterium Castellaniella defragrans 65Phen utilizes acyclic, monocyclic and bicyclic monoterpenes as sole carbon source under oxic as well as anoxic conditions. A biotransformation pathway of the acyclic β-myrcene required linalool dehydratase-isomerase as initial enzyme acting on the hydrocarbon. An in-frame deletion mutant did not use myrcene, but was able to grow on monocyclic monoterpenes. The genome sequence and a comparative proteome analysis together with a random transposon mutagenesis were conducted to identify genes involved in the monocyclic monoterpene metabolism. Metabolites accumulating in cultures of transposon and in-frame deletion mutants disclosed the degradation pathway. Results Castellaniella defragrans 65Phen oxidizes the monocyclic monoterpene limonene at the primary methyl group forming perillyl alcohol. The genome of 3.95 Mb contained a 70 kb genome island coding for over 50 proteins involved in the monoterpene metabolism. This island showed higher homology to genes of another monoterpene-mineralizing betaproteobacterium, Thauera terpenica 58EuT, than to genomes of the family Alcaligenaceae, which harbors the genus Castellaniella. A collection of 72 transposon mutants unable to grow on limonene contained 17 inactivated genes, with 46 mutants located in the two genes ctmAB (cyclic terpene metabolism). CtmA and ctmB were annotated as FAD-dependent oxidoreductases and clustered together with ctmE, a 2Fe-2S ferredoxin gene, and ctmF, coding for a NADH:ferredoxin oxidoreductase. Transposon mutants of ctmA, B or E did not grow aerobically or anaerobically on limonene, but on perillyl alcohol. The next steps in the pathway are catalyzed by the geraniol dehydrogenase GeoA and the geranial dehydrogenase GeoB, yielding perillic acid. Two transposon mutants had inactivated genes of the monoterpene ring cleavage (mrc) pathway. 2-Methylcitrate synthase and 2-methylcitrate dehydratase were also essential for the monoterpene metabolism but not for growth on acetate. Conclusions The genome of Castellaniella defragrans 65Phen is related to other genomes of Alcaligenaceae, but contains a genomic island with genes of the monoterpene metabolism. Castellaniella defragrans 65Phen degrades limonene via a limonene dehydrogenase and the oxidation of perillyl alcohol. The initial oxidation at the primary methyl group is independent of molecular oxygen. PMID:24952578

Emission and Accumulation of Monoterpene and the Key Terpene Synthase (TPS) Associated with Monoterpene Biosynthesis in Osmanthus fragrans Lour.

PubMed

Zeng, Xiangling; Liu, Cai; Zheng, Riru; Cai, Xuan; Luo, Jing; Zou, Jingjing; Wang, Caiyun

2015-01-01

Osmanthus fragrans is an ornamental and economically important plant known for its magnificent aroma, and the most important aroma-active compounds in flowers are monoterpenes, mainly β-ocimene, linalool and linalool derivatives. To understand the molecular mechanism of monoterpene production, we analyzed the emission and accumulation patterns of these compounds and the transcript levels of the genes involved in their biosynthesis in two O. fragrans cultivars during flowering stages. The results showed that both emission and accumulation of monoterpenes varied with flower development and glycosylation had an important impact on floral linalool emission during this process. Gene expression demonstrated that the transcript levels of terpene synthase (TPS) genes probably played a key role in monoterpene production, compared to the genes in the MEP pathway. Phylogenetic analysis showed that OfTPS1 and OfTPS2 belonged to a TPS-g subfamily, and OfTPS3 and OfTPS4 clustered into a TPS-b subfamily. Their transient and stable expression in tobacco leaves suggested that OfTPS1 and OfTPS2 exclusively produced β-linalool, and trans-β-ocimene was the sole product from OfTPS3, while OfTPS4, a predictive sesquiterpene synthase, produced α-farnesene. These results indicate that OfTPS1, OfTPS2, and OfTPS3 could account for the major floral monoterpenes, linalool and trans-β-ocimene, produced in O. fragrans flowers.

Emission and Accumulation of Monoterpene and the Key Terpene Synthase (TPS) Associated with Monoterpene Biosynthesis in Osmanthus fragrans Lour

PubMed Central

Zeng, Xiangling; Liu, Cai; Zheng, Riru; Cai, Xuan; Luo, Jing; Zou, Jingjing; Wang, Caiyun

2016-01-01

Osmanthus fragrans is an ornamental and economically important plant known for its magnificent aroma, and the most important aroma-active compounds in flowers are monoterpenes, mainly β-ocimene, linalool and linalool derivatives. To understand the molecular mechanism of monoterpene production, we analyzed the emission and accumulation patterns of these compounds and the transcript levels of the genes involved in their biosynthesis in two O. fragrans cultivars during flowering stages. The results showed that both emission and accumulation of monoterpenes varied with flower development and glycosylation had an important impact on floral linalool emission during this process. Gene expression demonstrated that the transcript levels of terpene synthase (TPS) genes probably played a key role in monoterpene production, compared to the genes in the MEP pathway. Phylogenetic analysis showed that OfTPS1 and OfTPS2 belonged to a TPS-g subfamily, and OfTPS3 and OfTPS4 clustered into a TPS-b subfamily. Their transient and stable expression in tobacco leaves suggested that OfTPS1 and OfTPS2 exclusively produced β-linalool, and trans-β-ocimene was the sole product from OfTPS3, while OfTPS4, a predictive sesquiterpene synthase, produced α-farnesene. These results indicate that OfTPS1, OfTPS2, and OfTPS3 could account for the major floral monoterpenes, linalool and trans-β-ocimene, produced in O. fragrans flowers. PMID:26793212

Pheromone Production by an Invasive Bark Beetle Varies with Monoterpene Composition of its Naïve Host.

PubMed

Taft, Spencer; Najar, Ahmed; Erbilgin, Nadir

2015-06-01

The secondary chemistry of host plants can have cascading impacts on the establishment of new insect herbivore populations, their long-term population dynamics, and their invasion potential in novel habitats. Mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae) has recently expanded its range into forests of jack pine, Pinus banksiana Lamb., in western Canada. We investigated whether variations in jack pine monoterpenes affect beetle pheromone production, as the primary components of the beetle's aggregation pheromone, (-)-trans-verbenol and anti-aggregation pheromone (-)-verbenone, are biosynthesized from the host monoterpene α-pinene. Jack pine bolts were collected from five Canadian provinces east of the beetle's current range, live D. ponderosae were introduced into them, and their monoterpene compositions were characterized. Production of (-)-trans-verbenol and (-)-verbenone emitted by beetles was measured to determine whether pheromone production varies with monoterpene composition of jack pines. Depending on particular ratios of major monoterpenes in host phloem, jack pine could be classified into three monoterpenoid groups characterized by high amounts of (+)-α-pinene, 3-carene, or a more moderate blend of monoterpenes, and beetle pheromone production varied among these groups. Specifically, beetles reared in trees characterized by high (+)-α-pinene produced the most (-)-trans-verbenol and (-)-verbenone, while beetles in trees characterized by high 3-carene produced the least. Our results indicate that pheromone production by D. ponderosae will remain a significant aspect and important predictor of its survival and persistence in the boreal forest.

The role of ecophysiology in determining monoterpene concentrations and emissions from pinyon pine under drought conditions

NASA Astrophysics Data System (ADS)

Trowbridge, A. M.; Adams, H. D.; Breshears, D. D.; Stoy, P.; Monson, R. K.

2012-12-01

While much research has focused on the primary metabolic mechanisms underlying pinyon pine's sensitivity to severe and abrupt drought conditions, there remains a gap in our knowledge concerning how the resulting shift in carbon allocation toward plant secondary compounds, particularly monoterpenes, affects both atmospheric process and ecological species interactions. Because of the large global emission rate of monoterpenes and their effect on atmospheric chemistry, identifying the primary controls over and sensitivities to environmental change is critical for global emission models. Furthermore, monoterpenes are also known to impact insect behavior and act as defense compounds against herbivores, contributing to fluctuations in the population densities of herbivores either directly through toxicity, or indirectly by influencing an insect's susceptibility to parasitism. While pinyon mortality events are thought to be exacerbated by their susceptibility to herbivores resulting from weakened secondary chemical defenses, the impact of current and predicted drought on the chemical defense status of pinyons and the potential consequences for atmospheric composition and ecological interactions remains unknown. We performed a manipulative field study to untangle the effects of drought on plant carbon assimilation, growth, and defense throughout the year. Transplanting pinyons from their natural habitat into a desert environment, we were able to increase mean annual temperature by ~4 degrees C. Throughout the growing season, we measured pinyon physiology and monoterpene composition and emissions under different water (well-watered, ambient, or drought-stresed) and temperature (natural pinyon habitat or desert transplants) regimes. We hypothesized that increased drought would increase tissue concentrations in accordance with the carbon-nutrient balance hypothesis (CNBH). Furthermore, we predicted that higher temperatures and lower water availability together would influence monoterpene emission rates, but only through shifts in tissue concentrations. Our results showed that neither total needle monoterpene concentrations nor emission rates differed between sites, and furthermore, foliar concentrations were not a significant predictor of emissions. Rather, stomatal conductance was significantly and positively correlated with monoterpene emission rates below 1 μg C gDW-1 h-1, explaining 10% of the variation in the data when measured across the growing season, but only in the pinyon pine native habitat. However, we also observed periods of emission rates > 1 μg C gDW-1 h-1at both sites during the month of June, which were not controlled by stomatal conductance or tissue monoterpene concentration. Thus, there appear to be yet-to-be-identified phenological factors that exert control over these extremely high mid-season emission rates. Our results suggest that drought has no significant influence over tissue monoterpene concentrations in this system, which are likely under tight genetic control. However, drought and phenology may exert dominant controls over the emission of monoterpenes through influences on stomatal conductance and other plant processes. Our results demonstrate a greater role than previously recognized for ecophysiological processes in controlling monoterpene fluxes from semi-arid conifer species.

An overview of the pharmacological properties and potential applications of natural monoterpenes.

PubMed

Kozioł, Agata; Stryjewska, Agnieszka; Librowski, Tadeusz; Sałat, Kinga; Gaweł, Magdalena; Moniczewski, Andrzej; Lochyński, Stanisław

2014-01-01

Monoterpenes, the major components of essential oils, belong to the group of isoprenoids containing ten carbon atoms. Being widely distributed in the plant kingdom they are extensively used in cuisine and human health care products. Studies have shown that both natural monoterpenes and their synthetic derivatives are endowed with various pharmacological properties including antifungal, antibacterial, antioxidant, anticancer, antiarrhythmic, anti-aggregating, local anesthetic, antinociceptive, anti-inflammatory, antihistaminic and anti-spasmodic activities. Monoterpenes act also as regulators of growth, heat, transpiration, tumor inhibitors, inhibitors of oxidative phosphorylation, insect repellants, feline and canine attractants and antidiabetics. These interesting activities which might be potentially used not only in pharmaceutical, but also food and cosmetic industries are discussed below.

Monoterpene emission from ponderosa pine

NASA Technical Reports Server (NTRS)

Lerdau, Manual; Dilts, Stephen B.; Westberg, Hal; Lamb, Brian K.; Allwine, Eugene J.

1994-01-01

We explore the variability in monoterpene emissions from ponderosa pine beyond that which can be explained by temperature alone. Specifically, we examine the roles that photosynthesis and needle monoterpene concentrations play in controlling emissions. We measure monoterpene concentrations and emissions, photosynthesis, temperature, and light availability in the late spring and late summer in a ponderosa pine forest in central Oregon. We use a combination of measurements from cuvettes and Teflon bag enclosures to show that photosynthesis is not correlated with emissions in the short term. We also show that needle monoterpene concentrations are highly correlated with emissions for two compounds, alpha-pinene and beta-pinene, but that Delta-carene concentrations are not correlated with emissions. We suggest that direct effects of light and photosynthesis do not need to be included in emission algorithms. Our results indicate that the role of needle concentration bears further investigation; our results for alpha-pinene and beta-pinene are explainable by a Raoult's law relationship, but we cannot yet explain the cause of our results with Delta-carene.

UFVA, A Combined Linear and Nonlinear Factor Analysis Program Package for Chemical Data Evaluation.

DTIC Science & Technology

1980-11-01

that one cluster consists of the monoterpenes and Isoprene; the second is of the sesquiterpenes. Compound 8 (Caryophyllene) should therefore belong to...two clusters very clearly (Fig. 6). Figure 6 The very similar fragmentation pattern of Isoprene and the monoterpenes is reflected by their close...13 of another set of 13 terpene components. These are Isoprene, four monoterpenes (Myrcene, Menthol, Camphene, Umbellulone), four sesquiterpenes

Pondering the monoterpene composition of Pinus serotina Michx.: can limonene be used as a chemotaxonomic marker for the identification of old turpentine stumps?

Treesearch

Thomas L. Eberhardt; Jolie M. Mahfouz; Philip M. Sheridan

2010-01-01

Wood samples from old turpentine stumps in Virginia were analyzed by GC-MS to determine if the monoterpene compositions could be used for species identification. Given that limonene is reported to be the predominant monoterpene for pond pine (Pinus serotina Michx.), low relative proportions of limonene in these samples appeared to suggest that these...

Observations of speciated monoterpenes above a Southeastern United States Forest and comparison with a 0-D model

NASA Astrophysics Data System (ADS)

Mcavey, K. M.; Groff, C. J.; Harkins, A. D.; Bertman, S. B.; Starn, T.; Seeley, J. S.; Shepson, P. B.

2013-12-01

Biogenic emissions of monoterpenes play a role in the formation of secondary organic aerosols (SOA) and tropospheric ozone, as well as impacting the fate of nitrogen through production of organic nitrates. Monoterpene emissions can interact with anthropgenic emissions (e.g. sulfate aerosol) to produce a variety of SOA components, such as organosulfates. Concentrations of several monoterpenes, including some combination of α-pinene, β-pinene, camphene, limonene, terpinolene, γ-terpinene, myrcene, and ρ-cymene (depending on chromatographic resolution) were quantified in a forested site in rural Alabama using an automated solid sorbent sampler/2D-GC, as part of the Southern Oxidant and Aerosol Study (SOAS). Monoterpene concentrations were relatively large in this mixed coniferous/deciduous forest, with individual terpenes maximizing at concentrations as high as 1 ppb or more, making them important OH sinks, as well as organic nitrate precursors. α-pinene was the dominant terpene measured. Diurnal patterns show a clear increase in observed monoterpene concentrations occurring in the later evening hours. In this presentation we will compare the observed terpene distribution with that from a simple landcover survey and emissions model, and discuss the relative role of isoprene and the terpenes as OH sinks, and precursors to organic nitrates, which are themselves potentially important SOA components.

Monoterpenes Support Systemic Acquired Resistance within and between Plants

PubMed Central

Ghirardo, Andrea; Knappe, Claudia; Koch, Kerstin; Dey, Sanjukta; Parker, Jane E.

2017-01-01

This study investigates the role of volatile organic compounds in systemic acquired resistance (SAR), a salicylic acid (SA)-associated, broad-spectrum immune response in systemic, healthy tissues of locally infected plants. Gas chromatography coupled to mass spectrometry analyses of SAR-related emissions of wild-type and non-SAR-signal-producing mutant plants associated SAR with monoterpene emissions. Headspace exposure of Arabidopsis thaliana to a mixture of the bicyclic monoterpenes α-pinene and β-pinene induced defense, accumulation of reactive oxygen species, and expression of SA- and SAR-related genes, including the SAR regulatory AZELAIC ACID INDUCED1 (AZI1) gene and three of its paralogs. Pinene-induced resistance was dependent on SA biosynthesis and signaling and on AZI1. Arabidopsis geranylgeranyl reductase1 mutants with reduced monoterpene biosynthesis were SAR-defective but mounted normal local resistance and methyl salicylate-induced defense responses, suggesting that monoterpenes act in parallel with SA. The volatile emissions from SAR signal-emitting plants induced defense in neighboring plants, and this was associated with the presence of α-pinene, β-pinene, and camphene in the emissions of the “sender” plants. Our data suggest that monoterpenes, particularly pinenes, promote SAR, acting through ROS and AZI1, and likely function as infochemicals in plant-to-plant signaling, thus allowing defense signal propagation between neighboring plants. PMID:28536145

Drought and soil amendment effects on monoterpene emission in rosemary plants.

PubMed

Nogués, I; Muzzini, V; Loreto, F; Bustamante, M A

2015-12-15

The aim of this work was to study the changes during 15days in the monoterpene emission rates of the Mediterranean shrub rosemary (Rosmarinus officinalis L.), in response to increasing drought stress and fertilisation using two different composts derived from livestock anaerobic digestates (cattle and pig slurry). Drought stress considerably reduced photosynthetic rates, stomatal conductance and isoprenoid emissions and also induced a change in blend composition. In the drought stressed rosemary plants, a positive relationship of non-oxygenated monoterpene emissions and a negative relationship of oxygenated monoterpene with photosynthesis were observed, indicating a different control mechanism over the emissions of the two types of isoprenoids. The emission of non-oxygenated monoterpenes seemed to depend more on photosynthesis and "de novo" synthesis, whereas emission of oxygenate monoterpenes was more dependent on volatilisation from storage, mainly driven by cumulative temperatures. In the short term, the addition of composted organic materials to the soil did not induce a significant effect on isoprenoid emission rates in the rosemary plants. However, the effect of the interaction between fertilisation and seasonality on isoprenoid emission rates was influenced by the amendment origin. Also, we emphasized changes in potential isoprenoid emission factors throughout the experiment, probably indicating changes in the leaf developmental stage. Copyright © 2015. Published by Elsevier B.V.

Airborne Monoterpenes Emitted from a Cupressus lusitanica Cell Culture Induce a Signaling Cascade that Produces β-Thujaplicin.

PubMed

Fujita, Koki; Kambe, Ryo; De Alwis, Ransika; Yagi, Tatsuya; Tsutsumi, Yuji

2016-08-01

A cell culture of Cupressus lusitanica was used to investigate the reaction of a plant to certain airborne chemicals. Compared with laboratory and field methods using intact plants or tissues, a cell culture is advantageous because it is not affected by environmental factors, and the experiments are easier to reproduce. When exposed to an elicitor, our cell line produces 10 monoterpenes and β-thujaplicin, which is a strong phytoalexin. These monoterpenes are emitted into the vapor phase and are expected to play a role in airborne signaling. In the present study, the cells were exposed to monoterpene vapors, and the volatiles present in the culture flasks were monitored. When the culture cells were exposed to low doses of sabinene, we detected γ-terpinene and p-cymene. After exposure to γ-terpinene, we found p-cymene and terpinolene, whereas p-cymene exposure resulted in terpinolene emission. By contrast, the other seven monoterpenes we investigated did not induce any emissions of other monoterpenes. These results strongly suggest that in C. lusitanica a signaling cascade exists that starts with the emission of sabinene and moves to γ-terpinene, p-cymene, and finally to terpinolene, which accelerates the production of the phytoalexin β-thujaplicin.

Basin-scale observations of isoprene and monoterpenes in the Arctic and Atlantic Oceans

NASA Astrophysics Data System (ADS)

Carpenter, L.; Hackenberg, S.; Andrews, S.; Minaeian, J.; Chance, R.; Arnold, S.; Spracklen, D. V.; Walker, H.; Brewin, R. J.; Tarran, G.; Tilstone, G.; Small, A.; Bouman, H. A.

2016-12-01

We report surface ocean concentrations, atmospheric mixing ratios and calculated sea-to-air fluxes of isoprene and six monoterpenes (α- and β-pinene, myrcene, Δ 3-carene, ocimene, and limonene) spanning approximately 130 degrees of latitude (80 °N- 50 °S) in the Arctic and Atlantic Oceans. Oceanic isoprene concentrations showed covariance with a number of concurrently monitored biological parameters, and these relationships were dependent on sea surface temperatures. Parameterisations of isoprene seawater concentrations based on linear regression analyses of these relationships perform well for Arctic and Atlantic data. Levels of all monoterpenes were generally low, with oceanic concentrations ranging from below the detection limit of <1 pmol L-1 to 5 pmol L-1 . In air, monoterpene mixing ratios varied from below the detection limit ( 1 pptv) to 5 pptv, after careful filtering for ship-related contamination. Unlike in previous studies, no clear trends or relationships of the monoterpenes with biological data were found. Limonene showed generally the highest levels in water (up to 84 pmol L-1 in the Atlantic Ocean) and air; however this was attributed mostly to shipborne contamination. We calculate global sea-air fluxes of isoprene and monoterpenes based on this data and compare to previous estimates.

A Blend of Ethanol and (-)-α-Pinene were Highly Attractive to Native Siricid Woodwasps (Siricidae, Siricinae) Infesting Conifers of the Sierra Nevada and the Allegheny Mountains.

PubMed

Erbilgin, Nadir; Stein, Jack D; Acciavatti, Robert E; Gillette, Nancy E; Mori, Sylvia R; Bischel, Kristi; Cale, Jonathan A; Carvalho, Carline R; Wood, David L

2017-02-01

Woodwasps in Sirex and related genera are well-represented in North American conifer forests, but the chemical ecology of native woodwasps is limited to a few studies demonstrating their attraction to volatile host tree compounds, primarily monoterpene hydrocarbons and monoterpene alcohols. Thus, we systematically investigated woodwasp-host chemical interactions in California's Sierra Nevada and West Virginia's Allegheny Mountains. We first tested common conifer monoterpene hydrocarbons and found that (-)-α-pinene, (+)-3-carene, and (-)-β-pinene were the three most attractive compounds. Based on these results and those of earlier studies, we further tested three monoterpene hydrocarbons and four monoterpene alcohols along with ethanol in California: monoterpene hydrocarbons caught 72.3% of all woodwasps. Among monoterpene hydrocarbons, (+)-3-carene was the most attractive followed by (-)-β-pinene and (-)-α-pinene. Among alcohols, ethanol was the most attractive, catching 41.4% of woodwasps trapped. Subsequent tests were done with fewer selected compounds, including ethanol, 3-carene, and ethanol plus (-)-α-pinene in both Sierra Nevada and Allegheny Mountains. In both locations, ethanol plus (-)-α-pinene caught more woodwasps than other treatments. We discussed the implications of these results for understanding the chemical ecology of native woodwasps and invasive Sirex noctilio in North America. In California, 749 woodwasps were caught, representing five species: Sirex areolatus Cresson, Sirex behrensii Cresson, Sirex cyaneus Fabricius, Sirex longicauda Middlekauff, and Urocerus californicus Norton. In West Virginia 411 woodwasps were caught representing four species: Sirex edwardsii Brullé, Tremex columba Linnaeus, Sirex nigricornis F., and Urocerus cressoni Norton.

Chemical composition and antibacterial activity of the essential oils from flower, leaf and stem of Ferula cupularis growing wild in Iran.

PubMed

Alipour, Ziba; Taheri, Poroshat; Samadi, Nasrin

2015-04-01

Ferula cupularis (Boiss.) Spalik et S. R. Downie (Apiaceae) is a common plant in Iran that grows in the foothills of Dena Mountain. In traditional folk medicine, this plant has different applications, but there are no studies proving their uses. This study is the first attempt to investigate the chemical composition and antibacterial effect of the essential oils of F. cupularis. The essential oils from flower, leaf, and stem of F. cupularis were analyzed by using GC and GC-MS. Antibacterial activity of essential oils was determined by microdilution method against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The essential oil from flower of F. cupularis contained 15 monoterpene, 13 oxygenated monoterpene, and 2 sesquiterpene hydrocarbons. The leaf essential oil contained 12 monoterpene, 13 oxygenated monoterpene, 2 sesquiterpene, 6 oxygenated sesquiterpene hydrocarbons, and 3 non-terpenoid components. Stem essential oil contained one monoterpene, 23 oxygenated monoterpene, 2 sesquiterpene, and 6 oxygenated sesquiterpene hydrocarbons. The MIC value of stem essential oil was 2.85 mg/mL against both Gram-positive bacteria and Gram-negative bacteria except P. aeruginosa which was inhibited at 22.75 mg/mL. The MIC values of leaf and flower essential oils were higher than 5.69 and 22.75 mg/mL, respectively. This study highlighted the strong antibacterial effect of Ferula cupularis's essential oil which might be due to its high content of oxygenated monoterpene hydrocarbons. Our results suggested that this plant may be a good candidate for further biological and pharmacological investigations.

Profiling monoterpenol glycoconjugation in Vitis vinifera L. cv. Muscat of Alexandria using a novel putative compound database approach, high resolution mass spectrometry and collision induced dissociation fragmentation analysis.

PubMed

Hjelmeland, Anna K; Zweigenbaum, Jerry; Ebeler, Susan E

2015-08-05

In this work we present a novel approach for the identification of plant metabolites using ultrahigh performance liquid chromatography coupled to accurate mass time-of-flight mass spectrometry. The workflow involves developing an in-house compound database consisting of exact masses of previously identified as well as putative compounds. The database is used to screen accurate mass spectrometry (MS) data to identify possible compound matches. Subsequent tandem MS data is acquired for possible matches and used for structural elucidation. The methodology is applied to profile monoterpene glycosides in Vitis vinifera cv. Muscat of Alexandria grape berries over three developmental stages. Monoterpenes are a subclass of terpenes, the largest class of plant secondary metabolites, and are found in two major forms in the plant, "bound" to one or more sugar moieties or "free" of said sugar moieties. In the free form, monoterpenes are noted for their fragrance and play important roles in plant defense and as attractants for pollinators. However, glycoconjugation renders these compounds odorless, and it is this form that the plant uses for monoterpene storage. In order to gain insight into monoterpene biochemistry and their fate in the plant an analysis of intact glycosides is essential. Eighteen monoterpene glycosides were identified including a monoterpene trisaccharide glycoside, which is tentatively identified here for this first time in any plant. Additionally, while previous studies have identified monoterpene malonylated glucosides in other grapevine tissue, we tentatively identify them for the first time in grape berries. This analytical approach can be readily applied to other plants and the workflow approach can also be used for other classes of compounds. This approach, in general, provides researchers with data to support the identification of putative compounds, which is especially useful when no standard is available. Copyright © 2015 Elsevier B.V. All rights reserved.

Untangling the primary drivers of pinyon monoterpene production and emissions under predicted drought

NASA Astrophysics Data System (ADS)

Trowbridge, A. M.; Adams, H. D.; Breshears, D. D.; Monson, R. K.

2012-04-01

Climate and insect herbivory have important consequences for plant function, atmospheric composition, and the functioning of ecosystems and ecological communities. Within the last decade, pinyon-juniper woodlands throughout the southwestern U.S. have suffered large-scale mortality, especially of pinyon pine, due to drought and associated insect outbreaks. While much research has focused on the primary metabolic mechanisms underlying pinyon's sensitivity to drought, there remains a gap in our knowledge concerning how the resulting shift in carbon allocation toward plant secondary compounds, particularly monoterpenes, affects atmospheric process and ecological interactions. Monoterpenes are the principal constituents of pinyon resin. Because of their large global emission rates and effect on atmospheric chemistry, particularly ozone creation, identifying controls over emissions and sensitivities to environmental change is critical for global emission models. Furthermore, monoterpenes are known to impact insect behavior and act as defense compounds against herbivores, contributing to insect population fluctuations either directly through toxicity, or indirectly by influencing parasitism susceptibility. Pinyon mortality events are thought to be exacerbated by their susceptibility to herbivores resulting from weakened secondary chemical defenses, but the impact of current and predicted drought on the chemical defense status of pinyons and subsequent atmospheric and ecological consequences remain unknown. A field study was developed to examine the impact of seasonality and climate, particularly drought, on pinyon pine physiology and chemistry in the context of tiger moth (Lophocampa ingens) herbivory in pinyon-juniper woodlands. We demonstrate the importance of geography and seasonality, particularly mid-summer drought and late summer monsoons, in driving physiology and monoterpene concentrations and emissions. Emission rates significantly decreased throughout the summer and increased with a release from drought stress. Pinyons with past herbivore damage emitted significantly higher levels of monoterepenes (P<0.05), suggesting an interactive effect between herbivory and drought. Furthermore, neither temperature nor foliar monoterpene concentrations predicted emission rates, a result most likely due to the composite physiological response to both drought and insect herbivory. To tease apart the primary drivers of monoterpene emissions under drought stress, we developed a manipulative study by transplanting pinyons into a desert environment and increasing mean annual temperature by ~4 °C. We then measured pinyon physiology and monoterpene composition and emissions under different water and temperature regimes. Similar to our previous study, we saw that monoterpene emissions decreased with water availability across our treatments (P<0.05), with a 60% decrease in emissions from well-watered to drought stressed trees. While monoterpene emission rates early in the growing season in the native habitat were correlated with foliar concentrations and temperature, they were more constrained by water availability in transplanted trees as the growing season progressed. A possible explanation for these results could be that, unlike temperate species, semi-arid trees are physiologically more sensitive to water availability; therefore, we determined specific drought stress level and water potential thresholds at which this decoupling of temperature-dependent monoterpene emissions occurs. These results have led to the development of hypotheses about the consequences of future shifts in monoterpene concentrations and emissions due to drought affecting herbivore species interactions, outbreaks, and atmospheric processes.

Predictors of monoterpene exposure in the Danish furniture industry.

PubMed

Hagström, Katja; Jacobsen, Gitte; Sigsgaard, Torben; Schaumburg, Inger; Erlandsen, Mogens; Schlunssen, Vivi

2012-04-01

Individuals who work with pine in the furniture industry may be exposed to monoterpenes, the most abundant of which are α-pinene, β-pinene, and Δ(3)-carene. Monoterpenes are suspected to cause dermatitis and to harm the respiratory system. An understanding of the predictors of monoterpene exposure is therefore important in preventing these adverse effects. These predictors may include general characteristics of the work environment and specific work operations. We sought to assess the extent to which workers are exposed to monoterpenes and to identify possible predictors of monoterpene exposure in the pine furniture industry in Denmark. Passive measurements of the levels of selected monoterpenes (α-pinene, β-pinene, and Δ(3)-carene) were performed on 161 subjects from 17 pine furniture factories in Viborg County, Denmark; one sample was acquired from each worker. Additionally, wood dust samples were collected from 145 workers. Data on potential predictors of exposure were acquired over the course of the day on which the exposure measurements were recorded and could be assigned to one of four hierarchic ordered levels: worker, machine, department, and factory. In addition to univariate analyses, a mixed model was used to account for imbalances within the data and random variation with each of the hierarchically ordered levels. The geometric mean (GM) monoterpene content observed over the 161 measurements was 7.8 mg m(-3) [geometric standard deviation (GSD): 2.4]; the GM wood dust level over 145 measurements was 0.58 mg m(-3) (GSD: 1.49). None of the measured samples exceeded the occupational exposure limit for terpenes in Denmark (25 ppm, 150 mg m(-3)). In the univariate analyses, half of the predictors tested were found to be significant; the multivariate model indicated that only three of the potential predictors were significant. These were the recirculation of air in rooms used for the processing of wood (a factory level predictor), the presence of a supplementary cold air intake (departmental level), and the operation of a glue press (machine level). However, only one factory of the 17 examined used a supplementary cold air intake, and while very high monoterpene levels were observed there, this may be due to factors other than the supplementary intake. In contrast to the situation with wood dust, we found that the bulk of the variation in the data (65%) was attributable to variability on the factory level, with comparatively little being due to the departmental (16%) and machine (0.5%) levels. The fixed terms in the model accounted for 31.8% of the total variance. The predictors of monoterpenes are not the same as those for wood dust exposure; this has implications for the implementation of preventative measures in factories. In order to decrease monoterpene exposure, efforts should be focused on minimizing the recirculation of air in rooms used for woodworking and on increasing awareness of the importance of effective ventilation and enclosure when operating a glue press.

2,2-Diphenyl-1-picrylhydrazyl as a screening tool for recombinant monoterpene biosynthesis.

PubMed

Behrendorff, James Byh; Vickers, Claudia E; Chrysanthopoulos, Panagiotis; Nielsen, Lars K

2013-08-23

Monoterpenes are a class of natural C10 compounds with a range of potential applications including use as fuel additives, fragrances, and chemical feedstocks. Biosynthesis of monoterpenes in heterologous systems is yet to reach commercially-viable levels, and therefore is the subject of strain engineering and fermentation optimization studies. Detection of monoterpenes typically relies on gas chromatography/mass spectrometry; this represents a significant analytical bottleneck which limits the potential to analyse combinatorial sets of conditions. To address this, we developed a high-throughput method for pre-screening monoterpene biosynthesis. An optimised DPPH assay was developed for detecting monoterpenes from two-phase microbial cultures using dodecane as the extraction solvent. The assay was useful for reproducible qualitative ranking of monoterpene concentrations, and detected standard preparations of myrcene and γ-terpinene dissolved in dodecane at concentrations as low as 10 and 15 μM, respectively, and limonene as low as 200 μM. The assay could not be used quantitatively due to technical difficulties in capturing the initial reaction rate in a multi-well plate and the presence of minor DPPH-reactive contaminants. Initially, limonene biosynthesis in Saccharomyces cerevisiae was tested using two different limonene synthase enzymes and three medium compositions. The assay indicated that limonene biosynthesis was enhanced in a supplemented YP medium and that the Citrus limon limonene synthase (CLLS) was more effective than the Mentha spicata limonene synthase (MSLS). GC-MS analysis revealed that the DPPH assay had correctly identified the best limonene synthase (CLLS) and culture medium (supplemented YP medium). Because only traces of limonene were detected in SD medium, we subsequently identified medium components that improved limonene production and developed a defined medium based on these findings. The best limonene titres obtained were 1.48 ± 0.22 mg limonene per L in supplemented YP medium and 0.9 ± 0.15 mg limonene per L in a pH-adjusted supplemented SD medium. The DPPH assay is useful for detecting biosynthesis of limonene. Although the assay cannot be used quantitatively, it proved successful in ranking limonene production conditions qualitatively and thus is suitable as a first-tier screen. The DPPH assay will likely be applicable in detecting biosynthesis of several other monoterpenes and for screening libraries of monoterpene-producing strains.

2,2-Diphenyl-1-picrylhydrazyl as a screening tool for recombinant monoterpene biosynthesis

PubMed Central

2013-01-01

Background Monoterpenes are a class of natural C10 compounds with a range of potential applications including use as fuel additives, fragrances, and chemical feedstocks. Biosynthesis of monoterpenes in heterologous systems is yet to reach commercially-viable levels, and therefore is the subject of strain engineering and fermentation optimization studies. Detection of monoterpenes typically relies on gas chromatography/mass spectrometry; this represents a significant analytical bottleneck which limits the potential to analyse combinatorial sets of conditions. To address this, we developed a high-throughput method for pre-screening monoterpene biosynthesis. Results An optimised DPPH assay was developed for detecting monoterpenes from two-phase microbial cultures using dodecane as the extraction solvent. The assay was useful for reproducible qualitative ranking of monoterpene concentrations, and detected standard preparations of myrcene and γ-terpinene dissolved in dodecane at concentrations as low as 10 and 15 μM, respectively, and limonene as low as 200 μM. The assay could not be used quantitatively due to technical difficulties in capturing the initial reaction rate in a multi-well plate and the presence of minor DPPH-reactive contaminants. Initially, limonene biosynthesis in Saccharomyces cerevisiae was tested using two different limonene synthase enzymes and three medium compositions. The assay indicated that limonene biosynthesis was enhanced in a supplemented YP medium and that the Citrus limon limonene synthase (CLLS) was more effective than the Mentha spicata limonene synthase (MSLS). GC-MS analysis revealed that the DPPH assay had correctly identified the best limonene synthase (CLLS) and culture medium (supplemented YP medium). Because only traces of limonene were detected in SD medium, we subsequently identified medium components that improved limonene production and developed a defined medium based on these findings. The best limonene titres obtained were 1.48 ± 0.22 mg limonene per L in supplemented YP medium and 0.9 ± 0.15 mg limonene per L in a pH-adjusted supplemented SD medium. Conclusions The DPPH assay is useful for detecting biosynthesis of limonene. Although the assay cannot be used quantitatively, it proved successful in ranking limonene production conditions qualitatively and thus is suitable as a first-tier screen. The DPPH assay will likely be applicable in detecting biosynthesis of several other monoterpenes and for screening libraries of monoterpene-producing strains. PMID:23968454

Biogenic volatile organic compounds (BVOCs) emissions from Abies alba in a French forest.

PubMed

Moukhtar, S; Couret, C; Rouil, L; Simon, V

2006-02-01

Air quality studies need to be based on accurate and reliable data, particularly in the field of the emissions. Biogenic emissions from forests, crops, and grasslands are now considered as major compounds in photochemical processes. Unfortunately, depending on the type of vegetation, these emissions are not so often reliably defined. As an example, although the silver fir (Abies alba) is a very widespread conifer tree in the French and European areas, its standard emission rate is not available in the literature. This study investigates the isoprene and monoterpenes emission from A. alba in France measured during the fieldwork organised in the Fossé Rhénan, from May to June 2003. A dynamic cuvette method was used. Limonene was the predominant monoterpene emitted, followed by camphene, alpha-pinene and eucalyptol. No isoprene emission was detected. The four monoterpenes measured showed different behaviours according to micrometeorological conditions. In fact, emissions of limonene, alpha-pinene and camphene were temperature-dependant while eucalyptol emissions were temperature and light dependant. Biogenic volatile organic compounds emissions were modeled using information gathered during the field study. Emissions of the three monoterpenes previously quoted were achieved using the monoterpenes algorithm developed by Tingey et al. (1980) [Tingey D, Manning M, Grothaus L, Burns W. Influence of light and temperature on monoterpene emission rates from slash pine. Plant Physiol 1980;65: 797-801.] and the isoprene algorithm [Guenther, A., Monson, R., Fall, R., 1991. Isoprene and monoterpene emission rate variability: observations with eucalyptus and emission rate algorithm development. J Geophys Res 26A: 10799-10808.]; [Guenther, A., Zimmerman, P., Harley, P., Monson, R., Fall, R., 1993. Isoprene and monoterpene emission rate variability: model evaluation and sensitivity analysis. J Geophys Res 98D: 12609-12617.]) was used for the eucalyptol emission. With these methods, simulation results and observations agreed fairly well. The standard emission rate (303 K) and beta-coefficient averaged for limonene, camphene and alpha-pinene were respectively of 0.63 microg gdw-1 h-1 and 0.06 K-1. For eucalyptol, the standard emission rate (T=303 K and PAR=1000 micromol m-2 s-1) was 0.26 microg gdw-1 h-1. This classified A. alba as a weak monoterpenes emitter.

Flowery odor formation revealed by differential expression of monoterpene biosynthetic genes and monoterpene accumulation in rose (Rosa rugosa Thunb.).

PubMed

Feng, Liguo; Chen, Chen; Li, Tinglin; Wang, Meng; Tao, Jun; Zhao, Daqiu; Sheng, Lixia

2014-02-01

Rosa rugosa is an important ornamental and economical plant. In this paper, four genes encoding 1-deoxy-D-xylulose-5-phosphate synthase (DXS), 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), alcohol acyltransferase (AAT) and linalool synthase (LIS) involved in the monoterpene biosynthesis pathways were isolated from R. rugosa 'Tangzi', and the expression patterns of these genes in different flower development stages and different parts of floral organs were determined by real-time quantitative fluorescence PCR. Furthermore, a comprehensive analysis was carried out into the relationship between expression of four monoterpene synthesis genes and accumulation of main volatile monoterpenes and their acetic acid ester derivatives. The results showed that the genes RrDXS, RrDXR and RrLIS showed consistent expressions during the development process for R. rugosa flower from budding to withering stage, the overall expression levels of gene RrDXS and RrLIS were obviously lower as compared with those of gene RrDXR and RrAAT. Although the gene RrDXS, RrDXR, RrAAT and RrLIS were expressed in all parts of R. rugosa floral organs, the expression levels varied significantly. The variations in the constituent and content of volatile monoterpenes including citronellol, geraniol, nerol, linalool, citronellyl acetate, geranyl acetate and neryl acetate at different development stages and parts of floral organs were significantly different. On this basis, we concluded that the gene RrDXR and RrAAT might play a key role in the biosynthesis of volatile monoterpenes in R. rugosa flowers, and the two genes are important candidate genes for the regulation of secondary metabolism for rose aromatic components. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Pharmacokinetics and disposition of monoterpene glycosides derived from Paeonia lactiflora roots (Chishao) after intravenous dosing of antiseptic XueBiJing injection in human subjects and rats.

PubMed

Cheng, Chen; Lin, Jia-zhen; Li, Li; Yang, Jun-ling; Jia, Wei-wei; Huang, Yu-hong; Du, Fei-fei; Wang, Feng-qing; Li, Mei-juan; Li, Yan-fen; Xu, Fang; Zhang, Na-ting; Olaleye, Olajide E; Sun, Yan; Li, Jian; Sun, Chang-hai; Zhang, Gui-ping; Li, Chuan

2016-04-01

Monoterpene glycosides derived from Paeonia lactiflora roots (Chishao) are believed to be pharmacologically important for the antiseptic herbal injection XueBiJing. This study was designed to characterize the pharmacokinetics and disposition of monoterpene glycosides. Systemic exposure to Chishao monoterpene glycosides was assessed in human subjects receiving an intravenous infusion and multiple infusions of XueBiJing injection, followed by assessment of the pharmacokinetics of the major circulating compounds. Supportive rat studies were also performed. Membrane permeability and plasma-protein binding were assessed in vitro. A total of 18 monoterpene glycosides were detected in XueBiJing injection (content levels, 0.001-2.47 mmol/L), and paeoniflorin accounted for 85.5% of the total dose of monoterpene glycosides detected. In human subjects, unchanged paeoniflorin exhibited considerable levels of systemic exposure with elimination half-lives of 1.2-1.3 h; no significant metabolite was detected. Oxypaeoniflorin and albiflorin exhibited low exposure levels, and the remaining minor monoterpene glycosides were negligible or undetected. Glomerular-filtration-based renal excretion was the major elimination pathway of paeoniflorin, which was poorly bound to plasma protein. In rats, the systemic exposure level of paeoniflorin increased proportionally as the dose was increased. Rat lung, heart, and liver exposure levels of paeoniflorin were lower than the plasma level, with the exception of the kidney level, which was 4.3-fold greater than the plasma level; brain penetration was limited by the poor membrane permeability. Due to its significant systemic exposure and appropriate pharmacokinetic profile, as well as previously reported antiseptic properties, paeoniflorin is a promising XueBiJing constituent of therapeutic importance.

Potential contribution of exposed resin to ecosystem emissions of monoterpenes

NASA Astrophysics Data System (ADS)

Eller, Allyson S. D.; Harley, Peter; Monson, Russell K.

2013-10-01

Conifers, especially pines, produce and store under pressure monoterpene-laden resin in canals located throughout the plant. When the plants are damaged and resin canals punctured, the resin is exuded and the monoterpenes are released into the atmosphere, a process that has been shown to influence ecosystem-level monoterpene emissions. Less attention has been paid to the small amounts of resin that are exuded from branches, expanding needles, developing pollen cones, and terminal buds in the absence of any damage. The goal of this study was to provide the first estimate of the potential of this naturally-exposed resin to influence emissions of monoterpenes from ponderosa pine (Pinus ponderosa) ecosystems. When resin is first exuded as small spherical beads from undamaged tissues it emits monoterpenes to the atmosphere at a rate that is four orders of magnitude greater than needle tissue with an equivalent exposed surface area and the emissions from exuded beads decline exponentially as the resin dries. We made measurements of resin beads on the branches of ponderosa pine trees in the middle of the growing season and found, on average, 0.15 cm2 of exposed resin bead surface area and 1250 cm2 of total needle surface area per branch tip. If the resin emerged over the course of 10 days, resin emissions would make up 10% of the ecosystem emissions each day. Since we only accounted for exposed resin at a single point in time, this is probably an underestimate of how much total resin is exuded from undamaged pine tissues over the course of a growing season. Our observations, however, reveal the importance of this previously unrecognized source of monoterpenes emitted from pine forests and its potential to influence regional atmospheric chemistry dynamics.

Gene discovery for enzymes involved in limonene modification or utilization by the mountain pine beetle-associated pathogen Grosmannia clavigera.

PubMed

Wang, Ye; Lim, Lynette; Madilao, Lina; Lah, Ljerka; Bohlmann, Joerg; Breuil, Colette

2014-08-01

To successfully colonize and eventually kill pine trees, Grosmannia clavigera (Gs cryptic species), the main fungal pathogen associated with the mountain pine beetle (Dendroctonus ponderosae), has developed multiple mechanisms to overcome host tree chemical defenses, of which terpenoids are a major component. In addition to a monoterpene efflux system mediated by a recently discovered ABC transporter, Gs has genes that are highly induced by monoterpenes and that encode enzymes that modify or utilize monoterpenes [especially (+)-limonene]. We showed that pine-inhabiting Ophiostomale fungi are tolerant to monoterpenes, but only a few, including Gs, are known to utilize monoterpenes as a carbon source. Gas chromatography-mass spectrometry (GC-MS) revealed that Gs can modify (+)-limonene through various oxygenation pathways, producing carvone, p-mentha-2,8-dienol, perillyl alcohol, and isopiperitenol. It can also degrade (+)-limonene through the C-1-oxygenated pathway, producing limonene-1,2-diol as the most abundant intermediate. Transcriptome sequencing (RNA-seq) data indicated that Gs may utilize limonene 1,2-diol through beta-oxidation and then valine and tricarboxylic acid (TCA) metabolic pathways. The data also suggested that at least two gene clusters, located in genome contigs 108 and 161, were highly induced by monoterpenes and may be involved in monoterpene degradation processes. Further, gene knockouts indicated that limonene degradation required two distinct Baeyer-Villiger monooxygenases (BVMOs), an epoxide hydrolase and an enoyl coenzyme A (enoyl-CoA) hydratase. Our work provides information on enzyme-mediated limonene utilization or modification and a more comprehensive understanding of the interaction between an economically important fungal pathogen and its host's defense chemicals.

Gene Discovery for Enzymes Involved in Limonene Modification or Utilization by the Mountain Pine Beetle-Associated Pathogen Grosmannia clavigera

PubMed Central

Wang, Ye; Lim, Lynette; Madilao, Lina; Lah, Ljerka; Bohlmann, Joerg

2014-01-01

To successfully colonize and eventually kill pine trees, Grosmannia clavigera (Gs cryptic species), the main fungal pathogen associated with the mountain pine beetle (Dendroctonus ponderosae), has developed multiple mechanisms to overcome host tree chemical defenses, of which terpenoids are a major component. In addition to a monoterpene efflux system mediated by a recently discovered ABC transporter, Gs has genes that are highly induced by monoterpenes and that encode enzymes that modify or utilize monoterpenes [especially (+)-limonene]. We showed that pine-inhabiting Ophiostomale fungi are tolerant to monoterpenes, but only a few, including Gs, are known to utilize monoterpenes as a carbon source. Gas chromatography-mass spectrometry (GC-MS) revealed that Gs can modify (+)-limonene through various oxygenation pathways, producing carvone, p-mentha-2,8-dienol, perillyl alcohol, and isopiperitenol. It can also degrade (+)-limonene through the C-1-oxygenated pathway, producing limonene-1,2-diol as the most abundant intermediate. Transcriptome sequencing (RNA-seq) data indicated that Gs may utilize limonene 1,2-diol through beta-oxidation and then valine and tricarboxylic acid (TCA) metabolic pathways. The data also suggested that at least two gene clusters, located in genome contigs 108 and 161, were highly induced by monoterpenes and may be involved in monoterpene degradation processes. Further, gene knockouts indicated that limonene degradation required two distinct Baeyer-Villiger monooxygenases (BVMOs), an epoxide hydrolase and an enoyl coenzyme A (enoyl-CoA) hydratase. Our work provides information on enzyme-mediated limonene utilization or modification and a more comprehensive understanding of the interaction between an economically important fungal pathogen and its host's defense chemicals. PMID:24837377

Effects of monoterpenes on mortality, growth, fecundity, and ovarian development of Bactrocera zonata (Saunders) (Diptera: Tephritidae).

PubMed

El-Minshawy, Abdelaziz M; Abdelgaleil, Samir A M; Gadelhak, Gadelhak G; Al-Eryan, Mohamed A; Rabab, Rafiaa A

2018-06-01

The peach fruit fly (PFF), Bactrocera zonata, is a serious insect pest infesting fruits and vegetables. The insecticidal activity of three monoterpenes, namely, (R)-camphor, (R)-carvone, and (1R,2S,5R)-menthol, was evaluated on the second-instar larvae of B. zonata. In addition, the latent effects of monoterpenes on pupation, adult emergence, deformation, oviposition, adult longevity, and ovarian development were also examined. The three tested monoterpenes showed pronounced insecticidal activity against B. zonata larvae with (R)-carvone being the most potent toxicant. When the second-instar larvae of B. zonata were treated with monoterpenes at concentrations of 20, 50, and 70 mg/kg for 72 h, significant reduction in pupation and adult emergence was observed. The three monoterpenes caused complete suppression of adult emergence at 100 mg/kg. Moreover, monoterpenes induced complete inhibition of egg deposition at all tested concentrations. Some adult deformations were also noticed at 20, 50, and 70 mg/kg. However, (R)-carvone was more effective than (1R,2S,5R)-menthol and (R)-camphor on the examined biological parameters. On the other hand, histological examination of the ovaries of emerged females from larvae that fed on diet treated with (R)-carvone, (1R,2S,5R)-menthol, and (R)-camphor at 20 and 50 mg/L indicated that both concentrations caused retardation in the development of ovarioles. It is clear that all the egg chambers are empty; the germarium region is constricted at base due to the failure of oocyte formation. Many vacant spaces were present between ovarioles.

Metabolic engineering of monoterpene biosynthesis in tomato fruits via introduction of the non-canonical substrate neryl diphosphate.

PubMed

Gutensohn, Michael; Nguyen, Thuong T H; McMahon, Richard D; Kaplan, Ian; Pichersky, Eran; Dudareva, Natalia

2014-07-01

Recently it was shown that monoterpenes in tomato trichomes (Solanum lycopersicum) are synthesized by phellandrene synthase 1 (PHS1) from the non-canonical substrate neryl diphosphate (NPP), the cis-isomer of geranyl diphosphate (GPP). As PHS1 accepts both NPP and GPP substrates forming different monoterpenes, it was overexpressed in tomato fruits to test if NPP is also available in a tissue highly active in carotenoid production. However, transgenic fruits overexpressing PHS1 produced only small amounts of GPP-derived PHS1 monoterpene products, indicating the absence of endogenous NPP. Therefore, NPP formation was achieved by diverting the metabolic flux from carotenoids via expression of tomato neryl diphosphate synthase 1 (NDPS1). NDPS1 transgenic fruits produced NPP-derived monoterpenes, including nerol, neral and geranial, while displaying reduced lycopene content. NDPS1 co-expression with PHS1 resulted in a monoterpene blend, including β-phellandrene, similar to that produced from NPP by PHS1 in vitro and in trichomes. Unexpectedly, PHS1×NDPS1 fruits showed recovery of lycopene levels compared to NDPS1 fruits, suggesting that redirection of metabolic flux is only partially responsible for the reduction in carotenoids. In vitro assays demonstrated that NPP serves as an inhibitor of geranylgeranyl diphosphate synthase, thus its consumption by PHS1 leads to recovery of lycopene levels. Monoterpenes produced in PHS1×NDPS1 fruits contributed to direct plant defense negatively affecting feeding behavior of the herbivore Helicoverpa zea and displaying antifungal activity against Botrytis cinerea. These results show that NPP-derived terpenoids can be produced in plant tissues; however, NPP has to be consumed to avoid negative impacts on plant metabolism. Copyright © 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

NIOSH Health Hazard Evaluation for d-Limonene

DTIC Science & Technology

1993-11-01

of natural hydrocarbons referred to as terpenes (d-limonene is a monoterpene ). The other form of limonene is called 1-limonene, and a mixture of the...as a flavor and fragrance additive in perfumes, soaps, foods, chewing gum and beverages, and is the most widely distribiit. monoterpene ." 4’ The use of...effect and skin irritation of monocyclic monoterpenes . Drug Des Deliv 6:229-238. 29. Hooser SB, Beasley VR, Everitt J1 [1986]. Effects of an

Monoterpenes Support Systemic Acquired Resistance within and between Plants.

PubMed

Riedlmeier, Marlies; Ghirardo, Andrea; Wenig, Marion; Knappe, Claudia; Koch, Kerstin; Georgii, Elisabeth; Dey, Sanjukta; Parker, Jane E; Schnitzler, Jörg-Peter; Vlot, A Corina

2017-06-01

This study investigates the role of volatile organic compounds in systemic acquired resistance (SAR), a salicylic acid (SA)-associated, broad-spectrum immune response in systemic, healthy tissues of locally infected plants. Gas chromatography coupled to mass spectrometry analyses of SAR-related emissions of wild-type and non-SAR-signal-producing mutant plants associated SAR with monoterpene emissions. Headspace exposure of Arabidopsis thaliana to a mixture of the bicyclic monoterpenes α-pinene and β-pinene induced defense, accumulation of reactive oxygen species, and expression of SA- and SAR-related genes, including the SAR regulatory AZELAIC ACID INDUCED1 ( AZI1 ) gene and three of its paralogs. Pinene-induced resistance was dependent on SA biosynthesis and signaling and on AZI1 Arabidopsis geranylgeranyl reductase1 mutants with reduced monoterpene biosynthesis were SAR-defective but mounted normal local resistance and methyl salicylate-induced defense responses, suggesting that monoterpenes act in parallel with SA The volatile emissions from SAR signal-emitting plants induced defense in neighboring plants, and this was associated with the presence of α-pinene, β-pinene, and camphene in the emissions of the "sender" plants. Our data suggest that monoterpenes, particularly pinenes, promote SAR, acting through ROS and AZI1 , and likely function as infochemicals in plant-to-plant signaling, thus allowing defense signal propagation between neighboring plants. © 2017 American Society of Plant Biologists. All rights reserved.

Monoterpene derivatives with anti-allergic activity from red peony root, the root of Paeonia lactiflora.

PubMed

Shi, Yan-Hong; Zhu, Shu; Ge, Yue-Wei; He, Yu-Min; Kazuma, Kohei; Wang, Zhengtao; Yoshimatsu, Kayo; Komatsu, Katsuko

2016-01-01

The methanolic extract and its subfractions from red peony root, the dried roots of Paeonia lactiflora Pallas showed potent antiallergic effects, as inhibition of immunoglobulin E (IgE)-mediated degranulation in rat basophil leukemia (RBL)-2H3 cells. Bioassay-guided fractionation led to the isolation of 16 monoterpene derivatives, including 3 new compounds, paeoniflorol (1), 4'-hydroxypaeoniflorigenone (2) and 4-epi-albiflorin (3), together with 13 known ones (4-16). The chemical structures of the new compounds were elucidated on the basis of spectroscopic and chemical evidences. Among the isolated monoterpene derivatives, nine compounds showed potent anti-allergic effects and compound 1 was the most effective. A primary structure-activity relationship of monoterpene derivatives was discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Antitumor Activity of Monoterpenes Found in Essential Oils

PubMed Central

Sobral, Marianna Vieira; Xavier, Aline Lira; Lima, Tamires Cardoso; de Sousa, Damião Pergentino

2014-01-01

Cancer is a complex genetic disease that is a major public health problem worldwide, accounting for about 7 million deaths each year. Many anticancer drugs currently used clinically have been isolated from plant species or are based on such substances. Accumulating data has revealed anticancer activity in plant-derived monoterpenes. In this review the antitumor activity of 37 monoterpenes found in essential oils is discussed. Chemical structures, experimental models, and mechanisms of action for bioactive substances are presented. PMID:25401162

A novel Fast Gas Chromatography based technique for higher time resolution measurements of speciated monoterpenes in air

NASA Astrophysics Data System (ADS)

Jones, C. E.; Kato, S.; Nakashima, Y.; Kajii, Y.

2013-12-01

Biogenic emissions supply the largest fraction of non-methane volatile organic compounds (VOC) from the biosphere to the atmospheric boundary layer, and typically comprise a complex mixture of reactive terpenes. Due to this chemical complexity, achieving comprehensive measurements of biogenic VOC (BVOC) in air within a satisfactory time resolution is analytically challenging. To address this, we have developed a novel, fully automated Fast Gas Chromatography (Fast-GC) based technique to provide higher time resolution monitoring of monoterpenes (and selected other C9-C15 terpenes) during plant emission studies and in ambient air. To our knowledge, this is the first study to apply a Fast-GC based separation technique to achieve quantification of terpenes in air. Three chromatography methods have been developed for atmospheric terpene analysis under different sampling scenarios. Each method facilitates chromatographic separation of selected BVOC within a significantly reduced analysis time compared to conventional GC methods, whilst maintaining the ability to quantify individual monoterpene structural isomers. Using this approach, the C10-C15 BVOC composition of single plant emissions may be characterised within a ~ 14 min analysis time. Moreover, in situ quantification of 12 monoterpenes in unpolluted ambient air may be achieved within an ~ 11 min chromatographic separation time (increasing to ~ 19 min when simultaneous quantification of multiple oxygenated C9-C10 terpenoids is required, and/or when concentrations of anthropogenic VOC are significant). This corresponds to a two- to fivefold increase in measurement frequency compared to conventional GC methods. Here we outline the technical details and analytical capability of this chromatographic approach, and present the first in situ Fast-GC observations of 6 monoterpenes and the oxygenated BVOC linalool in ambient air. During this field deployment within a suburban forest ~ 30 km west of central Tokyo, Japan, the Fast-GC limit of detection with respect to monoterpenes was 4-5 ppt, and the agreement between Fast-GC and PTR-MS derived total monoterpene mixing ratios was consistent with previous GC/PTR-MS comparisons. The measurement uncertainties associated with the Fast-GC quantification of monoterpenes are ≤ 10%, while larger uncertainties (up to ~ 25%) are associated with the OBVOC and sesquiterpene measurements.

Isoprene and monoterpene emissions in south-east Australia: comparison of a multi-layer canopy model with MEGAN and with atmospheric observations

NASA Astrophysics Data System (ADS)

Emmerson, Kathryn M.; Cope, Martin E.; Galbally, Ian E.; Lee, Sunhee; Nelson, Peter F.

2018-05-01

One of the key challenges in atmospheric chemistry is to reduce the uncertainty of biogenic volatile organic compound (BVOC) emission estimates from vegetation to the atmosphere. In Australia, eucalypt trees are a primary source of biogenic emissions, but their contribution to Australian air sheds is poorly quantified. The Model of Emissions of Gases and Aerosols from Nature (MEGAN) has performed poorly against Australian isoprene and monoterpene observations. Finding reasons for the MEGAN discrepancies and strengthening our understanding of biogenic emissions in this region is our focus. We compare MEGAN to the locally produced Australian Biogenic Canopy and Grass Emissions Model (ABCGEM), to identify the uncertainties associated with the emission estimates and the data requirements necessary to improve isoprene and monoterpene emissions estimates for the application of MEGAN in Australia. Previously unpublished, ABCGEM is applied as an online biogenic emissions inventory to model BVOCs in the air shed overlaying Sydney, Australia. The two models use the same meteorological inputs and chemical mechanism, but independent inputs of leaf area index (LAI), plant functional type (PFT) and emission factors. We find that LAI, a proxy for leaf biomass, has a small role in spatial, temporal and inter-model biogenic emission variability, particularly in urban areas for ABCGEM. After removing LAI as the source of the differences, we found large differences in the emission activity function for monoterpenes. In MEGAN monoterpenes are partially light dependent, reducing their dependence on temperature. In ABCGEM monoterpenes are not light dependent, meaning they continue to be emitted at high rates during hot summer days, and at night. When the light dependence of monoterpenes is switched off in MEGAN, night-time emissions increase by 90-100 % improving the comparison with observations, suggesting the possibility that monoterpenes emitted from Australian vegetation may not be as light dependent as vegetation globally. Targeted measurements of emissions from in situ Australian vegetation, particularly of the light dependence issue are critical to improving MEGAN for one of the world's major biogenic emitting regions.

Impact of heat stress on the emissions of monoterpenes, sesquiterpenes, phenolic BVOC and green leaf volatiles from several tree species

NASA Astrophysics Data System (ADS)

Kleist, E.; Mentel, T. F.; Andres, S.; Bohne, A.; Folkers, A.; Kiendler-Scharr, A.; Rudich, Y.; Springer, M.; Tillmann, R.; Wildt, J.

2012-07-01

Changes in the biogenic volatile organic compound (BVOC) emissions from European beech, Palestine oak, Scots pine, and Norway spruce exposed to heat stress were measured in a laboratory setup. In general, heat stress decreased the de novo emissions of monoterpenes, sesquiterpenes and phenolic BVOC. Decreasing emission strength with heat stress was independent of the tree species and whether the de novo emissions being constitutive or induced by biotic stress. In contrast, heat stress induced emissions of green leaf volatiles. It also amplified the release of monoterpenes stored in resin ducts of conifers probably due to heat-induced damage of these resin ducts. The increased release of monoterpenes could be strong and long lasting. But, despite of such strong monoterpene emission pulses, the net effect of heat stress on BVOC emissions from conifers can be an overall decrease. In particular during insect attack on conifers the plants showed de novo emissions of sesquiterpenes and phenolic BVOC which exceeded constitutive monoterpene emissions from pools. The heat stress induced decrease of these de novo emissions was larger than the increased release caused by damage of resin ducts. We project that global change induced heat waves may cause increased BVOC emissions only in cases where the respective areas are predominantly covered with conifers that do not emit high amounts of sesquiterpenes and phenolic BVOC. Otherwise the overall effect of heat stress will be a decrease in BVOC emissions.

Differences in Monoterpene Biosynthesis and Accumulation in Pistacia palaestina Leaves and Aphid-Induced Galls.

PubMed

Rand, Karin; Bar, Einat; Ari, Matan Ben; Davidovich-Rikanati, Rachel; Dudareva, Natalia; Inbar, Moshe; Lewinsohn, Efraim

2017-02-01

Certain insect species can induce gall formation on numerous plants species. Although the mechanism of gall development is largely unknown, it is clear that insects manipulate their hosts' anatomy, physiology, and chemistry for their own benefit. It is well known that insect-induced galls often contain vast amounts of plant defensive compounds as compared to non-colonized tissues, but it is not clear if defensive compounds can be produced in situ in the galled tissues. To answer this question, we analyzed terpene accumulation patterns and possible independent biosynthetic potential of galls induced by the aphid Baizongia pistaciae L. on the terminal buds of Pistacia palaestina Boiss. We compared monoterpene levels and monoterpene synthase enzyme activity in galls and healthy leaves from individual trees growing in a natural setting. At all developmental stages, monoterpene content and monoterpene synthase activity were consistently (up to 10 fold on a fresh weight basis) higher in galls than in intact non-colonized leaves. A remarkable tree to tree variation in the products produced in vitro from the substrate geranyl diphosphate by soluble protein extracts derived from individual trees was observed. Furthermore, galls and leaves from the same trees displayed enhanced and often distinct biosynthetic capabilities. Our results clearly indicate that galls possess independent metabolic capacities to produce and accumulate monoterpenes as compared to leaves. Our study indicates that galling aphids manipulate the enzymatic machinery of their host plant, intensifying their own defenses against natural enemies.

Structurally Related Monoterpenes p-Cymene, Carvacrol and Thymol Isolated from Essential Oil from Leaves of Lippia sidoides Cham. (Verbenaceae) Protect Mice against Elastase-Induced Emphysema.

PubMed

Games, Ellen; Guerreiro, Marina; Santana, Fernanda R; Pinheiro, Nathalia M; de Oliveira, Emerson A; Lopes, Fernanda D T Q S; Olivo, Clarice R; Tibério, Iolanda F L C; Martins, Mílton A; Lago, João Henrique G; Prado, Carla M

2016-10-20

Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airflow obstruction and inflammation. Natural products, such as monoterpenes, displayed anti-inflammatory and anti-oxidant activities and can be used as a source of new compounds to COPD treatment. Our aim was to evaluate, in an elastase-induced pulmonary emphysema in mice, the effects of and underlying mechanisms of three related natural monoterpenes ( p -cymene, carvacrol and thymol) isolated from essential oil from leaves Lippia sidoides Cham. (Verbenaceae). Mices received porcine pancreatic elastase (PPE) and were treated with p -cymene, carvacrol, thymol or vehicle 30 min later and again on 7th, 14th and 28th days. Lung inflammatory profile and histological sections were evaluated. In the elastase-instilled animals, the tested monoterpenes reduced alveolar enlargement, macrophages and the levels of IL-1β, IL-6, IL-8 and IL-17 in bronchoalveolar lavage fluid (BALF), and collagen fibers, MMP-9 and p-65-NF-κB-positive cells in lung parenchyma ( p < 0.05). All treatments attenuated levels of 8-iso-PGF2α but only thymol was able to reduced exhaled nitric oxide ( p < 0.05). Monoterpenes p -cymene, carvacrol and thymol reduced lung emphysema and inflammation in mice. No significant differences among the three monoterpenes treatments were found, suggesting that the presence of hydroxyl group in the molecular structure of thymol and carvacrol do not play a central role in the anti-inflammatory effects.

Allelopathic Monoterpenes Interfere with Arabidopsis thaliana Cuticular Waxes and Enhance Transpiration

PubMed Central

Kussmann, Petra; Knop, Mona; Kriegs, Bettina; Gresens, Frank; Eichert, Thomas; Ulbrich, Andreas; Marx, Friedhelm; Fabricius, Heinz; Goldbach, Heiner; Noga, Georg

2007-01-01

Exposure to the allelopathic monoterpenes camphor (100 mg/10 L) and menthol (50 mg/10 L) for 24 h enhanced transpiration of Arabidopsis thaliana fully developed rosette leaves similar to de-waxing. As ascertained by ESEM analyses the leaf surfaces were spotted with platelet like structures which seem to be partly mixed with the lipophilic epicuticular layers. The structures are supposed to contain the condensed monoterpenes, which could be identified by GC. Long term exposure (more than 48 h) to 100 mg/50 mg killed the plants by desiccation, a 24 h exposure caused necrotic spots that became visible one to two days after the treatment. Examinations of the stomatal apertures indicated that monoterpenes induced stomatal opening followed by extreme swelling and a final break down of the protoplasts. Exposure of Arabidopsis thaliana to volatiles of Mentha piperita, Lavandula latifolia and Artemisia camphorata resulted in a dramatic increase of the stomata aperture but swelling of the protoplasts was less exhibited. In contrast to de-waxing, expression of the fatty acid condensing enzyme encoding CER6 gene and de novo synthesis of CER6 protein was not induced after 24 h of exposure to the monoterpenes. The aim of the study was to demonstrate that the lipophilic layers of the leaf surface and the stomata are primary targets of monoterpene allelopathic attack. Enhanced transpiration results from a combination of affected lipophilic wax layers and a disturbed stomata function. PMID:19516993

Inhibition of the NorA multi-drug transporter by oxygenated monoterpenes.

PubMed

Coêlho, Mayara Ladeira; Ferreira, Josie Haydée Lima; de Siqueira Júnior, José Pinto; Kaatz, Glenn W; Barreto, Humberto Medeiros; de Carvalho Melo Cavalcante, Ana Amélia

2016-10-01

The aim of this study was to investigate intrinsic antimicrobial activity of three monoterpenes nerol, dimethyl octanol and estragole, against bacteria and yeast strains, as well as, investigate if these compounds are able to inhibit the NorA efflux pump related to fluoroquinolone resistance in Staphylococcus aureus. Minimal inhibitory concentrations (MICs) of the monoterpenes against Staphylococcus aureus, Escherichia coli and Candida albicans strains were determined by micro-dilution assay. MICs of the norfloxacin against a S. aureus strain overexpressing the NorA protein were determined in the absence or in the presence of the monoterpenes at subinhibitory concentrations, aiming to verify the ability of this compounds act as efflux pump inhibitors. The monoterpenes were inactive against S. aureus however the nerol was active against E. coli and C. albicans. The addition of the compounds to growth media at sub-inhibitory concentrations enhanced the activity of norfloxacin against S. aureus SA1199-B. This result shows that bioactives tested, especially the nerol, are able to inhibit NorA efflux pump indicating a potential use as adjuvants of norfloxacin for therapy of infections caused by multi-drug resistant S. aureus strains. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of gibberellin and daminozide on the expression of terpene synthases and on monoterpenes in common sage (Salvia officinalis).

PubMed

Schmiderer, Corinna; Grausgruber-Gröger, Sabine; Grassi, Paolo; Steinborn, Ralf; Novak, Johannes

2010-07-01

Common sage (Salvia officinalis L., Lamiaceae) is one of the most important medicinal and aromatic plants, with antioxidant, antimicrobial, spasmolytic, astringent, antihidrotic and specific sensorial properties. The essential oil of the plant, composed mainly of the monoterpenes 1,8-cineole, alpha-thujone, beta-thujone and camphor, is responsible for some of these effects. Gibberellins regulate diverse physiological processes in plants, such as seed germination, shoot elongation and cell division. In this study, we analyzed the effect of exogenously applied plant growth regulators, namely gibberellic acid (GA(3)) and daminozide, on leaf morphology and essential oil formation of two leaf stages during the period of leaf expansion. Essential oil content increased with increasing levels of gibberellins and decreased when gibberellin biosynthesis was blocked with daminozide. With increasing levels of gibberellins, 1,8-cineole and camphor contents increased. Daminozide blocked the accumulation of alpha- and beta-thujone. GA(3) at the highest level applied also led to a significant decrease of alpha- and beta-thujone. Monoterpene synthases are a class of enzymes responsible for the first step in monoterpene biosynthesis, competing for the same substrate geranylpyrophosphate. The levels of gene expression of the three most important monoterpene synthases in sage were investigated, 1,8-cineole synthase leading directly to 1,8-cineole, (+)-sabinene synthase responsible for the first step in the formation of alpha- and beta-thujone, and (+)-bornyl diphosphate synthase, the first step in camphor biosynthesis. The foliar application of GA(3) increased, while daminozide significantly decreased gene expression of the monoterpene synthases. The amounts of two of the end products, 1,8-cineole and camphor, were directly correlated with the levels of gene expression of the respective monoterpene synthases, indicating transcriptional control, while the formation of alpha- and beta-thujone was not transcriptionally regulated. 2010 Elsevier GmbH. All rights reserved.

Chemical analysis of particulate and gaseous products from the monoterpene oxidation in the SAPHIR chamber during the EUCAARI campaign 2008

NASA Astrophysics Data System (ADS)

Kahnt, A.; Iinuma, Y.; Herrmann, H.; Mentel, T. F.; Fisseha, R.; Kiendler-Scharr, A.

2009-04-01

The atmospheric oxidation of monoterpenes leads to multifunctional products with lower vapour pressure. These products condense and coagulate to existing particles leading to particle formation and growth. In order to obtain better insights into the mechanisms and the importance of sources to organic aerosol, a mixture of monoterpenes was oxidised in the SAPHIR outdoor chamber during the EUCAARI campaign in 2008. The mixture was made of α-pinene, β-pinene, limonene, 3-carene and ocimene, representing a typical monoterpene emission from a boreal forest. In addition, two sesquiterpenes (α-farnesene and caryophyllene) were reacted together with the monoterpene mixture in some experiments. The VOC (volatile organic compound) mixture was reacted under tropospheric oxidation and light conditions in a prolonged time scale over two days. In the present study, a special emphasis is put on the detection of carbonyl compounds from the off-line analysis of collected filter and denuder samples from the campaign in 2008. The oxidation products which contain carbonyl groups are important first stable intermediates during the monoterpene and sesquiterpene oxidation. They react further with atmospheric oxidants to form lower volatile acidic compounds, contributing to secondary organic aerosol (SOA). Commonly used methods for the analysis of carbonyl compounds involve derivatisation steps prior to separation and subsequent UV or MS detection. In the present study, 2,4-dinitrophenylhydrazine (DNPH) was used to derivatise the extracted filter and denuder samples. The DNPH converts aldehyde- and keto-groups to stable hydrazones, which can be purified afterwards using a solid phase extraction (SPE) cartridge. The derivatised samples were analysed with HPLC/ESI-TOFMS which allowed us to determine the exact chemical formula of unknown products. In addition to known carbonyl compounds from monoterpene oxidation such as pinonaldehyde and nopinon, previously unreported molecular masses were found. These were tentatively identified as hydroxycarbonyl compounds with the molecular weight of 168 (C10H16O2) and 154 (C9H14O2 ).

Increased and Altered Fragrance of Tobacco Plants after Metabolic Engineering Using Three Monoterpene Synthases from Lemon

PubMed Central

Lücker, Joost; Schwab, Wilfried; van Hautum, Bianca; Blaas, Jan; van der Plas, Linus H. W.; Bouwmeester, Harro J.; Verhoeven, Harrie A.

2004-01-01

Wild-type tobacco (Nicotiana tabacum) plants emit low levels of terpenoids, particularly from the flowers. By genetic modification of tobacco cv Petit Havana SR1 using three different monoterpene synthases from lemon (Citrus limon L. Burm. f.) and the subsequent combination of these three into one plant by crossings, we show that it is possible to increase the amount and alter the composition of the blend of monoterpenoids produced in tobacco plants. The transgenic tobacco plant line with the three introduced monoterpene synthases is emitting β-pinene, limonene, and γ-terpinene and a number of side products of the introduced monoterpene synthases, from its leaves and flowers, in addition to the terpenoids emitted by wild-type plants. The results show that there is a sufficiently high level of substrate accessible for the introduced enzymes. PMID:14718674

Dynamics of Monoterpene Formation in Spike Lavender Plants.

PubMed

Mendoza-Poudereux, Isabel; Kutzner, Erika; Huber, Claudia; Segura, Juan; Arrillaga, Isabel; Eisenreich, Wolfgang

2017-12-19

The metabolic cross-talk between the mevalonate (MVA) and the methylerythritol phosphate (MEP) pathways was analyzed in spike lavender ( Lavandula latifolia Med) on the basis of 13 CO₂-labelling experiments using wildtype and transgenic plants overexpressing the 3-hydroxy-3-methylglutaryl CoA reductase (HMGR), the first and key enzyme of the MVA pathway. The plants were labelled in the presence of 13 CO₂ in a gas chamber for controlled pulse and chase periods of time. GC/MS and NMR analysis of 1,8-cineole and camphor, the major monoterpenes present in their essential oil, indicated that the C5-precursors, isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) of both monoterpenes are predominantly biosynthesized via the MEP pathway. Surprisingly, overexpression of HMGR did not have significant impact upon the crosstalk between the MVA and MEP pathways indicating that the MEP route is the preferred pathway for the synthesis of C5 monoterpene precursors in spike lavender.

New zwitterionic monoterpene indole alkaloids from Uncaria rhynchophylla.

PubMed

Guo, Qiang; Yang, Hongshuai; Liu, Xinyu; Si, Xiali; Liang, Hong; Tu, Pengfei; Zhang, Qingying

2018-01-31

Four new zwitterionic monoterpene indole alkaloids, rhynchophyllioniums A-D (1-4), together with eight known alkaloids (5-12), were isolated from the hook-bearing stems of Uncaria rhynchophylla. Their structures were elucidated by extensive spectroscopic data analysis of MS, 1D and 2D NMR, and ECD, and the zwitterionic forms and absolute configurations of 1 and 2 were unambiguously confirmed by single crystal X-ray diffraction analysis. All the isolates, including the monoterpene indole alkaloids with free C-22 carboxyl group and those with C-22 carboxyl methyl ester, were proved to be naturally coexisting in the herb by LC-MS analysis. This is the first report of monoterpene indole alkaloids that exist in the form of zwitterion. Additionally, the cytotoxic activities of all isolates against A549, HepG2, and MCF-7 cell lines are reported. Copyright © 2018 Elsevier B.V. All rights reserved.

Monoterpene separation by coupling proton transfer reaction time-of-flight mass spectrometry with fastGC.

PubMed

Materić, Dušan; Lanza, Matteo; Sulzer, Philipp; Herbig, Jens; Bruhn, Dan; Turner, Claire; Mason, Nigel; Gauci, Vincent

2015-10-01

Proton transfer reaction mass spectrometry (PTR-MS) is a well-established technique for real-time analysis of volatile organic compounds (VOCs). Although it is extremely sensitive (with sensitivities of up to 4500 cps/ppbv, limits of detection <1 pptv and the response times of approximately 100 ms), the selectivity of PTR-MS is still somewhat limited, as isomers cannot be separated. Recently, selectivity-enhancing measures, such as manipulation of drift tube parameters (reduced electric field strength) and using primary ions other than H3O(+), such as NO(+) and O2 (+), have been introduced. However, monoterpenes, which belong to the most important plant VOCs, still cannot be distinguished so more traditional technologies, such as gas chromatography mass spectrometry (GC-MS), have to be utilised. GC-MS is very time consuming (up to 1 h) and cannot be used for real-time analysis. Here, we introduce a sensitive, near-to-real-time method for plant monoterpene research-PTR-MS coupled with fastGC. We successfully separated and identified six of the most abundant monoterpenes in plant studies (α- and β-pinenes, limonene, 3-carene, camphene and myrcene) in less than 80 s, using both standards and conifer branch enclosures (Norway spruce, Scots pine and black pine). Five monoterpenes usually present in Norway spruce samples with a high abundance were separated even when the compound concentrations were diluted to 20 ppbv. Thus, fastGC-PTR-ToF-MS was shown to be an adequate one-instrument solution for plant monoterpene research.

Laboratory and field measurements of enantiomeric monoterpene emissions as a function of chemotype, light and temperature

NASA Astrophysics Data System (ADS)

Song, W.; Staudt, M.; Bourgeois, I.; Williams, J.

2013-10-01

Plants emit significant amounts of monoterpenes into the Earth's atmosphere where they react rapidly to form a multitude of gas phase species and particles. Many monoterpenes exist in mirror images forms or enantiomers. In this study the enantiomeric monoterpene profile for several representative plants (Quercus ilex L., Rosmarinus officinalis L., and Pinus halepensis Mill.) was investigated as a function of chemotype, light and temperature both in the laboratory and in the field. Analysis of enantiomeric monoterpenes from 19 Quercus ilex individuals from Southern France and Spain revealed four regiospecific chemotypes (genetically fixed emission patterns). In agreement with previous work, only Quercus ilex emissions increased strongly with light. However, for all three plant species no consistent enantiomeric variation was observed as a function of light, and the enantiomeric ratio of α-pinene was found vary by less than 20% from 100 and 1000 μmol m-2 s-1 PAR. The rate of monoterpene emission increased with temperature from all three plant species, but little variation in the enantiomeric distribution of α-pinene was observed with temperature. There was more enantiomeric variability between individuals of the same species than could be induced by either light or temperature. Field measurements of α-pinene enantiomer mixing ratios in the air taken at a Quercus ilex forest in Southern France, and several other previously reported field enantiomeric ratio diel cycle profiles are compared. All show smoothly varying diel cycles (some positive and some negative) even over changing wind directions. This is surprising in comparison with variations of enantiomeric emission patterns shown by individuals of the same species.

Behavioral and toxicological responses of Rhodnius prolixus and Triatoma infestans (Hemiptera: Reduviidae) to 10 monoterpene alcohols.

PubMed

Moretti, A N; Zerba, E N; Alzogaray, Raúl A

2013-09-01

The effect on locomotor activity, the repellency, and the knock-down produced by 10 monoterpene alcohols were evaluated on first-instar nymphs of Rhodnius prolixus and Triatoma infestans, vectors of Chagas disease. A video tracking technique was used to evaluate locomotor activity and repellency by exposure to papers impregnated with monoterpenes. Eugenol on R. prolixus and (S)-cis-verbenol on T. infestans did not modify the locomotor activity. The remaining monoterpenes produced hyperactivity on both species, although the concentration required was at least a 1,000 times higher than that of deltamethrin (positive control). Carvacrol, eugenol, and geraniol resulted as repellent as N,N-diethyl-m-toluamide (positive control) for both species. A similar result was observed for almost every monoterpene on T. infestans. Knock-down effect was evaluated by exposing the nymphs in closed recipients. The order of increasing toxicity on R. prolixus was (KT50 values in min): geraniol (213.7) < alpha-terpineol (164.5) < linalool (124.2) < carvacrol (111.6) < eugenol (89.8) < thymol (78.9), and on T. infestans: alpha-terpineol (289.8) < eugenol (221.3) < carvacrol (164.2) < linalool (154.9) < thymol (96.7). All monoterpenes were less toxic than the positive control, dichlorvos (3.6 min for R. prolixus and 3.9 min for T. infestans). After 7 h of exposure, (-)-carveol, citronellol, and menthol (on both species) and geraniol (on T. infestans) produced < 50% of knock-down. After these results, it is worthwhile to explore more deeply the potential of these compounds as tools for controlling Chagas disease vectors.

Fluxes of isoprene and monoterpenes emitted by Tapajos National Forest, eastern central Amazonian rainforest, Santarem-PA, Brazil

NASA Astrophysics Data System (ADS)

Alves, E. G.; Batalha, S. S. A.; Park, J. H.; Seco, R.; Tota, J.; Santana, R. A. S. D.; Guenther, A. B.; Kim, S.; Smith, J. N.; Souza, R. A. F. D.

2014-12-01

Biogenic Volatile Organic Compounds (BVOCs) play an important role in atmospheric chemistry and biogeochemical cycles. It is known that tropical forests are the biggest source of the dominant BVOCs (i.e. isoprene and monoterpenes) emitted to the atmosphere. Nevertheless, Amazonian rainforest, the world's largest tropical rainforest, has been poorly explored for isoprene and monoterpene emissions. Recently (June and July 2014), we deployed a PTR-TOF-MS (Proton Transfer Reaction - Time of Flight - Mass Spectrometer) to quantify isoprene and monoterpene emissions using the eddy covariance flux method at the FLONA Tapajos (Floresta Nacional do Tapajos; Tapajos National Forest) in the eastern central Amazon rainforest, Santarem-PA, Brazil. The sample inlet and a 3D-sonic anemometer were located above the forest canopy (~65m), and the air was sampled through a long Teflon tube (100m) with high flow rate (40L/min) to the PTR-TOF-MS. From preliminary results for the first 3 days, concentrations and fluxes of m/z 69 (isoprene; C5H8-H+) and m/z 137 (total monoterpenes; C10H16-H+) showed a clear circadian cycle (high during daytime and low at nighttime), suggesting the emissions of these compounds are light and temperature dependent. Our study provides the first PTR-TOF-MS flux observations of isoprene and total monoterpenes at the Flona Tapajos. Moreover, since there are variations on the emissions, when comparing different environments of the huge Amazon basin, these results from eastern central Amazonia will contribute to improving regional and global BVOC emission model estimates.

A novel fast gas chromatography method for higher time resolution measurements of speciated monoterpenes in air

NASA Astrophysics Data System (ADS)

Jones, C. E.; Kato, S.; Nakashima, Y.; Kajii, Y.

2014-05-01

Biogenic emissions supply the largest fraction of non-methane volatile organic compounds (VOC) from the biosphere to the atmospheric boundary layer, and typically comprise a complex mixture of reactive terpenes. Due to this chemical complexity, achieving comprehensive measurements of biogenic VOC (BVOC) in air within a satisfactory time resolution is analytically challenging. To address this, we have developed a novel, fully automated Fast Gas Chromatography (Fast-GC) based technique to provide higher time resolution monitoring of monoterpenes (and selected other C9-C15 terpenes) during plant emission studies and in ambient air. To our knowledge, this is the first study to apply a Fast-GC based separation technique to achieve quantification of terpenes in ambient air. Three chromatography methods have been developed for atmospheric terpene analysis under different sampling scenarios. Each method facilitates chromatographic separation of selected BVOC within a significantly reduced analysis time compared to conventional GC methods, whilst maintaining the ability to quantify individual monoterpene structural isomers. Using this approach, the C9-C15 BVOC composition of single plant emissions may be characterised within a 14.5 min analysis time. Moreover, in-situ quantification of 12 monoterpenes in unpolluted ambient air may be achieved within an 11.7 min chromatographic separation time (increasing to 19.7 min when simultaneous quantification of multiple oxygenated C9-C10 terpenoids is required, and/or when concentrations of anthropogenic VOC are significant). These analysis times potentially allow for a twofold to fivefold increase in measurement frequency compared to conventional GC methods. Here we outline the technical details and analytical capability of this chromatographic approach, and present the first in-situ Fast-GC observations of 6 monoterpenes and the oxygenated BVOC (OBVOC) linalool in ambient air. During this field deployment within a suburban forest ~30 km west of central Tokyo, Japan, the Fast-GC limit of detection with respect to monoterpenes was 4-5 ppt, and the agreement between Fast-GC and PTR-MS derived total monoterpene mixing ratios was consistent with previous GC/PTR-MS comparisons. The measurement uncertainties associated with the Fast-GC quantification of monoterpenes are ≤ 12%, while larger uncertainties (up to ~25%) are associated with the OBVOC and sesquiterpene measurements.

Identification and Characterization of the Iridoid Synthase Involved in Oleuropein Biosynthesis in Olive (Olea europaea) Fruits*

PubMed Central

Kries, Hajo; Panara, Francesco; Baldoni, Luciana; O'Connor, Sarah E.; Osbourn, Anne

2016-01-01

The secoiridoids are the main class of specialized metabolites present in olive (Olea europaea L.) fruit. In particular, the secoiridoid oleuropein strongly influences olive oil quality because of its bitterness, which is a desirable trait. In addition, oleuropein possesses a wide range of pharmacological properties, including antioxidant, anti-inflammatory, and anti-cancer activities. In accordance, obtaining high oleuropein varieties is a main goal of molecular breeding programs. Here we use a transcriptomic approach to identify candidate genes belonging to the secoiridoid pathway in olive. From these candidates, we have functionally characterized the olive homologue of iridoid synthase (OeISY), an unusual terpene cyclase that couples an NAD (P)H-dependent 1,4-reduction step with a subsequent cyclization, and we provide evidence that OeISY likely generates the monoterpene scaffold of oleuropein in olive fruits. OeISY, the first pathway gene characterized for this type of secoiridoid, is a potential target for breeding programs in a high value secoiridoid-accumulating species. PMID:26709230

Monoterpene alcohol metabolism: identification, purification, and characterization of two geraniol dehydrogenase isoenzymes from Polygonum minus leaves.

PubMed

Hassan, Maizom; Maarof, Nur Diyana; Ali, Zainon Mohd; Noor, Normah Mohd; Othman, Roohaida; Mori, Nobuhiro

2012-01-01

NADP(+)-dependent geraniol dehydrogenase (EC 1.1.1.183) is an enzyme that catalyzes the oxidation of geraniol to geranial. Stable, highly active cell-free extract was obtained from Polygonum minus leaves using polyvinylpolypyrrolidone, Amberlite XAD-4, glycerol, 2-mercaptoethanol, thiourea, and phenylmethylsulfonylfluoride in tricine-NaOH buffer (pH 7.5). The enzyme preparation was separated into two activity peaks, geraniol-DH I and II, by DEAE-Toyopearl 650M column chromatography at pH 7.5. Both isoenzymes were purified to homogeneity in three chromatographic steps. The geraniol-DH isoenzymes were similar in molecular mass, optimal temperature, and pH, but the isoelectric point, substrate specificity, and kinetic parameters were different. The K(m) values for geraniol of geraniol-DH I and II appeared to be 0.4 mM and 0.185 mM respectively. P. minus geraniol-DHs are unusual among geraniol-DHs in view of their thermal stability and optimal temperatures, and also their high specificity for allylic alcohols and NADP(+).

The Biosynthetic Origin of Irregular Monoterpenes in Lavandula

PubMed Central

Demissie, Zerihun A.; Erland, Lauren A. E.; Rheault, Mark R.; Mahmoud, Soheil S.

2013-01-01

Lavender essential oils are constituted predominantly of regular monoterpenes, for example linalool, 1,8-cineole, and camphor. However, they also contain irregular monoterpenes including lavandulol and lavandulyl acetate. Although the majority of genes responsible for the production of regular monoterpenes in lavenders are now known, enzymes (including lavandulyl diphosphate synthase (LPPS)) catalyzing the biosynthesis of irregular monoterpenes in these plants have not been described. Here, we report the isolation and functional characterization of a novel cis-prenyl diphosphate synthase cDNA, termed Lavandula x intermedia lavandulyl diphosphate synthase (LiLPPS), through a homology-based cloning strategy. The LiLPPS ORF, encoding for a 305-amino acid long protein, was expressed in Escherichia coli, and the recombinant protein was purified by nickel-nitrilotriacetic acid affinity chromatography. The approximately 34.5-kDa bacterially produced protein specifically catalyzed the head-to-middle condensation of two dimethylallyl diphosphate units to LPP in vitro with apparent Km and kcat values of 208 ± 12 μm and 0.1 s−1, respectively. LiLPPS is a homodimeric enzyme with a sigmoidal saturation curve and Hill coefficient of 2.7, suggesting a positive co-operative interaction among its catalytic sites. LiLPPS could be used to modulate the production of lavandulol and its derivatives in plants through metabolic engineering. PMID:23306202

Underestimation of terpene exposure in the Nordic wood industry.

PubMed

Granström, Karin M

2010-03-01

This study determined that emission of sesquiterpenes from processed wood warrants attention in the work environment. Currently, only the monoterpenes in the terpene group are monitored in occupational hygiene studies. Terpene emissions are a work environment issue for industries that process wood, as they are known to cause respiratory difficulties and mucous membrane irritation. Fresh sawdust of the most common boreal conifers, Norway spruce (Picea abies) and Scots pine (Pinus sylvestris), was subjected to processing (drying), and the emissions were analyzed with a gas chromatograph-mass spectrometer. The data indicate that workers are exposed to significant amounts of sesquiterpenes, an observation that has not been recorded previously at wood processing plants. On average, the proportion of sesquiterpenes to monoterpenes was 21 +/- 5% (STD, n = 11) for spruce and 15 +/- 5% (STD, n = 13) for pine. The composition of terpenes emitted in air from spruce wood differs from the composition in resin. The sum of monoterpenes and sesquiterpenes can exceed the occupational exposure limit for turpentine for processes where monoterpene concentrations are already close to the occupational exposure limit, and for processes involving the processing of bark. Findings suggest that future studies of health effects from terpenes in air should measure monoterpenes and sesquiterpenes to assess whether the current OELs are appropriate.

Monoterpene concentrations in fresh, senescent, and decaying foliage of singleleaf pinyon (Pinus monophylla Torr. & Frem.: Pinaceae) from the western Great Basin.

PubMed

Wilt, F M; Miller, G C; Everett, R L; Hackett, M

1993-02-01

Senescent foliage from pines is potentially a large contributor to the total monoterpene content of the litter layer, and the availability of these compounds as phytotoxins may result from release of these compounds into the vapor phase. In order to determine the fate of several monoterpene hydrocarbons in the natural environment, we examined their concentrations in fresh, senescent, and decaying needles from 32 single-leaf pinyon pine (Pinus monophylla Torr. & Frem.: Pinaceae) trees growing at two different locations. Total monoterpene content was highest in the fresh needles (mean=5.6 ± 2.2 mg/g extracted air dry weight), but also remained relatively high in senescent needles (mean=3.6 ±1.8 mg/g extracted air dry weight), either still attached to the tree or forming the freshest layer of understory litter. Decaying needles within a dark decomposing layer of litter material 5-20 cm from the surface were found to contain much lower amounts of total monoterpenes (average: =0.12 ±0.06 mg/g extracted air dry weight). Further investigation of the fate of these compounds in the pinyon understory is required to determine if these hydrocarbons are indeed exerting phytotoxic characteristics.

Diel cycles of isoprenoids in the emissions of Norway spruce, different Scots pine chemotypes, and in Boreal forest ambient air during HUMPPA-COPEC-2010

NASA Astrophysics Data System (ADS)

Yassaa, N.; Williams, J.; Song, W.; Vanhatalo, A.; Bäck, J.; Lelieveld, J.

2012-04-01

Cuvette based emission rates of monoterpenes and sesquiterpenes from four chemotypes of Scots pine (Pinus sylvestris) and one chemotype of Norway spruce (Picea abies) as well as the ambient mixing ratios of monoterpenes were determined during HUMPPA-COPEC 2010 summer campaign. Differences in chemical composition as well as in emission strength were observed between the different chemotypes. The chemotypes of Scots pine can be classified according to species with high, no and intermediate content of Δ3-carene. The "no- Δ3-carene" chemotype was found to be the strongest emitter of monoterpenes. From this chemotype, β-myrcene, a very reactive organic gas, was the dominant species accounting for more than 35 % of the total emission rates of isoprenoids followed by ß-phellandrene (~34%). Myrcene emission rates ranged from 0.8 up to 24 µg/g (dw)/h. α-farnesene was the dominant sesquiterpene species, with measured average emission rates of 318 ng/g (dw)/h. In the high Δ3-carene chemotype, which is the most studied in Hyytiälä, Δ3-carene was more than 48 % of the total monoterpene emission. The mean Δ3-carene emission rate, circa 609 ng/g (dw)/h reported here is consistent with the previously reported value during the same season. The terpene emission from spruce was dominated by limonene (35%), ß-phellandrene (15%), α-pinene (14 %) and eucalyptol (9%). Total spruce monoterpene emissions ranged from 0.549 up to 12.2 µg/g (dw)/h. Overall the total terpene flux (monoterpenes + sesquiterpenes) from all studied plant species varied from 230 ng/g (dw)/h up to 66 µg/g (dw)/h. The total ambient monoterpenes (including α-pinene, Δ3-carene, ß-pinene and ß-myrcene) measured during the campaign varied in mixing ratio from a few ppt to over one ppb. The most abundant biogenic VOCs measured above the canopy were α-pinene and Δ3-carene and these two compounds together contributed more than 50% of the total monoterpenes. The diel cycles of isoprenoid mixing ratios showed high levels during the night-time which is consistent with continued low nocturnal emission and a low and stable boundary layer. The chirality of α-pinene was dominated by (+)-enantiomers both in the direct emission and in the atmosphere. The effect of herbivore attack on the plant shoot was studied and found to significantly influence the enantiomeric signature of monoterpenes in similar manner as has been observed from mechanical damage. The exceptionally hot temperatures recorded in the summer of 2010 were reflected by strong emission of terpenes and consequently high ambient mixing ratios.

A REVIEW AND SYNTHESIS OF MONOTERPENE SPECIATION FROM FORESTS IN THE UNITED STATES

EPA Science Inventory

The monoterpene composition (emission and tissue internal concentration) of major forest tree species in the United States is discussed. Of the 14 most commonly occurring compounds ( -pinene, -pinene, 3-carene, d-limonene, camphene, myrcene, -terpinenen, -phellandrene, sabin...

Low temperature fluidized wood chip drying with monoterpene analysis

Treesearch

Bridget N. Bero; Alarick Reiboldt; Ward Davis; Natalie Bedard; Evan Russell

2011-01-01

This paper describes the drying of ponderosa pine wood chips at low (20°C and 50°C) temperatures using a bench-scale batch pulsed fluidizer to evaluate both volatile pine oils (monoterpenes) and moisture losses during drying.

Seasonal monoterpene and sesquiterpene emissions from Pinus taeda and Pinus virginiana

EPA Science Inventory

Seasonal volatile organic compound emission data from loblolly pine (Pinus taeda) and Virginia pine (Pinus virginiana) were collected using branch enclosure techniques in Central North Carolina, USA. Pinus taeda monoterpene emission rates were at least ten times higher than oxyge...

Comparable Monoterpene emission from pine forests across 500 mm precipitation gradient in the semi-arid transition zone

NASA Astrophysics Data System (ADS)

Seco, Roger; Karl, Thomas; Turnipseed, Andrew; Greenberg, Jim; Guenther, Alex; Llusia, Joan; Penuelas, Josep; Dicken, Uri; Rotenberg, Eyal; Rohatyn, Shani; Preisler, Yakir; Yakir, Dan

2014-05-01

Atmospheric volatile organic compounds (VOCs) have key environmental and biological roles, and can affect atmospheric chemistry, secondary aerosol formation, and as a consequence also climate. At the same time, global changes in climate arising from human activities can modify the VOC emissions of vegetation in the coming years. Monoterpene emission fluxes were measured during April 2013 at two forests in the semi-arid climate of Israel. Both forests were dominated by Pinus halepensis trees of similar age, but differed in the amount of annual average precipitation received (~276 and ~760 mm at the Yatir and Birya sites, respectively). Measurements performed included leaf-level sampling and gas exchange, as well as canopy-level flux calculations. Leaf level monoterpene emissions were sampled from leaf cuvettes with adsorbent cartridges and later analyzed by GC-MS. Canopy scale fluxes were calculated with the Disjunct Eddy Covariance technique by means of a Quadrupole PTRMS and eddy-covariance system. We report the differences observed between the two forests in terms of photosynthetic activity and monoterpene emissions, aiming to see the effect of the different climatic regimes at each location. Significantly higher emission rates of monoterpenes were observed in the wetter site during mid-day, in both the leaf scale and canopy scale measurements. Remarkably, however, normalized to 30C and corrected for tree density differences between the sites indicated comparable emission rates for both sites, with higher emission rated in the evening hours in the dry site at the edge of the Negev Desert. Modeling the monoterpene emission rates using MEGAN v2.1 indicated better agreement with observations in the wetter site then in the dry site, especially with respect to fluxes during the evening hours.

Stomatal uptake and stomatal deposition of ozone in isoprene and monoterpene emitting plants.

PubMed

Fares, S; Loreto, F; Kleist, E; Wildt, J

2008-01-01

Volatile isoprenoids were reported to protect plants against ozone. To understand whether this could be the result of a direct scavenging of ozone by these molecules, the stomatal and non-stomatal uptake of ozone was estimated in plants emitting isoprene or monoterpenes. Ozone uptake by holm oak (Quercus ilex, a monoterpene emitter) and black poplar (Populus nigra, an isoprene emitter) was studied in whole plant enclosures (continuously stirred tank reactors, CSTR). The ozone uptake by plants was estimated measuring ozone concentration at the inlet and outlet of the reactors, after correcting for the uptake of the enclosure materials. Destruction of ozone at the cuticle or at the plant stems was found to be negligible compared to the ozone uptake through the stomata. For both plant species, a relationship between stomatal conductance and ozone uptake was found. For the poplar, the measured ozone losses were explained by the uptake of ozone through the stomata only, and ozone destruction by gas phase reactions with isoprene was negligible. For the oak, gas phase reactions of ozone with the monoterpenes emitted by the plants contributed significantly to ozone destruction. This was confirmed by two different experiments showing a) that in cases of high stomatal conductance but under low CO(2) concentration, a reduction of monoterpene emission was still associated with reduced O(3) uptake; and b) that ozone losses due to the gas phase reactions only can be measured when using the exhaust from a plant chamber to determine the gas phase reactivity in an empty reaction chamber. Monoterpenes can therefore relevantly scavenge ozone at leaf level contributing to protection against ozone.

Laboratory and field measurements of enantiomeric monoterpene emissions as a function of chemotype, light and temperature

NASA Astrophysics Data System (ADS)

Song, W.; Staudt, M.; Bourgeois, I.; Williams, J.

2014-03-01

Plants emit significant amounts of monoterpenes into the earth's atmosphere, where they react rapidly to form a multitude of gas phase species and particles. Many monoterpenes exist in mirror-image forms or enantiomers. In this study the enantiomeric monoterpene profile for several representative plants (Quercus ilex L., Rosmarinus officinalis L., and Pinus halepensis Mill.) was investigated as a function of chemotype, light and temperature both in the laboratory and in the field. Analysis of enantiomeric monoterpenes from 19 Quercus ilex individuals from Southern France and Spain revealed four regiospecific chemotypes (genetically fixed emission patterns). In agreement with previous work, only Quercus ilex emissions increased strongly with light. However, for all three plant species no consistent enantiomeric variation was observed as a function of light, and the enantiomeric ratio of α-pinene was found to vary by less than 20% from 100 and 1000 μmol m-2 s-1 PAR (photosynthetically active radiation). The rate of monoterpene emission increased with temperature from all three plant species, but little variation in the enantiomeric distribution of α-pinene was observed with temperature. There was more enantiomeric variability between individuals of the same species than could be induced by either light or temperature. Field measurements of α-pinene enantiomer mixing ratios in the air, taken at a Quercus ilex forest in Southern France, and several other previously reported field enantiomeric ratio diel cycle profiles are compared. All show smoothly varying diel cycles (some positive and some negative) even over changing wind directions. This is surprising in comparison with variations of enantiomeric emission patterns shown by individuals of the same species.

Temperature Dependency of the Correlation between Secondary Organic Aerosol and Monoterpenes Concentrations at a Boreal Forest Site in Finland

NASA Astrophysics Data System (ADS)

Zhou, Y.; Zhang, W.; Rinne, J.

2016-12-01

Climate feedbacks represent the large uncertainty in the climate projection partly due to the difficulties to quantify the feedback mechanisms in the biosphere-atmosphere interaction. Recently, a negative climate feedback mechanism whereby higher temperatures and CO2-levels boost continental biomass production, leading to increased biogenic secondary organic aerosol (SOA) and cloud condensation nuclei concentrations, tending to cause cooling, has been attached much attention. To quantify the relationship between biogenic organic compounds (BVOCs) and SOA, a five-year data set (2008, 2010-2011,2013-2014) for SOA and monoterpenes concentrations (the dominant fraction of BVOCs) measured at the SMEAR II station in Hyytiälä, Finland, is analyzed. Our results show that there is a moderate linear correlation between SOA and monoterpenes concentration with the correlation coefficient (R) as 0.66. To rule out the influence of anthropogenic aerosols, the dataset is further filtered by selecting the data at the wind direction of cleaner air mass, leading to an improved R as 0.68. As temperature is a critical factor for vegetation growth, BVOC emissions, and condensation rate, the correlation between SOA and monoterpenes concentration at different temperature windows are studied. The result shows a higher R and slope of linear regression as temperature increases. To identify the dominant oxidant responsible for the BVOC-SOA conversion, the correlations between SOA concentration and the monoterpenes oxidation rates by O3 and OH are compared, suggesting more SOA is contributed by O3 oxidation process. Finally, the possible processes and factors such as the atmospheric boundary layer depth, limiting factor in the monoterpenes oxidation process, as well as temperature sensitivity in the condensation process contributing to the temperature dependence of correlation between BVOA and SOA are investigated.

A critical role for autoxidation in the alpha-pinene + OH aerosol system

EPA Science Inventory

Oxidation of monoterpenes results in efficient formation of secondary organic aerosol (SOA) and is included as an SOA source in most chemical transport models. However, current model parameterizations lack a mechanistic dependence of monoterpene SOA on NOx and oxidant identity (e...

The contribution of wine-derived monoterpene glycosides to retronasal odour during tasting.

PubMed

Parker, Mango; Black, Cory A; Barker, Alice; Pearson, Wes; Hayasaka, Yoji; Francis, I Leigh

2017-10-01

This study investigated the sensory significance of monoterpene glycosides during tasting, by retronasal perception of odorant aglycones released in-mouth. Monoterpene glycosides were isolated from Gewürztraminer and Riesling juices and wines, chemically characterised and studied using sensory time-intensity methodology, together with a synthesised monoterpene glucoside. When assessed in model wine at five times wine-like concentration, Gewürztraminer glycosides and geranyl glucoside gave significant fruity flavour, although at wine-like concentrations, or in the presence of wine volatiles, the effect was not significant. Gewürztraminer glycosides, geranyl glucoside and guaiacyl glucoside were investigated using a sensory panel (n=39), revealing large inter-individual variability, with 77% of panellists responding to at least one glycoside. The study showed for the first time that grape-derived glycosides can contribute perceptible fruity flavour, providing a means of enhancing flavour in wines, and confirms the results of previous studies that the effect is highly variable across individuals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enantiomeric and non-enantiomeric monoterpenes of Juniperus communis L. and Juniperus oxycedrus needles and berries determined by HS-SPME and enantioselective GC/MS.

PubMed

Foudil-Cherif, Yazid; Yassaa, Noureddine

2012-12-01

For the first time, enantiomeric and non-enantiomeric distribution of monoterpenes in the headspace of Juniperus communis L. and Juniperus oxycedrus needles and berries has been determined using HS-SPME combined with enantioselective GC/MS. The essential oils from needles and berries of both Juniperus species obtained by hydrodistillation were also performed. HS-SPME has shown good potential to reproduce the same results as the commonly used hydrodistillation extraction technique. While needles and berries of J. communis showed high contents of sabinene, α-pinene and β-myrcene with 19-30%, 12-24% and 9-20%, respectively, J. oxycedrus was strongly dominated by α-pinene with 85-92% in both needles and berries. Large variations in chiral distribution of monoterpenes within the same plant species and between the two junipers were observed. Interestingly, similar enantiomeric preferences of monoterpenes were obtained between needles and berries of the two junipers. Copyright © 2012 Elsevier Ltd. All rights reserved.

Dynamics of Monoterpene Formation in Spike Lavender Plants

PubMed Central

Kutzner, Erika; Huber, Claudia; Segura, Juan; Arrillaga, Isabel

2017-01-01

The metabolic cross-talk between the mevalonate (MVA) and the methylerythritol phosphate (MEP) pathways was analyzed in spike lavender (Lavandula latifolia Med) on the basis of 13CO2-labelling experiments using wildtype and transgenic plants overexpressing the 3-hydroxy-3-methylglutaryl CoA reductase (HMGR), the first and key enzyme of the MVA pathway. The plants were labelled in the presence of 13CO2 in a gas chamber for controlled pulse and chase periods of time. GC/MS and NMR analysis of 1,8-cineole and camphor, the major monoterpenes present in their essential oil, indicated that the C5-precursors, isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) of both monoterpenes are predominantly biosynthesized via the MEP pathway. Surprisingly, overexpression of HMGR did not have significant impact upon the crosstalk between the MVA and MEP pathways indicating that the MEP route is the preferred pathway for the synthesis of C5 monoterpene precursors in spike lavender. PMID:29257083

Evidence of the photosynthetic origin of monoterpenes emitted by quercus ilex L. leaves by {sup 13}C labeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loreto, F.; Ciccioli, P.; Cecinato, A.

1996-04-01

The carbon of the four main monoterpenes emitted by Quercus ilex L. leaves was completely labeled with {sup 13}C after a 20-min feeding with 99% {sup 13}CO{sub 2}. This labeling time course is comparable with the labeling time course of isoprene, the terpenoid emitted by other Quercus species and synthesized in leaf chloroplasts. It is also comparable with that of phosphoglyceric acid. Our experiment therefore provides evidence that monoterpenes emitted by Q. ilex are formed photosynthesis intermediates and may share the same synthetic pathway with isoprene. By analyzing the rate and the distribution of labeling in the different fragments, wemore » looked for evidence of differential carbon labeling in the {alpha}-pinene emitted. However, the labeling pattern was quite uniform in the different fragments, suggesting that the carbon skeleton of the emitted monoterpenes comes from a unique carbon source. 16 refs., 3 figs., 1 tab.« less

Quantitative Intensity Studies of Three Gas-Phase Monoterpenes in the Infrared: α-PINENE, β-PINENE and D-Limonene

NASA Astrophysics Data System (ADS)

Brauer, Carolyn S.; Johnson, Timothy J.; Blake, Thomas A.; Sams, Robert L.

2013-06-01

Monoterpenes are a class of biogenic volatile organic compounds (VOCs) whose general formula is C_{10}H_{16}. Like other VOCs, monoterpenes play an important role in the atmosphere as they are produced by vegetation in large quantities, and have recently been discovered in biomass burning plumes. Absorption coefficients and integrated band intensities are reported in the 600 - 6500 cm^{-1} region for three monoterpenes: α-pinene, β-pinene and d-limonene. The pressure broadened (1 atmosphere N_2) spectra were recorded in a 19.96 cm path length cell with 0.112 cm^{-1} resolution at two temperatures and a minimum of six different partial pressures using a Bruker 66V FTIR. These data are part of the PNNL Spectral Database, which contains quantitative spectra of over 600 molecules. Potential atmospheric applications will be discussed Timothy J. Johnson, Luisa T. M. Profeta, Robert L. Sams, David W. T. Griffith, Robert L. Yokelson Vibrational Spectroscopy {53}(1);97-102 (2010).

Herbivory and climate interact serially to control monoterpene emissions from pinyon pine forests.

PubMed

Trowbridge, Amy M; Daly, Ryan W; Helmig, Detlev; Stoy, Paul C; Monson, Russell K

2014-06-01

The emission of volatile monoterpenes from coniferous trees impacts the oxidative state of the troposphere and multi-trophic signaling between plants and animals. Previous laboratory studies have revealed that climate anomalies and herbivory alter the rate of tree monoterpene emissions. However, no studies to date have been conducted to test these relations in situ. We conducted a two-year field experiment at two semiarid sites dominated by pinyon pine (Pinus edulis) during outbreaks of a specialist herbivore, the southwestern tiger moth (Lophocampa ingens: Arctiidae). We discovered that during the early spring, when herbivory rates were highest, monoterpene emission rates were approximately two to six times higher from undamaged needles on damaged trees, with this increase in emissions due to alpha-pinene, beta-pinene, and camphene at both sites. During mid-summer, emission rates did not differ between previously damaged and undamaged trees at the site on the Western Slope of the Rocky Mountains, but rather tracked changes in the temperature and precipitation regime characteristic of the region. As the mid-summer drought progressed at the Eastern Slope site, emission rates were low, but differences between previously damaged and undamaged trees were not statistically significant. Despite no difference in emissions, mid-summer tissue monoterpene concentrations were significantly lower in previously damaged trees at both sites. With the onset of monsoon rains during late summer, emission rates from previously damaged trees increased to levels higher than those of undamaged trees despite the lack of herbivory. We conclude that (1) herbivory systemically increases the flux of terpenes to the atmosphere during the spring, (2) drought overrides the effect of past herbivory as the primary control over emissions during the mid-summer, and (3) a release from drought and the onset of late-summer rains is correlated with a secondary increase in emissions, particularly from herbivore-damaged trees, possibly due to a drought-delayed stimulation of induced monoterpene synthesis and/or increases in stomatal conductance. A greater understanding of the interactive effects of seasonality and herbivory on monoterpene emissions provides much needed information regarding the atmospheric and ecological consequences that these compounds will have for semiarid ecosystems.

Turbulent transport and chemistry of isoprene and monoterpenes within and above tropical forest canopies

NASA Astrophysics Data System (ADS)

Gerken, T.; Chamecki, M.; Fuentes, J. D.; Stoy, P. C.; Trowbridge, A.; Wei, D.

2016-12-01

The Amazon rainforest and other rainforests emit large quantities of biogenic volatile organic compounds (BVOCs), including isoprene and monoterpenes, which react with and produce atmospheric oxidants such as ozone and the hydroxyl radical. Some of the resulting reaction products condense to form secondary organic aerosols, which due to the typically clean tropical air can make up a large portion of the total atmospheric aerosols and may thus impact cloud development and regional climate. To better understand the role of tropical forests on cloud development and climate, it is necessary to quantify not only BVOC emissions, but also turbulent transport and the resulting atmospheric chemistry within both the forest canopy and atmospheric boundary-layer. To date, most research has ignored within-canopy chemical processes that are typically not resolved in regional models that treat the forest as a lower boundary condition. We use canopy-resolving Large Eddy Simulation (LES) to study the role of turbulence and chemistry in the isoprene lifetime under conditions observed during a 2014 field campaign in central Amazonia. The LES includes a simple chemical mechanism for the oxidation of isoprene and aggregated monoterpenes (34 reactions), which we use to quantify the impact of within-canopy and boundary-layer processes on the transport and air chemistry of isoprene, monoterpenes, and primary reaction products on their export at the top of the boundary layer. LES results show air parcel residence times in the dense Amazon rainforest, which govern the time available for in-canopy reactions, to range from a few seconds near the canopy top to 30 minutes near the ground. Such residence times are comparable to chemical lifetimes of many reactive species and the convective eddy turnover timescale. Additionally, monoterpene oxidation with ambient ozone levels can increase within-canopy hydroxyl radical concentrations from 5 x 104 to 3 x 105 radicals cm-3, thus greatly increasing the oxidative capacity of the near surface air; within-canopy oxidation is significant for isoprene (5%) and monoterpene chemistry (25%). Results demonstrate that monoterpene chemistry - in addition to isoprene chemistry - needs to be considered when investigating the role of BVOCs to surface-atmosphere interactions in tropical rainforests.

Fluxes of biogenic volatile organic compounds measured and modelled above a Norway spruce forest

NASA Astrophysics Data System (ADS)

Juráň, Stanislav; Fares, Silvano; Pallozzi, Emanuele; Guidolotti, Gabriele; Savi, Flavia; Alivernini, Alessandro; Calfapietra, Carlo; Večeřová, Kristýna; Křůmal, Kamil; Večeřa, Zbyněk; Cudlín, Pavel; Urban, Otmar

2016-04-01

Fluxes of biogenic volatile organic compounds (BVOCs) were investigated at Norway spruce forest at Bílý Kříž in Beskydy Mountains of the Czech Republic during the summer 2014. A proton-transfer-reaction-time-of-flight mass spectrometer (PTR-TOF-MS, Ionicon Analytik, Austria) has been coupled with eddy-covariance system. Additionally, Inverse Lagrangian Transport Model has been used to derive fluxes from concentration gradient of various monoterpenes previously absorbed into n-heptane by wet effluent diffusion denuder with consequent quantification by gas chromatography with mass spectrometry detection. Modelled data cover each one day of three years with different climatic conditions and previous precipitation patterns. Model MEGAN was run to cover all dataset with monoterpene fluxes and measured basal emission factor. Highest fluxes measured by eddy-covariance were recorded during the noon hours, represented particularly by monoterpenes and isoprene. Inverse Lagrangian Transport Model suggests most abundant monoterpene fluxes being α- and β-pinene. Principal component analysis revealed dependencies of individual monoterpene fluxes on air temperature and particularly global radiation; however, these dependencies were monoterpene specific. Relationships of monoterpene fluxes with CO2 flux and relative air humidity were found to be negative. MEGAN model correlated to eddy-covariance PTR-TOF-MS measurement evince particular differences, which will be shown and discussed. Bi-directional fluxes of oxygenated short-chain volatiles (methanol, formaldehyde, acetone, acetaldehyde, formic acid, acetic acid, methyl vinyl ketone, methacrolein, and methyl ethyl ketone) were recorded by PTR-TOF-MS. Volatiles of anthropogenic origin as benzene and toluene were likely transported from the most benzene polluted region in Europe - Ostrava city and adjacent part of Poland around Katowice, where metallurgical and coal mining industries are located. Those were accumulated during the night bellow a shallow boundary layer and subsequently resuspended during the day. We discuss here the importance of wide-spread temperate Norway spruce forests in biosphere-atmosphere exchange under climate change. Although temperate forests could play a key role in air pollutants removal, these contribute at the same time to a secondary organic aerosol formation by production of BVOCs. Measurements of trace gases are important for further parametrization of biosphere-atmosphere continuum transport models.

Ambient Organic Compounds in the Tropics and their Relationship to Microbial Effects.

DTIC Science & Technology

and condensed organic materials; and a laboratory phase which used controlled experiments to study relationships among selected monoterpenes , fungi and...that monoterpenes influence both the growth rate of fungi and their metabolic products. The study confirmed that biologically inert substrates form a

Monoterpene engineering in a woody plant Eucalyptus camaldulensis using a limonene synthase cDNA.

PubMed

Ohara, Kazuaki; Matsunaga, Etsuko; Nanto, Kazuya; Yamamoto, Kyoko; Sasaki, Kanako; Ebinuma, Hiroyasu; Yazaki, Kazufumi

2010-01-01

Metabolic engineering aimed at monoterpene production has become an intensive research topic in recent years, although most studies have been limited to herbal plants including model plants such as Arabidopsis. The genus Eucalyptus includes commercially important woody plants in terms of essential oil production and the pulp industry. This study attempted to modify the production of monoterpenes, which are major components of Eucalyptus essential oil, by introducing two expression constructs containing Perilla frutescens limonene synthase (PFLS) cDNA, whose gene products were designed to be localized in either the plastid or cytosol, into Eucalyptus camaldulensis. The expression of the plastid-type and cytosol-type PFLS cDNA in transgenic E. camaldulensis was confirmed by real-time polymerase chain reaction (PCR). Gas chromatography with a flame ionization detector analyses of leaf extracts revealed that the plastidic and cytosolic expression of PFLS yielded 2.6- and 4.5-times more limonene than that accumulated in wild-type E. camaldulensis, respectively, while the ectopic expression of PFLS had only a small effect on the emission of limonene from the leaves of E. camaldulensis. Surprisingly, the high level of PFLS in Eucalyptus was accompanied by a synergistic increase in the production of 1,8-cineole and alpha-pinene, two major components of Eucalyptus monoterpenes. This genetic engineering of monoterpenes demonstrated a new potential for molecular breeding in woody plants.

The biosynthetic origin of irregular monoterpenes in Lavandula: isolation and biochemical characterization of a novel cis-prenyl diphosphate synthase gene, lavandulyl diphosphate synthase.

PubMed

Demissie, Zerihun A; Erland, Lauren A E; Rheault, Mark R; Mahmoud, Soheil S

2013-03-01

Lavender essential oils are constituted predominantly of regular monoterpenes, for example linalool, 1,8-cineole, and camphor. However, they also contain irregular monoterpenes including lavandulol and lavandulyl acetate. Although the majority of genes responsible for the production of regular monoterpenes in lavenders are now known, enzymes (including lavandulyl diphosphate synthase (LPPS)) catalyzing the biosynthesis of irregular monoterpenes in these plants have not been described. Here, we report the isolation and functional characterization of a novel cis-prenyl diphosphate synthase cDNA, termed Lavandula x intermedia lavandulyl diphosphate synthase (LiLPPS), through a homology-based cloning strategy. The LiLPPS ORF, encoding for a 305-amino acid long protein, was expressed in Escherichia coli, and the recombinant protein was purified by nickel-nitrilotriacetic acid affinity chromatography. The approximately 34.5-kDa bacterially produced protein specifically catalyzed the head-to-middle condensation of two dimethylallyl diphosphate units to LPP in vitro with apparent Km and kcat values of 208 ± 12 μm and 0.1 s(-1), respectively. LiLPPS is a homodimeric enzyme with a sigmoidal saturation curve and Hill coefficient of 2.7, suggesting a positive co-operative interaction among its catalytic sites. LiLPPS could be used to modulate the production of lavandulol and its derivatives in plants through metabolic engineering.

Analysis of trends in isoprene and monoterpenes in a remote forest and an anthropogenic influenced forest

NASA Astrophysics Data System (ADS)

Usenko, S.; Sheesley, R. J.; Winfield, Z.; Yoon, S.; Erickson, M.; Flynn, J. H., III; Alvarez, S. L.; Wallace, H. W., IV; Griffin, R. J.

2017-12-01

The University of Houston Mobile Air Quality Laboratory (MAQL) was deployed to the University of Michigan Biological Station (UMBS) in July 2016 as part of the PROPHET-AMOS study and then was deployed to Jones Forest located north of Houston, TX from August 12 through September 23, 2016. Both sites are heavily forested, but UMBS is remote with no anthropogenic influence while Jones Forest sees frequent pollution transport from Houston. UMBS experienced periods of high isoprene:monoterpenes and periods of equivalent isoprene:monoterpenes, while Jones Forest had a consistently high isoprene:monoterpenes. This provided for a test bed to look at the interactions within two forested environments as well as the influence of anthropogenic sources. The MAQL was outfitted to measure O3 (2B Technology), NOy and SO2 (Thermo Scientific), NO/NOx (Air Quality Design), CO (Los Gatos), and select biogenic volatile organic carbon (BVOC) with their oxidation products (Ionicon PTR-MS). The instruments sampled from MAQL's 6 m tower at both sites. The UMBS site was below canopy and the Jones Forest site was in an open field surrounded by forest. The trends in isoprene and monoterpenes were explored in relation to time-of-day, temperature, and precipitation for both locations. In addition, the production of methyl vinyl ketone and methacrolein under these different conditions of meteorology, trace gas composition and BVOC composition was explored.

Bark beetles, pityogenes bidentatus, orienting to aggregation pheromone avoid conifer monoterpene odors when flying but not when walking

USDA-ARS?s Scientific Manuscript database

Previous studies have provided evidence that monoterpene odors from healthy host Scotch pine (Pinus sylvestris) and non-host Norway spruce (Picea abies) significantly reduce the attraction of flying bark beetles, Pityogenes bidentatus, to their aggregation pheromone components (grandisol and cis-ver...

Alpha-Terpineol, a natural monoterpene: A review of its biological properties

USDA-ARS?s Scientific Manuscript database

Terpineols are monocyclic monoterpene tertiary alcohols and they are naturally present in plant species. There are five common isomers of terpineols, alpha-, beta-, gamma-, delta- and terpinen-4-ol, of which alpha-terpineol and its isomer terpinen-4-ol are the most common terpineols found in nature....

Variation in phenology and monoterpene patterns of defoliated and nondefoliated douglas-fir ( pseudotsuga menziesii var. glauca'). Forest Service research paper

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muzika, R.M.; Engle, J.; Parks, C.

1993-02-01

Foliage was collected from paired Douglas-fir (Pseudotsuga menziesii) trees characterized as either resistant' or susceptible' to western spruce budworm (Choristoneura occidentalis) (Lepidoptera: Tortricidae) attack. Resistant trees produced more foliage monoterpenes and broke bud 7 to 10 days earlier than susceptible trees.

Field Bioassays of Synthetic Pheromones and Host Monoterpenes for Conophthorus coniperda (Coleoptera: Scolytidae)

Treesearch

Peter de Groot; Gary L. DeBarr; Goran Birgersson

1998-01-01

Four major monoterpenes, (±)-a-pinene,1 (S)-(-)-ß-pinene,(R)-(+)-limonene, and myrcene are found in the cones of eastern white pines, Pinus strobus L. Mixtures ofthese, as well as. a-pinene or ß-pinene alone. increased catches of male white pine cone...

Investigating the Role of Cooperative Interactions Between the Neu Protooncogene and the Other erbB Family Members in Rat Mammary Carcinogenesis

DTIC Science & Technology

1999-07-01

antiestrogen tamoxifen or the monoterpene perillyl alcohol can prevent the formation of neu associated mammary cancers in this transgenic model. II...general breast cancer prevention agents; the monoterpenes (perillyl alcohol) and determine if the number of preneoplastic lesions and cancers

The Use of Monoterpenes as Kairomones by Ips latidens (LeConte) (Coleoptera: Scolytidae)

Treesearch

D.R. Miller; J.H. Borden

1990-01-01

The responses of Ips lutidens (LeConte) to multiple-funnel traps baited with various monoterpenes were determined in stands of lodgepole pine in British Columbia. ß-Phellandrene was attractive to I. lutidens in the absence of the pheromone ipsenol ß-Phellandrene increased the attraction of I. lutidens to...

Variation in monoterpene content among geographic sources of eastern white pine

Treesearch

A.R. Gilmore; J.J. Jokela

1977-01-01

Variations of monoterpenes in cortical oleoresins and foliar samples were determined for seed from 16 provenances of eastern white pine (Pinus strobus L.). The experiment was analyzed using the "raw" and the arcsine "transformed" data. Alpha-pinene, camphene, and β-pinene varied between seed sources when "raw" data were analyzed...

Variations in the monoterpene composition of ponderosa pine wood oleoresin

Treesearch

Richard H. Smith

1964-01-01

A wide range in quantitative composition of the wood oleoresin monoterpenes was found among 64 ponderosa pines in the central Sierra Nevada by gas chromatographic analysis. An inverse relationship was found in the amount of β-pinene and Δ3-carene. Practically no difference in composition could be associated with (a) type of...

Monoterpene emissions from Pinus halepensis forests in a semi-arid region (Israel)

NASA Astrophysics Data System (ADS)

Seco, R.; Karl, T.; Turnipseed, A. A.; Greenberg, J.; Guenther, A. B.; Llusia, J.; Penuelas, J.; Kim, S.; Dicken, U.; Rotenberg, E.; Rohatyn, S.; Preisler, Y.; Yakir, D.

2013-12-01

Atmospheric volatile organic compounds (VOCs) have key environmental and biological roles, and can affect atmospheric chemisty, secondary aerosol formation, and as a consequence also climate. At the same time, global changes in climate arising from human activities can modify the VOC emissions of vegetation in the coming years. Monoterpene emission fluxes were measured during April 2013 at two forests in the semi-arid climate of Israel. Both forests were dominated by the same pine species, Pinus halepensis, but differed in the amount of annual average precipitation received (280 and 800 mm at Yatir and Birya, respectively). Measurements performed included leaf-level sampling as well as canopy-level flux calculations. Leaf level monoterpene emissions were sampled from leaf cuvettes with adsorbent cartridges and later analyzed by GC-MS. Canopy scale fluxes were calculated with the Disjunct Eddy Covariance technique by means of a Quadrupole PTRMS. We report the differences observed between the two forests in terms of photosynthetic activity and monoterpene emissions, aiming to see the effect of the different precipitation regimes at each location.

Effects of sunlight exclusion on the profiles of monoterpene biosynthesis and accumulation in grape exocarp and mesocarp.

PubMed

Zhang, Erpeng; Chai, Fengmei; Zhang, Haohao; Li, Shaohua; Liang, Zhenchang; Fan, Peige

2017-12-15

Terpenes are important aroma compounds in table Muscat grape and wine, and their content in the berry can be affected by sunlight. The effects of sunlight exclusion on monoterpene profiles and relevant gene expression profiles in the exocarp and mesocarp of table Muscat grape 'Jingxiangyu' at different development stages were thoroughly surveyed by bagging pre-veraison clusters in special opaque boxes. The responses of monoterpenes to sunlight treatments varied in three types, representatively linalool, ocimene and geraniol. Linalool was the most sensitive compound to sunlight, whose biosynthesis was severely inhibited by sunlight exclusion and then was elevated by re-exposure. Ocimene and glycosylated geraniol showed a certain suppressive and stimulative responses to sunlight exclusion respectively. Further transcription analysis revealed that VvPNLinNer1, VvCSbOci, VvGT7 and VvGT14 genes were mainly responsible for monoterpene accumulation and sensitivity to sunlight. VvDXS2 and VvDXR genes were partially related to the differential accumulation of total terpenes under different sunlight treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Laboratory studies of monoterpene secondary organic aerosol formation and evolution

NASA Astrophysics Data System (ADS)

Thornton, J. A.; D'Ambro, E.; Zhao, Y.; Lee, B. H.; Pye, H. O. T.; Schobesberger, S.; Shilling, J.; Liu, J.

2017-12-01

We have conducted a series of chamber experiments to study the molecular composition and properties of secondary organic aerosol (SOA) formed from monoterpenes under a range of photochemical and dark conditions. We connect variations in the SOA mass yield to molecular composition and volatility, and use a detailed Master Chemical Mechanism (MCM) based chemical box model with dynamic gas-particle partitioning to examine the importance of various peroxy radical reaction mechanisms in setting the SOA yield and properties. We compare the volatility distribution predicted by the model to that inferred from isothermal room-temperature evaporation experiments using the FIGAERO-CIMS where SOA particles collected on a filter are allowed to evaporate under humidified pure nitrogen flow stream for up to 24 hours. We show that the combination of results requires prompt formation of low volatility SOA from predominantly gas-phase mechanisms, with important differences between monoterpenes (alpha-Pinene and delta-3-Carene) followed by slower non-radical particle phase chemistry that modulates both the chemical and physical properties of the SOA. Implications for the regional evolution of atmospheric monoterpene SOA are also discussed.

Interactions between SO2 oxidation and Secondary Organic Aerosol formation through Criegee intermediate chemistry

NASA Astrophysics Data System (ADS)

Chan, A. W. H.; Ye, J.; Abbatt, J.

2016-12-01

Ozonolysis of monoterpenes is an important source of atmospheric biogenic secondary organic aerosol (BSOA). While enhanced BSOA formation has been repeatedly observed under sulfate-rich conditions in both field studies and laboratory experiments, the underlying mechanisms remain poorly understood. In this work, the effect of SO2 on BSOA formation from monoterpene ozonolysis was investigated. The role of stabilized Criegee biradicals (sCIs) generated from alkene ozonolysis on SO2 oxidation was examined under different humidity conditions (<5% vs. 50%). Experiments were conducted in a 1 m3 Teflon chamber. BSOA was produced from ozonolysis of a-pinene or limonene. SO2 concentration was injected at various levels ranging from 30 to 100 ppb. In all experiments, cyclohexane was used as OH scavenger and added at sufficient amount to minimize the influence from OH + monoterpenes reaction. SOA samples were collected for composition analysis. Preliminary results show that BSOA from monoterpene ozonolysis is significantly enhanced in the presence of SO2 under dry conditions. SOA enhancement increases with increasing the concentration of SO2. However, the enhancement became negligible as the conditions became more humid. Control experiments show that SO2 is consumed at timescales consistent with oxidation by sCIs indicating that gaseous SO2 interacts directly with reactive intermediates during monoterpene ozonolysis. Organosulfate formation is probed by electrospray ionization-ion mobility time of flight mass spectrometer (ESI-IMS/TOF). The effect of SO2 on ozonolysis mechanism and chemical composition will be discussed.

Evaluating the Potential Importance of Monoterpene Degradation for Global Acetone Production

NASA Astrophysics Data System (ADS)

Kelp, M. M.; Brewer, J.; Keller, C. A.; Fischer, E. V.

2015-12-01

Acetone is one of the most abundant volatile organic compounds (VOCs) in the atmosphere, but estimates of the global source of acetone vary widely. A better understanding of acetone sources is essential because acetone serves as a source of HOx in the upper troposphere and as a precursor to the NOx reservoir species peroxyacetyl nitrate (PAN). Although there are primary anthropogenic and pyrogenic sources of acetone, the dominant acetone sources are thought to be from direct biogenic emissions and photochemical production, particularly from the oxidation of iso-alkanes. Recent work suggests that the photochemical degradation of monoterpenes may also represent a significant contribution to global acetone production. We investigate that hypothesis using the GEOS-Chem chemical transport model. In this work, we calculate the emissions of eight terpene species (α-pinene, β-pinene, limonene, Δ3-carene, myrcene, sabinene, trans-β-ocimene, and an 'other monoterpenes' category which contains 34 other trace species) and couple these with upper and lower bound literature yields from species-specific chamber studies. We compare the simulated acetone distributions against in situ acetone measurements from a global suite of NASA aircraft campaigns. When simulating an upper bound on yields, the model-to-measurement comparison improves for North America at both the surface and in the upper troposphere. The inclusion of acetone production from monoterpene degradation also improves the ability of the model to reproduce observations of acetone in East Asian outflow. However, in general the addition of monoterpenes degrades the model comparison for the Southern Hemisphere.

Variations in foliar monoterpenes across the range of jack pine reveal three widespread chemotypes: implications to host expansion of invasive mountain pine beetle.

PubMed

Taft, Spencer; Najar, Ahmed; Godbout, Julie; Bousquet, Jean; Erbilgin, Nadir

2015-01-01

The secondary compounds of pines (Pinus) can strongly affect the physiology, ecology and behaviors of the bark beetles (Coleoptera: Curculionidae, Scolytinae) that feed on sub-cortical tissues of hosts. Jack pine (Pinus banksiana) has a wide natural distribution range in North America (Canada and USA) and thus variations in its secondary compounds, particularly monoterpenes, could affect the host expansion of invasive mountain pine beetle (Dendroctonus ponderosae), which has recently expanded its range into the novel jack pine boreal forest. We investigated monoterpene composition of 601 jack pine trees from natural and provenance forest stands representing 63 populations from Alberta to the Atlantic coast. Throughout its range, jack pine exhibited three chemotypes characterized by high proportions of α-pinene, β-pinene, or limonene. The frequency with which the α-pinene and β-pinene chemotypes occurred at individual sites was correlated to climatic variables, such as continentality and mean annual precipitation, as were the individual α-pinene and β-pinene concentrations. However, other monoterpenes were generally not correlated to climatic variables or geographic distribution. Finally, while the enantiomeric ratios of β-pinene and limonene remained constant across jack pine's distribution, (-):(+)-α-pinene exhibited two separate trends, thereby delineating two α-pinene phenotypes, both of which occurred across jack pine's range. These significant variations in jack pine monoterpene composition may have cascading effects on the continued eastward spread and success of D. ponderosae in the Canadian boreal forest.

Monoterpene chemical speciation in a tropical rainforest:variation with season, height, and time of dayat the Amazon Tall Tower Observatory (ATTO)

NASA Astrophysics Data System (ADS)

María Yáñez-Serrano, Ana; Nölscher, Anke Christine; Bourtsoukidis, Efstratios; Gomes Alves, Eliane; Ganzeveld, Laurens; Bonn, Boris; Wolff, Stefan; Sa, Marta; Yamasoe, Marcia; Williams, Jonathan; Andreae, Meinrat O.; Kesselmeier, Jürgen

2018-03-01

Speciated monoterpene measurements in rainforest air are scarce, but they are essential for understanding the contribution of these compounds to the overall reactivity of volatile organic compound (VOC) emissions towards the main atmospheric oxidants, such as hydroxyl radicals (OH), ozone (O3) and nitrate radicals (NO3). In this study, we present the chemical speciation of gas-phase monoterpenes measured in the tropical rainforest at the Amazon Tall Tower Observatory (ATTO, Amazonas, Brazil). Samples of VOCs were collected by two automated sampling systems positioned on a tower at 12 and 24 m height and analysed using gas chromatography-flame ionization detection. The samples were collected in October 2015, representing the dry season, and compared with previous wet and dry season studies at the site. In addition, vertical profile measurements (at 12 and 24 m) of total monoterpene mixing ratios were made using proton-transfer-reaction mass spectrometry. The results showed a distinctly different chemical speciation between day and night. For instance, α-pinene was more abundant during the day, whereas limonene was more abundant at night. Reactivity calculations showed that higher abundance does not generally imply higher reactivity. Furthermore, inter- and intra-annual results demonstrate similar chemodiversity during the dry seasons analysed. Simulations with a canopy exchange modelling system show simulated monoterpene mixing ratios that compare relatively well with the observed mixing ratios but also indicate the necessity of more experiments to enhance our understanding of in-canopy sinks of these compounds.

Evident elevation of atmospheric monoterpenes due to degradation-induced species changes in a semi-arid grassland.

PubMed

Wang, Hongjun; Wang, Xinming; Zhang, Yanli; Mu, Yujing; Han, Xingguo

2016-01-15

Biogenic volatile organic compounds (BVOCs) emitted from plants have substantial effects on atmospheric chemistry/physics and feedbacks on ecosystem function. The on-going climate change and anthropogenic disturbance have been confirmed to cause the evident degradation of grassland with shift of plant community, and hence BVOCs emissions were suspected to be altered due to the different BOVCs emission potentials of different species. In this study, we investigated BVOCs concentration above ground surface during growing season in a degraded semi-arid grassland (41°2' N-45°6' N, 113°5'-117°8') in Inner Mongolia. The observed monoterpenes' concentrations varied from 0.10 to 215.78 μg m(-3) (34.88 ± 9.73 μg m(-3) in average) across 41 sites. Compared to non-degraded grassland, concentrations of monoterpenes were about 180 times higher at the sites dominated by subshrub--Artemisia frigida, a preponderant species under drought stress and over-grazing. The biomass of A. frigida explained 51.39% of the variation of monoterpenes' concentrations. α-pinene, β-pinene and γ-terpinene dominated in the 10 determined monoterpenes, accounting for 37.72 ± 2.98%, 14.65 ± 2.55% and 10.50 ± 2.37% of the total monoterpenes concentration, respectively. Low isoprene concentrations (≤ 3.25 μg m(-3)) were found and sedge biomass contributed about 51.76% to their spatial variation. α-pinene and isoprene emissions at noon were as high as 515.53 ± 88.34 μg m(-2)h(-1) and 7606.19 ± 1073.94 μg m(-2) h(-1) in A. frigida- and sedge-dominated areas where their biomass were 236.90 g m(-2) and 72.37 g m(-2), respectively. Our results suggested that the expansion of A. frigida and sedge caused by over-grazing and climatic stresses may increase local ambient BVOCs concentration in grassland. Copyright © 2015 Elsevier B.V. All rights reserved.

Physiology of deletion mutants in the anaerobic β-myrcene degradation pathway in Castellaniella defragrans

PubMed Central

2012-01-01

Background Monoterpenes present a large and versatile group of unsaturated hydrocarbons of plant origin with widespread use in the fragrance as well as food industry. The anaerobic β-myrcene degradation pathway in Castellaniella defragrans strain 65Phen differs from well known aerobic, monooxygenase-containing pathways. The initial enzyme linalool dehydratase-isomerase ldi/LDI catalyzes the hydration of β-myrcene to (S)-(+)-linalool and its isomerization to geraniol. A high-affinity geraniol dehydrogenase geoA/GeDH and a geranial dehydrogenase geoB/GaDH contribute to the formation of geranic acid. A genetic system was for the first time applied for the betaproteobacterium to prove in vivo the relevance of the linalool dehydratase-isomerase and the geraniol dehydrogenase. In-frame deletion cassettes were introduced by conjugation and two homologous recombination events. Results Polar effects were absent in the in-frame deletion mutants C. defragrans Δldi and C. defragrans ΔgeoA. The physiological characterization of the strains demonstrated a requirement of the linalool dehydratase-isomerase for growth on acyclic monoterpenes, but not on cyclic monoterpenes. The deletion of geoA resulted in a phenotype with hampered growth rate on monoterpenes as sole carbon and energy source as well as reduced biomass yields. Enzyme assays revealed the presence of a second geraniol dehydrogenase. The deletion mutants were in trans complemented with the broad-host range expression vector pBBR1MCS-4ldi and pBBR1MCS-2geoA, restoring in both cases the wild type phenotype. Conclusions In-frame deletion mutants of genes in the anaerobic β-myrcene degradation revealed novel insights in the in vivo function. The deletion of a high-affinity geraniol dehydrogenase hampered, but did not preclude growth on monoterpenes. A second geraniol dehydrogenase activity was present that contributes to the β-myrcene degradation pathway. Growth on cyclic monoterpenes independent of the initial enzyme LDI suggests the presence of a second enzyme system activating unsaturated hydrocarbons. PMID:22947208

Seasonal and interannual variations in whole-ecosystem BVOC emissions from a subtropical plantation in China

NASA Astrophysics Data System (ADS)

Bai, Jianhui; Guenther, Alex; Turnipseed, Andrew; Duhl, Tiffany; Greenberg, James

2017-07-01

Measurements of BVOC emissions, ozone concentration and environmental parameters were carried out from May 2013 to January 2016 in a subtropical Pinus plantation in China. Isoprene and monoterpene emissions were measured using a relaxed eddy accumulation (REA) system and a gradient technique on an above-canopy tower. In 2013, isoprene comprised 21.2% of total terpenoid emissions, while α-pinene, camphene, β-pinene and limonene constituting 51.5%, 2.4%, 9.1%, and 13.0% of total emissions, respectively. Monoterpenes together were the dominant VOCs measured contributing 71.6%. α-pinene, camphene, β-pinene and limonene constituted 67.7%, 3.2%, 11.9%, 17.2% of total monoterpene emissions. Isoprene and monoterpene emissions displayed strong diurnal variations, with lower emissions in the morning and late evening, and the highest emissions around noon. BVOC peak emissions typically occurred a few hours after the noon PAR peak. Isoprene and monoterpene emissions varied with season and were the highest in summer, contributing more than half of the total annual emission, and the lowest emissions were in winter. Evident interannual variations of isoprene, monoterpenes and total BVOCs were observed. Compared to 2013, annual BVOC emissions decreased in 2015, associated with decreases of PAR, Temperature, water vapor, and an increase of all substances in gas, liquid and solid phases in the atmospheric column (e.g., S/Q, the ratio of solar scattered radiation to global radiation). Ozone concentration showed clear diurnal variation with PAR, higher around noon and lower in the early morning and late evening. Generally, there were no evident correlations between ozone concentrations and BVOC emissions, or the vertical gradients of ozone concentrations and BVOC concentrations. Under all sky conditions (including cloudy skies), no strong correlations at a high confidence level or very similar variation patterns were observed between any two following parameters, BVOC emissions, PAR, temperature, water vapor, and S/Q. The major factors controlling BVOC emissions were PAR and temperature but biomass burning smoke and phenology (pine florescence) may also play a role. The mean emission factors at standard conditions determined using the MEGAN model emission algorithms and empirical model of BVOC emissions were 0.71 and 1.19 mg m-2 h-1 for isoprene and 1.39 and 1.65 mg m-2 h-1 for total monoterpenes, respectively.

Geographical Variation in the Terpene Composition of the Leaf Oil of Douglas Fir,

DTIC Science & Technology

The two forms of Douglas fir, Pseudotsuga menziesii var. menziesii and var. glauca, differ quite considerably with regard to the monoterpenes of...their leaf oils. Several chemical races, differing quantitatively in certain monoterpenes , appear to exist in each variety and the leaf oil composition seems to be particularly useful in classifying intermediate forms. (Author)

Monoterpene composition of pine species and hybrids...some preliminary findings

Treesearch

Richard H. Smith

1967-01-01

Xylem resin samples, obtained from 72 freshly cut pine stumps at the Institute of Forest Genetics, Placerville, Calif., were analyzed for monoterpenes by gasliquid chromatography. Very little or no qualitative or quantitative variation could be attributed to annual ring, time of securing sample, and period of storage of sample up to 1 year. The 34 hybrids sampled...

Acaricidal efficacies of Lippia gracilis essential oil and its phytochemicals against organophosphate-resistant and susceptible strains of Rhipicephalus (Boophilus) microplus

USDA-ARS?s Scientific Manuscript database

Plant-derived natural products can serve as an alternative to synthetic compounds for control of ticks of veterinary and medical importance. Lippia gracilis is an aromatic plant that produces essential oil with high content of carvacrol and thymol monoterpenes. These monoterpenes have high acaricida...

Characterization of a monoterpene synthase from Paeonia lactiflora producing α-pinene as its single product.

PubMed

Ma, Xiaohui; Guo, Juan; Ma, Ying; Jin, Baolong; Zhan, Zhilai; Yuan, Yuan; Huang, Luqi

2016-07-01

To identify a terpene synthase that catalyzes the conversion of geranyl pyrophosphate (GPP) to α-pinene and is involved in the biosynthesis of paeoniflorin. Two new terpene synthase genes were isolated from the transcriptome data of Peaonia lactiflora. Phylogenetic analysis and sequence characterization revealed that one gene, named PlPIN, encoded a monoterpene synthase that might be involved in the biosynthesis of paeoniflorin. In vitro enzyme assay showed that, in contrast to most monoterpene synthases, PlPIN encoded an α-pinene synthase which converted GPP into α-pinene as a single product. This newly identified α-pinene synthase could be used for improving paeoniflorin accumulation by metabolic engineering or for producing α-pinene via synthetic biology.

Monoterpene emissions from a Ponderosa Pine forest. Does age matter?

NASA Astrophysics Data System (ADS)

Madronich, M. B.; Guenther, A. B.; Wessman, C. A.

2011-12-01

Determining the emissions rate of biogenic volatile organic carbon (BVOC) from plants is a challenge. Biological variability makes it difficult to assess accurately those emissions rates. It is known that photosynthetic active radiation (PAR), temperature, nutrients as well as the biology of the plant affect emissions. However, less is known about the variability of the emissions with respect to the life cycle of the plants. This study is focusing on the difference of monoterpene emission rates from mature Ponderosa Pine trees and saplings in the field. Preliminary calculations show that there is a significant difference between total monoterpene emissions in mature trees (0.24±0.04 μgC/gdwh) and saplings (0.37±0.02 μgC/gdwh).

Synthesis and Biological Evaluation of Novel Phosphatidylcholine Analogues Containing Monoterpene Acids as Potent Antiproliferative Agents

PubMed Central

Gliszczyńska, Anna; Niezgoda, Natalia; Gładkowski, Witold; Czarnecka, Marta; Świtalska, Marta; Wietrzyk, Joanna

2016-01-01

The synthesis of novel phosphatidylcholines with geranic and citronellic acids in sn-1 and sn-2 positions is described. The structured phospholipids were obtained in high yields (59–87%) and evaluated in vitro for their cytotoxic activity against several cancer cell lines of different origin: MV4-11, A-549, MCF-7, LOVO, LOVO/DX, HepG2 and also towards non-cancer cell line BALB/3T3 (normal mice fibroblasts). The phosphatidylcholines modified with monoterpene acid showed a significantly higher antiproliferative activity than free monoterpene acids. The highest activity was observed for the terpene-phospholipids containing the isoprenoid acids in sn-1 position of phosphatidylcholine and palmitic acid in sn-2. PMID:27310666

Above Canopy Emissions of Isoprene and Monoterpenes from a Southeast Asian Tropical Forest

NASA Astrophysics Data System (ADS)

Baker, B.; Johnson, C.; Cai, Z.; Guenther, A.; Greenberg, J.; Bai, J.; Li, Q.

2003-12-01

Fluxes of isoprene were measured using the eddy covariance technique and an ozone chemiluminescence isoprene sensor above a secondary tropical forest/rubber tree plantation located in the Xishuangbanna region of southern China during the wet and dry seasons. Fluxes of monoterpenes were inferred from ambient boundary layer concentrations (wet season) and from relaxed eddy accumulation measurements (dry season). Isoprene emissions were comparable to what has been observed from other tropical forests in Africa and South America. In this forest, monoterpene emissions were much higher during the wet season due to the senescence of the rubber trees during the dry season. These flux measurements represent the first ecosystem level flux measurements reported from Southeast Asian tropical forests.

Identification and Characterization of the Iridoid Synthase Involved in Oleuropein Biosynthesis in Olive (Olea europaea) Fruits.

PubMed

Alagna, Fiammetta; Geu-Flores, Fernando; Kries, Hajo; Panara, Francesco; Baldoni, Luciana; O'Connor, Sarah E; Osbourn, Anne

2016-03-11

The secoiridoids are the main class of specialized metabolites present in olive (Olea europaea L.) fruit. In particular, the secoiridoid oleuropein strongly influences olive oil quality because of its bitterness, which is a desirable trait. In addition, oleuropein possesses a wide range of pharmacological properties, including antioxidant, anti-inflammatory, and anti-cancer activities. In accordance, obtaining high oleuropein varieties is a main goal of molecular breeding programs. Here we use a transcriptomic approach to identify candidate genes belonging to the secoiridoid pathway in olive. From these candidates, we have functionally characterized the olive homologue of iridoid synthase (OeISY), an unusual terpene cyclase that couples an NAD (P)H-dependent 1,4-reduction step with a subsequent cyclization, and we provide evidence that OeISY likely generates the monoterpene scaffold of oleuropein in olive fruits. OeISY, the first pathway gene characterized for this type of secoiridoid, is a potential target for breeding programs in a high value secoiridoid-accumulating species. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Cyclic monoterpene mediated modulations of Arabidopsis thaliana phenotype

PubMed Central

Kriegs, Bettina; Jansen, Marcus; Hahn, Katrin; Peisker, Helga; Šamajová, Olga; Beck, Martina; Braun, Silvia; Ulbrich, Andreas; Baluška, František

2010-01-01

Monoterpenes at high atmospheric concentrations are strong growth inhibitors in allelopathic interactions. Effects depend on dose, molecular structure of the monoterpene and on the species of the receiver plant. Stomata are among the first targets affected by camphor and menthol. Previously, it could be demonstrated that the compounds induce swelling of the protoplasts, prevent stomatal closure and enhance transpiration. In this study, we show that the block of stomatal closure is accompanied by changes to the cytoskeleton, which has a direct role in stomatal movements. Although MPK3 (MAP3 kinase) and ABF4 gene expressions are induced within six hours, stomatal closure is prevented. In contrast to ABF4, ABF2 (both transcription factors) is not induced. MPK3 and ABF4 both encode for proteins involved in the process of stomatal closure. The expression of PEPCase, an enzyme important for stomatal opening, is downregulated. The leaves develop stress symptoms, mirrored by transient changes in the expression profile of additional genes: lipoxygenase 2 (LOX2), CER5, CER6 (both important for wax production) and RD29B (an ABA inducible stress protein). Non-invasive methods showed a fast response of the plant to camphor fumigations both in a rapid decrease of the quantum yield and in the relative growth rate. Repeated exposures to the monoterpenes resulted finally in growth reduction and a stress related change in the phenotype. It is proposed that high concentrations or repeated exposure to monoterpenes led to irreversible damages, whereas low concentrations or short-term fumigations may have the potential to strengthen the plant fitness. PMID:20484979

Monoterpene isolated from the essential oil of Trachyspermum ammi is cytotoxic to multidrug-resistant Pseudomonas aeruginosa and Staphylococcus aureus strains.

PubMed

Hosseinkhani, Faride; Jabalameli, Fereshteh; Banar, Maryam; Abdellahi, Nafiseh; Taherikalani, Morovat; Leeuwen, Willem B van; Emaneini, Mohammad

2016-04-01

The aim of this study was to determine whether an herbal extract containing monoterpene exhibited activity against multidrug-resistant Staphylococcus aureus and Pseudomonas aeruginosa isolated from clinical infection samples. The essential oil of Trachyspermum ammi (L.) Sprague ex Turrill (Apiaceae) fruit was extracted by hydrodistillation. Fruit residues were treated with hydrochloric acid and re-hydrodistilled to obtain volatile compounds. Compounds in the distilled oil were identified using gas-chromatography (GC) and GC-mass spectrometry (MS). The antibiotic susceptibility of all bacterial isolates was analyzed using both the disc diffusion method and determination of the minimum inhibitory concentration (MIC). The sensitivity of antibiotic-resistant isolates to essential oil was also determined by using the disc diffusion method and MIC determination. Of 26 clinical isolates, 92% were multidrug-resistant (MDR). Aromatic monoterpenes (thymol, paracymene, and gamma-terpinene) were the major (90%) components of the oil. Growth of S. aureus strains was successfully inhibited by the oil, with an inhibitory zone diameter (IZD) between 30-60mm and MIC <0.02μL/mL. The oil had no antimicrobial activity against clinical isolates of P. aeruginosa; rather, it prevented pigment production in these isolates. This study revealed that the essential oil of Trachyspermum ammi, which contains monoterpene, has good antibacterial potency. Monoterpenes could thus be incorporated into antimicrobial ointment formulas in order to treat highly drug-resistant S. aureus infections. Our findings also underscore the utility of research on natural products in order to combat bacterial multidrug resistance.

Monoterpene concentration in Douglas-fir in relation to geographic location and resistance to attack by the Douglas-fir beetle

Treesearch

J.W. Hanover; M.M. Furniss

1966-01-01

The concentration of monoterpenes in Pinus monticola Dougl. has been shown to be genetically controlled (Hanover, in preparation). Genetic control of terpene concentration has been implied, also, from analyses of parents or interspecies hybrids in other species (Bannister et al. 1959; Williams and Bannister 1962; Smith 1964, and Forde 1964). Evidence...

A blend of ethanol and (−)-α-pinene were highly attractive to native siricid woodwasps (Siricidae, Siricinae) infesting conifers of the Sierra Nevada and the Allegheny Mountains

Treesearch

Nadir Erbilgin; Jack D. Stein; Robert E. Acciavatti; Nancy E. Gillette; Sylvia R. Mori; Kristi Bischel; Jonathan A. Cale; Carline R. Carvalho; David L. Wood

2017-01-01

Woodwasps in Sirex and related genera are well-represented in North American conifer forests, but the chemical ecology of native woodwasps is limited to a few studies demonstrating their attraction to volatile host tree compounds, primarily monoterpene hydrocarbons and monoterpene alcohols. Thus, we...

Geographic variation in shortleaf pine (Pinus echinata Mill.) - cortical monoterpenes

Treesearch

R.C. Schmidtling; J.H. Myszewski; C.E. McDaniel

2005-01-01

Cortical monoterpenes were assayed in bud tissue from 16 Southwide Southern Pine Seed Source Study (SSPSS) sources and from 6 seed orchard sources fiom across the natural range of the species, to examine geogaphic variation in shortleaf pine. Spruce pine and pond pine were also sampled. The results show geographic differences in all of the major terpenes. There was no...

Xylem monoterpenes of some hard pines of Western North America: three studies

Treesearch

Richard H. Smith

1982-01-01

Monoterpene composition was studied in a number of hard pine species and results were compared with earlier work. (1) Intratree measurements showed strong constancy of composition in both single-stemmed and forked trees of ponderosa, Jeffrey, Coulter, and Jeffrey x ponderosa pines. In grafts of these and other pines, the scion influenced the root stock, but not the...

Beta-cyclodextrin enhanced gastroprotective effect of (-)-linalool, a monoterpene present in rosewood essential oil, in gastric lesion models.

PubMed

da Silva, Francilene Vieira; de Barros Fernandes, Hélio; Oliveira, Irisdalva Sousa; Viana, Ana Flávia Seraine Custódio; da Costa, Douglas Soares; Lopes, Miriam Teresa Paz; de Lira, Kamila Lopes; Quintans-Júnior, Lucindo José; de Sousa, Adriano Antunes; de Cássia Meneses Oliveira, Rita

2016-11-01

(-)-Linalool is a monoterpene constituent of many essential oils. This particular monoterpene has both anti-inflammatory and antimicrobial activity. Moreover, this compound has been shown to be antinociceptive. However, the poor chemical stability and short half-life prevents the clinical application of (-)-linalool and many other essential oils. Important to the topic of this study, β-cyclodextrin (β-CD) has been used to increase the solubility, stability, and pharmacological effects of numerous lipophilic compounds in vivo. In this study, the gastroprotective activities of (-)-linalool (LIN) and linalool incorporated into inclusion complex containing β-cyclodextrin (LIN-βCD) were evaluated using models of acute and chronic gastric ulcers in rodents. LIN and LIN-βCD showed strong gastroprotective activity (p < 0.001). The LIN-βCD complex revealed that the gastroprotective effect was significantly improved compared with LIN uncomplexed, suggesting that this improvement is related to increased solubility and stability. Taking together the potentiation of the antioxidant profile of this monoterpene, our results suggest that β-CD may represent an important tool for improved gastroprotective activity of (-)-linalool and other water-insoluble compounds.

The Effect of Resin and Monoterpenes on Spore Germination and Growth in Fusarium circinatum.

PubMed

Slinski, S L; Zakharov, F; Gordon, T R

2015-01-01

Resin obtained from Pinus radiata and five monoterpene components of resin (limonene, α-pinene, β-pinene, camphene, and myrcene) were tested to determine their effects on mycelial growth and germination and survival of spores of Fusarium circinatum, the cause of pitch canker in pine, and F. temperatum, which is interfertile with F. circinatum but not pathogenic to pine. Averaged across all treatments, F. temperatum sustained the greatest reduction in radial growth (16.9±0.02% of control). The greatest reduction in dry weight also occurred in F. temperatum (11.7±0.01% of control), and all isolates of F. circinatum were significantly less affected (P<0.05). Spore germination rates in a saturated atmosphere of monoterpenes were relatively high for all tested isolates but, when placed in direct contact with resin, spore survival was significantly greater for F. circinatum than for F. temperatum. Our results are consistent with the hypothesis that greater tolerance of resin is one factor distinguishing F. circinatum from the nonpathogenic F. temperatum. However, differential tolerance of monoterpene components of resin is not sufficient to explain the observed variation in virulence to pine in F. circinatum.

Monoterpenes as Perspective to Chronic Pain Management: A Systematic Review.

PubMed

Gouveia, Daniele Nascimento; Pina, Lícia Tairiny Santos; Rabelo, Thallita Kelly; da Rocha Santos, Wagner Barbosa; Quintans, Jullyana S S; Guimarães, Adriana Gibara

2017-07-11

Individuals with chronic diseases have persistent pain as the main symptom, which can often reduce their life quality and functional capacity. The suffering of patients results from the interaction of aversive perception of pain with physical disability, social and family isolation, financial worries and fear of mutilation and death. As an individual and subjective phenomenon that involves many complex aspects, chronic pain should be evaluated and treated in its various components. Several drugs are currently used, but besides the high cost, they have side effects that are harmful to patients. Therefore, there is the need to search for new options for pain relief. Natural products as monoterpenes have been the target of many researchers. This systematic review aimed to briefly summarize the knowledge of the analgesic potential of monoterpenes facing chronic pain. After a search in PubMed, Lilacs, Scopus and Cochrane, 27 articles were selected, which described the analgesic potential of 16 monoterpenes for relief of chronic pain. After analyzing the data, it can be suggested that these compounds are strong candidates for the treatment of painful states. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Cloning of a sesquiterpene synthase from Lavandula x intermedia glandular trichomes.

PubMed

Sarker, Lukman S; Demissie, Zerihun A; Mahmoud, Soheil S

2013-11-01

The essential oil (EO) of Lavandula is dominated by monoterpenes, but can also contain small amounts of sesquiterpenes, depending on species and environmental conditions. For example, the sesquiterpene 9-epi-caryophyllene can make up to 8 % of the EO in a few species, including those commercially propagated for EO production. Here, we report the cloning and functional characterization of 9-epi-caryophyllene synthase (LiCPS) from the glandular trichomes of Lavandula x intermedia, cv. Grosso. The 1,617 bp open reading frame of LiCPS, which did not encode a transit peptide, was expressed in Escherichia coli and the recombinant protein purified by Ni-NTA agarose affinity chromatography. The ca. 60 kDa recombinant protein specifically converted farnesyl diphosphate to 9-epi-caryophyllene. LiCPS also produced a few monoterpenes when assayed with the monoterpene precursor geranyl diphosphate (GPP), but--unlike most monoterpene synthases--was not able to derive detectable amounts of any products from the cis isomer of GPP, neryl diphosphate. The LiCPS transcripts accumulated in developing L. x intermedia flowers and were highly enriched in glandular trichomes, but were not detected in leaves suggesting that the transcriptional expression of this gene is spatially and developmentally regulated.

Sulfate turpentine: a resource of tick repellent compounds.

PubMed

Schubert, Fredrik; Pålsson, Katinka; Santangelo, Ellen; Borg-Karlson, Anna-Karin

2017-07-01

Compounds with tick (Ixodes ricinus) repellent properties were isolated from sulfate turpentine consisting of Norway spruce (80%) and Scots pine (20%) from southern Sweden. The turpentine was divided into two fractions by distillation under reduced pressure resulting in one monoterpene hydrocarbon fraction and a residual containing higher boiling terpenoids. The monoterpene fraction was further oxidized with SeO 2 to obtain oxygenated monoterpenes with potential tick repellent properties. The oxidized fraction and the high boiling distillation residual were each separated by medium pressure liquid chromatography. The fractions were tested for tick repellency and the compounds in those with highest tick repellency were identified by GC-MS. The fractions with highest repellency contained, mainly (-)-borneol, and mixtures of (+)- and (-)-1-terpineol and terpinen-4-ol. The enantiomers of borneol showed similar tick repellent properties.

Selective removal of monoterpenes from bergamot oil by inclusion in deoxycholic acid.

PubMed

Fantin, Giancarlo; Fogagnolo, Marco; Maietti, Silvia; Rossetti, Stefano

2010-05-12

A new approach for removing monoterpenes (MTs) from bergamot oil by selective inclusion in deoxycholic acid (DCA) is proposed. The inclusion process is very efficient, the included fraction being composed mainly of limonene (71.7%) and gamma-terpinene (19.8%). On the other hand, the deterpenated bergamot oil fraction showed for the linalool and linalyl acetate derivatives significant increases from 16.6 and 21.4% to 18.3 and 42.2%, respectively. The major advantages of this methodology are its simplicity, the mild conditions employed, and the quantitative recovery of both host (DCA) and guest (monoterpenes) compounds. Differential scanning calorimetry (DSC), thermal gravimetry (TG), powder X-ray diffractometry (XRPD), infrared spectroscopy (IR), and proton magnetic resonance ((1)H NMR) analysis were used to investigate and characterize the inclusion compounds.

Two new monoterpene glucosides from Xanthium strumarium subsp. sibiricum with their anti-inflammatory activity.

PubMed

Jiang, Hai; Xing, Xudong; Yan, Meiling; Guo, Xinyue; Yang, Lin; Yang, Liu

2018-06-01

Two new monoterpene glucosides: xanmonoter A (1) and xanmonoter B (2) were isolated from Xanthium strumarium. Their structures were elucidated on the basis of 1D and 2D NMR, MS and CD analysis. Compounds 1 and 2 were tested for their anti-inflammatory activity with IC 50 values of 17.4, 22.1 μM, respectively.

EMISSION OF 2-METHYL-3-BUTEN-2-OL BY PINES: A POTENTIALLY LARGE NATURAL SOURCE OF REACTIVE CARBON TO THE ATMOSPHERE

EPA Science Inventory

High rates of emission of 2-methyl-3-buten-2-ol (MBO) were measured from needles of several pine species. Emissions of MBO in the light were 1 to 2 orders of magnitude higher than emissions of monoterpenes and, in contrast to monoterpene emissions from pines, were absent in the d...

Xylem monoterpenes of pines: distribution, variation, genetics, function

Treesearch

Richard Smith

2000-01-01

The monoterpenes of about 16,000 xylem resin samples of pine (Pinus) speciesand hybrids—largely from the western United States—were analyzed in this long-term study of the resistance of pines to attack by bark beetles (Coleoptera:Scolytidae), with special emphasis on resistance to the western pine beetle(Dendroctonus brevicomis). The samples were analyzed by gas liquid...

Monoterpene Unknowns Identified Using IR, [to the first power]H-NMR, [to the thirteenth power]C-NMR, DEPT, COSY, and HETCOR

ERIC Educational Resources Information Center

Alty, Lisa T.

2005-01-01

A study identifies a compound from a set of monoterpenes using infrared (IR) and one-dimensional (1D) nuclear magnetic resonance (NMR) techniques. After identifying the unknown, each carbon and proton signal can be interpreted and assigned to the structure using the information in the two-dimensional (2D) NMR spectra, correlation spectroscopy…

Dose-Dependent and Species-Specific Responses of Pine Bark Beetles (Coeoptera: Scolytidae) to Monoterpenes in Association with Phermones

Treesearch

Daniel R. Miller; John H. Borden

2000-01-01

Monoterpenes affected the attraction of three sympatric species of bark beetles (Coleoptera: Scolytidae) to pheromone-baited multiple-funnel traps in stands of lodgepole pine. Catches of Ips pini(Say) in traps baited with its pheromone, ipsdienol, were directly related to the release rates of 3-carene, ß-pphellandrene, and ß-pinene. Catches of

SOA Formation Potential of Emissions from Soil and Leaf Litter

NASA Astrophysics Data System (ADS)

Faiola, C. L.; Vanderschelden, G. S.; Wen, M.; Cobos, D. R.; Jobson, B. T.; VanReken, T. M.

2013-12-01

In the United States, emissions of volatile organic compounds (VOCs) from natural sources exceed all anthropogenic sources combined. VOCs participate in oxidative chemistry in the atmosphere and impact the concentrations of ozone and particulate material. The formation of secondary organic aerosol (SOA) is particularly complex and is frequently underestimated using state-of-the-art modeling techniques. We present findings that suggest emissions of important SOA precursors from soil and leaf litter are higher than current inventories would suggest, particularly under conditions typical of Fall and Spring. Soil and leaf litter samples were collected at Big Meadow Creek from the University of Idaho Experimental Forest. The dominant tree species in this area of the forest are ponderosa pine, Douglas-fir, and western larch. Samples were transported to the laboratory and housed within a 0.9 cubic meter Teflon dynamic chamber where VOC emissions were continuously monitored with a GC-FID-MS and PTR-MS. Aerosol was generated from soil and leaf litter emissions by pumping the emissions into a 7 cubic meter Teflon aerosol growth chamber where they were oxidized with ozone in the absence of light. The evolution of particle microphysical and chemical characteristics was monitored over the following eight hours. Particle size distribution and chemical composition were measured with a SMPS and HR-ToF-AMS respectively. Monoterpenes dominated the emission profile with emission rates up to 283 micrograms carbon per meter squared per hour. The dominant monoterpenes emitted were beta-pinene, alpha-pinene, and delta-3-carene in descending order. The composition of the SOA produced was similar to biogenic SOA formed from oxidation of ponderosa pine emissions and alpha-pinene. Measured soil/litter monoterpene emission rates were compared with modeled canopy emissions. Results suggest that during fall and spring when tree emissions are lower, monoterpene emissions within forests may be dominated by soil/litter emissions--soil/litter monoterpene emissions in spring could contribute up to 63% of total forest emissions. If this is the case, a significant portion of total forest monoterpene emission rates would be controlled by factors that affect soil/litter emissions rather than factors that affect plant emissions.

Chemical composition and phytotoxicity of volatile essential oil from intact and fallen leaves of Eucalyptus citriodora.

PubMed

Batish, Daizy R; Singh, Harminder P; Setia, Nidhi; Kaur, Shalinder; Kohli, Ravinder K

2006-01-01

A total of 23 volatile constituents was identified and characterized by GC and GC-MS in the volatile essential oil extracted from intact (juvenile and adult) and fallen (senescent and leaf litter) leaves of lemon-scented eucalyptus (Eucalyptus citriodora Hook.). The leaves differed in their pigment, water and protein content, and C/N ratio. The oils were, in general, monoterpenoid in nature with 18 monoterpenes and 5 sesquiterpenes. However, a great variability in the amount of essential oils and their individual constituents was observed in different leaf tissues. The amount was maximum in the senescent leaves collected from the floor of the tree closely followed by that from juvenile leaves. In all, 19 constituents were identified in oil from juvenile and senescent leaves compared to 23 in adult leaves and 20 in leaf litter, respectively. Citronellal, a characteristic monoterpene of the oil reported hitherto was found to be more (77-78%) in the juvenile and senescent leaves compared to 48 and 54%, respectively, in the adult leaves and leaf litter. In the adult leaves, however, the content of citronellol--another important monoterpene-- was very high (21.9%) compared to other leaf types (7.8-12.2%). Essential oil and its two major monoterpenes viz. citronellal and citronellol were tested for their phytotoxicity against two weeds (Amaranthus viridis and Echinochloa crus-galli) and two crops (Triticum aestivum and Oryza sativa) under laboratory conditions. A difference in the phytotoxicity, measured in terms of seedling length and dry weight, of oil from different leaves and major monoterpenes was observed. Oil from adult leaves was found to be most phytotoxic although it occurs in smaller amount (on unit weight basis). The different toxicity of different oil types was due to the relative amount of individual monoterpenes present in the oil, their solubility and interactive action. The study concludes that oil from senescent and juvenile leaves being rich in citronellal could be used as commercial source of citronellal whereas that from adult leaves for weed management programmes as it was the most phytotoxic.

Supercritical CO2 Extraction of Lavandula angustifolia Mill. Flowers: Optimisation of Oxygenated Monoterpenes, Coumarin and Herniarin Content.

PubMed

Jerković, Igor; Molnar, Maja; Vidović, Senka; Vladić, Jelena; Jokić, Stela

2017-11-01

Lavandula angustifolia is good source of oxygenated monoterpenes containing coumarins as well, which are all soluble in supercritical CO 2 (SC-CO 2 ). The study objective is to investigate SC-CO 2 extraction parameters on: the total yield; GC-MS profile of the extracts; relative content of oxygenated monoterpenes; the amount of coumarin and herniarin; and to determine optimal SC-CO 2 extraction conditions by response surface methodology (RSM). SC-CO 2 extraction was performed under different pressure, temperature and CO 2 flow rate determined by Box-Behnken design (BBD). The sample mass and the extraction time were kept constant. The chemical profiles and relative content of oxygenated monoterpenes (as coumarin equivalents, CE) were determined by GC-MS. Coumarin and herniarin concentrations were dosed by HPLC. SC-CO 2 extracts contained linalool (57.4-217.9 mg CE/100 g), camphor (10.6-154.4 mg CE/100 g), borneol (6.2-99.9 mg CE/100 g), 1,8-cineole (5.0-70.4 mg CE/100 g), linalyl acetate (86.1-267.9 mg CE/100 g), coumarin (0.95-18.16 mg/100 g), and herniarin (0.95-13.63 mg/100 g). The interaction between the pressure and CO 2 flow rate as well as between the temperature and CO 2 flow rate showed statistically significant influence on the extraction yield. Applying BBD, the optimum extraction conditions for higher monoterpenes and lower coumarin content were at 10 MPa, 41°C and CO 2 flow rate 2.3 kg/h, and at 30 MPa, 50°C and CO 2 flow rate 3 kg/h for higher monoterpenes and coumarin content. SC-CO 2 extraction is a viable technique for obtaining lavender extracts with desirable flavour components. The second-order model based on BBD predicts the results for SC-CO 2 extraction quite satisfactorily. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

For a Limited Time Only? How Long Can Trees Maintain Enhanced Chemical Defenses During Pre-Mortality Heat and Drought Stress

NASA Astrophysics Data System (ADS)

Trowbridge, A.; Adams, H. D.; Cook, A. A.; Hofland, M.; Weaver, D.; McDowell, N. G.

2016-12-01

The relative contribution of forest pests to climate and drought-induced tree mortality is complex and largely absent from current process-based models. Recent efforts have focused on developing frameworks to integrate insects into models of tree mortality, citing the need for a better mechanistic understanding of the links between stress-induced tree physiology and insect behavior and population dynamics. Secondary plant metabolites (SPMs) play a critical role in plant resistance and their synthesis and mobilization are coupled to carbon assimilation, hydraulic conductivity, and herbivory itself. Insect host choice also depends in part on behavioral responses to host SPMs. Monoterpenes are the dominant SPMs in conifers, and while high concentrations of monoterpenes are toxic to bark beetles, lower concentrations serve as precursors for a number of aggregation pheromones. Thus, the impact of monoterpenes on bark beetle behavior is complex and is impacted by environmental effects on primary metabolism including heat and drought stress. Here, we quantify the dynamics of piñon pine monoterpene chemistry as a function of predicted and prolonged drought stress implemented at the SUrvival MOrtality (SUMO) experimental site at the Los Alamos National Laboratory, NM, USA. In both woody and needle tissues, total monoterpene concentrations in ambient trees were not significantly different from those observed in trees exposed to heat stress, but drought trees showed higher total concentration while heat+drought trees were observed to have the highest levels (2 fold increase over ambient). These treatment effects were sustained over a two-year period despite seasonal variation in tree water status; however, total concentration in the xylem and phloem were closely coupled to tree water potential and treatment effects took longer to manifest relative to the needles. Individual compounds responded differently to the treatments, suggesting cyclase-level enzyme regulation, while α-pinene - an important bark beetle aggregate pheromone precursor - dominated total monoterpene concentration dynamics. These results have important implications for piñon-bark beetle interactions during drought and provide a missing link between drought-induced physiology and insect behavior.

Ice core records of monoterpene- and isoprene-SOA tracers from Aurora Peak in Alaska since 1660s: Implication for climate change variability in the North Pacific Rim

NASA Astrophysics Data System (ADS)

Pokhrel, Ambarish; Kawamura, Kimitaka; Ono, Kaori; Seki, Osamu; Fu, Pingqing; Matoba, Sumio; Shiraiwa, Takayuki

2016-04-01

Monoterpene and isoprene secondary organic aerosol (SOA) tracers are reported for the first time in an Alaskan ice core to better understand the biological source strength before and after the industrial revolution in the Northern Hemisphere. We found significantly high concentrations of monoterpene- and isoprene-SOA tracers (e.g., pinic, pinonic, and 2-methylglyceric acids, 2-methylthreitol and 2-methylerythritol) in the ice core, which show historical trends with good correlation to each other since 1660s. They show positive correlations with sugar compounds (e.g., mannitol, fructose, glucose, inositol and sucrose), and anti-correlations with α-dicarbonyls (glyoxal and methylglyoxal) and fatty acids (e.g., C18:1) in the same ice core. These results suggest similar sources and transport pathways for monoterpene- and isoprene-SOA tracers. In addition, we found that concentrations of C5-alkene triols (e.g., 3-methyl-2,3,4-trihydroxy-1-butene, cis-2-methyl 1,3,4-trihydroxy-1-butene and trans-2-methyl-1,3,4-trihydroxy-1-butene) in the ice core have increased after the Great Pacific Climate Shift (late 1970s). They show positive correlations with α-dicarbonyls and fatty acids (e.g., C18:1) in the ice core, suggesting that enhanced oceanic emissions of biogenic organic compounds through the marine boundary layer are recorded in the ice core from Alaska. Photochemical oxidation process for these monoterpene- and isoprene-/sesquiterpene-SOA tracers are suggested to be linked with the periodicity of multi-decadal climate oscillations and retreat of sea ice in the Northern Hemisphere.

Reversal of efflux mediated antifungal resistance underlies synergistic activity of two monoterpenes with fluconazole.

PubMed

Ahmad, Aijaz; Khan, Amber; Manzoor, Nikhat

2013-01-23

Thymol (THY) and carvacrol (CARV), the principal chemical components of thyme oil have long been known for their wide use in medicine due to antimicrobial and disinfectant properties. This study, however, draws attention to a possible synergistic antifungal effect of these monoterpenes with azole antimycotic-fluconazole. Resistance to azoles in Candida albicans involves over-expression of efflux-pump genes MDR1, CDR1, CDR2 or mutations and over-expression of target gene ERG11. The inhibition of drug efflux pumps is considered a feasible strategy to overcome clinical antifungal resistance. To put forward this approach, we investigated the combination effects of these monoterpenes and FLC against 38 clinically obtained FLC-sensitive, and eleven FLC-resistant Candida isolates. Synergism was observed with combinations of THY-FLC and CARV-FLC evaluated by checkerboard microdilution method and nature of the interactions was calculated by FICI. In addition, antifungal activity was assessed using agar-diffusion and time-kill curves. The drug efflux activity was determined using two dyes, Rhodamine6G (R6G) and fluorescent Hoechst 33342. No significant differences were observed in dye uptakes between FLC-susceptible and resistant isolates, incubated in glucose free buffer. However, a significantly higher efflux was recorded in FLC-resistant isolates when glucose was added. Both monoterpenes inhibited efflux by 70-90%, showing their high potency to block drug transporter pumps. Significant differences, in the expression levels of CDR1 and MDR1, induced by monoterpenes revealed reversal of FLC-resistance. The selectively fungicidal characteristics and ability to restore FLC susceptibility in resistant isolates signify a promising candidature of THY and CARV as antifungal agents in combinational treatments for candidiasis. Copyright © 2012 Elsevier B.V. All rights reserved.

Observations and models of emissions of volatile terpenoid compounds from needles of ponderosa pine trees growing in situ: control by light, temperature and stomatal conductance.

PubMed

Harley, Peter; Eller, Allyson; Guenther, Alex; Monson, Russell K

2014-09-01

Terpenoid emissions from ponderosa pine (Pinus ponderosa subsp. scopulorum) were measured in Colorado, USA over two growing seasons to evaluate the role of incident light, needle temperature, and stomatal conductance in controlling emissions of 2-methyl-3-buten-2-ol (MBO) and several monoterpenes. MBO was the dominant daylight terpenoid emission, comprising on average 87% of the total flux, and diurnal variations were largely determined by light and temperature. During daytime, oxygenated monoterpenes (especially linalool) comprised up to 75% of the total monoterpenoid flux from needles. A significant fraction of monoterpenoid emissions was dependent on light and 13CO2 labeling studies confirmed de novo production. Thus, modeling of monoterpenoid emissions required a hybrid model in which a significant fraction of emissions was dependent on both light and temperature, while the remainder was dependent on temperature alone. Experiments in which stomata were forced to close using abscisic acid demonstrated that MBO and a large fraction of the monoterpene flux, presumably linalool, could be limited at the scale of seconds to minutes by stomatal conductance. Using a previously published model of terpenoid emissions, which explicitly accounts for the physicochemical properties of emitted compounds, we were able to simulate these observed stomatal effects, whether induced experimentally or arising under naturally fluctuation conditions of temperature and light. This study shows unequivocally that, under naturally occurring field conditions, de novo light-dependent monoterpenes comprise a significant fraction of emissions in ponderosa pine. Differences between the monoterpene composition of ambient air and needle emissions imply a significant non-needle emission source enriched in Δ-3-carene.

Improving monoterpene geraniol production through geranyl diphosphate synthesis regulation in Saccharomyces cerevisiae.

PubMed

Zhao, Jianzhi; Bao, Xiaoming; Li, Chen; Shen, Yu; Hou, Jin

2016-05-01

Monoterpenes have wide applications in the food, cosmetics, and medicine industries and have recently received increased attention as advanced biofuels. However, compared with sesquiterpenes, monoterpene production is still lagging in Saccharomyces cerevisiae. In this study, geraniol, a valuable acyclic monoterpene alcohol, was synthesized in S. cerevisiae. We evaluated three geraniol synthases in S. cerevisiae, and the geraniol synthase Valeriana officinalis (tVoGES), which lacked a plastid-targeting peptide, yielded the highest geraniol production. To improve geraniol production, synthesis of the precursor geranyl diphosphate (GPP) was regulated by comparing three specific GPP synthase genes derived from different plants and the endogenous farnesyl diphosphate synthase gene variants ERG20 (G) (ERG20 (K197G) ) and ERG20 (WW) (ERG20 (F96W-N127W) ), and controlling endogenous ERG20 expression, coupled with increasing the expression of the mevalonate pathway by co-overexpressing IDI1, tHMG1, and UPC2-1. The results showed that overexpressing ERG20 (WW) and strengthening the mevalonate pathway significantly improved geraniol production, while expressing heterologous GPP synthase genes or down-regulating endogenous ERG20 expression did not show positive effect. In addition, we constructed an Erg20p(F96W-N127W)-tVoGES fusion protein, and geraniol production reached 66.2 mg/L after optimizing the amino acid linker and the order of the proteins. The best strain yielded 293 mg/L geraniol in a fed-batch cultivation, a sevenfold improvement over the highest titer previously reported in an engineered S. cerevisiae strain. Finally, we showed that the toxicity of geraniol limited its production. The platform developed here can be readily used to synthesize other monoterpenes.

Conifer Monoterpene Chemistry during an Outbreak Enhances Consumption and Immune Response of an Eruptive Folivore.

PubMed

Trowbridge, Amy M; Bowers, M Deane; Monson, Russell K

2016-12-01

Changes in the chemical composition of plant defense compounds during herbivory can impact herbivore resource allocation patterns and thereby herbivore survival, growth, and immune response against endoparasitoid infection. Few studies have investigated folivore responses to changes in plant chemistry that occur under outbreak conditions in mature conifer systems. Using data from an earlier observational field study, we carried out laboratory bioassays to test how variation in monoterpenes in piñon pine trees (Pinus edulis, Pinaceae) during an outbreak affects growth, consumption, and immune response of a specialist herbivore, the Southwestern tiger moth (Lophocampa ingens, Arctiidae). Larvae were fed on artificial diets containing four monoterpenes at concentrations that mimicked those observed in undamaged and herbivore-damaged trees in situ during an outbreak. Damaged trees contained 30% lower total monoterpene concentrations, likely reflecting volatile losses as observed in a previous field study Trowbridge et al. (Ecology 95:1591-1603, Trowbridge et al. 2014). Herbivores reared on diets mimicking terpene concentrations in the needles of damaged trees exhibited an approximately 60% increase in consumption relative to larvae reared on diets characteristic of trees without herbivore damage. Higher consumption was accompanied by a 40% increase in immune response with no change in growth rate. These observations suggest preferential resource allocation towards immunity and/or a strong genetic component that determines growth under these conditions. These outcomes, which favor the herbivore, point to: (i) a potential positive feedback mechanism that may increase L. ingens's chance of escaping parasitism during the early phases of an outbreak; and (ii) the important role of monoterpenes in mediating conifer-folivore interactions specifically for P. edulis, which has suffered large-scale drought-induced mortality events exacerbated by the presence of insects.

Seasonal influence on gene expression of monoterpene synthases in Salvia officinalis (Lamiaceae).

PubMed

Grausgruber-Gröger, Sabine; Schmiderer, Corinna; Steinborn, Ralf; Novak, Johannes

2012-03-01

Garden sage (Salvia officinalis L., Lamiaceae) is one of the most important medicinal and aromatic plants and possesses antioxidant, antimicrobial, spasmolytic, astringent, antihidrotic and specific sensorial properties. The essential oil of the plant, formed mainly in very young leaves, is in part responsible for these activities. It is mainly composed of the monoterpenes 1,8-cineole, α- and β-thujone and camphor synthesized by the 1,8-cineole synthase, the (+)-sabinene synthase and the (+)-bornyl diphosphate synthase, respectively, and is produced and stored in epidermal glands. In this study, the seasonal influence on the formation of the main monoterpenes in young, still expanding leaves of field-grown sage plants was studied in two cultivars at the level of mRNA expression, analyzed by qRT-PCR, and at the level of end-products, analyzed by gas chromatography. All monoterpene synthases and monoterpenes were significantly influenced by cultivar and season. 1,8-Cineole synthase and its end product 1,8-cineole remained constant until August and then decreased slightly. The thujones increased steadily during the vegetative period. The transcript level of their corresponding terpene synthase, however, showed its maximum in the middle of the vegetative period and declined afterwards. Camphor remained constant until August and then declined, exactly correlated with the mRNA level of the corresponding terpene synthase. In summary, terpene synthase mRNA expression and respective end product levels were concordant in the case of 1,8-cineole (r=0.51 and 0.67 for the two cultivars, respectively; p<0.05) and camphor (r=0.75 and 0.82; p<0.05) indicating basically transcriptional control, but discordant for α-/β-thujone (r=-0.05 and 0.42; p=0.87 and 0.13, respectively). Copyright © 2011 Elsevier GmbH. All rights reserved.

Susceptibility to Verticillium longisporum is linked to monoterpene production by TPS23/27 in Arabidopsis.

PubMed

Roos, Jonas; Bejai, Sarosh; Mozūraitis, Raimondas; Dixelius, Christina

2015-02-01

The fungus Verticillium longisporum is a soil-borne plant pathogen of increasing economic importance, and information on plant responses to it is limited. To identify the genes and components involved in the early stages of infection, transcripts in roots of V. longisporum-challenged Arabidopsis Col-0 and the susceptible NON-RACE SPECIFIC DISEASE RESISTANCE 1 (ndr1-1) mutant were compared using ATH1 gene chips. The analysis revealed altered transcript levels of several terpene biosynthesis genes, including the monoterpene synthase TPS23/27. When transgenic 35S:TPS23/27 and TPS23/27-amiRNA plants were monitored the over-expresser line showed enhanced fungal colonization whereas the silenced genotype was indistinguishable from Col-0. Transcript analysis of terpene biosynthesis genes suggested that only the TPS23/27 pathway is affected in the two transgenic genotypes. To confirm changes in monoterpene production, emitted volatiles were determined using solid-phase microextraction and gas chromatography-mass spectrometry. Levels of all identified TPS23/27 monoterpene products were significantly altered in the transgenic plants. A stimulatory effect on conidial germination and hyphal growth of V. longisporum was also seen in co-cultivation with 35S:TPS23/27 plants and upon exposure to 1,8-cineole, the main product of TPS23/27. Methyl jasmonate treatments of myc2-1 and myc2-2 mutants and analysis of TPS23/27:uidA in the myc2-2 background suggested a dependence on jasmonic acid mediated by the transcription factor MYC2. Taken together, our results show that TPS23/27-produced monoterpenes stimulate germination and subsequent invasion of V. longisporum in Arabidopsis roots. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Soil microorganisms alleviate the allelochemical effects of a thyme monoterpene on the performance of an associated grass species.

PubMed

Ehlers, Bodil K

2011-01-01

Plant allelochemicals released into the soil can significantly impact the performance of associated plant species thereby affecting their competitive ability. Soil microbes can potentially affect the interaction between plant and plant chemicals by degrading the allelochemicals. However, most often plant-plant chemical interactions are studied using filter paper bioassays examining the pair-wise interaction between a plant and a plant chemical, not taking into account the potential role of soil microorganisms. To explore if the allelopathic effects on a grass by the common thyme monoterpene "carvacrol" are affected by soil microorganisms. Seedlings of the grass Agrostis capillaris originating from 3 different thyme sites were raised in the greenhouse. Seedlings were grown under four different soil treatments in a 2*2 fully factorial experiment. The monoterpene carvacrol was either added to standard greenhouse soil or left out, and soil was either sterilized (no soil microorganisms) or not (soil microorganisms present in soil). The presence of carvacrol in the soil strongly increased mortality of Agrostis plants, and this increase was highest on sterile soil. Plant biomass was reduced on soil amended with carvacrol, but only when the soil was also sterilized. Plants originating from sites where thyme produces essential oils containing mostly carvacrol had higher survival on soil treated with that monoterpene than plants originating from a site where thyme produced different types of terpenes, suggesting an adaptive response to the locally occurring terpene. The study shows that presence of soil microorganisms can alleviate the negative effect of a common thyme monoterpene on the performance of an associated plant species, emphasizing the role of soil microbes in modulating plant-plant chemical interactions.

Acaricidal efficacies of Lippia gracilis essential oil and its phytochemicals against organophosphate-resistant and susceptible strains of Rhipicephalus (Boophilus) microplus.

PubMed

Costa-Júnior, Livio M; Miller, Robert J; Alves, Péricles B; Blank, Arie F; Li, Andrew Y; Pérez de León, Adalberto A

2016-09-15

Plant-derived natural products can serve as an alternative to synthetic compounds for control of ticks of veterinary and medical importance. Lippia gracilis is an aromatic plant that produces essential oil with high content of carvacrol and thymol monoterpenes. These monoterpenes have high acaricidal activity against Rhipicephalus (Boophilus) microplus. However, there are no studies that show efficacy differences of essential oils between susceptible and organophosphate resistant strains of R. (B.) microplus. The aim of the present study was to compare acaricidal effects of essential oils extracted from two different genotypes of L. gracilis and the main monoterpenes on larvae of both susceptible and organophosphate resistant R. (B.) microplus larvae. The efficacy of the essential oil of two genotypes of L. gracilis (106 and 201) and their monoterpenes carvacrol and thymol was measured using the larval immersion test on coumaphos-resistant and susceptible strains of R. (B.) microplus. Lethal concentrations were calculated using GraphPad Prism 6.0. Chemical analysis was performed by GC-MS and FID. Thymol and carvacrol were observed to be major constituents in 106 and 201L. gracilis genotype essential oils, respectively. Essential oils of both genotypes were more effective against organophosphate-resistant tick strain than susceptible tick strain. Carvacrol was 3.2 times more toxic to organophosphate resistant strain than to susceptible strain. Thymol was equally toxic to resistant and susceptible tick strains. The significantly higher efficacy monoterpene carvacrol against resistant ticks may lead to development of new natural product acaricide formulations for use to control organophosphate resistant R. (B.) microplus populations. Copyright © 2016 Elsevier B.V. All rights reserved.

Induction of Terpene Biosynthesis in Berries of Microvine Transformed with VvDXS1 Alleles.

PubMed

Dalla Costa, Lorenza; Emanuelli, Francesco; Trenti, Massimiliano; Moreno-Sanz, Paula; Lorenzi, Silvia; Coller, Emanuela; Moser, Sergio; Slaghenaufi, Davide; Cestaro, Alessandro; Larcher, Roberto; Gribaudo, Ivana; Costantini, Laura; Malnoy, Mickael; Grando, M Stella

2017-01-01

Terpenoids, especially monoterpenes, are major aroma-impact compounds in grape and wine. Previous studies highlighted a key regulatory role for grapevine 1-deoxy-D-xylulose 5-phosphate synthase 1 (VvDXS1), the first enzyme of the methylerythritol phosphate pathway for isoprenoid precursor biosynthesis. Here, the parallel analysis of VvDXS1 genotype and terpene concentration in a germplasm collection demonstrated that VvDXS1 sequence has a very high predictive value for the accumulation of monoterpenes and also has an influence on sesquiterpene levels. A metabolic engineering approach was applied by expressing distinct VvDXS1 alleles in the grapevine model system "microvine" and assessing the effects on downstream pathways at transcriptional and metabolic level in different organs and fruit developmental stages. The underlying goal was to investigate two potential perturbation mechanisms, the former based on a significant over-expression of the wild-type (neutral) VvDXS1 allele and the latter on the ex-novo expression of an enzyme with increased catalytic efficiency from the mutated (muscat) VvDXS1 allele. The integration of the two VvDXS1 alleles in distinct microvine lines was found to alter the expression of several terpenoid biosynthetic genes, as assayed through an ad hoc developed TaqMan array based on cDNA libraries of four aromatic cultivars. In particular, enhanced transcription of monoterpene, sesquiterpene and carotenoid pathway genes was observed. The accumulation of monoterpenes in ripe berries was higher in the transformed microvines compared to control plants. This effect is predominantly attributed to the improved activity of the VvDXS1 enzyme coded by the muscat allele, whereas the up-regulation of VvDXS1 plays a secondary role in the increase of monoterpenes.

Soil Microorganisms Alleviate the Allelochemical Effects of a Thyme Monoterpene on the Performance of an Associated Grass Species

PubMed Central

Ehlers, Bodil K.

2011-01-01

Background Plant allelochemicals released into the soil can significantly impact the performance of associated plant species thereby affecting their competitive ability. Soil microbes can potentially affect the interaction between plant and plant chemicals by degrading the allelochemicals. However, most often plant-plant chemical interactions are studied using filter paper bioassays examining the pair-wise interaction between a plant and a plant chemical, not taking into account the potential role of soil microorganisms. Methodology/Principal findings To explore if the allelopathic effects on a grass by the common thyme monoterpene “carvacrol” are affected by soil microorganisms. Seedlings of the grass Agrostis capillaris originating from 3 different thyme sites were raised in the greenhouse. Seedlings were grown under four different soil treatments in a 2*2 fully factorial experiment. The monoterpene carvacrol was either added to standard greenhouse soil or left out, and soil was either sterilized (no soil microorganisms) or not (soil microorganisms present in soil). The presence of carvacrol in the soil strongly increased mortality of Agrostis plants, and this increase was highest on sterile soil. Plant biomass was reduced on soil amended with carvacrol, but only when the soil was also sterilized. Plants originating from sites where thyme produces essential oils containing mostly carvacrol had higher survival on soil treated with that monoterpene than plants originating from a site where thyme produced different types of terpenes, suggesting an adaptive response to the locally occurring terpene. Conclusions/Significance The study shows that presence of soil microorganisms can alleviate the negative effect of a common thyme monoterpene on the performance of an associated plant species, emphasizing the role of soil microbes in modulating plant-plant chemical interactions. PMID:22125596

Seasonal variations in VOC emission rates from gorse (Ulex europaeus)

NASA Astrophysics Data System (ADS)

Boissard, C.; Cao, X.-L.; Juan, C.-Y.; Hewitt, C. N.; Gallagher, M.

Seasonal variations of biogenic volatile organic compound (VOC) emission rates and standardised emission factors from gorse (Ulex europaeus) have been measured at two sites in the United Kingdom, from October 1994 to September 1995, within temperature and PAR conditions ranging from 3 to 34°C and 10-1300 μmol m-2 s-1, respectively. Isoprene was the dominant emitted compound with a relative composition fluctuating from 7% of the total VOC (winter) to 97% (late summer). The monoterpenes α-pinene, camphene, sabinene, β-pinene, myrcene, limonene, trans-ocimene and γ-terpinene were also emitted, with α-pinene being the dominant monoterpene during most the year. Trans-ocimene represented 33-66% of the total monoterpene during the hottest months from June to September. VOC emissions were found to be accurately predicted using existing algorithms. Standard (normalised) emission factors of VOCs from gorse were calculated using experimental parameters measured during the experiment and found to fluctuate with season, from 13.3±2.1 to 0.1±0.1 μg C (g dwt)-1 h-1 in August 1995 and January 1995, respectively, for isoprene, and from 2.5±0.2 to 0.4±0.2 μg C (g dwt)-1 h-1 in July and November 1995, respectively, for total monoterpenes. No simple clear relation was found to allow prediction of these seasonal variations with respect to temperature and light intensity. The effects of using inappropriate algorithms to derive VOC fluxes from gorse were assessed for isoprene and monoterpenes. Although on an annual basis the discrepancies are not significant, monthly estimation of isoprene were found to be overestimated by more than a factor of 50 during wintertime when the seasonality of emission factors is not considered.

Observations and models of emissions of volatile terpenoid compounds from needles of ponderosa pine trees growing in situ: control by light, temperature and stomatal conductance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harley, Peter; Eller, Allyson; Guenther, Alex

Terpenoid emissions from ponderosa pine (Pinus ponderosa subsp. scopulorum) were measured in Colorado, USA over two growing seasons to evaluate the role of incident light, needle temperature and stomatal conductance in controlling emissions of 2-methyl-3-buten-2-ol (MBO) and several monoterpenes. MBO was the dominant daylight terpenoid emission, comprising on average 87% of the total flux, and diurnal variations were largely determined by light and temperature. During daytime, oxygenated monoterpenes (especially linalool) comprised up to 75% of the total monoterpenoid flux from needles. A significant fraction of monoterpenoid emissions was light dependent and 13CO2 labeling studies confirmed de novo production. Thus, modelingmore » of monoterpenoid emissions required a hybrid model in which a significant fraction of emissions was dependent on both light and temperature, while the remainder was dependent on temperature alone. Experiments in which stomata were forced to close using abscisic acid demonstrated that MBO and a large fraction of the monoterpene flux, presumably linalool, could be limited at the scale of seconds to minutes by stomatal conductance. Using a previously published model of terpenoid emissions which explicitly accounts for the physico-chemical properties of emitted compounds, we are able to simulate these observed stomatal effects, whether induced through experimentation or arising under naturally fluctuation conditions of temperature and light. This study shows unequivocally that, under naturally occurring field conditions, de novo light dependent monoterpenes can comprise a large fraction of emissions. Differences between the monoterpene composition of ambient air and needle emissions imply a significant non-needle emission source enriched in Δ-3-carene.« less

Chemical composition and biological activities of the essential oil of Skimmia laureola leaves.

PubMed

Barkatullah; Ibrar, Muhammad; Muhammad, Naveed; De Feo, Vincenzo

2015-03-16

The composition of the essential oil from leaves of Skimmia laureola was determined by GC and GC-MS. Twenty-eight components were identified, accounting for 93.9% of the total oil. The oil is mainly composed of monoterpenes (93.5%), of which monoterpene hydrocarbons and oxygenated monoterpenes represent 11.0% and 82.5%, respectively. Sesquiterpenes constitute only 0.3% of the total oil. Linalyl acetate is the main component (50.5%), with linalool (13.1%), geranyl acetate (8.5%) and cis-p-menth-2-en-1-ol (6.2%) as other principal constituents. The essential oil showed a significant antispasmodic activity, in a dose range of 0.03-10 mg/mL. The essential oil also possesses antibacterial and antifungal activities against some pathogenic strains. The phytotoxic and cytotoxic activities were also assessed.

Profiling of the Terpene Metabolome in Carrot Fruits of Wild ( Daucus carota L. ssp. carota) Accessions and Characterization of a Geraniol Synthase.

PubMed

Yahyaa, Mosaab; Ibdah, Muhammad; Marzouk, Sally; Ibdah, Mwafaq

2018-03-14

Fruits from wild carrot ( Daucus carota L. ssp. carota) have been used for medicinal purposes since ancient times. The oil of its seeds, with their abundant monoterpenes and sesquiterpenes, has drawn attention in recent years because of its potential pharmaceutical application. A combined chemical, biochemical, and molecular study was conducted to evaluate the differential accumulation of terpene volatiles in carrot fruits of wild accessions. This work reports a similarity-based cloning strategy identification and functional characterization of one carrot monoterpene terpene synthase, WtDcTPS1. Recombinant WtDcTPS1 protein produces mainly geraniol, the predominant monoterpene in carrot seeds of wild accession 23727. The results suggest a role for the WtDcTPS1 gene in the biosynthesis of carrot fruit aroma and flavor compounds.

Monoterpenes are the largest source of summertime organic aerosol in the southeastern United States

DOE PAGES

Zhang, Haofei; Yee, Lindsay D.; Lee, Ben H.; ...

2018-02-12

The chemical complexity of atmospheric organic aerosol (OA) has caused substantial uncertainties in understanding its origins and environmental impacts. Here, we provide constraints on OA origins through compositional characterization with molecular-level details. Our results suggest that secondary OA (SOA) from monoterpene oxidation accounts for approximately half of summertime fine OA in Centreville, AL, a forested area in the southeastern United States influenced by anthropogenic pollution. We find that different chemical processes involving nitrogen oxides, during days and nights, play a central role in determining the mass of monoterpene SOA produced. These findings elucidate the strong anthropogenic–biogenic interaction affecting ambient aerosolmore » in the southeastern United States and point out the importance of reducing anthropogenic emissions, especially under a changing climate, where biogenic emissions will likely keep increasing.« less

Monoterpenes are the largest source of summertime organic aerosol in the southeastern United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Haofei; Yee, Lindsay D.; Lee, Ben H.

The chemical complexity of atmospheric organic aerosol (OA) has caused substantial uncertainties in understanding its origins and environmental impacts. Here, we provide constraints on OA origins through compositional characterization with molecular-level details. Our results suggest that secondary OA (SOA) from monoterpene oxidation accounts for approximately half of summertime fine OA in Centreville, AL, a forested area in the southeastern United States influenced by anthropogenic pollution. We find that different chemical processes involving nitrogen oxides, during days and nights, play a central role in determining the mass of monoterpene SOA produced. These findings elucidate the strong anthropogenic–biogenic interaction affecting ambient aerosolmore » in the southeastern United States and point out the importance of reducing anthropogenic emissions, especially under a changing climate, where biogenic emissions will likely keep increasing.« less

A monoterpene glucoside and three megastigmane glycosides from Juniperus communis var. depressa.

PubMed

Nakanishi, Tsutomu; Iida, Naoki; Inatomi, Yuka; Murata, Hiroko; Inada, Akira; Murata, Jin; Lang, Frank A; Iinuma, Munekazu; Tanaka, Toshiyuki; Sakagami, Yoshikazu

2005-07-01

A new monoterpene glucoside (1) and three new natural megastigmane glycosides (2-4) were isolated along with a known megastigmane glucoside (5) from twigs with leaves of Juniperus communis var. depressa (Cupressaceae) collected in Oregon, U.S.A., and their structures were determined on the basis of spectral and chemical evidence. In addition, the antibacterial activities of the isolated components against Helicobacter pylori were also investigated.

Effects of diterpene acids on components of a conifer bark beetle–fungal interaction: tolerance by Ips pini and sensitivity by its associate Ophiostoma ips

Treesearch

Brian J. Kopper; Barbara L. Illman; Philip J. Kersten; Kier D. Klepzig; Kenneth F. Raffa

2005-01-01

Conifer resin and phloem tissue contain several phytochemical groups,composed primarily of monoterpenes,diterpene acids, and stilbene phenolics. The effects of monoterpenes and phenolics on stem-colonizing bark beetles and their associated microorganisms have been studied to some extent, but the roles of diterpene acids are largely unknown. Diterpene acids are known to...

Effects of diterpene acids on components of a conifer bark beetle-fungal interaction : tolerance by Ips pini and sensitivity by its associate Ophiostoma ips

Treesearch

Brian J. Kopper; Barbara L. Illman; Philip J. Kersten; Kier D. Klepzig; Kenneth F. Raffa

2005-01-01

Conifer resin and phloem tissue contain several phytochemical groups, composed primarily of monoterpenes, diterpene acids, and stilbene phenolics. The effects of monoterpenes and phenolics on stem-colonizing bark beetles and their associated microorganisms have been studied to some extent, but the roles of diterpene acids are largely unknown. Diterpene acids are known...

Onset of photosynthesis in spring speeds up monoterpene synthesis and leads to emission bursts

PubMed Central

Porcar‐Castell, A.; Atherton, J.; Kolari, P.; Pohja, T.; Hari, P.; Nikinmaa, E.; PetÄJÄ, T.; Bäck, J.

2015-01-01

Abstract Emissions of biogenic volatile organic compounds (BVOC) by boreal evergreen trees have strong seasonality, with low emission rates during photosynthetically inactive winter and increasing rates towards summer. Yet, the regulation of this seasonality remains unclear. We measured in situ monoterpene emissions from Scots pine shoots during several spring periods and analysed their dynamics in connection with the spring recovery of photosynthesis. We found high emission peaks caused by enhanced monoterpene synthesis consistently during every spring period (monoterpene emission bursts, MEB). The timing of the MEBs varied relatively little between the spring periods. The timing of the MEBs showed good agreement with the photosynthetic spring recovery, which was studied with simultaneous measurements of chlorophyll fluorescence, CO 2 exchange and a simple, temperature history‐based proxy for state of photosynthetic acclimation, S. We conclude that the MEBs were related to the early stages of photosynthetic recovery, when the efficiency of photosynthetic carbon reactions is still low whereas the light harvesting machinery actively absorbs light energy. This suggests that the MEBs may serve a protective functional role for the foliage during this critical transitory state and that these high emission peaks may contribute to atmospheric chemistry in the boreal forest in springtime. PMID:25850935

Synthesis of 'cineole cassette' monoterpenes in Nicotiana section Alatae: gene isolation, expression, functional characterization and phylogenetic analysis.

PubMed

Fähnrich, Anke; Brosemann, Anne; Teske, Laura; Neumann, Madeleine; Piechulla, Birgit

2012-08-01

The scent bouquets of flowers of Nicotiana species, particularly those of section Alatae, are rich in monoterpenes, including 1,8-cineole, limonene, β-myrcene, α- and β-pinene, sabinene, and α-terpineol. New terpene synthase genes were isolated from flowers of Nicotiana bonariensis, N. forgetiana, N. longiflora, and N. mutabilis. The recombinant enzymes synthesize simultaneously the characteristic 'cineole cassette' monoterpenes with 1,8-cineole as the dominant volatile product. Interestingly, amino acid sequence comparison and phylogenetic tree construction clustered the newly isolated cineole synthases (CIN) of section Alatae together with the catalytically similar CIN of N. suaveolens of section Suaveolentes, thus suggesting a common ancestor. These CIN genes of N. bonariensis, N. forgetiana, N. longiflora, and N. mutabilis are distinct from the terpineol synthases (TERs) of the taxonomically related N. alata and N. langsdorfii (both Alatae), thus indicating gene diversification of monoterpene synthases in section Alatae. Furthermore, the presence of CINs in species of the American section Alatae supports the hypothesis that one parent of the Australian section Suaveolentes was a member of the present section Alatae. Amino acid sequences of the Nicotiana CINs and TERs were compared to identify relevant amino acids of the cyclization reaction from α-terpineol to 1,8-cineole.

High-resolution MALDI mass spectrometry imaging of gallotannins and monoterpene glucosides in the root of Paeonia lactiflora

NASA Astrophysics Data System (ADS)

Li, Bin; Bhandari, Dhaka Ram; Römpp, Andreas; Spengler, Bernhard

2016-10-01

High-resolution atmospheric-pressure scanning microprobe matrix-assisted laser desorption/ionization mass spectrometry imaging (AP-SMALDI MSI) at 10 μm pixel size was performed to unravel the spatio-chemical distribution of major secondary metabolites in the root of Paeonia lactiflora. The spatial distributions of two major classes of bioactive components, gallotannins and monoterpene glucosides, were investigated and visualized at the cellular level in tissue sections of P. lactiflora roots. Accordingly, other primary and secondary metabolites were imaged, including amino acids, carbohydrates, lipids and monoterpenes, indicating the capability of untargeted localization of metabolites by using high-resolution MSI platform. The employed AP-SMALDI MSI system provides significant technological advancement in the visualization of individual molecular species at the cellular level. In contrast to previous histochemical studies of tannins using unspecific staining reagents, individual gallotannin species were accurately localized and unequivocally discriminated from other phenolic components in the root tissues. High-quality ion images were obtained, providing significant clues for understanding the biosynthetic pathway of gallotannins and monoterpene glucosides and possibly helping to decipher the role of tannins in xylem cells differentiation and in the defence mechanisms of plants, as well as to investigate the interrelationship between tannins and lignins.

High-resolution MALDI mass spectrometry imaging of gallotannins and monoterpene glucosides in the root of Paeonia lactiflora.

PubMed

Li, Bin; Bhandari, Dhaka Ram; Römpp, Andreas; Spengler, Bernhard

2016-10-31

High-resolution atmospheric-pressure scanning microprobe matrix-assisted laser desorption/ionization mass spectrometry imaging (AP-SMALDI MSI) at 10 μm pixel size was performed to unravel the spatio-chemical distribution of major secondary metabolites in the root of Paeonia lactiflora. The spatial distributions of two major classes of bioactive components, gallotannins and monoterpene glucosides, were investigated and visualized at the cellular level in tissue sections of P. lactiflora roots. Accordingly, other primary and secondary metabolites were imaged, including amino acids, carbohydrates, lipids and monoterpenes, indicating the capability of untargeted localization of metabolites by using high-resolution MSI platform. The employed AP-SMALDI MSI system provides significant technological advancement in the visualization of individual molecular species at the cellular level. In contrast to previous histochemical studies of tannins using unspecific staining reagents, individual gallotannin species were accurately localized and unequivocally discriminated from other phenolic components in the root tissues. High-quality ion images were obtained, providing significant clues for understanding the biosynthetic pathway of gallotannins and monoterpene glucosides and possibly helping to decipher the role of tannins in xylem cells differentiation and in the defence mechanisms of plants, as well as to investigate the interrelationship between tannins and lignins.

Direct suppression of a rice bacterial blight (Xanthomonas oryzae pv. oryzae) by monoterpene (S)-limonene.

PubMed

Lee, Gun Woong; Chung, Moon-Soo; Kang, Mihyung; Chung, Byung Yeoup; Lee, Sungbeom

2016-05-01

Rice bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is a severe disease of rice plants. Upon pathogen infection, rice biosynthesizes phytoalexins, including diterpenoids such as momilactones, phytocassanes, and oryzalexins. However, information on headspace volatiles in response to Xoo infection is limited. We have examined headspace volatile terpenes, induced by the infection of Xoo, and investigated their biological roles in the rice plant. Monoterpenes α-thujene, α-pinene, sabinene, myrcene, α-terpene, and (S)-limonene and sesquiterpenes cyclosativene, α-copaene, and β-elemene were detected from 1-week-old Xoo-infected rice seedlings, by solid-phase microextraction-gas chromatography-mass spectrometry. All monoterpenes were constitutively released from rice seedlings before Xoo infection. However, (S)-limonene emission was further elicited after exposure of the seedlings to Xoo in coincidence with upregulation of limonene synthase gene (OsTPS20) transcripts. Only the stereospecific (S)-limonene [and not (R)-limonene or other monoterpenes] severely inhibited Xoo growth, as confirmed by disc diffusion and liquid culture assays. Rice seedlings showed suppressed pathogenic symptoms suggestive of resistance to Xoo infection after foliar treatment with (S)-limonene. Collectively, our findings suggest that (S)-limonene is a volatile phytoanticipin, which plays a significant role in suppressing Xoo growth in rice seedlings.

Onset of photosynthesis in spring speeds up monoterpene synthesis and leads to emission bursts.

PubMed

Aalto, J; Porcar-Castell, A; Atherton, J; Kolari, P; Pohja, T; Hari, P; Nikinmaa, E; Petäjä, T; Bäck, J

2015-11-01

Emissions of biogenic volatile organic compounds (BVOC) by boreal evergreen trees have strong seasonality, with low emission rates during photosynthetically inactive winter and increasing rates towards summer. Yet, the regulation of this seasonality remains unclear. We measured in situ monoterpene emissions from Scots pine shoots during several spring periods and analysed their dynamics in connection with the spring recovery of photosynthesis. We found high emission peaks caused by enhanced monoterpene synthesis consistently during every spring period (monoterpene emission bursts, MEB). The timing of the MEBs varied relatively little between the spring periods. The timing of the MEBs showed good agreement with the photosynthetic spring recovery, which was studied with simultaneous measurements of chlorophyll fluorescence, CO2 exchange and a simple, temperature history-based proxy for state of photosynthetic acclimation, S. We conclude that the MEBs were related to the early stages of photosynthetic recovery, when the efficiency of photosynthetic carbon reactions is still low whereas the light harvesting machinery actively absorbs light energy. This suggests that the MEBs may serve a protective functional role for the foliage during this critical transitory state and that these high emission peaks may contribute to atmospheric chemistry in the boreal forest in springtime. © 2015 John Wiley & Sons Ltd.

Essential Oil Composition and Volatile Profile of Seven Helichrysum Species Grown in Italy.

PubMed

Giovanelli, Silvia; De Leo, Marinella; Cervelli, Claudio; Ruffoni, Barbara; Ciccarelli, Daniela; Pistelli, Luisa

2018-03-06

Helichrysum genus consists of about 600 species widespread throughout the world, especially in South Africa and in the Mediterranean area. In this study the aroma profile (HS-SPME) and the EO compositions of seven Helichrysum species (H. cymosum, H. odoratissimum, H. petiolare, H. fontanesii, H. saxatile, H. sanguineum, and H. tenax) were evaluated. All the plants were grown in Italy under the same growth conditions. The volatile constituents, particularly monoterpenes, depended by the plant's genotype and ecological adaptation. This study represents the first headspace evaluation on the selected plants and the results evidenced that monoterpenes represented the main class of constituents in five of the seven species analysed (from 59.2% to 95.0%). The higher content in sesquiterpene hydrocarbons was observed in the Mediterranean species of H. sanguineum (68.0%). Only H. saxatile showed relative similar abundance of monoterpenes and sesquiterpene hydrocarbons. The essential oil composition of the majority of examined species are characterised by high percentage of sesquiterpenes (especially β-caryophyllene and δ-cadinene) ranging from 51.3% to 92.0%, except for H. cymosum, H. tenax, and H. sanguineum leaves where monoterpenes predominated (from 51.7% to 74.7%). © 2018 Wiley-VHCA AG, Zurich, Switzerland.

The evolution of floral scent and insect chemical communication.

PubMed

Schiestl, Florian P

2010-05-01

Plants have evolved a range of strategies to manipulate the behaviour of their insect partners. One powerful strategy is to produce signals that already have a role in the animals' own communication systems. To investigate to what extent the evolution of floral scents is correlated with chemical communication in insects, I analyse the occurrence, commonness, and evolutionary patterns of the 71 most common 'floral' volatile organic compounds (VOCs) in 96 plant families and 87 insect families. I found an overlap of 87% in VOCs produced by plants and insects. 'Floral' monoterpenes showed strong positive correlation in commonness between plants (both gymnosperms and angiosperms) and herbivores, whereas the commonness of 'floral' aromatics was positively correlated between angiosperms and both pollinators and herbivores. According to a multivariate regression analysis the commonness of 'floral' aromatics was best explained by their commonness in pollinators, whereas monoterpenes were best explained by herbivores. Among pollinator orders, aromatics were significantly more common in Lepidoptera than in Hymenoptera, whereas monoterpenes showed no difference among the two orders. Collectively, these patterns suggest that plants and insects converge in overall patterns of volatile production, both for attraction and defence. Monoterpenes seem to have evolved primarily for defence under selection by herbivores, whereas aromatics evolved signalling functions in angiosperms, primarily for pollinator attraction.

Analysis of enantiomeric and non-enantiomeric monoterpenes in plant emissions using portable dynamic air sampling/solid-phase microextraction (PDAS-SPME) and chiral gas chromatography/mass spectrometry

NASA Astrophysics Data System (ADS)

Yassaa, Noureddine; Williams, Jonathan

A portable dynamic air sampler (PDAS) using a porous polymer solid-phase microextraction (SPME) fibre has been validated for the determination of biogenic enantiomeric and non-enantiomeric monoterpenes in air. These compounds were adsorbed in the field, and then thermally desorbed at 250 °C in a gas chromatograph injector port connected via a β-cyclodextrin capillary separating column to a mass spectrometer. The optimized method has been applied for investigating the emissions of enantiomeric monoterpenes from Pseudotsuga menziesii (Douglas-fir), Rosmarinus officinalis (Rosemary) and Lavandula lanata (Lavender) which were selected as representative of coniferous trees and aromatic plants, respectively. The enantiomers of α-pinene, sabinene, camphene, δ-3-carene, β-pinene, limonene, β-phellandrene, 4-carene and camphor were successfully determined in the emissions from the three plants. While Douglas-fir showed a strong predominance toward (-)-enantiomers, Rosemary and Lavender demonstrated a large variation in enantiomeric distribution of monoterpenes. The simplicity, rapidity and sensitivity of dynamic sampling with porous polymer coated SPME fibres coupled to chiral capillary gas chromatography/mass spectrometry (GC/MS) makes this method potentially useful for in-field investigations of atmosphere-biosphere interactions and studies of optically explicit atmospheric chemistry.

[Analysis of variation of monoterpene glycosides and polyhydroxy compounds in paeoniae radix alba during preliminary processing].

PubMed

Xu, Yuan; Liu, Pei; Yan, Hui; Qian, Da-Wei; Duan, Jin-Ao

2014-05-01

To investigate variation of monoterpene glycosides and polyhydroxy compounds in Paeoniae Radix Alba dried by different processing methods. The crude drugs were processed sequentially as washed, removed the head, tail, fine roots and dried. The samples were divided into eight groups by whether peeled and decocted or not. Each group was dried by 35, 45, 60, 80,100, 120 degrees C, sun-dried and shade-dried. HPLC-PDA method was adopted to determine the content of monoterpene glycosides compounds (paeoniflorin alibiflorin, oxypaeoniflorin and benzoylpaeoniflorin), polyhydroxy compounds (catechin and gallic acid) and benzoic acid. Chromatographic conditions: Phecad C18 column (250 mm x 4.6 mm, 5 microm). A principal component analysis (PCA) method was used subsequently to get data processed. The retained content of seven constituents decreased in those peeled crude drug, and after cooked, monoterpene glycosides and polyhydroxy compounds increased while the benzoic acid decreased. It was believed that rele- vant enzymes were inactivated while being cooked so that drying temperature showed little influence on the biotransformation. Contents of effective ingredients in Paeoniae Radix Alba are influenced by drying processing. The preferable method shows to be that crude drug should be cooked before being peeled and dried. As a matter of processing convtence, it is suggested to be peeled and sliced before being dried.

Global Emissions of Terpenoid VOCs from Terrestrial Vegetation in the Last Millennium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acosta Navarro, J. C.; Smolander, S.; Struthers, H.

2014-06-16

We investigated the millennial variability of global BVOC emissions by using two independent numerical models: The Model of Emissions of Gases and Aerosols from Nature (MEGAN), for isoprene, monoterpene and sesquiterpene and Lund-Potsdam-Jena General Ecosystem Simulator (LPJ8 GUESS), for isoprene and monoterpenes. We found the millennial trends of global isoprene emissions to be mostly affected by land cover and atmospheric carbon dioxide changes, whereas monoterpene and sesquiterpene emission were dominated by temperature change. Isoprene emissions declined substantially in regions with large and rapid land cover change. In addition, isoprene emission sensitivity to drought proved to have signicant short term globalmore » effects. By the end of the past millennium MEGAN isoprene emissions were 634 TgC yr-1 (13% and 19% less than during during 1750-1850 and 1000- 15 1200, respectively) and LPJ-GUESS emissions were 323 TgC yr-1 (15% and 20% less than during 1750-1850 and 1000-1200, respectively). Monoterpene emissions were 89 TgC yr-1 (10% and 6% higher than during 1750-1850 and 1000-1200, respectively) in MEGAN, and 24 TgC yr-1 (2% higher and 5% 19 20 less than during 1750-1850 and 1000-1200, respectively) in LPJ-GUESS. MEGAN sesquiterpene emissions were 36 TgC yr-1 (10% and 4% higher than during1750-1850 and 1000-1200, respectively). Although both models capture similar We investigated the millennial variability of global BVOC emissions by using two independent numerical models: The Model of Emissions of Gases and Aerosols from Nature (MEGAN), for isoprene, monoterpene and sesquiterpene and Lund-Potsdam-Jena General Ecosystem Simulator (LPJ8GUESS), for isoprene and monoterpenes. We found the millennial trends ofglobal isoprene emissions to be mostly a*ected by land cover and atmospheric carbon dioxide changes, whereas monoterpene and sesquiterpene emission were dominated by temperature change. Isoprene emissions declined substantially in regions with large and rapid land cover change. In addition, isoprene emission sensitivity to drought proved to have signifcant short term global effects. By the end of the past millennium MEGAN isoprene emissions were 634 TgC yr-1 (13% and 19% less than during during 1750-1850 and 1000- 1200, respectively) and LPJ-GUESS emissions were 323 TgC yr-1 (15% and 16 17 20% less than during 1750-1850 and 1000-1200, respectively). Monoterpene emissions were 89 TgC yr-1 (10% and 6% higher than during 1750-1850 and 18 1000-1200, respectively) in MEGAN, and 24 TgC yr-1 (2% higher and 5% less than during 1750-1850 and 1000-1200, respectively) in LPJ-GUESS. MEGAN sesquiterpene emissions were 36 TgC yr-1 (10% and 4% higher than during1750-1850 and 1000-1200, respectively). Although both models capture similar emission trends, the magnitude of the emissions are different. This highlights the importance of building better constraints on VOC emissions from terrestrial vegetation.emission trends, the magnitude of the emissions are different. This highlights the importance of building better constraints on VOC emissions from terrestrial vegetation.« less

Cloning and Characterizing Genes Involved in Monoterpene Induced Mammary Tumor Regression.

DTIC Science & Technology

1996-10-01

causes morphologic differentiation within 4 hours as characterized by neurite outgrowths (12). Monoterpenes inhibit enzymes in the mevalonate-lipid...metabolism pathway, including a selective inhibition of isoprenylation of 21-26 kDa small G proteins (13-15) and inhibition of ubiquinone ( CoQ ) and...Letters 269(2), 305-10 18 FOOTNOTES 1 The abbreviations used are: DMBA, 7,12-dimethylbenz[a]anthracene; NMU, N-methyl-N- nitrosourea; CoQ , ubiquinone

A non-synonymous nucleotide substitution can account for one evolutionary route to sesquiterpene synthase activity in the TPS-b subgroup.

PubMed

Green, Sol; Baker, Edward N; Laing, William

2011-06-23

Plant sesquiterpene and hemiterpene synthases in the monoterpene synthase dominated TPS-b subgroup are thought to have evolved independently from a monoterpene synthase ancestor. A TPS-b sesquiterpene synthase from apple (MdAFS1), which predominantly produces α-farnesene, can also synthesize the monoterpene (E)-β-ocimene. The dual activity offered a functional link to an ancestral MdAFS1 enzyme and a rational basis for investigation of the evolution of TPS-b sesquiterpene enzymes. Protein modelling and mutagenesis analysis of the MdAFS1 active site identified a non-synonymous nucleotide substitution that could account for the requisite shift in substrate specificity necessary for the emergence of its sesquiterpene activity during the evolution of the TPS-b enzymes. Copyright © 2011 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Boundary layer concentrations and landscape scale emissions of volatile organic compounds in early spring

NASA Astrophysics Data System (ADS)

Haapanala, S.; Rinne, J.; Hakola, H.; Hellén, H.; Laakso, L.; Lihavainen, H.; Janson, R.; Kulmala, M.

2006-10-01

Boundary layer concenrations of several volatile organic compounds (VOC) were measured during two campaigns in springs of 2003 and 2006. Measurements were conducted over boreal forests near SMEAR II measurement station in Hyytiälä, Southern Finland. In 2003 the measuremens were performed using light aircraft and in 2006 using hot air ballon. Isoprene concentrarions were low, usually below detection limit. This is explained by low biogenic production due to cold weather. Monoterpenes were observed frequently. Average total monoterpene concentration in the boundary layer was 33 pptv. Many anthropogenic compounds e.g. benzene, xylene and toluene, were observed in high amounts. Ecosystem scale surface emissions were estimated using simple mixed box budget methodology. Total monoterpene fluxes varied up to 80 μg m-2 h-1, α-pinene contributing typically more than two thirds of that. Highest fluxes of anthropogenic compounds were those of p/m xylene.

Secondary organic aerosols over oceans via oxidation of isoprene and monoterpenes from Arctic to Antarctic.

PubMed

Hu, Qi-Hou; Xie, Zhou-Qing; Wang, Xin-Ming; Kang, Hui; He, Quan-Fu; Zhang, Pengfei

2013-01-01

Isoprene and monoterpenes are important precursors of secondary organic aerosols (SOA) in continents. However, their contributions to aerosols over oceans are still inconclusive. Here we analyzed SOA tracers from isoprene and monoterpenes in aerosol samples collected over oceans during the Chinese Arctic and Antarctic Research Expeditions. Combined with literature reports elsewhere, we found that the dominant tracers are the oxidation products of isoprene. The concentrations of tracers varied considerably. The mean average values were approximately one order of magnitude higher in the Northern Hemisphere than in the Southern Hemisphere. High values were generally observed in coastal regions. This phenomenon was ascribed to the outflow influence from continental sources. High levels of isoprene could emit from oceans and consequently have a significant impact on marine SOA as inferred from isoprene SOA during phytoplankton blooms, which may abruptly increase up to 95 ng/m³ in the boundary layer over remote oceans.

Observations of ambient monoterpenes at a costal site in the East Mediterranean

NASA Astrophysics Data System (ADS)

Tzitzikalaki, Evaggelia; Kalivitis, Nikolaos; Kouvarakis, Giorgos; Kanakidou, Maria; Mihalopoulos, Nikolaos

2015-04-01

Observations of ambient monoterpenes at a costal site in the East Mediterranean Biogenic Volatile Organic Compounds (BVOCs) affect the oxidizing capacity of the atmosphere since they react with hydroxyl radicals, nitrate radicals and ozone, and participate in ozone formation in the presence of sufficient amounts of nitrogen oxides. Moreover, BVOC oxidation products contribute to new particle formation and growth processes. While isoprene is emitted in the largest amount among BVOCs into the atmosphere, monoterpenes are also important for atmospheric chemistry. Tree species are responsible of the most BVOC emissions to the atmosphere but little is known about the contribution of shrub and long-range transport to the ambient BVOC concentrations. In the Mediterranean region monoterpene measurements are scarce and are limited in temporal and ecosystem coverage (forested areas). The present study presents long- term measurements of monoterpenes at a remote coastal site without tree vegetation under typical phrygana vegetation of Crete island in Greece. Measurements took place (35° 20' N, 25° 40' E, 250m a.s.l) on the north east side of the island of Crete at the Finokalia monitoring station of the University of Crete (http://finokalia.chemistry.uoc.gr). Two intensive campaigns took place, one during spring (13/03-08/04/2014) and one during summer(19/06 - 04/08/2014). During each campaign diurnal cycles were measured collecting 9 samples per day(every two hours). In addition, one diurnal cycle per week has been measured since 13/10/2014. Off-line sampling took place in adsorption tubes, using stainless steel cartridges filled with Tenax TA for one hour at 200 ml/min flow rate. Samples were stored at 40C and analyzed within two days. The samples were after desorption by a Thermal Desorber were analyzed by a GC-FID system. The most abundant monoterpenes were found to be Δ3-carene and limonene.Highest concentrations were observed during autumn when a clear diurnal cycle has been seen with maximum for both Δ3-carene and limonene at late afternoon. During summer, no clear diurnal variance was observed while in spring the cycle was weaker. The results are analyzed together with new particle formation observations at the Finokalia station to estimate possible links of BVOCs to the formation and growth processes of atmospheric particles in the area.

Large drought-induced variations in oak leaf volatile organic compound emissions during PINOT NOIR 2012.

PubMed

Geron, Chris; Daly, Ryan; Harley, Peter; Rasmussen, Rei; Seco, Roger; Guenther, Alex; Karl, Thomas; Gu, Lianhong

2016-03-01

Leaf-level isoprene and monoterpene emissions were collected and analyzed from five of the most abundant oak (Quercus) species in Central Missouri's Ozarks Region in 2012 during PINOT NOIR (Particle Investigations at a Northern Ozarks Tower - NOx, Oxidants, Isoprene Research). June measurements, prior to the onset of severe drought, showed isoprene emission rates and leaf temperature responses similar to those previously reported in the literature and used in Biogenic Volatile Organic Compound (BVOC) emission models. During the peak of the drought in August, isoprene emission rates were substantially reduced, and response to temperature was dramatically altered, especially for the species in the red oak subgenus (Erythrobalanus). Quercus stellata (in the white oak subgenus Leucobalanus), on the other hand, increased its isoprene emission rate during August, and showed no decline at high temperatures during June or August, consistent with its high tolerance to drought and adaptation to xeric sites at the prairie-deciduous forest interface. Mid-late October measurements were conducted after soil moisture recharge, but were affected by senescence and cooler temperatures. Isoprene emission rates were considerably lower from all species compared to June and August data. The large differences between the oaks in response to drought emphasizes the need to consider BVOC emissions at the species level instead of just the whole canopy. Monoterpene emissions from Quercus rubra in limited data were highest among the oaks studied, while monoterpene emissions from the other oak species were 80-95% lower and less than assumed in current BVOC emission models. Major monoterpenes from Q. rubra (and in ambient air) were p-cymene, α-pinene, β-pinene, d-limonene, γ-terpinene, β-ocimene (predominantly1,3,7-trans-β-ocimene, but also 1,3,6-trans-β-ocimene), tricyclene, α-terpinene, sabinene, terpinolene, and myrcene. Results are discussed in the context of canopy flux studies conducted at the site during PINOT NOIR, which are described elsewhere. The leaf isoprene emissions before and during the drought were consistent with above canopy fluxes, while leaf and branch monoterpene emissions were an order of magnitude lower than the observed above canopy fluxes, implying that other sources may be contributing substantially to monoterpene fluxes at this site. This strongly demonstrates the need for further simultaneous canopy and enclosure BVOC emission studies. Published by Elsevier Ltd.

Isolation and expression of cytochrome P450 genes in the antennae and gut of pine beetle Dendroctonus rhizophagus (Curculionidae: Scolytinae) following exposure to host monoterpenes

Treesearch

Claudia Cano-Ramirez; Maria Fernanda Lopez; Ana K. Cesar-Ayala; Veronica Pineda-Martinez; Brian T. Sullivan; Gerardo and Zuniga

2013-01-01

Bark beetles oxidize the defensive monoterpenes of their host trees both to detoxify them and convert them into components of their pheromone system. This oxidation is catalyzed by cytochrome P450 enzymes and occurs in different tissues of the insect, including the gut (i.e., the site where the beetle's pheromones are produced and accumulated) and the antennae (i....

Essential-Oil Variability in Natural Populations of Pinus mugo Turra from the Julian Alps.

PubMed

Bojović, Srdjan; Jurc, Maja; Ristić, Mihailo; Popović, Zorica; Matić, Rada; Vidaković, Vera; Stefanović, Milena; Jurc, Dušan

2016-02-01

The composition and variability of the terpenes and their derivatives isolated from the needles of a representative pool of 114 adult trees originating from four natural populations of dwarf mountain pine (Pinus mugo Turra) from the Julian Alps were investigated by GC-FID and GC/MS analyses. In total, 54 of the 57 detected essential-oil components were identified. Among the different compound classes present in the essential oils, the chief constituents belonged to the monoterpenes, comprising an average content of 79.67% of the total oil composition (74.80% of monoterpene hydrocarbons and 4.87% of oxygenated monoterpenes). Sesquiterpenes were present in smaller amounts (average content of 19.02%), out of which 16.39% were sesquiterpene hydrocarbons and 2.62% oxygenated sesquiterpenes. The most abundant components in the needle essential oils were the monoterpenes δ-car-3-ene, β-phellandrene, α-pinene, β-myrcene, and β-pinene and the sesquiterpene β-caryophyllene. From the total data set of 57 detected compounds, 40 were selected for principal-component analysis (PCA), discriminant analysis (DA), and cluster analysis (CA). The overlap tendency of the four populations suggested by PCA, was as well observed by DA. CA also demonstrated similarity among the populations, which was the highest between Populations I and II. Copyright © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

Assessment of the repellent effect of Lippia alba essential oil and major monoterpenes on the cattle tick Rhipicephalus microplus.

PubMed

Lima, A da Silva; Carvalho, J F de; Peixoto, M G; Blank, A F; Borges, L M F; Costa Junior, L M

2016-03-01

The control of Rhipicephalus microplus (Ixodida: Ixodidae) is achieved using synthetic acaricides. However, resistant tick populations are widespread around the world. Plant essential oils can act as repellents, keeping ticks away from hosts and decreasing the selection pressure on synthetic acaricides. The aim of this study was to evaluate the in vitro repellent effect of Lippia alba essential oil on R. microplus larvae. Leaves from two L. alba genotypes maintained under the same agronomic and environmental conditions were collected. Essential oil was extracted by hydrodistillation and analysed by gas chromatography-mass spectrometry (GC-MS). The major monoterpenes detected in the chemical analysis were commercially acquired and tested. For the repellency test, a glass rod was vertically fixed to measure active climbing of approximately 30 R. microplus larvae aged 14-21 days in response to essential oils and monoterpenes. Repellency was evaluated at 1 h, 3 h and 5 h after treatment. Variation in repellent action was detected between the genotypes. The major monoterpenes identified in the essential oils (limonene and carvone) showed low repellent effects in comparison with intact essential oils. Thus, the present results showed that L. alba essential oil contains bioactive compounds with great repellent activity against ticks that varies according to the plant genotype. © 2015 The Royal Entomological Society.

α,β-Unsaturated monoterpene acid glucose esters: structural diversity, bioactivities and functional roles.

PubMed

Goodger, Jason Q D; Woodrow, Ian E

2011-12-01

The glycosylation of lipophilic small molecules produces many important plant secondary metabolites. The majority of these are O-glycosides with relatively fewer occurring as glucose esters of aromatic or aliphatic acids. In particular, monoterpene acid glucose esters have much lower structural diversity and distribution compared to monoterpene glycosides. Nevertheless, there have been over 20 monoterpene acid glucose esters described from trees in the genus Eucalyptus (Myrtaceae) in recent years, all based on oleuropeic acid, menthiafolic acid or both. Here we review all of the glucose esters containing these monoterpenoids identified in plants to date. Many of the compounds contain phenolic aglycones and all contain at least one α,β-unsaturated carbonyl, affording a number of important potential therapeutic reactivities such as anti-tumor promotion, carcinogenesis suppression, and anti-oxidant and anti-inflammatory activities. Additional properties such as cytotoxicity, bitterness, and repellency are suggestive of a role in plant defence, but we also discuss their localization to the exterior of foliar secretory cavity lumina, and suggest they may also protect secretory cells from toxic terpenes housed within these structures. Finally we discuss how the use of a recently developed protocol to isolate secretory cavities in a functional state could be used in conjunction with systems biology approaches to help characterize their biosynthesis and roles in plants. Copyright © 2011 Elsevier Ltd. All rights reserved.

Irreversible impacts of heat on the emissions of monoterpenes, sesquiterpenes, phenolic BVOC and green leaf volatiles from several tree species

NASA Astrophysics Data System (ADS)

Kleist, E.; Mentel, T. F.; Andres, S.; Bohne, A.; Folkers, A.; Kiendler-Scharr, A.; Rudich, Y.; Springer, M.; Tillmann, R.; Wildt, J.

2012-12-01

Climate change will induce extended heat waves to parts of the vegetation more frequently. High temperatures may act as stress (thermal stress) on plants changing emissions of biogenic volatile organic compounds (BVOCs). As BVOCs impact the atmospheric oxidation cycle and aerosol formation, it is important to explore possible alterations of BVOC emissions under high temperature conditions. Applying heat to European beech, Palestine oak, Scots pine, and Norway spruce in a laboratory setup either caused the well-known exponential increases of BVOC emissions or induced irreversible changes of BVOC emissions. Considering only irreversible changes of BVOC emissions as stress impacts, we found that high temperatures decreased the de novo emissions of monoterpenes, sesquiterpenes and phenolic BVOC. This behaviour was independent of the tree species and whether the de novo emissions were constitutive or induced by biotic stress. In contrast, application of thermal stress to conifers amplified the release of monoterpenes stored in resin ducts of conifers and induced emissions of green leaf volatiles. In particular during insect attack on conifers, the plants showed de novo emissions of sesquiterpenes and phenolic BVOCs, which exceeded constitutive monoterpene emissions from pools. The heat-induced decrease of de novo emissions was larger than the increased monoterpene release caused by damage of resin ducts. For insect-infested conifers the net effect of thermal stress on BVOC emissions could be an overall decrease. Global change-induced heat waves may put hard thermal stress on plants. If so, we project that BVOC emissions increase is more than predicted by models only in areas predominantly covered with conifers that do not emit high amounts of sesquiterpenes and phenolic BVOCs. Otherwise overall effects of high temperature stress will be lower increases of BVOC emissions than predicted by algorithms that do not consider stress impacts.

[Contributions to the chemical study of the essential oil isolated from coriander fruits (Sandra cultivar)].

PubMed

Trifan, Adriana; Aprotosoaie, Ana Clara; Spac, A; Hăncianu, Monica; Miron, Anca; Stănescu, Ursula

2011-01-01

Coriandrum sativum L. (Apiaceae) is a well known herb, native to the Mediterranean region, also intensively cultivated in Romania. The essential oil obtained from Coriandri fructus posseses antimicrobial, antioxidant and anxiolytic effects. Many parameters such as genetic and climatic factors or agronomical practices can influence the yield and composition of the volatile fraction. Plant density is an important factor for the microenvironment in coriander field. In order to study the effect of planting density on the yield of the essential oil and its composition, a bifactorial experiment was carried out on coriander plants (Sandra cultivar). The experiment was performed with three plant densities on the row (0, 15 and 20 cm); the distance between plant rows was 12.5, 25 and 50 cm, respectively. So, it resulted nine experimental variants. The essential oils obtained by hydrodistillation from fruits have been characterized using gas chromatography and mass spectroscopy analysis (GC-MS). The highest yield (7.9866 kg/ha) was obtained for the plants spaced at 20 cm in between and 25 cm row spacing. The highest content of monoterpene alcohols (50.96%) was obtained with 25 cm row spacing and plant spaced at 0 cm on the row. The main components in all oils were monoterpene alcohols (40.75% - 50.96%) and monoterpenes (32.43-38.44%). The essential oil of coriander fruits (Sandra cultivar) does not meet the requirements of the European Pharmacopoeia, especially concerning the content in linalool. Nevertheless, the high content in monoterpene alcohols and monoterpenes recommends the use of the essential oil as immunomodulatory, analgesic and antiinflammatory agent in rheumatology and also as an antibacterial and antiviral agent. Consequently, the changes in yield and composition of the essential oil of Sandra coriander should be assesed during several periods of vegetation in order to conclude on its pharmaceutical quality.

Chemical composition of Juniperus communis L. fruits supercritical CO2 extracts: dependence on pressure and extraction time.

PubMed

Barjaktarović, Branislava; Sovilj, Milan; Knez, Zeljko

2005-04-06

Ground fruits of the common juniper (Juniperus communis L.), with a particle size range from 0.250-0.400 mm, forming a bed of around 20.00 +/- 0.05 g, were extracted with supercritical CO(2) at pressures of 80, 90, and 100 bars and at a temperature of 40 degrees C. The total amount of extractable substances or global yield (mass of extract/mass of raw material) for the supercritical fluid extraction process varied from 0.65 to 4.00% (wt). At each investigated pressure, supercritical CO(2) extract fractions collected in successive time intervals over the course of the extraction were analyzed by capillary gas chromatography, using flame ionization (GC-FID) and mass spectrometric detection (GC-MS). More than 200 constituents were detected in the extracts, and the contents of 50 compounds were reported in the work. Dependence of the percentage yields of monoterpene, sesquiterpene, oxygenated monoterpene, and oxygenated sesquiterpene hydrocarbon groups on the extraction time was investigated, and conditions that favored the yielding of each terpene groups were emphasized. At all pressures, monoterpene hydrocarbons were almost completely extracted from the berries in the first 0.6 h. It was possible to extract oxygenated monoterpenes at 100 bar in 0.5 h and at 90 bar in 1.2 h. Contrary to that, during an extraction period of 4 h at 80 bar, it was possible to extract only 75% of the maximum yielded value of oxygenated monoterpene at 100 bar. Intensive extraction of sesquiterpenes could be by no means avoided at any pressure, but at the beginning of the process (the first 0.5 h) at 80 bar, they were extracted about 8 and 3 times slower than at 100 and 90 bar, respectively. Oxygenated sesquiterpenes were yielded at fast, constant extraction rates at 100 and 90 bar in 1.2 and 3 h, respectively. This initial fast extraction period was consequently followed by much slower extraction of oxygenated sesquiterpenes.

The role of genetic and chemical variation of Pinus sylvestris seedlings in influencing slug herbivory.

PubMed

O'Reilly-Wapstra, Julianne M; Iason, Glenn R; Thoss, Vera

2007-05-01

This study investigated the genetic and chemical basis of resistance of Pinus sylvestris seedlings to herbivory by a generalist mollusc, Arion ater. Using feeding trials with captive animals, we examined selective herbivory by A. ater of young P. sylvestris seedlings of different genotypes and correlated preferences with seedling monoterpene levels. We also investigated the feeding responses of A. ater to artificial diets laced with two monoterpenes, Delta(3)-carene and alpha-pinene. Logistic regression indicated that two factors were the best predictors of whether seedlings in the trial would be consumed. Individual slug variation (replicates) was the most significant factor in the model; however, alpha-pinene concentration (also representing beta-pinene, Delta(3)-carene and total monoterpenes due to multicollinearity) of needles was also a significant factor. While A. ater did not select seedlings on the basis of family, seedlings not eaten were significantly higher in levels of alpha-pinene compared to seedlings that were consumed. We also demonstrated significant genetic variation in alpha-pinene concentration of seedlings between different families of P. sylvestris. Nitrogen and three morphological seedling characteristics (stem length, needle length and stem diameter) also showed significant genetic variation between P. sylvestris families. Artificial diets laced with high (5 mg g(-1) dry matter) quantities of either Delta(3)-carene or alpha-pinene, were eaten significantly less than control diets with no added monoterpenes, supporting the results of the seedling feeding trial. This study demonstrates that A. ater selectively feed on P. sylvestris seedlings and that this selection is based, in part, on the monoterpene concentration of seedlings. These results, coupled with significant genetic variation in alpha-pinene concentration of seedlings and evidence that slug herbivory is detrimental to P. sylvestris fitness, are discussed as possible evidence for A. ater as a selective force on the evolution of defensive chemistry in P. sylvestris.

Monoterpene and herbivore-induced emissions from cabbage plants grown at elevated atmospheric CO 2 concentration

NASA Astrophysics Data System (ADS)

Vuorinen, Terhi; Reddy, G. V. P.; Nerg, Anne-Marja; Holopainen, Jarmo K.

The warming of the lower atmosphere due to elevating CO 2 concentration may increase volatile organic compound (VOC) emissions from plants. Also, direct effects of elevated CO 2 on plant secondary metabolism are expected to lead to increased VOC emissions due to allocation of excess carbon on secondary metabolites, of which many are volatile. We investigated how growing at doubled ambient CO 2 concentration affects emissions from cabbage plants ( Brassica oleracea subsp. capitata) damaged by either the leaf-chewing larvae of crucifer specialist diamondback moth ( Plutella xylostella L.) or generalist Egyptian cotton leafworm ( Spodoptera littoralis (Boisduval)). The emission from cabbage cv. Lennox grown in both CO 2 concentrations, consisted mainly of monoterpenes (sabinene, limonene, α-thujene, 1,8-cineole, β-pinene, myrcene, α-pinene and γ-terpinene). ( Z)-3-Hexenyl acetate, sesquiterpene ( E, E)- α-farnesene and homoterpene ( E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) were emitted mainly from herbivore-damaged plants. Plants grown at 720 μmol mol -1 of CO 2 had significantly lower total monoterpene emissions per shoot dry weight than plants grown at 360 μmol mol -1 of CO 2, while damage by both herbivores significantly increased the total monoterpene emissions compared to intact plants. ( Z)-3-Hexenyl acetate, ( E, E)- α-farnesene and DMNT emissions per shoot dry weight were not affected by the growth at elevated CO 2. The emission of DMNT was significantly enhanced from plants damaged by the specialist P. xylostella compared to the plants damaged by the generalist S. littoralis. The relative proportions of total monoterpenes and total herbivore-induced compounds of total VOCs did not change due to the growth at elevated CO 2, while insect damage increased significantly the proportion of induced compounds. The results suggest that VOC emissions that are induced by the leaf-chewing herbivores will not be influenced by elevated CO 2 concentration.

OH radical-initiated oxidation of (E)- and (Z)-β-ocimene in the presence of NOx: the role of light-dependent monoterpenes in organic nitrate and secondary organic aerosol formation in the above-canopy forest environment

NASA Astrophysics Data System (ADS)

Slade, J. H., Jr.; Jayarathne, T.; Morales, A. C.; Shepson, P. B.

2017-12-01

Biogenic volatile organic compound (BVOC) oxidation represents a significant pathway in the production of secondary organic aerosol (SOA). BVOC oxidation products, including organic nitrates (ON), impact both the SOA burden and the oxidative capacity of the atmosphere by sequestering NOx. A recent field study in the mixed deciduous/coniferous forest of northern Michigan showed that concentrations of multifunctional monoterpene-derived hydroxy nitrates (MTN) and SOA can be greater in the above-canopy environment during daytime, but the source of MTN is unclear as model simulations cannot replicate the higher concentrations above canopy. Light-dependent monoterpenes, including the polyolefinic species, trans-ocimene, may be one such contributor to the higher measured ON and SOA above canopy as this compound has been predicted to be an important source of monoterpene-derived ON during daytime in this environment. However, there are currently no measurements of the ON (and SOA yields) from trans-ocimene oxidation by OH in the presence of NOx, the dominant pathway for daytime ON production. Here we conduct photochemical reaction chamber studies of the OH radical-initiated oxidation of authentic (E)- and (Z)-β-ocimene isomers in the presence of NOx to examine the total (gas and particle) ON, hydroxy nitrate, and SOA yields. The effects of variable chamber relative humidity and seed particle acidity on the ON and SOA yields are examined to better understand the role of hydrolysis on SOA formation and the lifetime of ocimene-derived ON in the particles. This work underscores the importance of light-dependent monoterpenes on mediating the oxidative capacity of the near canopy forest environment and has important implications for understanding NOx cycling and the formation of SOA in forests, which are not currently included in atmospheric models.

Remote sensing estimation of isoprene and monoterpene emissions generated by natural vegetation in Monterrey, Mexico.

PubMed

Gastelum, Sandra L; Mejía-Velázquez, G M; Lozano-García, D Fabián

2016-06-01

In addition to oxygen, hydrocarbons are the most reactive chemical compounds produced by plants into the atmosphere. These compounds are part of the family of volatile organic compounds (VOCs) and are discharged in a great variety of forms. Among the VOCs produced by natural sources such as vegetation, the most studied until today are the isoprene and monoterpene. These substances can play an important role in the chemical balance of the atmosphere of a region. In this project, we develop a methodology to estimate the natural (vegetation) emission of isoprene and monoterpenes and applied it to the Monterrey Metropolitan Area, Mexico and its surrounding areas. Landsat-TM data was used to identify the dominant vegetation communities and field work to determine the foliage biomass density of key species. The studied communities were submontane scrub, oak, and pine forests and a combination of both. We carried out the estimation of emissions for isoprene and monoterpenes compounds in the different plant communities, with two different criteria: (1) taking into account the average foliage biomass density obtained from the various sample point in each vegetation community, and (2) using the foliage biomass density obtained for each transect, associated to an individual spectral class within a particular vegetation type. With this information, we obtained emission maps for each case. The results show that the main producers of isoprene are the communities that include species of the genus Quercus, located mainly on the Sierra Madre Oriental and Sierra de Picachos, with average isoprene emissions of 314.6 ton/day and 207.3 ton/day for the two methods utilized. The higher estimates of monoterpenes were found in the submontane scrub areas distributed along the valley of the metropolitan zone, with an estimated average emissions of 47.1 ton/day and 181.4 tons for the two methods respectively.

Structural investigation of the β-cyclodextrin complexes with chiral bicyclic monoterpenes - Influence of the functionality group on the host-guest stoichiometry

NASA Astrophysics Data System (ADS)

Ceborska, Magdalena

2017-10-01

The crystal structures of the complexes of β-cyclodextrin with (+)- and (-)-camphors are presented. The comparison of the obtained crystal structures with available data for other complexes of β-cyclodextrin with chiral bicyclic monoterpenes (hydrocarbon (+)-fenchene and alcohols: (-)-isopinocampheol, and (+)-, and (-)-borneols) obtained from Cambridge Structural Database (CSD) shows the trend of alcohols to form dimeric complexes of 2:3 stoichiometry, while hydrocarbons and ketones prefer to form 2:2 host-guest inclusion complexes.

Chiral ligands derived from monoterpenes: application in the synthesis of optically pure secondary alcohols via asymmetric catalysis.

PubMed

El Alami, Mohammed Samir Ibn; El Amrani, Mohamed Amin; Agbossou-Niedercorn, Francine; Suisse, Isabelle; Mortreux, André

2015-01-19

The preparation of optically pure secondary alcohols in the presence of catalysts based on chiral ligands derived from monoterpenes, such as pinenes, limonenes and carenes, is reviewed. A wide variety of these ligands has been synthesized and used in several catalytic reactions, including hydrogen transfer, C-C bond formation via addition of organozinc compounds to aldehydes, hydrosilylation, and oxazaborolidine reduction, leading to high activities and enantioselectivities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A synthetic biochemistry platform for cell free production of monoterpenes from glucose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korman, Tyler P.; Opgenorth, Paul H.; Bowie, James U.

Cell-free systems designed to perform complex chemical conversions of biomass to biofuels or commodity chemicals are emerging as promising alternatives to the metabolic engineering of living cells. We design a system comprises 27 enzymes for the conversion of glucose into monoterpenes that generates both NAD(P)H and ATP in a modified glucose breakdown module and utilizes both cofactors for building terpenes. Different monoterpenes are produced in our system by changing the terpene synthase enzyme. The system is stable for the production of limonene, pinene and sabinene, and can operate continuously for at least 5 days from a single addition of glucose.more » We also obtain conversion yields 495% and titres 415 g l -1. The titres are an order of magnitude over cellular toxicity limits and thus difficult to achieve using cell-based systems. Overall, these results highlight the potential of synthetic biochemistry approaches for producing bio-based chemicals.« less

BOREAS TGB-8 Monoterpene Concentration Data over the SSA-OBS

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Lerdau, Manuel

2000-01-01

The BOREAS TGB-8 team collected data to investigate the controls over NMHC fluxes from boreal forest tree species. This data set contains measurements of monoterpene concentrations in collected foliar gas emissions and foliar samples. The data were collected at the OJP and OBS tower flux sites in the SSA and were the locus for the monoterpene emission measurements. These areas contained mature stands of jack pine and black spruce and were the focal sites in the BOREAS program for studies of biosphere/atmosphere exchange from these two habitat types. The OBS site is situated in a black spruce/sphagnum bog with the largest trees 155 years old and 10-15 m tall. The OJP site is in a jack pine forest, 80 to 120 years old, which lies on a sandy bench of glacial outwash with the largest tree standing 15 m tall. Temporally, the data cover the period of 24-May-1994 to 19-Sep-1994. The data are stored in tabular ASCII files.

Comprehensive comparative analysis of volatile compounds in citrus fruits of different species.

PubMed

Zhang, Haipeng; Xie, Yunxia; Liu, Cuihua; Chen, Shilin; Hu, Shuangshuang; Xie, Zongzhou; Deng, Xiuxin; Xu, Juan

2017-09-01

The volatile profiles of fruit peels and juice sacs from 108 citrus accessions representing seven species were analyzed. Using GC-MS 162 and 107 compounds were determined in the peels and juice sacs, respectively. In the peels, monoterpene alcohols were accumulated in loose-skin mandarins; clementine tangerines and papedas were rich in sesquiterpene alcohols, sesquiterpenes, monoterpene alcohols and monoterpene aldehydes. β-pinene and sabinene were specifically accumulated in 4 of 5 lemon germplasms. Furthermore, concentrations of 34 distinctive compounds were selected to best represent the volatile profiles of seven species for HCA analysis, and the clustering results were in agreement with classic citrus taxonomy. Comparison of profiles from different growing seasons and production areas indicated that environmental factors play important roles in volatile metabolism. In addition, a few citrus germplasms that accumulated certain compounds were determined as promising breeding materials. Notably, volatile biosynthesis via MVA pathway in C. ichangensis 'Huaihua' was enhanced. Copyright © 2017. Published by Elsevier Ltd.

A synthetic biochemistry platform for cell free production of monoterpenes from glucose

DOE PAGES

Korman, Tyler P.; Opgenorth, Paul H.; Bowie, James U.

2017-05-24

Cell-free systems designed to perform complex chemical conversions of biomass to biofuels or commodity chemicals are emerging as promising alternatives to the metabolic engineering of living cells. We design a system comprises 27 enzymes for the conversion of glucose into monoterpenes that generates both NAD(P)H and ATP in a modified glucose breakdown module and utilizes both cofactors for building terpenes. Different monoterpenes are produced in our system by changing the terpene synthase enzyme. The system is stable for the production of limonene, pinene and sabinene, and can operate continuously for at least 5 days from a single addition of glucose.more » We also obtain conversion yields 495% and titres 415 g l -1. The titres are an order of magnitude over cellular toxicity limits and thus difficult to achieve using cell-based systems. Overall, these results highlight the potential of synthetic biochemistry approaches for producing bio-based chemicals.« less

Emission rates of organics from vegetation in California's Central Valley

NASA Astrophysics Data System (ADS)

Winer, Arthur M.; Arey, Janet; Atkinson, Roger; Aschmann, Sara M.; Long, William D.; Morrison, C. Lynn; Olszyk, David M.

Rates of emission of speciated hydrocarbons have been determined for more than 30 of the most dominant (based on acreage) agricultural and natural plant types found in California's Central Valley. These measurements employed flow-through Teflon chambers, sample collection on solid adsorbent and thermal desorption gas chromatography (GC) and GC-mass spectrometry analysis to identify more than 40 individual organic compounds. In addition to isoprene and the monoterpenes, we observed sesquiterpenes, alcohols, acetates, aldehydes, ketones, ethers, esters, alkanes, alkenes and aromatics as emissions from these plant species. Mean emission rates for total monoterpenes ranged from none detected in the case of beans, grapes, rice and wheat, to as high as 12-30 μg h -1 g -1 for pistachio and tomato (normalized to dry leaf and total biomass, respectively). Other agricultural species exhibiting substantial rates of emission of monoterpenes included carrot, cotton, lemon, orange and walnut. All of the plant species studied showed total assigned compound emission rates in the range between 0.1 and 36 νg h -1 g -1.

Secondary organic aerosols over oceans via oxidation of isoprene and monoterpenes from Arctic to Antarctic

PubMed Central

Hu, Qi-Hou; Xie, Zhou-Qing; Wang, Xin-Ming; Kang, Hui; He, Quan-Fu; Zhang, Pengfei

2013-01-01

Isoprene and monoterpenes are important precursors of secondary organic aerosols (SOA) in continents. However, their contributions to aerosols over oceans are still inconclusive. Here we analyzed SOA tracers from isoprene and monoterpenes in aerosol samples collected over oceans during the Chinese Arctic and Antarctic Research Expeditions. Combined with literature reports elsewhere, we found that the dominant tracers are the oxidation products of isoprene. The concentrations of tracers varied considerably. The mean average values were approximately one order of magnitude higher in the Northern Hemisphere than in the Southern Hemisphere. High values were generally observed in coastal regions. This phenomenon was ascribed to the outflow influence from continental sources. High levels of isoprene could emit from oceans and consequently have a significant impact on marine SOA as inferred from isoprene SOA during phytoplankton blooms, which may abruptly increase up to 95 ng/m3 in the boundary layer over remote oceans. PMID:23880782

Release of lipoxygenase products and monoterpenes by tomato plants as an indicator of Botrytis cinerea-induced stress.

PubMed

Jansen, R M C; Miebach, M; Kleist, E; van Henten, E J; Wildt, J

2009-11-01

Changes in emission of volatile organic compounds (VOCs) from tomato induced by the fungus Botrytis cinerea were studied in plants inoculated by spraying with suspensions containing B. cinerea spores. VOC emissions were analysed using on-line gas chromatography-mass spectrometry, with a time resolution of about 1 h, for up to 2 days after spraying. Four phases were delimited according to the starting point and the applied day/night rhythm of the experiments. These phases were used to demonstrate changes in VOC flux caused by B. cinerea infestation. Tomato plants inoculated with B. cinerea emitted a different number and amount of VOCs after inoculation compared to control plants that had been sprayed with a suspension without B. cinerea spores. The changes in emissions were dependent on time after inoculation as well as on the severity of infection. The predominant VOCs emitted after inoculation were volatile products from the lipoxygenase pathway (LOX products). The increased emission of LOX products proved to be a strong indicator of a stress response, indicating that VOC emissions can be used to detect plant stress at an early stage. Besides emission of LOX products, there were also increases in monoterpene emissions. However, neither increased emission of LOX products nor of monoterpenes is specific for B. cinerea attack. The emission of LOX products is also induced by other stresses, and increased emission of monoterpenes seems to be the result of mechanical damage induced by secondary stress impacts on leaves.

Spearmint R2R3-MYB transcription factor MsMYB negatively regulates monoterpene production and suppresses the expression of geranyl diphosphate synthase large subunit (MsGPPS.LSU).

PubMed

Reddy, Vaishnavi Amarr; Wang, Qian; Dhar, Niha; Kumar, Nadimuthu; Venkatesh, Prasanna Nori; Rajan, Chakravarthy; Panicker, Deepa; Sridhar, Vishweshwaran; Mao, Hui-Zhu; Sarojam, Rajani

2017-09-01

Many aromatic plants, such as spearmint, produce valuable essential oils in specialized structures called peltate glandular trichomes (PGTs). Understanding the regulatory mechanisms behind the production of these important secondary metabolites will help design new approaches to engineer them. Here, we identified a PGT-specific R2R3-MYB gene, MsMYB, from comparative RNA-Seq data of spearmint and functionally characterized it. Analysis of MsMYB-RNAi transgenic lines showed increased levels of monoterpenes, and MsMYB-overexpressing lines exhibited decreased levels of monoterpenes. These results suggest that MsMYB is a novel negative regulator of monoterpene biosynthesis. Ectopic expression of MsMYB, in sweet basil and tobacco, perturbed sesquiterpene- and diterpene-derived metabolite production. In addition, we found that MsMYB binds to cis-elements of MsGPPS.LSU and suppresses its expression. Phylogenetic analysis placed MsMYB in subgroup 7 of R2R3-MYBs whose members govern phenylpropanoid pathway and are regulated by miR858. Analysis of transgenic lines showed that MsMYB is more specific to terpene biosynthesis as it did not affect metabolites derived from phenylpropanoid pathway. Further, our results indicate that MsMYB is probably not regulated by miR858, like other members of subgroup 7. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Production of extremely low volatile organic compounds from biogenic emissions: Measured yields and atmospheric implications

PubMed Central

Jokinen, Tuija; Berndt, Torsten; Makkonen, Risto; Kerminen, Veli-Matti; Junninen, Heikki; Stratmann, Frank; Herrmann, Hartmut; Guenther, Alex B.; Worsnop, Douglas R.; Kulmala, Markku; Ehn, Mikael; Sipilä, Mikko

2015-01-01

Oxidation products of monoterpenes and isoprene have a major influence on the global secondary organic aerosol (SOA) burden and the production of atmospheric nanoparticles and cloud condensation nuclei (CCN). Here, we investigate the formation of extremely low volatility organic compounds (ELVOC) from O3 and OH radical oxidation of several monoterpenes and isoprene in a series of laboratory experiments. We show that ELVOC from all precursors are formed within the first minute after the initial attack of an oxidant. We demonstrate that under atmospherically relevant concentrations, species with an endocyclic double bond efficiently produce ELVOC from ozonolysis, whereas the yields from OH radical-initiated reactions are smaller. If the double bond is exocyclic or the compound itself is acyclic, ozonolysis produces less ELVOC and the role of the OH radical-initiated ELVOC formation is increased. Isoprene oxidation produces marginal quantities of ELVOC regardless of the oxidant. Implementing our laboratory findings into a global modeling framework shows that biogenic SOA formation in general, and ELVOC in particular, play crucial roles in atmospheric CCN production. Monoterpene oxidation products enhance atmospheric new particle formation and growth in most continental regions, thereby increasing CCN concentrations, especially at high values of cloud supersaturation. Isoprene-derived SOA tends to suppress atmospheric new particle formation, yet it assists the growth of sub-CCN-size primary particles to CCN. Taking into account compound specific monoterpene emissions has a moderate effect on the modeled global CCN budget. PMID:26015574

Production of extremely low volatile organic compounds from biogenic emissions: Measured yields and atmospheric implications.

PubMed

Jokinen, Tuija; Berndt, Torsten; Makkonen, Risto; Kerminen, Veli-Matti; Junninen, Heikki; Paasonen, Pauli; Stratmann, Frank; Herrmann, Hartmut; Guenther, Alex B; Worsnop, Douglas R; Kulmala, Markku; Ehn, Mikael; Sipilä, Mikko

2015-06-09

Oxidation products of monoterpenes and isoprene have a major influence on the global secondary organic aerosol (SOA) burden and the production of atmospheric nanoparticles and cloud condensation nuclei (CCN). Here, we investigate the formation of extremely low volatility organic compounds (ELVOC) from O3 and OH radical oxidation of several monoterpenes and isoprene in a series of laboratory experiments. We show that ELVOC from all precursors are formed within the first minute after the initial attack of an oxidant. We demonstrate that under atmospherically relevant concentrations, species with an endocyclic double bond efficiently produce ELVOC from ozonolysis, whereas the yields from OH radical-initiated reactions are smaller. If the double bond is exocyclic or the compound itself is acyclic, ozonolysis produces less ELVOC and the role of the OH radical-initiated ELVOC formation is increased. Isoprene oxidation produces marginal quantities of ELVOC regardless of the oxidant. Implementing our laboratory findings into a global modeling framework shows that biogenic SOA formation in general, and ELVOC in particular, play crucial roles in atmospheric CCN production. Monoterpene oxidation products enhance atmospheric new particle formation and growth in most continental regions, thereby increasing CCN concentrations, especially at high values of cloud supersaturation. Isoprene-derived SOA tends to suppress atmospheric new particle formation, yet it assists the growth of sub-CCN-size primary particles to CCN. Taking into account compound specific monoterpene emissions has a moderate effect on the modeled global CCN budget.

Deposition Fluxes of Terpenes over Grassland

PubMed Central

Bamberger, I.; Hörtnagl, L.; Ruuskanen, T. M.; Schnitzhofer, R.; Müller, M.; Graus, M.; Karl, T.; Wohlfahrt, G.; Hansel, A.

2013-01-01

Eddy covariance flux measurements were carried out for two subsequent vegetation periods above a temperate mountain grassland in an alpine valley using a proton-transfer-reaction – mass spectrometer (PTR-MS) and a PTR-time of flight – mass spectrometer (PTR-TOF). In 2008 and during the first half of the vegetation period 2009 the volume mixing ratios (VMRs) for the sum of monoterpenes (MTs) were typically well below 1 ppbv and neither MT emission nor deposition was observed. After a hailstorm in July 2009 an order of magnitude higher amount of terpenes was transported to the site from nearby coniferous forests causing elevated VMRs. As a consequence, deposition fluxes of terpenes to the grassland, which continued over a time period of several weeks without significant re-emission, were observed. For days without precipitation the deposition occurred at velocities close to the aerodynamic limit. In addition to monoterpene uptake, deposition fluxes of the sum of sesquiterpenes (SQTs) and the sum of oxygenated terpenes (OTs) were detected. Considering an entire growing season for the grassland (i.e., 1st of April to 1st of November), the cumulative carbon deposition of monoterpenes reached 276 mg C m−2. This is comparable to the net carbon emission of methanol (329 mg C m−2), which is the dominant non methane volatile organic compound (VOC) emitted from this site, during the same time period. It is suggested that deposition of monoterpenes to terrestrial ecosystems could play a more significant role in the reactive carbon budget than previously assumed. PMID:24383048

Secondary organic aerosol formation from hydroxyl radical oxidation and ozonolysis of monoterpenes

NASA Astrophysics Data System (ADS)

Zhao, D. F.; Kaminski, M.; Schlag, P.; Fuchs, H.; Acir, I.-H.; Bohn, B.; Häseler, R.; Kiendler-Scharr, A.; Rohrer, F.; Tillmann, R.; Wang, M. J.; Wegener, R.; Wildt, J.; Wahner, A.; Mentel, Th. F.

2015-01-01

Oxidation by hydroxyl radical (OH) and ozonolysis are the two major pathways of daytime biogenic volatile organic compound (BVOC) oxidation and secondary organic aerosol (SOA) formation. In this study, we investigated the particle formation of several common monoterpenes (α-pinene, β-pinene and limonene) by OH-dominated oxidation, which has seldom been investigated. OH oxidation experiments were carried out in the SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction) chamber in Jülich, Germany, at low NOx (0.01 ~ 1 ppbV) and low ozone (O3) concentration (< 20 ppbV). OH concentration and total OH reactivity (kOH) were measured directly, and through this the overall reaction rate of total organics with OH in each reaction system was quantified. Multi-generation reaction process, particle growth, new particle formation (NPF), particle yield and chemical composition were analyzed and compared with that of monoterpene ozonolysis. Multi-generation products were found to be important in OH-dominated SOA formation. The relative role of functionalization and fragmentation in the reaction process of OH oxidation was analyzed by examining the particle mass and the particle size as a function of OH dose. We developed a novel method which quantitatively links particle growth to the reaction rate of OH with total organics in a reaction system. This method was also used to analyze the evolution of functionalization and fragmentation of organics in the particle formation by OH oxidation. It shows that functionalization of organics was dominant in the beginning of the reaction (within two lifetimes of the monoterpene) and fragmentation started to play an important role after that. We compared particle formation from OH oxidation with that from pure ozonolysis. In individual experiments, growth rates of the particle size did not necessarily correlate with the reaction rate of monoterpene with OH and O3. Comparing the size growth rates at the similar reaction rates of monoterpene with OH or O3 indicates that, generally, OH oxidation and ozonolysis had similar efficiency in particle growth. The SOA yield of α-pinene and limonene by ozonolysis was higher than that of OH oxidation. Aerosol mass spectrometry (AMS) shows SOA elemental composition from OH oxidation follows a slope shallower than -1 in the O / C vs. H / C diagram, also known as Van Krevelen diagram, indicating that oxidation proceeds without significant loss of hydrogen. SOA from OH oxidation had higher H / C ratios than SOA from ozonolysis. In ozonolysis, a process with significant hydrogen loss seemed to play an important role in SOA formation.

Monoterpenyl Glycosyltransferases Differentially Contribute to Production of Monoterpenyl Glycosides in Two Aromatic Vitis vinifera Varieties

PubMed Central

Li, Xiang-Yi; Wen, Ya-Qin; Meng, Nan; Qian, Xu; Pan, Qiu-Hong

2017-01-01

HIGHLIGHTS A similar trend on accumulation of glycosidically bound monoterpenes was observed in both varietiesTwo VvGT7 alleles mutations occurred at key sites in Muscat blanc à PetitVvGT14 exerted a major role in production of monoterpenyl glycosides in both varieties Terpenoids are the major aroma components and generally exist as both free and glycosidically-bound forms, of which nonvolatile glycosides account for a large fraction in grape berries. Our previous study has indicated that differential accumulation of monoterpenyl glycosides in Vitis vinifera “Muscat blanc à Petit” between two regions is closely correlated to monoterpenyl glucosyltransferase (VvGT14, XM_002285734.2) transcript abundance. However, it has not been determined yet whether this correlation also exists in other Vitis vinifera varieties. This study investigated the evolution of free and glycosidically bound monoterpenes in two Vitis vinifera variety “Muscat blanc à Petit” and “Gewurztraminer” under two vintages, and further assessed the relation between the accumulation of bound monoterpenes and two monoterpenyl glycosyltransferase transcript levels. Results showed that free monoterpenes exhibited three evolution patterns in both varieties during berry development of two vintages, whereas glycosidically bound monoterpenes showed a concentration elevation with berry maturation. The Cis-rose oxide and geraniol were major components contributing to the aroma odors of “Gewürztraminer” grapes while linalool was major aroma contributor to the “Muscat blanc à Petit grain” grapes. The accumulation of glycosidically bound monoterpenes in both varieties was accompanied with the high expression of VvGT7 (XM_002276510.2) and VvGT14. Only one allele of VvGT7 was found in the variety “Gewürztraminer” and no mutation was observed in its enzyme active sites. XB-VvGT7-4 and XB-VvGT7-5 were two alleles of VvGT7 detected in “Muscat blanc à Petit grain.” The mutation on its enzyme active site inhibited the activity of XB-VvGT7-4, whereas VvGT7-5 exhibited an alteration on enzyme activity due to the insertion mutation at the position 443. Only one VvGT14 allele was found in both varieties, and the VvGT14 allele in both varieties showed the similarity on amino acid sequence. No mutation occurred in active sites of VvGT14 allele. These indicated that VvGT7 and VvGT14 differentially contributed to the production of monoterpenyl glycosides in these Vitis Vinifera varieties. PMID:28751905

Monoterpenyl Glycosyltransferases Differentially Contribute to Production of Monoterpenyl Glycosides in Two Aromatic Vitis vinifera Varieties.

PubMed

Li, Xiang-Yi; Wen, Ya-Qin; Meng, Nan; Qian, Xu; Pan, Qiu-Hong

2017-01-01

HIGHLIGHTS A similar trend on accumulation of glycosidically bound monoterpenes was observed in both varietiesTwo VvGT7 alleles mutations occurred at key sites in Muscat blanc à Petit VvGT14 exerted a major role in production of monoterpenyl glycosides in both varieties Terpenoids are the major aroma components and generally exist as both free and glycosidically-bound forms, of which nonvolatile glycosides account for a large fraction in grape berries. Our previous study has indicated that differential accumulation of monoterpenyl glycosides in Vitis vinifera "Muscat blanc à Petit" between two regions is closely correlated to monoterpenyl glucosyltransferase ( VvGT14 , XM_002285734.2) transcript abundance. However, it has not been determined yet whether this correlation also exists in other Vitis vinifera varieties. This study investigated the evolution of free and glycosidically bound monoterpenes in two Vitis vinifera variety "Muscat blanc à Petit" and "Gewurztraminer" under two vintages, and further assessed the relation between the accumulation of bound monoterpenes and two monoterpenyl glycosyltransferase transcript levels. Results showed that free monoterpenes exhibited three evolution patterns in both varieties during berry development of two vintages, whereas glycosidically bound monoterpenes showed a concentration elevation with berry maturation. The Cis -rose oxide and geraniol were major components contributing to the aroma odors of "Gewürztraminer" grapes while linalool was major aroma contributor to the "Muscat blanc à Petit grain" grapes. The accumulation of glycosidically bound monoterpenes in both varieties was accompanied with the high expression of VvGT7 (XM_002276510.2) and VvGT14 . Only one allele of VvGT7 was found in the variety "Gewürztraminer" and no mutation was observed in its enzyme active sites. XB-VvGT7-4 and XB-VvGT7-5 were two alleles of VvGT7 detected in "Muscat blanc à Petit grain." The mutation on its enzyme active site inhibited the activity of XB-VvGT7-4 , whereas VvGT7-5 exhibited an alteration on enzyme activity due to the insertion mutation at the position 443. Only one VvGT14 allele was found in both varieties, and the VvGT14 allele in both varieties showed the similarity on amino acid sequence. No mutation occurred in active sites of VvGT14 allele. These indicated that VvGT7 and VvGT14 differentially contributed to the production of monoterpenyl glycosides in these Vitis Vinifera varieties.

Isolation of Monoterpene Dihydrochalcones from Piper montealegreanum Yuncker (Piperaceae).

PubMed

Alves, Harley da Silva; Rocha, Wilma Raianny Vieira da; Braz-Filho, Raimundo; Chaves, Maria Célia de Oliveira

2017-06-09

Four new compounds were isolated from the branches of Piper montealegreanum Yuncker, a shrub found in the Amazon rainforest, including two new dihydrochalcones named claricine ( 1 ) and maisine ( 2 ), a cinnamic acid derivative 3 and a phenylalkanoid 4 , along with a porphyrin identified as the known compound phaeophytin a ( 5 ). The structures were established using spectroscopic experiments, including 1D and 2D NMR and HRESIMS experiments, performed on the two monoterpene dihydrochalcones and their monoacetyl derivatives. The structural diversity of these substances is very important for the Piper genus chemotaxonomy.

The atmospheric impacts of monoterpene ozonolysis on global stabilised Criegee intermediate budgets and SO2 oxidation: experiment, theory and modelling

NASA Astrophysics Data System (ADS)

Newland, Mike J.; Rickard, Andrew R.; Sherwen, Tomás; Evans, Mathew J.; Vereecken, Luc; Muñoz, Amalia; Ródenas, Milagros; Bloss, William J.

2018-05-01

The gas-phase reaction of alkenes with ozone is known to produce stabilised Criegee intermediates (SCIs). These biradical/zwitterionic species have the potential to act as atmospheric oxidants for trace pollutants such as SO2, enhancing the formation of sulfate aerosol with impacts on air quality and health, radiative transfer and climate. However, the importance of this chemistry is uncertain as a consequence of limited understanding of the abundance and atmospheric fate of SCIs. In this work we apply experimental, theoretical and numerical modelling methods to quantify the atmospheric impacts, abundance and fate of the structurally diverse SCIs derived from the ozonolysis of monoterpenes, the second most abundant group of unsaturated hydrocarbons in the atmosphere. We have investigated the removal of SO2 by SCIs formed from the ozonolysis of three atmospherically important monoterpenes (α-pinene, β-pinene and limonene) in the presence of varying amounts of water vapour in large-scale simulation chamber experiments that are representative of boundary layer conditions. The SO2 removal displays a clear dependence on water vapour concentration, but this dependence is not linear across the range of [H2O] explored. At low [H2O] a strong dependence of SO2 removal on [H2O] is observed, while at higher [H2O] this dependence becomes much weaker. This is interpreted as being caused by the production of a variety of structurally (and hence chemically) different SCIs in each of the systems studied, which displayed different rates of reaction with water and of unimolecular rearrangement or decomposition. The determined rate constants, k(SCI+H2O), for those SCIs that react primarily with H2O range from 4 to 310 × 10-15 cm3 s-1. For those SCIs that predominantly react unimolecularly, determined rates range from 130 to 240 s-1. These values are in line with previous results for the (analogous) stereo-specific SCI system of syn-/anti-CH3CHOO. The experimental results are interpreted through theoretical studies of the SCI unimolecular reactions and bimolecular reactions with H2O, characterised for α-pinene and β-pinene at the M06-2X/aug-cc-pVTZ level of theory. The theoretically derived rates agree with the experimental results within the uncertainties. A global modelling study, applying the experimental results within the GEOS-Chem chemical transport model, suggests that > 97 % of the total monoterpene-derived global SCI burden is comprised of SCIs with a structure that determines that they react slowly with water and that their atmospheric fate is dominated by unimolecular reactions. Seasonally averaged boundary layer concentrations of monoterpene-derived SCIs reach up to 1.4 × 104 cm-3 in regions of elevated monoterpene emissions in the tropics. Reactions of monoterpene-derived SCIs with SO2 account for < 1 % globally but may account for up to 60 % of the gas-phase SO2 removal over areas of tropical forests, with significant localised impacts on the formation of sulfate aerosol and hence the lifetime and distribution of SO2.

Natural Variation in Monoterpene Synthesis in Kiwifruit: Transcriptional Regulation of Terpene Synthases by NAC and ETHYLENE-INSENSITIVE3-Like Transcription Factors1

PubMed Central

Nieuwenhuizen, Niels J.; Chen, Xiuyin; Wang, Mindy Y.; Matich, Adam J.; Perez, Ramon Lopez; Allan, Andrew C.; Green, Sol A.; Atkinson, Ross G.

2015-01-01

Two kiwifruit (Actinidia) species with contrasting terpene profiles were compared to understand the regulation of fruit monoterpene production. High rates of terpinolene production in ripe Actinidia arguta fruit were correlated with increasing gene and protein expression of A. arguta terpene synthase1 (AaTPS1) and correlated with an increase in transcript levels of the 2-C-methyl-d-erythritol 4-phosphate pathway enzyme 1-deoxy-d-xylulose-5-phosphate synthase (DXS). Actinidia chinensis terpene synthase1 (AcTPS1) was identified as part of an array of eight tandemly duplicated genes, and AcTPS1 expression and terpene production were observed only at low levels in developing fruit. Transient overexpression of DXS in Nicotiana benthamiana leaves elevated monoterpene synthesis by AaTPS1 more than 100-fold, indicating that DXS is likely to be the key step in regulating 2-C-methyl-d-erythritol 4-phosphate substrate flux in kiwifruit. Comparative promoter analysis identified potential NAC (for no apical meristem [NAM], Arabidopsis transcription activation factor [ATAF], and cup-shaped cotyledon [CUC])-domain transcription factor) and ETHYLENE-INSENSITIVE3-like transcription factor (TF) binding sites in the AaTPS1 promoter, and cloned members of both TF classes were able to activate the AaTPS1 promoter in transient assays. Electrophoretic mobility shift assays showed that AaNAC2, AaNAC3, and AaNAC4 bind a 28-bp fragment of the proximal NAC binding site in the AaTPS1 promoter but not the A. chinensis AcTPS1 promoter, where the NAC binding site was mutated. Activation could be restored by reintroducing multiple repeats of the 12-bp NAC core-binding motif. The absence of NAC transcriptional activation in ripe A. chinensis fruit can account for the low accumulation of AcTPS1 transcript, protein, and monoterpene volatiles in this species. These results indicate the importance of NAC TFs in controlling monoterpene production and other traits in ripening fruits. PMID:25649633

Characterization of a Root-Specific Arabidopsis Terpene Synthase Responsible for the Formation of the Volatile Monoterpene 1,8-Cineole1

PubMed Central

Chen, Feng; Ro, Dae-Kyun; Petri, Jana; Gershenzon, Jonathan; Bohlmann, Jörg; Pichersky, Eran; Tholl, Dorothea

2004-01-01

Arabidopsis is emerging as a model system to study the biochemistry, biological functions, and evolution of plant terpene secondary metabolism. It was previously shown that the Arabidopsis genome contains over 30 genes potentially encoding terpene synthases (TPSs). Here we report the characterization of a monoterpene synthase encoded by two identical, closely linked genes, At3g25820 and At3g25830. Transcripts of these genes were detected almost exclusively in roots. An At3g25820/At3g25830 cDNA was expressed in Escherichia coli, and the protein thus produced was shown to catalyze the formation of 10 volatile monoterpenes from geranyl diphosphate, with 1,8-cineole predominating. This protein was therefore designated AtTPS-Cin. The purified recombinant AtTPS-Cin displayed similar biochemical properties to other known monoterpene synthases, except for a relatively low Km value for geranyl diphosphate of 0.2 μm. At3g25820/At3g25830 promoter activity, measured with a β-glucuronidase (GUS) reporter gene, was primarily found in the epidermis, cortex, and stele of mature primary and lateral roots, but not in the root meristem or the elongation zone. Although the products of AtTPS-Cin were not detected by direct extraction of plant tissue, the recent report of 1,8-cineole as an Arabidopsis root volatile (Steeghs M, Bais HP, de Gouw J, Goldan P, Kuster W, Northway M, Fall R, Vivanco JM [2004] Plant Physiol 135: 47–58) suggests that the enzyme products may be released into the rhizosphere rather than accumulated. Among Arabidopsis TPSs, AtTPS-Cin is most similar to the TPS encoded by At3g25810, a closely linked gene previously shown to be exclusively expressed in flowers. At3g25810 TPS catalyzes the formation of a set of monoterpenes that is very similar to those produced by AtTPS-Cin, but its major products are myrcene and (E)-β-ocimene, and it does not form 1,8-cineole. These data demonstrate that divergence of organ expression pattern and product specificity are ongoing processes within the Arabidopsis TPS family. PMID:15299125

Natural variation in monoterpene synthesis in kiwifruit: transcriptional regulation of terpene synthases by NAC and ETHYLENE-INSENSITIVE3-like transcription factors.

PubMed

Nieuwenhuizen, Niels J; Chen, Xiuyin; Wang, Mindy Y; Matich, Adam J; Perez, Ramon Lopez; Allan, Andrew C; Green, Sol A; Atkinson, Ross G

2015-04-01

Two kiwifruit (Actinidia) species with contrasting terpene profiles were compared to understand the regulation of fruit monoterpene production. High rates of terpinolene production in ripe Actinidia arguta fruit were correlated with increasing gene and protein expression of A. arguta terpene synthase1 (AaTPS1) and correlated with an increase in transcript levels of the 2-C-methyl-D-erythritol 4-phosphate pathway enzyme 1-deoxy-D-xylulose-5-phosphate synthase (DXS). Actinidia chinensis terpene synthase1 (AcTPS1) was identified as part of an array of eight tandemly duplicated genes, and AcTPS1 expression and terpene production were observed only at low levels in developing fruit. Transient overexpression of DXS in Nicotiana benthamiana leaves elevated monoterpene synthesis by AaTPS1 more than 100-fold, indicating that DXS is likely to be the key step in regulating 2-C-methyl-D-erythritol 4-phosphate substrate flux in kiwifruit. Comparative promoter analysis identified potential NAC (for no apical meristem [NAM], Arabidopsis transcription activation factor [ATAF], and cup-shaped cotyledon [CUC])-domain transcription factor) and ETHYLENE-INSENSITIVE3-like transcription factor (TF) binding sites in the AaTPS1 promoter, and cloned members of both TF classes were able to activate the AaTPS1 promoter in transient assays. Electrophoretic mobility shift assays showed that AaNAC2, AaNAC3, and AaNAC4 bind a 28-bp fragment of the proximal NAC binding site in the AaTPS1 promoter but not the A. chinensis AcTPS1 promoter, where the NAC binding site was mutated. Activation could be restored by reintroducing multiple repeats of the 12-bp NAC core-binding motif. The absence of NAC transcriptional activation in ripe A. chinensis fruit can account for the low accumulation of AcTPS1 transcript, protein, and monoterpene volatiles in this species. These results indicate the importance of NAC TFs in controlling monoterpene production and other traits in ripening fruits. © 2015 American Society of Plant Biologists. All Rights Reserved.

Enhanced Oxidation of Isoprene and Monoterpenes in High and Low NOx Conditions

NASA Astrophysics Data System (ADS)

Tokarek, T. W.; Gilman, J.; Lerner, B. M.; Koss, A.; Yuan, B.; Taha, Y. M.; Osthoff, H. D.; Warneke, C.; De Gouw, J. A.

2015-12-01

In the troposphere, the photochemical oxidation of volatile organic compounds (VOCs) is primarily initiated by their reactions with the hydroxyl radical (OH) which yields peroxy radicals (HO2 and RO2). Concentrations of OH and the rates of VOC oxidation depend on the efficiency of peroxy radical recycling to OH. Radical recycling mainly occurs through reaction of HO2 with NO to produce NO2 and, ultimately, ozone (O3). Hence, the rate of VOC oxidation is dependent on NOx (=NO+NO2) concentration. The Shale Oil and Natural Gas Nexus (SONGNEX) campaign was conducted from March 17 to April 29, 2015 with the main goal of identifying and quantifying industrial sources of pollutants throughout the United States, in particular those associated with the production of oil and natural gas. In this work, a case study of biogenic VOC oxidation within and outside a power plant plume in the Haynesville basin near the border of Texas and Louisiana is presented. Isoprene, monoterpenes and their oxides were measured by H3O+ chemical ionization mass spectrometry (H3O+ CIMS) in high time resolution (1 s). Further, an improved Whole Air Sampler (iWAS) was used to collect samples for post-flight analysis by gas chromatography mass spectrometric detection (GC-MS) and yielded speciated quantification of biogenic VOCs. The monoterpene oxide to monoterpene ratio follows the spatial extent of the plume as judged by another tracer (NOx), tracking the enhancement of oxidation rates by NOx. The observations are rationalized with the aid of box modeling using the Master Chemical Mechanism (MCM).

De novo post-illumination monoterpene burst in Quercus ilex (holm oak).

PubMed

Srikanta Dani, K G; Marino, Giovanni; Taiti, Cosimo; Mancuso, Stefano; Atwell, Brian J; Loreto, Francesco; Centritto, Mauro

2017-02-01

Explicit proof for de novo origin of a rare post-illumination monoterpene burst and its consistency under low O 2 , shows interaction of photorespiration, photosynthesis, and isoprenoid biosynthesis during light-dark transitions. Quercus ilex L (holm oak) constitutively emits foliar monoterpenes in an isoprene-like fashion via the methyl erythritol phosphate (MEP) pathway located in chloroplasts. Isoprene-emitting plants are known to exhibit post-illumination isoprene burst, a transient emission of isoprene in darkness. An analogous post-illumination monoterpene burst (PiMB) had remained elusive and is reported here for the first time in Q. ilex. Using 13 CO 2 labelling, we show that PiMB is made from freshly fixed carbon. PiMB is rare at ambient (20%) O 2 , absent at high (50%) O 2 , and becomes consistent in leaves exposed to low (2%) O 2 . PiMB is stronger and occurs earlier at higher temperatures. We also show that primary and secondary post-illumination CO 2 bursts (PiCO 2 B) are sensitive to O 2 in Q. ilex. The primary photorespiratory PiCO 2 B is absent under both ambient and low O 2 , but is induced under high (>50%) O 2 , while the secondary PiCO 2 B (of unknown origin) is absent under ambient, but present at low and high O 2 . We propose that post-illumination recycling of photorespired CO 2 competes with the MEP pathway for photosynthetic carbon and energy, making PiMB rare under ambient O 2 and absent at high O 2 . PiMB becomes consistent when photorespiration is suppressed in Q. ilex.

Significance of wood terpenoids in the resistance of Scots pine provenances against the old house borer, Hylotrupes bajulus, and brown-rot fungus, Coniophora puteana.

PubMed

Nerg, A M; Heijari, J; Noldt, U; Viitanen, H; Vuorinen, M; Kainulainen, P; Holopainen, J K

2004-01-01

We tested how terpenoid (i.e., monoterpenes and resin acids) composition and concentration in wood affects resistance against wood-borers and decaying fungi. Scots pine (Pinus sylvestris) wood from nine provenances having variable terpenoid profiles was studied against the old house borer, Hylotrupes bajulus, and the decay fungus, Coniophora puteana. Provenances represented a 1200-km N-S transect from Estonia to northern Finland, but they were all cultivated for 7 years in the same nursery field, in central Finland. Mean relative growth rate (MRGR) of small H. hajulus larvae positively correlated with the total monoterpene concentration of wood, and feeding was associated with high proportion of levopimaric+palustric acid in wood. Provenance did not affect the MRGR of small or big larvae, but big larvae consumed more wood and produced more frass on the northern Ylitornio trees than on the southern Rakvere and Ruokolahti trees. Low beta-pinene and total monoterpene concentration and low beta: alpha-pinene ratio in wood were all associated with a high number of eggs. The most northern Muonio provenance was the most favored as an oviposition site, differing significantly from Saaremaa, Tenhola, and Suomussalmi. Wood from Saaremaa, Tenhola, Ruokolahti, and Suomussalmi provenance was most resistant against decay fungus, differing significantly from that of Kinnula provenance. However, decay resistance was not clearly associated with the concentrations of wood terpenoids. These results suggest that monoterpene composition of wood affects resistance against wood-boring Cerambycid beetles, but resistance against wood-decaying fungi is not as clearly associated with wood terpenoids.

Terpene exposure and respiratory effects among workers in Swedish joinery shops.

PubMed

Eriksson, K A; Levin, J O; Sandström, T; Lindström-Espeling, K; Lindén, G; Stjernberg, N L

1997-04-01

Exposure to monoterpenes (alpha-pinene, beta-pinene and delta 3-carene) in joinery shops was studied in Sweden during the processing of Scot's pine, and the acute respiratory effects among the employees were evaluated. A cross-sectional study of 38 workers was carried out in 4 joinery shops. The investigation included personal air sampling of monoterpenes, biological monitoring of metabolites of alpha-pinene in the workers' urine, interviews following a standardized questionnaire, and dynamic spirometry. The personal exposure to monoterpenes in the joinery shops was 10-214 mg/m3. The correlation (correlation coefficient = 0.69) between exposure to alpha-pinene and verbenols (metabolites from alpha-pinene) in urine was relatively good. No acute effects on forced vital capacity or forced expiratory volume during 1 s were detected. The workers had significantly reduced preshift lung function values when compared with the values of a local reference group, even when smokers and ex-smokers were excluded. Personal exposure to the monoterpenes alpha-pinene, and delta 3-carene in joinery shops may exceed the present Swedish occupational exposure limit of 150 mg/m3 during the winter season when workroom air is commonly recirculated. The determination of metabolites of alpha-pinene (verbenols) in urine can be used as an index of exposure to fumes released during wood-treating processes. The results from the lung function tests indicate chronic rather than acute reactions in the airways. The fact that there were no major changes in lung function over a workshift indicates chronic reaction in the airways.

Geraniol and geranyl acetate induce potent anticancer effects in colon cancer Colo-205 cells by inducing apoptosis, DNA damage and cell cycle arrest.

PubMed

Qi, Fei; Yan, Qiang; Zheng, Zhaozheng; Liu, Jian; Chen, Yan; Zhang, Guiyang

2018-01-01

Colon cancer ranks second in mortality among all human malignancies, creating thus a need for exploration of novel molecules that would prove effective, cost-effective and with lower toxicity. In the recent past monoterpenes have gained tremendous attention for their anticancer activity. In the present study we evaluated the anticancer effects of two important monoterpenes, geraniol and geranyl acetate against colo-205 cancer cells. The antiproliferative activity was determined by MTT assay. Apoptosis was assessed by DAPI staining and DNA damage was checked by comet assay. The cell cycle analysis was carried out by flow cytometry and protein expression was examined by western blotting. The results showed that both geraniol and geranyl acetate exhibited significant anticancer activity against colo-205 cancer cell line with IC50 values of 20 and 30 μM respectively. To find out the underlying mechanism, DAPI staining was carried out and it was observed that both the monoterpenes, geraniol and geranyl acetate, induced apoptosis in colo-205 cells. The apoptosis was also associated with upregulation of Bax and downregulation of Bcl-2 expressions, indicative of mitochondrial apoptosis. Moreover, these two monoterpenes could trigger DNA damage and G2/M cell cycle arrest in colo-205 cells. Taken together, we propose that geraniol and geranyl acetate may prove to be important lead molecular candidates for the treatment of colon cancer. Their anticancer activity can be attributed to the ability to trigger apoptosis, DNA damage and cell cycle arrest.

Global emissions of terpenoid VOCs from terrestrial vegetation in the last millennium.

PubMed

Acosta Navarro, J C; Smolander, S; Struthers, H; Zorita, E; Ekman, A M L; Kaplan, J O; Guenther, A; Arneth, A; Riipinen, I

2014-06-16

We investigated the millennial variability (1000 A.D.-2000 A.D.) of global biogenic volatile organic compound (BVOC) emissions by using two independent numerical models: The Model of Emissions of Gases and Aerosols from Nature (MEGAN), for isoprene, monoterpene, and sesquiterpene, and Lund-Potsdam-Jena-General Ecosystem Simulator (LPJ-GUESS), for isoprene and monoterpenes. We found the millennial trends of global isoprene emissions to be mostly affected by land cover and atmospheric carbon dioxide changes, whereas monoterpene and sesquiterpene emission trends were dominated by temperature change. Isoprene emissions declined substantially in regions with large and rapid land cover change. In addition, isoprene emission sensitivity to drought proved to have significant short-term global effects. By the end of the past millennium MEGAN isoprene emissions were 634 TgC yr -1 (13% and 19% less than during 1750-1850 and 1000-1200, respectively), and LPJ-GUESS emissions were 323 TgC yr -1 (15% and 20% less than during 1750-1850 and 1000-1200, respectively). Monoterpene emissions were 89 TgC yr -1 (10% and 6% higher than during 1750-1850 and 1000-1200, respectively) in MEGAN, and 24 TgC yr -1 (2% higher and 5% less than during 1750-1850 and 1000-1200, respectively) in LPJ-GUESS. MEGAN sesquiterpene emissions were 36 TgC yr -1 (10% and 4% higher than during 1750-1850 and 1000-1200, respectively). Although both models capture similar emission trends, the magnitude of the emissions are different. This highlights the importance of building better constraints on VOC emissions from terrestrial vegetation.

Potential Contribution of Fish Feed and Phytoplankton to the Content of Volatile Terpenes in Cultured Pangasius (Pangasianodon hypophthalmus) and Tilapia (Oreochromis niloticus).

PubMed

Podduturi, Raju; Petersen, Mikael A; Mahmud, Sultan; Rahman, Md Mizanur; Jørgensen, Niels O G

2017-05-10

Geosmin and 2-methylisoborneol are the most recognized off-flavors in freshwater fish, but terpenes may also contribute off-flavor in fish. We identified six monoterpenes, 11 sesquiterpenes, and three terpene-related compounds in pangasius and tilapia from aquaculture farms in Bangladesh. The concentrations of most of the volatiles were below published odor thresholds, except for α-pinene, limonene, β-caryophyllene, α-humulene, and β-ionone in tilapia, and limonene and β-ionone in pangasius. To identify sources of the terpenes, terpene profiles of fish feed and phytoplankton in the ponds were analyzed. In feed and mustard cake (feed ingredient), five monoterpenes and two sesquiterpenes were identified, and five of these compounds were also detected in the fish. In phytoplankton, 11 monoterpenes were found and three also occurred in the fish. The higher number of terpenes common to both fish and feed, than to fish and phytoplankton, suggests that feed was a more abundant source of odor-active terpenes in the fish than phytoplankton.

Boundary layer concentrations and landscape scale emissions of volatile organic compounds in early spring

NASA Astrophysics Data System (ADS)

Haapanala, S.; Rinne, J.; Hakola, H.; Hellén, H.; Laakso, L.; Lihavainen, H.; Janson, R.; O'Dowd, C.; Kulmala, M.

2007-04-01

Boundary layer concentrations of several volatile organic compounds (VOC) were measured during two campaigns in springs of 2003 and 2006. The measurements were conducted over boreal landscapes near SMEAR II measurement station in Hyytiälä, Southern Finland. In 2003 the measuremens were performed using a light aircraft and in 2006 using a hot air balloon. Isoprene concentrations were low, usually below detection limit. This can be explained by low biogenic production due to cold weather, phenological stage of the isoprene emitting plants, and snow cover. Monoterpenes were observed frequently. The average total monoterpene concentration in the boundary layer was 33 pptv. Many anthropogenic compounds such as benzene, xylene and toluene, were observed in high amounts. Ecosystem scale surface emissions were estimated using a simple mixed box budget methodology. Total monoterpene emissions varied up to 80 μg m-2 h-1, α-pinene contributing typically more than two thirds of that. These emissions were somewhat higher that those calculated using emission algorithm. The highest emissions of anthropogenic compounds were those of p/m xylene.

Volatile chemicals identified in extracts from leaves of Japanese mugwort (Artemisia princeps pamp.).

PubMed

Umano, K; Hagi, Y; Nakahara, K; Shoji, A; Shibamoto, T

2000-08-01

Extracts from leaves of Japanese mugwort (Artemisia princeps Pamp.) were obtained using two methods: steam distillation under reduced pressure followed by dichloromethane extraction (DRP) and simultaneous purging and extraction (SPSE). A total of 192 volatile chemicals were identified in the extracts obtained by both methods using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). They included 47 monoterpenoids (oxygenated monoterpenes), 26 aromatic compounds, 19 aliphatic esters, 18 aliphatic alcohols, 17 monoterpenes (hydrocarbon monoterpenes), 17 sesquiterpenes (hydrocarbon sesquiterpenes), 13 sesquiterpenoids (oxygenated sesquiterpenes), 12 aliphatic aldehydes, 8 aliphatic hydrocarbons, 7 aliphatic ketones, and 9 miscellaneous compounds. The major volatile constituents of the extract by DRP were borneol (10.27 ppm), alpha-thujone (3.49 ppm), artemisia alcohol (2.17 ppm), verbenone (1.85 ppm), yomogi alcohol (1.50 ppm), and germacren-4-ol (1.43 ppm). The major volatile constituents of the extract by SPSE were 1,8-cineole (8.12 ppm), artemisia acetate (4.22 ppm), alpha-thujone (3.20 ppm), beta-caryophyllene (2.39 ppm), bornyl acetate (2.05 ppm), borneol (1.80 ppm), and trans-beta-farnesene (1. 78 ppm).

Cloning and functional characterization of three terpene synthases from lavender (Lavandula angustifolia).

PubMed

Landmann, Christian; Fink, Barbara; Festner, Maria; Dregus, Márta; Engel, Karl-Heinz; Schwab, Wilfried

2007-09-15

The essential oil of lavender (Lavandula angustifolia) is mainly composed of mono- and sesquiterpenes. Using a homology-based PCR strategy, two monoterpene synthases (LaLIMS and LaLINS) and one sesquiterpene synthase (LaBERS) were cloned from lavender leaves and flowers. LaLIMS catalyzed the formation of (R)-(+)-limonene, terpinolene, (1R,5S)-(+)-camphene, (1R,5R)-(+)-alpha-pinene, beta-myrcene and traces of alpha-phellandrene. The proportions of these products changed significantly when Mn(2+) was supplied as the cofactor instead of Mg(2+). The second enzyme LaLINS produced exclusively (R)-(-)-linalool, the main component of lavender essential oil. LaBERS transformed farnesyl diphosphate and represents the first reported trans-alpha-bergamotene synthase. It accepted geranyl diphosphate with higher affinity than farnesyl diphosphate and also produced monoterpenes, albeit at low rates. LaBERS is probably derived from a parental monoterpene synthase by the loss of the plastidial signal peptide and by broadening its substrate acceptance spectrum. The identification and description of the first terpene synthases from L. angustifolia forms the basis for the biotechnological modification of essential oil composition in lavender.

SOA formation potential of emissions from soil and leaf litter.

PubMed

Faiola, Celia L; Vanderschelden, Graham S; Wen, Miao; Elloy, Farah C; Cobos, Douglas R; Watts, Richard J; Jobson, B Thomas; Vanreken, Timothy M

2014-01-21

Soil and leaf litter are significant global sources of small oxidized volatile organic compounds, VOCs (e.g., methanol and acetaldehyde). They may also be significant sources of larger VOCs that could act as precursors to secondary organic aerosol (SOA) formation. To investigate this, soil and leaf litter samples were collected from the University of Idaho Experimental Forest and transported to the laboratory. There, the VOC emissions were characterized and used to drive SOA formation via dark, ozone-initiated reactions. Monoterpenes dominated the emission profile with emission rates as high as 228 μg-C m(-2) h(-1). The composition of the SOA produced was similar to biogenic SOA formed from oxidation of ponderosa pine emissions and α-pinene. Measured soil and litter monoterpene emission rates were compared with modeled canopy emissions. Results suggest surface soil and litter monoterpene emissions could range from 12 to 136% of canopy emissions in spring and fall. Thus, emissions from leaf litter may potentially extend the biogenic emissions season, contributing to significant organic aerosol formation in the spring and fall when reduced solar radiation and temperatures reduce emissions from living vegetation.

Sweet Marjoram

PubMed Central

Bina, Fatemeh; Rahimi, Roja

2016-01-01

Origanum majorana L. commonly known as sweet marjoram has been used for variety of diseases in traditional and folklore medicines, including gastrointestinal, ocular, nasopharyngeal, respiratory, cardiac, rheumatologic, and neurological disorders. Essential oil containing monoterpene hydrocarbons and oxygenated monoterpenes as well as phenolic compounds are chemical constituents isolated and detected in O majorana. Wide range of pharmacological activities including antioxidant, hepatoprotective, cardioprotective, anti-platelet, gastroprotective, antibacterial and antifungal, antiprotozoal, antiatherosclerosis, anti-inflammatory, antimetastatic, antitumor, antiulcer, and anticholinesterase inhibitory activities have been reported from this plant in modern medicine. This article summarizes comprehensive information concerning traditional uses, phytochemistry, and pharmacological activities of sweet marjoram. PMID:27231340

Molecular Diversity of Terpene Synthases in the Liverwort Marchantia polymorpha[OPEN

PubMed Central

Zhuang, Xun; Jiang, Zuodong; Jia, Qidong; Babbitt, Patricia C.

2016-01-01

Marchantia polymorpha is a basal terrestrial land plant, which like most liverworts accumulates structurally diverse terpenes believed to serve in deterring disease and herbivory. Previous studies have suggested that the mevalonate and methylerythritol phosphate pathways, present in evolutionarily diverged plants, are also operative in liverworts. However, the genes and enzymes responsible for the chemical diversity of terpenes have yet to be described. In this study, we resorted to a HMMER search tool to identify 17 putative terpene synthase genes from M. polymorpha transcriptomes. Functional characterization identified four diterpene synthase genes phylogenetically related to those found in diverged plants and nine rather unusual monoterpene and sesquiterpene synthase-like genes. The presence of separate monofunctional diterpene synthases for ent-copalyl diphosphate and ent-kaurene biosynthesis is similar to orthologs found in vascular plants, pushing the date of the underlying gene duplication and neofunctionalization of the ancestral diterpene synthase gene family to >400 million years ago. By contrast, the mono- and sesquiterpene synthases represent a distinct class of enzymes, not related to previously described plant terpene synthases and only distantly so to microbial-type terpene synthases. The absence of a Mg2+ binding, aspartate-rich, DDXXD motif places these enzymes in a noncanonical family of terpene synthases. PMID:27650333

Respiratory symptoms and lung function in relation to wood dust and monoterpene exposure in the wood pellet industry.

PubMed

Löfstedt, Håkan; Hagström, Katja; Bryngelsson, Ing-Liss; Holmström, Mats; Rask-Andersen, Anna

2017-06-01

Wood pellets are used as a source of renewable energy for heating purposes. Common exposures are wood dust and monoterpenes, which are known to be hazardous for the airways. The purpose of this study was to study the effect of occupational exposure on respiratory health in wood pellet workers. Thirty-nine men working with wood pellet production at six plants were investigated with a questionnaire, medical examination, allergy screening, spirometry, and nasal peak expiratory flow (nasal PEF). Exposure to wood dust and monoterpenes was measured. The wood pellet workers reported a higher frequency of nasal symptoms, dry cough, and asthma medication compared to controls from the general population. There were no differences in nasal PEF between work and leisure time. A lower lung function than expected (vital capacity [VC], 95%; forced vital capacity in 1 second [FEV 1 ], 96% of predicted) was noted, but no changes were noted during shifts. There was no correlation between lung function and years working in pellet production. Personal measurements of wood dust at work showed high concentrations (0.16-19 mg/m 3 ), and exposure peaks when performing certain work tasks. Levels of monoterpenes were low (0.64-28 mg/m 3 ). There was no association between exposure and acute lung function effects. In this study of wood pellet workers, high levels of wood dust were observed, and that may have influenced the airways negatively as the study group reported upper airway symptoms and dry cough more frequently than expected. The wood pellet workers had both a lower VC and FEV 1 than expected. No cross-shift changes were found.

Characterization of two monoterpene synthases involved in floral scent formation in Hedychium coronarium.

PubMed

Yue, Yuechong; Yu, Rangcai; Fan, Yanping

2014-10-01

Hedychium coronarium, a perennial herb belonging to the family Zingiberaceae, is cultivated as a garden plant or cut flower as well as for medicine and aromatic oil. Its flowers emit a fresh and inviting scent, which is mainly because of monoterpenes present in the profile of the floral volatiles. However, fragrance produced as a result of monoterpenes has not been well studied. In the present study, two novel terpene synthase (TPS) genes (HcTPS7 and HcTPS8) were isolated to study the biosynthesis of monoterpenes in H. coronarium. In vitro characterization showed that the recombinant HcTPS7 was capable of generating sabinene as its main product, in addition to nine sub-products from geranyl diphosphate (GPP). Recombinant HcTPS8 almost specifically catalyzed the formation of linalool from GPP, while it converted farnesyl diphosphate (FPP) to α-bergamotene, cis-α-bisabolene, β-farnesene and other ten sesquiterpenes. Subcellular localization experiments revealed that HcTPS7 and HcTPS8 were located in plastids. Real-time PCR analyses showed that HcTPS7 and HcTPS8 genes were highly expressed in petals and sepals, but were almost undetectable in vegetative organs. The changes of their expression levels in petals were positively correlated with the emission patterns of sabinene and linalool, respectively, during flower development. The results indicated that HcTPS7 and HcTPS8 were involved in the biosynthesis of sabinene and linalool in H. coronarium flowers. Results on these two TPSs first characterized from H. coronarium provide new insights into molecular mechanisms of terpene biosynthesis in this species and also lay the basis for biotechnological modification of floral scent profile in Hedychium.

Transcriptome resources and functional characterization of monoterpene synthases for two host species of the mountain pine beetle, lodgepole pine (Pinus contorta) and jack pine (Pinus banksiana)

PubMed Central

2013-01-01

Background The mountain pine beetle (MPB, Dendroctonus ponderosae) epidemic has affected lodgepole pine (Pinus contorta) across an area of more than 18 million hectares of pine forests in western Canada, and is a threat to the boreal jack pine (Pinus banksiana) forest. Defence of pines against MPB and associated fungal pathogens, as well as other pests, involves oleoresin monoterpenes, which are biosynthesized by families of terpene synthases (TPSs). Volatile monoterpenes also serve as host recognition cues for MPB and as precursors for MPB pheromones. The genes responsible for terpene biosynthesis in jack pine and lodgepole pine were previously unknown. Results We report the generation and quality assessment of assembled transcriptome resources for lodgepole pine and jack pine using Sanger, Roche 454, and Illumina sequencing technologies. Assemblies revealed transcripts for approximately 20,000 - 30,000 genes from each species and assembly analyses led to the identification of candidate full-length prenyl transferase, TPS, and P450 genes of oleoresin biosynthesis. We cloned and functionally characterized, via expression of recombinant proteins in E. coli, nine different jack pine and eight different lodgepole pine mono-TPSs. The newly identified lodgepole pine and jack pine mono-TPSs include (+)-α-pinene synthases, (-)-α-pinene synthases, (-)-β-pinene synthases, (+)-3-carene synthases, and (-)-β-phellandrene synthases from each of the two species. Conclusion In the absence of genome sequences, transcriptome assemblies are important for defence gene discovery in lodgepole pine and jack pine, as demonstrated here for the terpenoid pathway genes. The product profiles of the functionally annotated mono-TPSs described here can account for the major monoterpene metabolites identified in lodgepole pine and jack pine. PMID:23679205

Global emissions of terpenoid VOCs from terrestrial vegetation in the last millennium

PubMed Central

Acosta Navarro, J C; Smolander, S; Struthers, H; Zorita, E; Ekman, A M L; Kaplan, J O; Guenther, A; Arneth, A; Riipinen, I

2014-01-01

We investigated the millennial variability (1000 A.D.–2000 A.D.) of global biogenic volatile organic compound (BVOC) emissions by using two independent numerical models: The Model of Emissions of Gases and Aerosols from Nature (MEGAN), for isoprene, monoterpene, and sesquiterpene, and Lund-Potsdam-Jena-General Ecosystem Simulator (LPJ-GUESS), for isoprene and monoterpenes. We found the millennial trends of global isoprene emissions to be mostly affected by land cover and atmospheric carbon dioxide changes, whereas monoterpene and sesquiterpene emission trends were dominated by temperature change. Isoprene emissions declined substantially in regions with large and rapid land cover change. In addition, isoprene emission sensitivity to drought proved to have significant short-term global effects. By the end of the past millennium MEGAN isoprene emissions were 634 TgC yr−1 (13% and 19% less than during 1750–1850 and 1000–1200, respectively), and LPJ-GUESS emissions were 323 TgC yr−1(15% and 20% less than during 1750–1850 and 1000–1200, respectively). Monoterpene emissions were 89 TgC yr−1(10% and 6% higher than during 1750–1850 and 1000–1200, respectively) in MEGAN, and 24 TgC yr−1 (2% higher and 5% less than during 1750–1850 and 1000–1200, respectively) in LPJ-GUESS. MEGAN sesquiterpene emissions were 36 TgC yr−1(10% and 4% higher than during 1750–1850 and 1000–1200, respectively). Although both models capture similar emission trends, the magnitude of the emissions are different. This highlights the importance of building better constraints on VOC emissions from terrestrial vegetation. PMID:25866703

A qualitative comparison of secondary organic aerosol yields and composition from ozonolysis of monoterpenes at varying concentrations of NO2

NASA Astrophysics Data System (ADS)

Draper, D. C.; Farmer, D. K.; Desyaterik, Y.; Fry, J. L.

2015-11-01

The effect of NO2 on secondary organic aerosol (SOA) formation from ozonolysis of α-pinene, β-pinene, Δ3-carene, and limonene was investigated using a dark flow-through reaction chamber. SOA mass yields were calculated for each monoterpene from ozonolysis with varying NO2 concentrations. Kinetics modeling of the first-generation gas-phase chemistry suggests that differences in observed aerosol yields for different NO2 concentrations are consistent with NO3 formation and subsequent competition between O3 and NO3 to oxidize each monoterpene. α-Pinene was the only monoterpene studied that showed a systematic decrease in both aerosol number concentration and mass concentration with increasing [NO2]. β-Pinene and Δ3-carene produced fewer particles at higher [NO2], but both retained moderate mass yields. Limonene exhibited both higher number concentrations and greater mass concentrations at higher [NO2]. SOA from each experiment was collected and analyzed by HPLC-ESI-MS, enabling comparisons between product distributions for each system. In general, the systems influenced by NO3 oxidation contained more high molecular weight products (MW > 400 amu), suggesting the importance of oligomerization mechanisms in NO3-initiated SOA formation. α-Pinene, which showed anomalously low aerosol mass yields in the presence of NO2, showed no increase in these oligomer peaks, suggesting that lack of oligomer formation is a likely cause of α-pinene's near 0 % yields with NO3. Through direct comparisons of mixed-oxidant systems, this work suggests that NO3 is likely to dominate nighttime oxidation pathways in most regions with both biogenic and anthropogenic influences. Therefore, accurately constraining SOA yields from NO3 oxidation, which vary substantially with the volatile organic compound precursor, is essential in predicting nighttime aerosol production.

A comparison of secondary organic aerosol (SOA) yields and composition from ozonolysis of monoterpenes at varying concentrations of NO2

NASA Astrophysics Data System (ADS)

Draper, D. C.; Farmer, D. K.; Desyaterik, Y.; Fry, J. L.

2015-05-01

The effect of NO2 on secondary organic aerosol (SOA) formation from ozonolysis of α-pinene, β-pinene, Δ3-carene, and limonene was investigated using a dark flow-through reaction chamber. SOA mass yields were calculated for each monoterpene from ozonolysis with varying NO2 concentrations. Kinetics modeling of the first generation gas-phase chemistry suggests that differences in observed aerosol yields for different NO2 concentrations are consistent with NO3 formation and subsequent competition between O3 and NO3 to oxidize each monoterpene. α-pinene was the only monoterpene studied that showed a systematic decrease in both aerosol number concentration and mass concentration with increasing [NO2]. β-pinene and Δ3-carene produced fewer particles at higher [NO2], but both retained moderate mass yields. Limonene exhibited both higher number concentrations and greater mass concentrations at higher [NO2]. SOA from each experiment was collected and analyzed by HPLC-ESI-MS, enabling comparisons between product distributions for each system. In general, the systems influenced by NO3 oxidation contained more high molecular weight products (MW >400 amu), suggesting the importance of oligomerization mechanisms in NO3-initiated SOA formation. α-pinene, which showed anomalously low aerosol mass yields in the presence of NO2, showed no increase in these oligomer peaks, suggesting that lack of oligomer formation is a likely cause of α-pinene's near 0% yields with NO3. Through direct comparisons of mixed-oxidant systems, this work suggests that NO3 is likely to dominate nighttime oxidation pathways in most regions with both biogenic and anthropogenic influences. Therefore, accurately constraining SOA yields from NO3 oxidation, which vary substantially with the VOC precursor, is essential in predicting nighttime aerosol production.

Physiological and Transcriptional Responses of Saccharomyces cerevisiae to d-Limonene Show Changes to the Cell Wall but Not to the Plasma Membrane

PubMed Central

Brennan, Timothy C. R.; Nielsen, Lars K.

2013-01-01

Monoterpenes can, upon hydrogenation, be used as light-fraction components of sustainable aviation fuels. Fermentative production of monoterpenes in engineered microorganisms, such as Saccharomyces cerevisiae, has gained attention as a potential route to deliver these next-generation fuels from renewable biomass. However, end product toxicity presents a formidable problem for microbial synthesis. Due to their hydrophobicity, monoterpene inhibition has long been attributed to membrane interference, but the molecular mechanism remains largely unsolved. In order to gain a better understanding of the mode of action, we analyzed the composition and structural integrity of the cell envelope as well as the transcriptional response of yeast cells treated with an inhibitory amount of d-limonene (107 mg/liter). We found no alterations in membrane fluidity, structural membrane integrity, or fatty acid composition after the solvent challenge. A 4-fold increase in the mean fluorescence intensity per cell (using calcofluor white stain) and increased sensitivity to cell wall-degrading enzymes demonstrated that limonene disrupts cell wall properties. Global transcript measurements confirmed the membrane integrity observations by showing no upregulation of ergosterol or fatty acid biosynthesis pathways, which are commonly overexpressed in yeast to reinforce membrane rigidity during ethanol exposure. Limonene shock did cause a compensatory response to cell wall damage through overexpression of several genes (ROM1, RLM1, PIR3, CTT1, YGP1, MLP1, PST1, and CWP1) involved with the cell wall integrity signaling pathway. This is the first report demonstrating that cell wall, rather than plasma membrane, deterioration is the main source of monoterpene inhibition. We show that limonene can alter the structure and function of the cell wall, which has a clear effect on cytokinesis. PMID:23542628

Novel polymeric micelles for insect pest control: encapsulation of essential oil monoterpenes inside a triblock copolymer shell for head lice control.

PubMed

Lucia, Alejandro; Toloza, Ariel Ceferino; Guzmán, Eduardo; Ortega, Francisco; Rubio, Ramón G

2017-01-01

Essential oil components (EOCs) are molecules with interesting application in pest control, these have been evaluated against different insect pest from more than 100 years, but their practical use is rather limited. Thus, the enhancement of their bioavailability and manageability due to their dispersion in water can open new perspective for the preparation of formulations for the control of insect pest. In this work, we studied the encapsulation of different monoterpenes in a poloxamer shell in order to prepare aqueous formulations that can be used for the development of platforms used in pest control. Micellar systems containing a 5 wt% of poloxamer 407 and 1.25 wt% of the different monoterpenes were prepared. Dynamic Light Scattering (DLS) experiments were carried out to characterize the dispersion of the EOCs in water. The pediculicidal activity of these micellar systems was tested on head lice using an ex vivo immersion test. The poloxamers allowed the dispersion of EOCs in water due to their encapsulation inside the hydrophobic core of the copolymer micelles. From this study, we concluded that it is possible to make stable micellar systems containing water (>90 wt%), 1.25 wt% of different monoterpenes and a highly safe polymer (5wt% Poloxamer 407). These formulations were effective against head lice with mortality ranging from 30 to 60%, being the most effective emulsions those containing linalool, 1,8-cineole, α -terpineol, thymol, eugenol, geraniol and nonyl alcohol which lead to mortalities above 50%. Since these systems showed good pediculicidal activity and high physicochemical stability, they could be a new route for the green fabrication of biocompatible and biosustainable insecticide formulations.

Biogenic emissions and CO 2 gas exchange investigated on four Mediterranean shrubs

NASA Astrophysics Data System (ADS)

Hansen, U.; van Eijk, J.; Bertin, N.; Staudt, M.; Kotzias, D.; Seufert, G.; Fugit, J.-L.; Torres, L.; Cecinato, A.; Brancaleoni, E.; Ciccioli, P.; Bomboi, T.

In order to investigate the impact of plant physiology on emissions of biogenic volatile organic compounds monoterpene emission rates from Rosmarinus officinalis (L.) and Pistacia lentiscus (L.) and isoprene emission rates from Erica arborea (L.) and Myrtus communis (L.) were determined. The study, an activity in the framework of BEMA (Biogenic Emissions in the Mediterranean Area), was carried out in May 1994 at Castelporziano near Rome in Italy, using a dynamic enclosure technique combined with recording CO 2 gas exchange, temperature and irradiance data. The monoterpenes dominating the emission pattern were 1,8-cineol, α-pinene and β-pinene for rosemary and α-pinene, linalool and β-pinene + sabinene for pistachio. Total monoterpene emission rates standardized to 30°C of 1.84 ± 0.24 and 0.35 ± 0.04 μg Cg -1 dw h -1 were found for rosemary and pistachio, respectively (on a leaf dry weight basis). Myrtle emitted 22.2 ± 4.9 μg C g -1 dw h -1 at standard conditions (30°C, PAR 1000 μmol photons m -2 s -1 as isoprene and erica 5.61 μg C g -1 dw h -1 The carbon loss due to terpenoid emissions per photosynthetically carbon uptake was about 0.01-0.1% for the monoterpene emitters. The isoprene emitting shrubs lost 0-0.9% of the assimilated carbon. The rapid induction of emissions in the sun after temporary shading indicates that isoprene emissions were closely linked to photosynthesis. A higher proportion of the assimilated carbon was lost as isoprene under conditions of high light and temperature compared to the morning and evening hours.

Quantitative Analysis of Bioactive Compounds from Aromatic Plants by Means of Dynamic Headspace Extraction and Multiple Headspace Extraction-Gas Chromatography-Mass Spectrometry.

PubMed

Omar, Jone; Olivares, Maitane; Alonso, Ibone; Vallejo, Asier; Aizpurua-Olaizola, Oier; Etxebarria, Nestor

2016-04-01

Seven monoterpenes in 4 aromatic plants (sage, cardamom, lavender, and rosemary) were quantified in liquid extracts and directly in solid samples by means of dynamic headspace-gas chromatography-mass spectrometry (DHS-GC-MS) and multiple headspace extraction-gas chromatography-mass spectrometry (MHSE), respectively. The monoterpenes were 1st extracted by means of supercritical fluid extraction (SFE) and analyzed by an optimized DHS-GC-MS. The optimization of the dynamic extraction step and the desorption/cryo-focusing step were tackled independently by experimental design assays. The best working conditions were set at 30 °C for the incubation temperature, 5 min of incubation time, and 40 mL of purge volume for the dynamic extraction step of these bioactive molecules. The conditions of the desorption/cryo-trapping step from the Tenax TA trap were set at follows: the temperature was increased from 30 to 300 °C at 150 °C/min, although the cryo-trapping was maintained at -70 °C. In order to estimate the efficiency of the SFE process, the analysis of monoterpenes in the 4 aromatic plants was directly carried out by means of MHSE because it did not require any sample preparation. Good linearity (r2) > 0.99) and reproducibility (relative standard deviation % <12) was obtained for solid and liquid quantification approaches, in the ranges of 0.5 to 200 ng and 10 to 500 ng/mL, respectively. The developed methods were applied to analyze the concentration of 7 monoterpenes in aromatic plants obtaining concentrations in the range of 2 to 6000 ng/g and 0.25 to 110 μg/mg, respectively. © 2016 Institute of Food Technologists®

Isolation and functional characterization of a methyl jasmonate-responsive 3-carene synthase from Lavandula x intermedia.

PubMed

Adal, Ayelign M; Sarker, Lukman S; Lemke, Ashley D; Mahmoud, Soheil S

2017-04-01

A methyl jasmonate responsive 3-carene synthase (Li3CARS) gene was isolated from Lavandula x intermedia and functionally characterized in vitro. Lavenders produce essential oils consisting mainly of monoterpenes, including the potent antimicrobial and insecticidal monoterpene 3-carene. In this study we isolated and functionally characterized a leaf-specific, methyl jasmonate (MeJA)-responsive monoterpene synthase (Li3CARS) from Lavandula x intermedia. The ORF excluding transit peptides encoded a 64.9 kDa protein that was expressed in E. coli, and purified with Ni-NTA agarose affinity chromatography. The recombinant Li3CARS converted GPP into 3-carene as the major product, with K m and k cat of 3.69 ± 1.17 µM and 2.01 s -1 respectively. Li3CARS also accepted NPP as a substrate to produce multiple products including a small amount of 3-carene. The catalytic efficiency of Li3CARS to produce 3-carene was over ten fold higher for GPP (k cat /K m = 0.56 µM -1 s -1 ) than NPP (k cat /K m = 0.044 µM -1 s -1 ). Production of distinct end product profiles from different substrates (GPP versus NPP) by Li3CARS indicates that monoterpene metabolism may be controlled in part through substrate availability. Li3CARS transcripts were found to be highly abundant in leaves (16-fold) as compared to flower tissues. The transcriptional activity of Li3CARS correlated with 3-carene production, and was up-regulated (1.18- to 3.8-fold) with MeJA 8-72 h post-treatment. The results suggest that Li3CARS may have a defensive role in Lavandula.

Respiratory symptoms and lung function in relation to wood dust and monoterpene exposure in the wood pellet industry

PubMed Central

Löfstedt, Håkan; Hagström, Katja; Bryngelsson, Ing-Liss; Holmström, Mats; Rask-Andersen, Anna

2017-01-01

Introduction Wood pellets are used as a source of renewable energy for heating purposes. Common exposures are wood dust and monoterpenes, which are known to be hazardous for the airways. The purpose of this study was to study the effect of occupational exposure on respiratory health in wood pellet workers. Materials and methods Thirty-nine men working with wood pellet production at six plants were investigated with a questionnaire, medical examination, allergy screening, spirometry, and nasal peak expiratory flow (nasal PEF). Exposure to wood dust and monoterpenes was measured. Results The wood pellet workers reported a higher frequency of nasal symptoms, dry cough, and asthma medication compared to controls from the general population. There were no differences in nasal PEF between work and leisure time. A lower lung function than expected (vital capacity [VC], 95%; forced vital capacity in 1 second [FEV1], 96% of predicted) was noted, but no changes were noted during shifts. There was no correlation between lung function and years working in pellet production. Personal measurements of wood dust at work showed high concentrations (0.16–19 mg/m3), and exposure peaks when performing certain work tasks. Levels of monoterpenes were low (0.64–28 mg/m3). There was no association between exposure and acute lung function effects. Conclusions In this study of wood pellet workers, high levels of wood dust were observed, and that may have influenced the airways negatively as the study group reported upper airway symptoms and dry cough more frequently than expected. The wood pellet workers had both a lower VC and FEV1 than expected. No cross-shift changes were found. PMID:28276782

Characterization of Geraniol Synthase from the Peltate Glands of Sweet Basil1

PubMed Central

Iijima, Yoko; Gang, David R.; Fridman, Eyal; Lewinsohn, Efraim; Pichersky, Eran

2004-01-01

The monoterpene fraction of the lemon-scented sweet basil (Ocimum basilicum) cv Sweet Dani consists mostly of citral (a mixture of geranial and neral), with lower levels of geraniol and nerol. These compounds are stored in the peltate glands found on the leaf epidermis. Younger leaves, which have a higher density of such glands, also have a higher content of monoterpenes than older leaves. Geraniol synthase (GES) activity, generating geraniol from geranyl diphosphate, was shown to be localized exclusively or almost exclusively to glands. GES activity resides in a homodimeric protein that was purified to near homogeneity. Basil GES requires Mn2+ as a divalent metal cofactor for activity and produces only geraniol from geranyl diphosphate. Km values of 21 and 51 μm were obtained for geranyl diphosphate and Mn2+, respectively. In the presence of 18O-labeled water, GES catalyzed the formation of 18O-geraniol from geranyl diphosphate, indicating that the reaction mechanism of GES is similar to that of other monoterpene synthases and is different from the action of phosphatases. A GES cDNA was isolated based on analysis of a glandular trichome expressed sequence tag database, and the sequence of the protein encoded by this cDNA shows some similarity to sequences of other terpene synthases. The expression of the GES cDNA in Escherichia coli resulted in a protein with enzymatic activity essentially identical to that of plant-purified GES. RNA gel-blot analysis indicated that GES is expressed in glands but not in leaves of basil cv Sweet Dani, whose glands contain geraniol and citral, and not in glands or leaves of another basil variety that makes other monoterpenes but not geraniol or citral. PMID:14657409

Novel polymeric micelles for insect pest control: encapsulation of essential oil monoterpenes inside a triblock copolymer shell for head lice control

PubMed Central

Guzmán, Eduardo; Ortega, Francisco; Rubio, Ramón G.

2017-01-01

Background Essential oil components (EOCs) are molecules with interesting application in pest control, these have been evaluated against different insect pest from more than 100 years, but their practical use is rather limited. Thus, the enhancement of their bioavailability and manageability due to their dispersion in water can open new perspective for the preparation of formulations for the control of insect pest. In this work, we studied the encapsulation of different monoterpenes in a poloxamer shell in order to prepare aqueous formulations that can be used for the development of platforms used in pest control. Methods Micellar systems containing a 5 wt% of poloxamer 407 and 1.25 wt% of the different monoterpenes were prepared. Dynamic Light Scattering (DLS) experiments were carried out to characterize the dispersion of the EOCs in water. The pediculicidal activity of these micellar systems was tested on head lice using an ex vivo immersion test. Results The poloxamers allowed the dispersion of EOCs in water due to their encapsulation inside the hydrophobic core of the copolymer micelles. From this study, we concluded that it is possible to make stable micellar systems containing water (>90 wt%), 1.25 wt% of different monoterpenes and a highly safe polymer (5wt% Poloxamer 407). These formulations were effective against head lice with mortality ranging from 30 to 60%, being the most effective emulsions those containing linalool, 1,8-cineole, α-terpineol, thymol, eugenol, geraniol and nonyl alcohol which lead to mortalities above 50%. Discussion Since these systems showed good pediculicidal activity and high physicochemical stability, they could be a new route for the green fabrication of biocompatible and biosustainable insecticide formulations. PMID:28439460

Drought stress leads to systemic induced susceptibility to a nectrotrophic fungus associated with mountain pine beetle in Pinus banksiana seedlings.

PubMed

Klutsch, Jennifer G; Shamoun, Simon Francis; Erbilgin, Nadir

2017-01-01

Conifers have complex defense responses to initial attacks by insects and pathogens that can have cascading effects on success of subsequent colonizers. However, drought can affect a plant's ability to respond to biotic agents by potentially altering the resources needed for the energetically costly production of induced defense chemicals. We investigated the impact of reduced water on induced chemical defenses of jack pine (Pinus banksiana) seedlings from initial attack by biotic agents and resistance to subsequent challenge inoculation with a pathogenic fungal associate of mountain pine beetle (Dendroctonus ponderosae), Grosmannia clavigera. Applications of phytohormones (methyl salicylate and methyl jasmonate) and G. clavigera were used for initial induction of defenses. Monoterpene concentrations varied with initial induction from fungal and phytohormone application while watering treatment had no effect. Seedlings treated with G. clavigera and methyl jasmonate had the greatest monoterpene concentrations compared to the control and methyl salicylate-treated seedlings. However, the monoterpene response to the challenge inoculation varied with watering treatments, not with prior induction treatments, with lower monoterpene concentrations in fungal lesions on seedlings in the low to moderate watering treatments compared to normal watering treatment. Furthermore, prior induction from phytohormones resulted in systemic cross-induction of resistance to G. clavigera under normal watering treatment but susceptibility under low watering treatment. Seedlings stressed by low water conditions, which also had lower stomatal conductance than seedlings in the normal watering treatment, likely allocated resources to initial defense response but were left unable to acquire further resources for subsequent responses. Our results demonstrate that drought can affect interactions among tree-infesting organisms through systemic cross-induction of susceptibility.

Drought stress leads to systemic induced susceptibility to a nectrotrophic fungus associated with mountain pine beetle in Pinus banksiana seedlings

PubMed Central

Shamoun, Simon Francis; Erbilgin, Nadir

2017-01-01

Conifers have complex defense responses to initial attacks by insects and pathogens that can have cascading effects on success of subsequent colonizers. However, drought can affect a plant’s ability to respond to biotic agents by potentially altering the resources needed for the energetically costly production of induced defense chemicals. We investigated the impact of reduced water on induced chemical defenses of jack pine (Pinus banksiana) seedlings from initial attack by biotic agents and resistance to subsequent challenge inoculation with a pathogenic fungal associate of mountain pine beetle (Dendroctonus ponderosae), Grosmannia clavigera. Applications of phytohormones (methyl salicylate and methyl jasmonate) and G. clavigera were used for initial induction of defenses. Monoterpene concentrations varied with initial induction from fungal and phytohormone application while watering treatment had no effect. Seedlings treated with G. clavigera and methyl jasmonate had the greatest monoterpene concentrations compared to the control and methyl salicylate-treated seedlings. However, the monoterpene response to the challenge inoculation varied with watering treatments, not with prior induction treatments, with lower monoterpene concentrations in fungal lesions on seedlings in the low to moderate watering treatments compared to normal watering treatment. Furthermore, prior induction from phytohormones resulted in systemic cross-induction of resistance to G. clavigera under normal watering treatment but susceptibility under low watering treatment. Seedlings stressed by low water conditions, which also had lower stomatal conductance than seedlings in the normal watering treatment, likely allocated resources to initial defense response but were left unable to acquire further resources for subsequent responses. Our results demonstrate that drought can affect interactions among tree-infesting organisms through systemic cross-induction of susceptibility. PMID:29216258

Monoterpene and sesquiterpene synthases and the origin of terpene skeletal diversity in plants.

PubMed

Degenhardt, Jörg; Köllner, Tobias G; Gershenzon, Jonathan

2009-01-01

The multitude of terpene carbon skeletons in plants is formed by enzymes known as terpene synthases. This review covers the monoterpene and sesquiterpene synthases presenting an up-to-date list of enzymes reported and evidence for their ability to form multiple products. The reaction mechanisms of these enzyme classes are described, and information on how terpene synthase proteins mediate catalysis is summarized. Correlations between specific amino acid motifs and terpene synthase function are described, including an analysis of the relationships between active site sequence and cyclization type and a discussion of whether specific protein features might facilitate multiple product formation.

Targeted Isolation of Monoterpene Indole Alkaloids from Palicourea sessilis.

PubMed

Klein-Júnior, Luiz C; Cretton, Sylvian; Allard, Pierre-Marie; Genta-Jouve, Grégory; Passos, Carolina S; Salton, Juliana; Bertelli, Pablo; Pupier, Marion; Jeannerat, Damien; Heyden, Yvan Vander; Gasper, André L; Wolfender, Jean-Luc; Christen, Philippe; Henriques, Amélia T

2017-11-22

Phytochemical investigation of the alkaloid extract of Palicourea sessilis by LC-HRMS/MS using molecular networking and an in silico MS/MS fragmentation approach suggested the presence of several new monoterpene indole alkaloids. These compounds were isolated by semipreparative HPLC, and their structures confirmed by means of HRMS, NMR, and ECD measurements as 4-N-methyllyaloside (3), 4-N-methyl-3,4-dehydrostrictosidine (4), 4β-hydroxyisodolichantoside (6), and 4α-hydroxyisodolichantoside (7), as well as the known alkaloids alline (1), N-methyltryptamine (2), isodolichantoside (5), and 5-oxodolichantoside (8). In addition, the acetylcholinesterase inhibitory activity of the compounds was evaluated up to 50 μM.

Evaluation of measurement uncertainty for purity of a monoterpenic acid by small-scale coulometry

NASA Astrophysics Data System (ADS)

Norte, L. C.; de Carvalho, E. M.; Tappin, M. R. R.; Borges, P. P.

2018-03-01

Purity of the perylic acid (HPe) which is a monoterpenic acid from natural product (NP) with anti-inflammatory and anticancer properties was analyzed by small-scale coulometry (SSC), due to the low availability of HPe on the pharmaceutic market and its high cost. This work aims to present the evaluation of the measurements uncertainty from the purity of HPe by using SSC. Coulometric mean of purity obtained from 5 replicates resulted in 94.23% ± 0.88% (k = 2.06, for an approximately 95% confidence level). These studies aim in the future to develop the production of certified reference materials from NPs.

Gas-phase chemiluminescent reactions of ozone with monoterpenes

NASA Astrophysics Data System (ADS)

Arora, P. K.; Chatha, J. P. S.; Vohra, K. G.

1983-08-01

Chemiluminescent reactions of ozone with monoterpenes such as linallol, geraniol, d-limonene and α-pinene have been studied in the gas phase at low pressures. Methylglyoxal phosphorescence has been observed in the first two reactions. Emissions from HCHO( 1A 2) and glyoxal ( 3A u) are observed in the reaction of ozone with d-limonene and formation of excited glyoxal is found to be first order in ozone. The reaction of ozone with β-pinene gives rise to emission from a α-dicarbonyl compound and this is found to be first order in ozone. The mechanisms for the formation of excited species are proposed.

Composition of essential oils isolated from the needles of Pinus uncinata and P. uliginosa grown in Poland.

PubMed

Bonikowski, Radosław; Celiński, Konrad; Wojnicka-Półtorak, Aleksandra; Maliński, Tomasz

2015-02-01

The compositions of mountain pine (Pinus uncinata) and peat-bog pine (P. uliginosa) needle essential oils were investigated. Enantiomeric compositions of selected monoterpene hydrocarbons were also examined. Respectively, fifty-three and seventy-six components of the essential oils were identified using GC-MS and retention indexes. The main group of essential oil components of mountain pine needles were monoterpenes, and bornyl acetate constituted approximately 30% (46.3 g/100 g) of the oil. In peat-bog pine essential oil, monoterpenes and sesquiterpenes exhibited a similar content (ca. 40%). Bornyl acetate and α-pinene were the main constituents of both essential oils. In the essential oil of P. uncinata needles, limonene, camphene, myrcene and (E)-β-caryophyllene were also noticeable, while in the essential oil of P. uliginosa needles, Δ-car-3-ene, (E)-β-caryophyllene, germacrene D, δ-cadinene, germacrene D 4-ol and α-cadinol were present in notable quantities. In both essential oils, borneol propionate, isobutyrate, 2-methylbutyrate and isovalerate were detected. Their presence was confirmed by synthesis and analysis of the standards; retention indexes on a non-polar column are published herein.

Induction of Senescence and Identification of Differentially Expressed Genes in Tomato in Response to Monoterpene

PubMed Central

Kumar, Vinay; Kumar, Anil; Irfan, Mohammad; Chakraborty, Niranjan; Chakraborty, Subhra; Datta, Asis

2013-01-01

Monoterpenes, which are among the major components of plant essential oils, are known for their ecological roles as well for pharmaceutical properties. Geraniol, an acyclic monoterpene induces cell cycle arrest and apoptosis/senescence in various cancer cells and plants; however, the genes involved in the process and the underlying molecular mechanisms are not well understood. In this study, we demonstrate that treatment of tomato plants with geraniol results in induction of senescence due to a substantial alteration in transcriptome. We have identified several geraniol-responsive protein encoding genes in tomato using suppression subtractive hybridization (SSH) approach. These genes comprise of various components of signal transduction, cellular metabolism, reactive oxygen species (ROS), ethylene signalling, apoptosis and DNA damage response. Upregulation of NADPH oxidase and antioxidant genes, and increase in ROS level after geraniol treatment point towards the involvement of ROS in geraniol-mediated senescence. The delayed onset of seedling death and induced expression of geraniol-responsive genes in geraniol-treated ethylene receptor mutant (Nr) suggest that geraniol-mediated senescence involves both ethylene dependent and independent pathways. Moreover, expression analysis during tomato ripening revealed that geraniol-responsive genes are also associated with the natural organ senescence process. PMID:24098759

Chemical alarm in the termite Termitogeton planus (Rhinotermitidae).

PubMed

Dolejšová, Klára; Krasulová, Jana; Kutalová, Kateřina; Hanus, Robert

2014-12-01

Effective defense is a common characteristic of insect societies. Indeed, the occurrence of specialized defenders, soldiers, has been the first step toward eusociality in several independent lineages, including termites. Among the multitude of defensive strategies used by termite soldiers, defense by chemicals plays a crucial role. It has evolved with complexity in advanced isopteran lineages, whose soldiers are equipped with a unique defensive organ, the frontal gland. Besides direct defense against predators, competitors, and pathogens, the chemicals emitted by soldiers from the frontal gland are used as signals of alarm. In this study, we investigated the chemical composition of the defensive secretion produced by soldiers of the termite Termitogeton planus (Isoptera: Rhinotermitidae), from West Papua, and the effects of this secretion on the behavior of termite groups. Detailed two-dimensional gas chromatography/mass spectrometry analyses of the soldier defensive secretion revealed the presence of four linear and nine monoterpene hydrocarbons. Soldier head extracts, as well as synthetic mixtures of the monoterpenes found in these extracts, elicited alarm behavior in both soldiers and pseudergates. Our results suggest that the alarm is not triggered by a single monoterpene from the defensive blend, but by a multi-component signal combining quantitatively major and minor compounds.

The Impact of Chemical Mechanism Design on Simulated Surface Ozone in CAM-Chem

NASA Astrophysics Data System (ADS)

Schwantes, R.; Emmons, L. K.; Orlando, J. J.; Tyndall, G. S.

2017-12-01

Many regions in the United States have poor air quality because of high levels of ozone. Global and regional chemical transport models are important tools for recommending regulatory policy directions to efficiently reduce ozone. Ozone is intrinsically hard to simulate in global and regional models because the amount of ozone present is controlled by large non-linear sources and sinks. Recent field campaigns have concluded that monoterpene chemistry is particularly important for the NOx budget and thereby O3 formation. However, many regional and global models have none or heavily reduced monoterpene chemical schemes. In this study, the chemical mechanism for isoprene and monoterpene oxidation will be significantly improved and updated in CAM-Chem (Community Atmosphere Model with chemistry), which is a component of the Community Earth System Model (CESM). In particular, the updates will focus on accurately portraying organic nitrate formation and fate. The impact of various uncertainties (e.g., nitrate yields, later generation chemistry, loss of organic nitrates to aerosols via hydrolysis, etc.) on ozone formation will be tested. This study will both improve the chemistry in CAM-Chem and reveal lingering uncertainties that have the largest impact on ozone formation.

SOA formation potential of emissions from soil and leaf litter

DOE PAGES

Faiola, Celia L.; VanderSchelden, Graham S.; Wen, Miao; ...

2013-12-13

Soil and leaf litter are significant global sources of small oxidized volatile organic compounds, VOCs (e.g., methanol and acetaldehyde). They may also be significant sources of larger VOCs that could act as precursors to secondary organic aerosol (SOA) formation. To investigate this, soil and leaf litter samples were collected from the University of Idaho Experimental Forest and transported to the laboratory. There, the VOC emissions were characterized and used to drive SOA formation via dark, ozone-initiated reactions. Monoterpenes dominated the emission profile with emission rates as high as 228 μg-C m –2 h –1. The composition of the SOA producedmore » was similar to biogenic SOA formed from oxidation of ponderosa pine emissions and α-pinene. Measured soil and litter monoterpene emission rates were compared with modeled canopy emissions. Results suggest surface soil and litter monoterpene emissions could range from 12 to 136% of canopy emissions in spring and fall. Furthermore, emissions from leaf litter may potentially extend the biogenic emissions season, contributing to significant organic aerosol formation in the spring and fall when reduced solar radiation and temperatures reduce emissions from living vegetation.« less

Alternative control of Aedes aegypti resistant to pyrethroids: lethal and sublethal effects of monoterpene bioinsecticides.

PubMed

Silva, Indira Ma; Martins, Gustavo F; Melo, Carlisson R; Santana, Alisson S; Faro, Ruan Rn; Blank, Arie F; Alves, Péricles B; Picanço, Marcelo C; Cristaldo, Paulo F; Araújo, Ana Paula A; Bacci, Leandro

2018-04-01

The mosquito Aedes aegypti is intensively controlled because it is a vector of viruses that cause numerous diseases, especially in tropical regions. As a consequence of the indiscriminate use of insecticides, populations from different regions have become resistant to pyrethroids. Here, we analyzed the lethal and sublethal effects of essential oil of Aristolochia trilobata and its major compounds on A. aegypti from susceptible and pyrethroid-resistant populations. Our results showed that the toxicity of the different compounds and behavioral changes in response to them are dependent on the stage of the insect life cycle. The monoterpene ρ-cymene caused high mortality in both larvae and adult females of A. aegypti, including those from the pyrethroid-resistant population. The monoterpenes limonene and linalool caused a sublethal effect in the larvae, triggering changes in the swimming pattern. This study highlights the potential of the essential oil of A. trilobata and its major compounds ρ-cymene and limonene for the control of A. aegypti and reveals the importance of analyzing sublethal effects on the population dynamics of the A. aegypti mosquito. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Eugenol and methyl eugenol chemotypes of essential oil of species Ocimum gratissimum L. and Ocimum campechianum Mill. from Colombia.

PubMed

Pino Benitez, Nayive; Meléndez León, Erika M; Stashenko, Elena E

2009-10-01

Essential oils chemical constituents of leaves of O. gratissimum and O. campechianum of the Lamiaceae family, collected in Chocó of northwest Colombian, were obtained by microwave-assisted hydrodistillation and analyzed by gas chromatography coupled with mass spectrometry. A total of 33 and 37 compounds were identified in the essential oil of O. gratissimum and O. campechianum, respectively. O. gratissimum's main essential oils were eugenol (43.2%), 1,8-cineole (12.8%) and beta-selinene (9.0%); in the O. campechianum essential oil, the main components were methyl eugenol (12.0%), germacrene D (10.1%), and eugenol (9.0%). Main distribution of compounds in these essential oils are 25.0% monoterpenes hydrocarbons, 15.0% monoterpenes oxygenated, 35.0% sesquiterpenes hydrocarbons, 7.5% other oxygenated components for O. gratissimum, 33.9% sesquiterpenes hydrocarbons, and 10.7% their respective oxygenated derivates; for O. campechianum, the distribution was 10.7% monoterpenes hydrocarbons and 7.1% their respective oxygenated derivates and 3.6% phenylpropanes. According to the essential oils chemical composition of Ocimum gratissimum and O. campechianum, they are classified as eugenol and methyl eugenol chemotype, respectively.

New foliage growth is a significant, unaccounted source for volatiles in boreal evergreen forests

NASA Astrophysics Data System (ADS)

Aalto, J.; Kolari, P.; Hari, P.; Kerminen, V.-M.; Schiestl-Aalto, P.; Aaltonen, H.; Levula, J.; Siivola, E.; Kulmala, M.; Bäck, J.

2014-03-01

Estimates of volatile organic compound (VOC) emissions from forests are based on the assumption that foliage has a steady emission potential over its lifetime, and that emissions are mainly modified by short-term variations in light and temperature. However, in many field studies this has been challenged, and high emissions and atmospheric concentrations have been measured during periods of low biological activity, such as in springtime. We conducted measurements during three years, using an online gas-exchange monitoring system to observe volatile organic emissions from a mature (1 year-old) and a growing Scots pine shoot. The emission rates of organic vapors from vegetative buds of Scots pine during the dehardening and rapid shoot growth stages were one to two orders of magnitude higher than those from mature foliage; this difference decreased and finally disappeared when the new shoot was maturing in late summer. On average, the springtime monoterpene emission rate of the bud was about 500 times higher than that of the mature needles; during the most intensive needle elongation period, the monoterpene emission rate of the growing needles was 3.5 higher than that of the mature needles, and in September the monoterpene emission rate of the same years' needles was even lower (50%) than that of the previous years' needles. For other measured compounds (methanol, acetone and methylbutenol) the values were of the same order of magnitude, except before bud break in spring, when the emission rates of buds for those compounds were on average about 20-30 times higher than that of mature needles. During spring and early summer the buds and growing shoots are a strong source of several VOCs, and if they are not accounted for in emission modeling a significant proportion of the emissions - from a few percent to even half of the annual cumulative emissions - will remain concealed. The diurnal emission pattern of growing shoots differed from the diurnal cycle in temperature as well as from the diurnal emission pattern of mature shoots, which may be related to processes involved in shoot or needle elongation. Our findings imply that global estimations of monoterpene emission rates from forests are in need of revision, and that the physiological state of the plants should be taken into account when emissions of the reactive gases such as monoterpenes are estimated.

Callistrilones A and B, Triketone-Phloroglucinol-Monoterpene Hybrids with a New Skeleton from Callistemon rigidus.

PubMed

Cao, Jia-Qing; Huang, Xiao-Jun; Li, Yu-Ting; Wang, Ying; Wang, Lei; Jiang, Ren-Wang; Ye, Wen-Cai

2016-01-04

The first triketone-phloroglucinol-monoterpene hybrids, callistrilones A and B (1 and 2), along with a postulated biosynthetic intermediate (3) were isolated from the leaves of Callistemon rigidus. Compounds 1 and 2 featured a new carbon skeleton with an unprecedented [1]benzofuro[2,3-a]xanthene or [1]benzofuro[3,2-b]xanthene pentacyclic ring system composed of three kinds of building blocks. Their structures and absolute configurations were elucidated by spectroscopic analysis, X-ray diffraction, and electronic circular dichroism (ECD) calculations. A plausible biogenetic pathway for the new compounds is also proposed. Compound 1 exhibited moderate antibacterial activity against Gram-positive bacteria including multiresistant strains.

Essential Oils’ Chemical Characterization and Investigation of Some Biological Activities: A Critical Review

PubMed Central

Dhifi, Wissal; Bellili, Sana; Jazi, Sabrine; Bahloul, Nada; Mnif, Wissem

2016-01-01

This review covers literature data summarizing, on one hand, the chemistry of essential oils and, on the other hand, their most important activities. Essential oils, which are complex mixtures of volatile compounds particularly abundant in aromatic plants, are mainly composed of terpenes biogenerated by the mevalonate pathway. These volatile molecules include monoterpenes (hydrocarbon and oxygenated monoterpens), and also sesquiterpenes (hydrocarbon and oxygenated sesquiterpens). Furthermore, they contain phenolic compounds, which are derived via the shikimate pathway. Thanks to their chemical composition, essential oils possess numerous biological activities (antioxidant, anti-inflammatory, antimicrobial, etc…) of great interest in food and cosmetic industries, as well as in the human health field. PMID:28930135

Pd(OAc)2/Ph3P-catalyzed dimerization of isoprene and synthesis of monoterpenic heterocycles.

PubMed

Kellner, Dominik; Weger, Maximilian; Gini, Andrea; Mancheño, Olga García

2017-01-01

The palladium-catalyzed dimerization of isoprene is a practical approach of synthesizing monoterpenes. Though several highly selective methods have been reported, most of them still required pressure or costly ligands for attaining the active system and desired selectivity. Herein, we present a simple and economical procedure towards the tail-to-tail dimer using readily available Pd(OAc) 2 and inexpensive triphenylphosphine as ligand. Furthermore, simple screw cap vials are employed, allowing carrying out the reaction at low pressure. In addition, the potential of the dimer as a chemical platform for the preparation of heterocyclic terpenes by subsequent (hetero)-Diels-Alder or [4 + 1]-cycloadditions with nitrenes is also depicted.

The monoterpene terpinolene from the oil of Pinus mugo L. in concert with alpha-tocopherol and beta-carotene effectively prevents oxidation of LDL.

PubMed

Grassmann, J; Hippeli, S; Spitzenberger, R; Elstner, E F

2005-06-01

Antioxidants from several nutrients, e.g. vitamin E, beta-carotene, or flavonoids, inhibit the oxidative modification of low-density lipoproteins. This protective effect could possibly retard atherogenesis and in consequence avoid coronary heart diseases. Some studies have shown a positive effect of those antioxidants on cardiovascular disease. Another class of naturally occurring antioxidants are terpenoids, which are found in essential oils. The essential oil of Pinus mugo and the contained monoterpene terpinolene effectively prevent low-density lipoprotein (LDL)-oxidation. In order to test the mechanism by which terpinolene protects LDL from oxidation, LDL from human blood plasma enriched in terpinolene was isolated. In this preparation not only the lipid part of LDL is protected against copper-induced oxidation--as proven by following the formation of conjugated dienes, but also the oxidation of the protein part is inhibited, since loss of tryptophan fluorescence is strongly delayed. This inhibition is due to a retarded oxidation of intrinsic carotenoids of LDL, and not, as in the case of some flavonoids, attributable to a protection of intrinsic alpha-tocopherol. These results are in agreement with our previous results, which showed the same effects for a monoterpene from lemon oil, i.e. gamma-terpinene.

Antimicrobial Impacts of Essential Oils on Food Borne-Pathogens.

PubMed

Ozogul, Yesim; Kuley, Esmeray; Ucar, Yilmaz; Ozogul, Fatih

2015-01-01

The antimicrobial activity of twelve essential oil (pine oil, eucalyptus, thyme, sage tea, lavender, orange, laurel, lemon, myrtle, lemon, rosemary and juniper) was tested by a disc diffusion method against food borne pathogens (Escherichia coli, Salmonella paratyphi A, Klebsiella pneumoniae, Yersinia enterocolitica, Pseudomonas aeruginosa, Aeromonas hydrophila, Campylobacter jejuni, Enterococcus faecalis, Staphylococcus aureus). The major components in essential oils were monoterpenes hydrocarbons, α-pinene, limonene; monoterpene phenol, carvacrol and oxygenated monoterpenes, camphor, 1,8-cineole, eucalyptol, linalool and linalyl acetate. Although the antimicrobial effect of essential oils varied depending on the chemical composition of the essential oils and specific microorganism tested, majority of the oils exhibited antibacterial activity against one or more strains. The essential oil with the lowest inhibition zones was juniper with the values varied from 1.5 to 6 mm. However, the components of essential oil of thyme and pine oil are highly active against food borne pathogen, generating the largest inhibition zones for both gram negative and positive bacteria (5.25-28.25 mm vs. 12.5-30 mm inhibition zones). These results indicate the possible use of the essential oils on food system as antimicrobial agents against food-borne pathogen. The article also offers some promising patents on applications of essential oils on food industry as antimicrobial agent.

Diurnal patterns in Scots pine stem oleoresin pressure in a boreal forest.

PubMed

Rissanen, K; Hölttä, T; Vanhatalo, A; Aalto, J; Nikinmaa, E; Rita, H; Bäck, J

2016-03-01

Coniferous tree stems contain large amounts of oleoresin under positive pressure in the resin ducts. Studies in North-American pines indicated that the stem oleoresin exudation pressure (OEP) correlates negatively with transpiration rate and soil water content. However, it is not known how the OEP changes affect the emissions of volatile vapours from the trees. We measured the OEP, xylem diameter changes indicating changes in xylem water potential and monoterpene emissions under field conditions in mature Scots pine (Pinus sylvestris L.) trees in southern Finland. Contrary to earlier reports, the diurnal OEP changes were positively correlated with temperature and transpiration rate. OEP was lowest at the top part of the stem, where water potentials were also more negative, and often closely linked to ambient temperature and stem monoterpene emissions. However, occasionally OEP was affected by sudden changes in vapour pressure deficit (VPD), indicating the importance of xylem water potential on OEP as well. We conclude that the oleoresin storage pools in tree stems are in a dynamic relationship with ambient temperature and xylem water potential, and that the canopy monoterpene emission rates may therefore be also regulated by whole tree processes and not only by the conditions prevailing in the upper canopy. © 2015 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

Assessment of the in vitro and in vivo genotoxicity of extracts and indole monoterpene alkaloid from the roots of Galianthe thalictroides (Rubiaceae).

PubMed

Fernandes, L M; Garcez, W S; Mantovani, M S; Figueiredo, P O; Fernandes, C A; Garcez, F R; Guterres, Z R

2013-09-01

Roots of Galianthe thalictroides K. Schum. (Rubiaceae) are used in folk medicine in the State of Mato Grosso do Sul, Brazil, for treating and preventing cancer. To gain information about the genotoxicity of extracts (aqueous and EtOH), the CHCl₃ phase resulting from partition of the EtOH extract and the indole monoterpene alkaloid 1 obtained from this plant. The genotoxicity of 1 and extracts was evaluated in vivo through the Drosophila melanogaster wing Somatic Mutation and Recombination Test - SMART, while in vitro cytotoxic (MTT) and Comet assays were performed only with alkaloid 1. The results obtained with the SMART test indicated that the aqueous extract had no genotoxic activity. The EtOH extract was not genotoxic to ST descendants but genotoxic to HB ones. The CHCl₃ phase was genotoxic and cytotoxic. Alkaloid 1 showed significant mutational events with SMART, in the cytotoxicity assay (MTT), it showed a high cytotoxicity for human hepatoma cells (HepG2), whereas for the Comet assay, not showing genotoxic activity. The ethanol extract was shown to be genotoxic to HB descendants in the SMART assay, while the results obtained in this test for the monoterpene indole alkaloid 1 isolated from this extract. Copyright © 2013 Elsevier Ltd. All rights reserved.

VOC Reactivity and the Ozone Climate Penalty: Modeled Impacts of Updated Aromatic and Monoterpene Chemistry on the Ozone-temperature Connection

NASA Astrophysics Data System (ADS)

Porter, W. C.; Heald, C. L.; Safieddine, S.

2016-12-01

Rising temperatures associated with global warming can increase concentrations of tropospheric ozone (O3) in many regions worldwide, a correlation often described as the "ozone climate penalty". This effect is driven by a variety of underlying chemical, physical, and biological mechanisms, including temperature-dependent reaction rates, emissions of volatile organic compounds (VOCs) from trees and other plant life, and correlations with other meteorological variables. While many of the most important O3-producing VOCs, such as isoprene, are represented in typical chemical transport models such as GEOS-Chem, others - including aromatics from fires and human activity and monoterpenes from natural sources - are not always included in gas-phase chemistry. Here we examine the impact of increased VOC reactivity on the ozone climate penalty due to a more comprehensive treatment of aromatics and monoterpenes in the chemical transport model GEOS-Chem, finding regional impacts not only on daily O3 levels themselves, but also on the O3/temperature relationship. While many uncertainties related to the emissions and chemistry of these species remain, the impact of their inclusion on both current simulations and future projections indicates their importance towards the overall goal of more accurately modeled surface O3.

Comparative glandular trichome transcriptome-based gene characterization reveals reasons for differential (-)-menthol biosynthesis in Mentha species.

PubMed

Akhtar, Md Qussen; Qamar, Nida; Yadav, Pallavi; Kulkarni, Pallavi; Kumar, Ajay; Shasany, Ajit Kumar

2017-06-01

The genes involved in menthol biosynthesis are reported earlier in Mentha × piperita. But the information on these genes is not available in Mentha arvensis. To bridge the gap in knowledge on differential biosynthesis of monoterpenes leading to compositional variation in the essential oil of these species, a comparative transcriptome analysis of the glandular trichome (GT) was carried out. In addition to the mevalonic acid (MVA) and methylerythritol phosphate (MEP) pathway genes, about 210 and 196 different terpene synthases (TPSs) transcripts were identified from annotation in M. arvensis and M. × piperita, respectively, and correlated to several monoterpenes present in the essential oil. Six isoforms of (-)-menthol dehydrogenases (MD), the last enzyme of the menthol biosynthetic pathway, were identified, cloned and characterized from the transcriptome data (three from each species). Varied expression levels and differential enzyme kinetics of these isoforms indicated the nature and composition of the product, as these isoforms generate both (-)-menthol and (+)-neomenthol from (-)-menthone and converts (-)-menthol to (-)-menthone in the reverse reaction, and hence together determine the quantity of (-)-menthol in the essential oil in these two species. Several genes for high value minor monoterpenes could also be identified from the transcriptome data. © 2017 Scandinavian Plant Physiology Society.

Linking biogenic hydrocarbons to biogenic aerosol in the Borneo rainforest

NASA Astrophysics Data System (ADS)

Hamilton, J. F.; Alfarra, M. R.; Robinson, N.; Ward, M. W.; Lewis, A. C.; McFiggans, G. B.; Coe, H.; Allan, J. D.

2013-11-01

Emissions of biogenic volatile organic compounds are though to contribute significantly to secondary organic aerosol formation in the tropics, but understanding these transformation processes has proved difficult, due to the complexity of the chemistry involved and very low concentrations. Aerosols from above a Southeast Asian tropical rainforest in Borneo were characterised using liquid chromatography-ion trap mass spectrometry, high-resolution aerosol mass spectrometry and Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) techniques. Oxygenated compounds were identified in ambient organic aerosol that could be directly traced back to isoprene, monoterpenes and sesquiterpene emissions, by combining field data on chemical structures with mass spectral data generated from synthetically produced products created in a simulation chamber. Eighteen oxygenated species of biogenic origin were identified in the rainforest aerosol from the precursors isoprene, α-pinene, limonene, α-terpinene and β-caryophyllene. The observations provide the unambiguous field detection of monoterpene and sesquiterpene oxidation products in SOA above a pristine tropical rainforest. The presence of 2-methyl tetrol organosulfates and an associated sulfated dimer provides direct evidence that isoprene in the presence of sulfate aerosol can make a contribution to biogenic organic aerosol above tropical forests. High-resolution mass spectrometry indicates that sulfur can also be incorporated into oxidation products arising from monoterpene precursors in tropical aerosol.

Linking biogenic hydrocarbons to biogenic aerosol in the Borneo rainforest

NASA Astrophysics Data System (ADS)

Hamilton, J. F.; Alfarra, M. R.; Robinson, N.; Ward, M. W.; Lewis, A. C.; McFiggans, G. B.; Coe, H.; Allan, J. D.

2013-07-01

Emissions of biogenic volatile organic compounds are though to contribute significantly to secondary organic aerosol formation in the tropics, but understanding the process of these transformations has proved difficult, due to the complexity of the chemistry involved and very low concentrations. Aerosols from above a South East Asian tropical rainforest in Borneo were characterised using liquid chromatography-ion trap mass spectrometry, high resolution aerosol mass spectrometry and fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) techniques. Oxygenated compounds were identified in ambient organic aerosol that could be directly traced back to isoprene, monoterpenes and sesquiterpene emissions, by combining field data on chemical structures with mass spectral data generated from synthetically produced products created in a simulation chamber. Eighteen oxygenated species of biogenic origin were identified in the rainforest aerosol from the precursors isoprene, α-pinene, limonene, α-terpinene and β-caryophyllene. The observations provide the unambiguous field detection of monoterpene and sesquiterpene oxidation products in SOA above a pristine tropical rainforest. The presence of 2-methyltetrol organosulfates and an associated sulfated dimer provides direct evidence that isoprene in the presence of sulfate aerosol can make a contribution to biogenic organic aerosol above tropical forests. High-resolution mass spectrometry indicates that sulfur can also be incorporated into oxidation products arising from monoterpene precursors in tropical aerosol.

Secondary organic aerosol production from pinanediol, a semi-volatile surrogate for first-generation oxidation products of monoterpenes

NASA Astrophysics Data System (ADS)

Ye, Penglin; Zhao, Yunliang; Chuang, Wayne K.; Robinson, Allen L.; Donahue, Neil M.

2018-05-01

We have investigated the production of secondary organic aerosol (SOA) from pinanediol (PD), a precursor chosen as a semi-volatile surrogate for first-generation oxidation products of monoterpenes. Observations at the CLOUD facility at CERN have shown that oxidation of organic compounds such as PD can be an important contributor to new-particle formation. Here we focus on SOA mass yields and chemical composition from PD photo-oxidation in the CMU smog chamber. To determine the SOA mass yields from this semi-volatile precursor, we had to address partitioning of both the PD and its oxidation products to the chamber walls. After correcting for these losses, we found OA loading dependent SOA mass yields from PD oxidation that ranged between 0.1 and 0.9 for SOA concentrations between 0.02 and 20 µg m-3, these mass yields are 2-3 times larger than typical of much more volatile monoterpenes. The average carbon oxidation state measured with an aerosol mass spectrometer was around -0.7. We modeled the chamber data using a dynamical two-dimensional volatility basis set and found that a significant fraction of the SOA comprises low-volatility organic compounds that could drive new-particle formation and growth, which is consistent with the CLOUD observations.

Dose- and tissue-specific interaction of monoterpenes with the gibberellin-mediated release of potato tuber bud dormancy, sprout growth and induction of α-amylases and β-amylases.

PubMed

Rentzsch, Sonja; Podzimska, Dagmara; Voegele, Antje; Imbeck, Madeleine; Müller, Kerstin; Linkies, Ada; Leubner-Metzger, Gerhard

2012-01-01

Gibberellins (GA) are involved in bud dormancy release in several species. We show here that GA-treatment released bud dormancy, initiated bud sprouting and promoted sprout growth of excised potato tuber bud discs ('eyes'). Monoterpenes from peppermint oil (PMO) and S-(+)-carvone (CAR) interact with the GA-mediated bud dormancy release in a hormesis-type response: low monoterpene concentrations enhance dormancy release and the initiation of bud sprouting, whereas high concentrations inhibit it. PMO and CAR did, however, not affect sprout growth rate after its onset. We further show that GA-induced dormancy release is associated with tissue-specific regulation of α- and β-amylases. Molecular phylogenetic analysis shows that potato α-amylases cluster into two distinct groups: α-AMY1 and α-AMY2. GA-treatment induced transcript accumulation of members of both α-amylase groups, as well as α- and β-amylase enzyme activity in sprout and 'sub-eye' tissues. In sprouts, CAR interacts with the GA-mediated accumulation of α-amylase transcripts in an α-AMY2-specific and dose-dependent manner. Low CAR concentrations enhance the accumulation of α-AMY2-type α-amylase transcripts, but do not affect the α-AMY1-type transcripts. Low CAR concentrations also enhance the accumulation of α- and β-amylase enzyme activity in sprouts, but not in 'sub-eye' tissues. In contrast, high CAR concentrations have no appreciable effect in sprouts on the enzyme activities and the α-amylase transcript abundances of either group. The dose-dependent effects on the enzyme activities and the α-AMY2-type α-amylase transcripts in sprouts are specific for CAR but not for PMO. Different monoterpenes therefore may have specific targets for their interaction with hormone signalling pathways.

Rapid “Breath-Print” of Liver Cirrhosis by Proton Transfer Reaction Time-of-Flight Mass Spectrometry. A Pilot Study.

PubMed Central

Morisco, Filomena; Aprea, Eugenio; Lembo, Vincenzo; Fogliano, Vincenzo; Vitaglione, Paola; Mazzone, Giovanna; Cappellin, Luca; Gasperi, Flavia; Masone, Stefania; De Palma, Giovanni Domenico; Marmo, Riccardo; Caporaso, Nicola; Biasioli, Franco

2013-01-01

The aim of the present work was to test the potential of Proton Transfer Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS) in the diagnosis of liver cirrhosis and the assessment of disease severity by direct analysis of exhaled breath. Twenty-six volunteers have been enrolled in this study: 12 patients (M/F 8/4, mean age 70.5 years, min-max 42–80 years) with liver cirrhosis of different etiologies and at different severity of disease and 14 healthy subjects (M/F 5/9, mean age 52.3 years, min-max 35–77 years). Real time breath analysis was performed on fasting subjects using a buffered end-tidal on-line sampler directly coupled to a PTR-ToF-MS. Twelve volatile organic compounds (VOCs) resulted significantly differently in cirrhotic patients (CP) compared to healthy controls (CTRL): four ketones (2-butanone, 2- or 3- pentanone, C8-ketone, C9-ketone), two terpenes (monoterpene, monoterpene related), four sulphur or nitrogen compounds (sulfoxide-compound, S-compound, NS-compound, N-compound) and two alcohols (heptadienol, methanol). Seven VOCs (2-butanone, C8-ketone, a monoterpene, 2,4-heptadienol and three compounds containing N, S or NS) resulted significantly differently in compensate cirrhotic patients (Child-Pugh A; CP-A) and decompensated cirrhotic subjects (Child-Pugh B+C; CP-B+C). ROC (Receiver Operating Characteristic) analysis was performed considering three contrast groups: CP vs CTRL, CP-A vs CTRL and CP-A vs CP-B+C. In these comparisons monoterpene and N-compound showed the best diagnostic performance. Conclusions Breath analysis by PTR-ToF-MS was able to distinguish cirrhotic patients from healthy subjects and to discriminate those with well compensated liver disease from those at more advanced severity stage. A breath-print of liver cirrhosis was assessed for the first time. PMID:23573204

Limonene dehydrogenase hydroxylates the allylic methyl group of cyclic monoterpenes in the anaerobic terpene degradation by Castellaniella defragrans.

PubMed

Puentes-Cala, Edinson; Liebeke, Manuel; Markert, Stephanie; Harder, Jens

2018-05-01

The enzymatic functionalization of hydrocarbons is a central step in the global carbon cycle initiating the mineralization of methane, isoprene and monoterpenes, the most abundant biologically produced hydrocarbons. Also, terpene-modifying enzymes have found many applications in the energy-economic biotechnological production of fine chemicals. Here we describe a limonene dehydrogenase that was purified from the facultatively anaerobic betaproteobacterium Castellaniella defragrans 65Phen grown on monoterpenes under denitrifying conditions in the absence of molecular oxygen. The purified limonene:ferrocenium oxidoreductase activity hydroxylated the methyl group of limonene (1-methyl-4-(1-methylethenyl)-cyclohex-1-ene) yielding perillyl alcohol ([4-(prop-1-en-2-yl)cyclohex-1-en-1-yl]methanol). The enzyme had a dithiothreitol:perillyl alcohol oxidoreductase activity yielding limonene. Mass spectrometry and molecular size determinations revealed a heterodimeric enzyme comprising CtmA and CtmB. Recently the two proteins had been identified by transposon mutagenesis and proteomics as part of the cyclic terpene metabolism ( ctm ) in Castellaniella defragrans and were annotated as FAD-dependent oxidoreductases of the protein domain family phytoene dehydrogenases and related proteins (COG1233). CtmAB is the first heterodimeric enzyme in this protein superfamily. Flavins in the purified CtmAB are oxidized by ferrocenium and are reduced by limonene. Heterologous expression of CtmA, CtmB and CtmAB in E. coli demonstrated that limonene dehydrogenase activity required both subunits carrying each a flavin cofactor. Native CtmAB oxidized a wide range of monocyclic monoterpenes containing the allylic methyl group motif (1-methyl-cyclohex-1-ene). In conclusion, we have identified CtmAB as a hydroxylating limonene dehydrogenase and the first heteromer in a family of FAD-dependent dehydrogenases acting on allylic methylene or methyl CH-bonds. We suggest a placement in EC 1.17.99.8. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Organic nitrate chemistry and its implications for nitrogen budgets in an isoprene- and monoterpene-rich atmosphere: constraints from aircraft (SEAC4RS) and ground-based (SOAS) observations in the Southeast US

PubMed Central

Fisher, J. A.; Jacob, D. J.; Travis, K. R.; Kim, P. S.; Marais, E. A.; Miller, C. Chan; Yu, K.; Zhu, L.; Yantosca, R. M.; Sulprizio, M. P.; Mao, J.; Wennberg, P. O.; Crounse, J. D.; Teng, A. P.; Nguyen, T. B.; St. Clair, J. M.; Cohen, R. C.; Romer, P.; Nault, B. A.; Wooldridge, P. J.; Jimenez, J. L.; Campuzano-Jost, P.; Day, D. A.; Hu, W.; Shepson, P. B.; Xiong, F.; Blake, D. R.; Goldstein, A. H.; Misztal, P. K.; Hanisco, T. F.; Wolfe, G. M.; Ryerson, T. B.; Wisthaler, A.; Mikoviny, T.

2018-01-01

Formation of organic nitrates (RONO2) during oxidation of biogenic volatile organic compounds (BVOCs: isoprene, monoterpenes) is a significant loss pathway for atmospheric nitrogen oxide radicals (NOx), but the chemistry of RONO2 formation and degradation remains uncertain. Here we implement a new BVOC oxidation mechanism (including updated isoprene chemistry, new monoterpene chemistry, and particle uptake of RONO2) in the GEOS-Chem global chemical transport model with ∼25 × 25 km2 resolution over North America. We evaluate the model using aircraft (SEAC4RS) and ground-based (SOAS) observations of NOx, BVOCs, and RONO2 from the Southeast US in summer 2013. The updated simulation successfully reproduces the concentrations of individual gas- and particle-phase RONO2 species measured during the campaigns. Gas-phase isoprene nitrates account for 25-50% of observed RONO2 in surface air, and we find that another 10% is contributed by gas-phase monoterpene nitrates. Observations in the free troposphere show an important contribution from long-lived nitrates derived from anthropogenic VOCs. During both campaigns, at least 10% of observed boundary layer RONO2 were in the particle phase. We find that aerosol uptake followed by hydrolysis to HNO3 accounts for 60% of simulated gas-phase RONO2 loss in the boundary layer. Other losses are 20% by photolysis to recycle NOx and 15% by dry deposition. RONO2 production accounts for 20% of the net regional NOx sink in the Southeast US in summer, limited by the spatial segregation between BVOC and NOx emissions. This segregation implies that RONO2 production will remain a minor sink for NOx in the Southeast US in the future even as NOx emissions continue to decline. PMID:29681921

Assessment of sensitization potential of monoterpenes using the rat popliteal lymph node assay.

PubMed

Friedrich, Karen; Delgado, Isabella F; Santos, Laísa M F; Paumgartten, Francisco J R

2007-08-01

The popliteal lymph node assay (PLNA) has been proposed as a screening test for detecting chemicals with potential of inducing allergic and auto-immune-like reactions in humans. In the present study, we used the rat PLNA to evaluate the immuno-sensitizing potential of 10 monoterpenes found in the essential oils of a variety of aromatic, edible and medicinal plants. The primary or direct PLNA was performed with the monoterpenes, and chlorpromazine (CPZ) and barbital were used as positive and negative controls, respectively. Female, 7-8 week-old Wistar rats were injected subcutaneously (50 microL) with the test substance (0.5, 2.5 or 5mg) into the right hind footpad while the contralateral footpad was injected with the vehicle (DMSO) alone. Weight (WI) and cellularity (CI) indices for draining PLNs were determined 7 days after treatment. PLNA was positive (WI >or= 2 and CI >or= 5) for CPZ, citral, alpha-terpinene, beta-myrcene and (-)-alpha-pinene, and negative for barbital, DMSO, (-)-menthol, 1,8-cineole, (+/-) citronellal, (+)-limonene, (+/-) camphor and terpineol. A secondary PLNA, a T-cell priming test, was carried out with the four substances that had been positive in the primary assay. Six weeks after being locally primed with 5 mg/paw, rats were sc injected into the same footpad with a dose (0.5 mg/paw) of the substance that had been previously found to be insufficient to cause a positive response. WI and CI were then calculated 4 and 7 days after the second injection. CPZ was also positive in the secondary assay thereby confirming that it is a sensitizing agent. Citral, alpha-terpinene, beta-myrcene and (-)-alpha-pinene, however, were negative in the secondary assay. In summary, citral, alpha-terpinene, beta-myrcene and (-)-alpha-pinene induced a clear immuno-stimulatory response due to their irritant properties but no monoterpene proved to be a sensitizing agent in the PLNA.

Canopy-scale flux measurements and bottom-up emission estimates of volatile organic compounds from a mixed oak and hornbeam forest in northern Italy

NASA Astrophysics Data System (ADS)

Acton, W. Joe F.; Schallhart, Simon; Langford, Ben; Valach, Amy; Rantala, Pekka; Fares, Silvano; Carriero, Giulia; Tillmann, Ralf; Tomlinson, Sam J.; Dragosits, Ulrike; Gianelle, Damiano; Hewitt, C. Nicholas; Nemitz, Eiko

2016-06-01

This paper reports the fluxes and mixing ratios of biogenically emitted volatile organic compounds (BVOCs) 4 m above a mixed oak and hornbeam forest in northern Italy. Fluxes of methanol, acetaldehyde, isoprene, methyl vinyl ketone + methacrolein, methyl ethyl ketone and monoterpenes were obtained using both a proton-transfer-reaction mass spectrometer (PTR-MS) and a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) together with the methods of virtual disjunct eddy covariance (using PTR-MS) and eddy covariance (using PTR-ToF-MS). Isoprene was the dominant emitted compound with a mean daytime flux of 1.9 mg m-2 h-1. Mixing ratios, recorded 4 m above the canopy, were dominated by methanol with a mean value of 6.2 ppbv over the 28-day measurement period. Comparison of isoprene fluxes calculated using the PTR-MS and PTR-ToF-MS showed very good agreement while comparison of the monoterpene fluxes suggested a slight over estimation of the flux by the PTR-MS. A basal isoprene emission rate for the forest of 1.7 mg m-2 h-1 was calculated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN) isoprene emission algorithms (Guenther et al., 2006). A detailed tree-species distribution map for the site enabled the leaf-level emission of isoprene and monoterpenes recorded using gas-chromatography mass spectrometry (GC-MS) to be scaled up to produce a bottom-up canopy-scale flux. This was compared with the top-down canopy-scale flux obtained by measurements. For monoterpenes, the two estimates were closely correlated and this correlation improved when the plant-species composition in the individual flux footprint was taken into account. However, the bottom-up approach significantly underestimated the isoprene flux, compared with the top-down measurements, suggesting that the leaf-level measurements were not representative of actual emission rates.

Canopy-scale flux measurements and bottom-up emission estimates of volatile organic compounds from a mixed oak and hornbeam forest in northern Italy

NASA Astrophysics Data System (ADS)

Acton, W. J. F.; Schallhart, S.; Langford, B.; Valach, A.; Rantala, P.; Fares, S.; Carriero, G.; Tillmann, R.; Tomlinson, S. J.; Dragosits, U.; Gianelle, D.; Hewitt, C. N.; Nemitz, E.

2015-10-01

This paper reports the fluxes and mixing ratios of biogenically emitted volatile organic compounds (BVOCs) 4 m above a mixed oak and hornbeam forest in northern Italy. Fluxes of methanol, acetaldehyde, isoprene, methyl vinyl ketone + methacrolein, methyl ethyl ketone and monoterpenes were obtained using both a proton transfer reaction-mass spectrometer (PTR-MS) and a proton transfer reaction-time of flight-mass spectrometer (PTR-ToF-MS) together with the methods of virtual disjunct eddy covariance (PTR-MS) and eddy covariance (PTR-ToF-MS). Isoprene was the dominant emitted compound with a mean day-time flux of 1.9 mg m-2 h-1. Mixing ratios, recorded 4 m above the canopy, were dominated by methanol with a mean value of 6.2 ppbv over the 28 day measurement period. Comparison of isoprene fluxes calculated using the PTR-MS and PTR-ToF-MS showed very good agreement while comparison of the monoterpene fluxes suggested a slight over estimation of the flux by the PTR-MS. A basal isoprene emission rate for the forest of 1.7 mg m-2 h-1 was calculated using the MEGAN isoprene emissions algorithms (Guenther et al., 2006). A detailed tree species distribution map for the site enabled the leaf-level emissions of isoprene and monoterpenes recorded using GC-MS to be scaled up to produce a "bottom-up" canopy-scale flux. This was compared with the "top-down" canopy-scale flux obtained by measurements. For monoterpenes, the two estimates were closely correlated and this correlation improved when the plant species composition in the individual flux footprint was taken into account. However, the bottom-up approach significantly underestimated the isoprene flux, compared with the top-down measurements, suggesting that the leaf-level measurements were not representative of actual emission rates.

RNA-Seq in the discovery of a sparsely expressed scent-determining monoterpene synthase in lavender (Lavandula).

PubMed

Adal, Ayelign M; Sarker, Lukman S; Malli, Radesh P N; Liang, Ping; Mahmoud, Soheil S

2018-06-09

Using RNA-Seq, we cloned and characterized a unique monoterpene synthase responsible for the formation of a scent-determining S-linalool constituent of lavender oils from Lavandula × intermedia. Several species of Lavandula produce essential oils (EOs) consisting mainly of monoterpenes including linalool, one of the most abundant and scent-determining oil constituents. Although R-linalool dominates the EOs of lavenders, varying amounts (depending on the species) of the S-linalool enantiomer can also be found in these plants. Despite its relatively low abundance, S-linalool contributes a sweet, pleasant scent and is an important constituent of lavender EOs. While several terpene synthase genes including R-linalool synthase have been cloned from lavenders many important terpene synthases including S-linalool synthase have not been described from these plants. In this study, we employed RNA-Seq and other complementary sequencing data to clone and functionally characterize the sparsely expressed S-linalool synthase cDNA (LiS-LINS) from Lavandula × intermedia. Recombinant LiS-LINS catalyzed the conversion of the universal monoterpene precursor geranyl diphosphate to S-linalool as the sole product. Intriguingly, LiS-LINS exhibited very low (~ 30%) sequence similarity to other Lavandula terpene synthases, including R-linalool synthase. However, the predicted 3D structure of this protein, including the composition and arrangement of amino acids at the active site, is highly homologous to known terpene synthase proteins. LiS-LINS transcripts were detected in flowers, but were much less abundant than those corresponding to LiR-LINS, paralleling enantiomeric composition of linalool in L. × intermedia oils. These data indicate that production of S-linalool is at least partially controlled at the level of transcription from LiS-LINS. The cloned LiS-LINS cDNA may be used to enhance oil composition in lavenders and other plants through metabolic engineering.

Observations of VOC emissions and photochemical products over US oil- and gas-producing regions using high-resolution H3O+ CIMS (PTR-ToF-MS)

NASA Astrophysics Data System (ADS)

Koss, Abigail; Yuan, Bin; Warneke, Carsten; Gilman, Jessica B.; Lerner, Brian M.; Veres, Patrick R.; Peischl, Jeff; Eilerman, Scott; Wild, Rob; Brown, Steven S.; Thompson, Chelsea R.; Ryerson, Thomas; Hanisco, Thomas; Wolfe, Glenn M.; St. Clair, Jason M.; Thayer, Mitchell; Keutsch, Frank N.; Murphy, Shane; de Gouw, Joost

2017-08-01

VOCs related to oil and gas extraction operations in the United States were measured by H3O+ chemical ionization time-of-flight mass spectrometry (H3O+ ToF-CIMS/PTR-ToF-MS) from aircraft during the Shale Oil and Natural Gas Nexus (SONGNEX) campaign in March-April 2015. This work presents an overview of major VOC species measured in nine oil- and gas-producing regions, and a more detailed analysis of H3O+ ToF-CIMS measurements in the Permian Basin within Texas and New Mexico. Mass spectra are dominated by small photochemically produced oxygenates and compounds typically found in crude oil: aromatics, cyclic alkanes, and alkanes. Mixing ratios of aromatics were frequently as high as those measured downwind of large urban areas. In the Permian, the H3O+ ToF-CIMS measured a number of underexplored or previously unreported species, including aromatic and cycloalkane oxidation products, nitrogen heterocycles including pyrrole (C4H5N) and pyrroline (C4H7N), H2S, and a diamondoid (adamantane) or unusual monoterpene. We additionally assess the specificity of a number of ion masses resulting from H3O+ ion chemistry previously reported in the literature, including several new or alternate interpretations.

Products of BVOC oxidation: ozone and organic aerosols

NASA Astrophysics Data System (ADS)

Wildt, Jürgen; Andres, Stefanie; Carriero, Giulia; Ehn, Mikael; Fares, Silvano; Hoffmann, Thorsten; Hacker, Lina; Kiendler-Scharr, Astrid; Kleist, Einhard; Paoletti, Elena; Pullinen, Iida; Rohrer, Franz; Rudich, Yinon; Springer, Monika; Tillmann, Ralf; Wahner, Andreas; Wu, Cheng; Mentel, Thomas

2015-04-01

Biogenic Volatile Organic Compounds (BVOC) are important precursors in photochemical O3 and secondary organic aerosol (SOA) formation. We conducted a series of laboratory experiments with OH-induced oxidation of monoterpenes to elucidate pathways and efficiencies of O3 and SOA formation. At high NOx conditions ([BVOC] / [NOx] < 7 ppbC / ppb) photochemical ozone formation was observed. For -pinene as individual BVOC as well as for the monoterpene mixes emitted from different plant species we observed increasing ozone formation with increasing [NOX]. Between 2 and 3 O3-molecules were formed from 1 monoterpene when ozone formation was BVOC limited. Under such high NOX conditions, new particle formation was suppressed. Increasing [BVOC] / [NOX] ratios caused increasing efficiency of new particle formation indicating that peroxy radicals are the key intermediates in both, photochemical ozone- and new particle formation. The classical chemistry of peroxy radicals is well established (e.g. Master Chemical Mechanism). Peroxy radicals are produced by addition of molecular oxygen to the alkyl radical formed after OH attack at the BVOC. They either react with NO which leads to ozone formation or they react with other peroxy radicals and form chemically stable products (hydroperoxides, alkoholes and ketones). Much less knowledge exists on such reactions for Highly Oxidized Peroxy Radicals, (HOPR). Such HOPR were observed during ozonolysis of several volatiles and, in case of monoterpenes as precursors, they can contain more than 12 Oxygen atoms (Mentel et al., 2015). Although the OH-initiated formation of HOPR is yet not fully understood, their basic gas phase reactions seem to follow classical photochemical rules. In reactions with NO they can act as precursor for O3 and in reactions with other HOPR or with classical less oxidized peroxy radicals they can form highly oxidized stable products and alkoxy radicals. In addition, HOPR-HOPR reactions lead to the formation of dimers that, in case of monoterpenes as reactants, consist of a skeleton with 20 carbon atoms. These dimers seem to play a major role in new particle formation and their existence may explain the observations of Wildt et al. (2014) who found power law dependence with an exponent approaching -2 between new particle formation and ozone formation. The monomer products of HOPR-HOPR reactions play a dominant role in SOA mass formation because their vapour pressures are low enough to allow condensation on pre-existing particulate matter (Ehn et al., 2014). Furthermore, the minor impacts of NOX on particle mass formation (Wildt et al., 2014) are explainable by similar yields of alkoxy radicals in HOPR-HOPR and HOPR-NO reactions, respectively.

Biogenic volatile organic compounds - small is beautiful

NASA Astrophysics Data System (ADS)

Owen, S. M.; Asensio, D.; Li, Q.; Penuelas, J.

2012-12-01

While canopy and regional scale flux measurements of biogenic volatile organic compounds (bVOCs) are essential to obtain an integrated picture of total compound reaching the atmosphere, many fascinating and important emission details are waiting to be discovered at smaller scales, in different ecological and functional compartments. We concentrate on bVOCs below ground to <2m above ground level. Emissions at leaf scale are well documented and widely presented, and are not discussed here. Instead we describe some details of recent research on rhizosphere bVOCs, and bVOCs associated with pollination of flowers. Although bVOC emissions from soil surfaces are small, bVOCs are exuded by roots of some plant species, and can be extracted from decaying litter. Naturally occurring monoterpenes in the rhizosphere provide a specialised carbon source for micro-organisms, helping to define the micro-organism community structure, and impacting on nutrient cycles which are partly controlled by microorganisms. Naturally occurring monoterpenes in the soil system could also affect the aboveground structure of ecosystems because of their role in plant defence strategies and as mediating chemicals in allelopathy. A gradient of monoterpene concentration was found in soil around Pinus sylvestris and Pinus halepensis, decreasing with distance from the tree. Some compounds (α-pinene, sabinene, humulene and caryophyllene) in mineral soil were linearly correlated with the total amount of each compound in the overlying litter, indicating that litter might be the dominant source of these compounds. However, α-pinene did not fall within the correlation, indicating a source other than litter, probably root exudates. We also show that rhizosphere bVOCs can be a carbon source for soil microbes. In a horizontal gradient from Populus tremula trees, microbes closest to the tree trunk were better enzymatically equipped to metabolise labeled monoterpene substrate. Monoterpenes can also increase the degradation rate in soil of the persistant organic pollutants, likely acting as analogues for the cometabo-lism of polychlorinated biphenyls (PCBs) Flowers of a ginger species (Alpinia kwangsiensis) and a fig species (Ficus hispida) showed different bVOC signals pre- and post pollination. For Ficus hispida, there are three floral stages of a fig-wasp dependency mechanism: receptive, post pollinator and interfloral. Of 28 compounds detected, transcaryophyllene with trans-β-farnesene were the most important at the receptor stage, trans-caryophyllene was the most abundant at the post-pollinator stage, and isoprene was the most abundant in the interfloral stage. Alpinia kwangsiensis presents two morphologies for the reproductive parts of the flower. The "anaflexistyle" morphology has the flower style lowered in the morning and raised in the afternoon. This is reversed for the "cataflexistyle" morphology. The bVOC mixture emitted by each morphology in morning and afternoon was complex. However for compounds showing a difference (cis-ocimene and Z + E epoxy -ocimene), the emissions from the anaflexistyle were greater than from the cataflexistyle, and were greater in the afternoon compared with the morning emissions. Where large flowering plant species are abundant, big changes in monoterpene emissions at < 2m above ground level over relatively small periods of time during pollination are likely to be missed in larger scale integrated flux measurements.

Activity antifungal of the essential oils; aqueous and ethanol extracts from Citrus aurantium L.

PubMed

Metoui, N; Gargouri, S; Amri, I; Fezzani, T; Jamoussi, B; Hamrouni, L

2015-01-01

Our study is about the essential oil of Citrus aurantium L. in Tunisia and its plant extract. The yield of this essential oil is 0, 56% but the yield of the extract of plant was 17.1% for the aqueous extract ant 18.3% for the ethanolic extract. The analysis of chemical composition by using GC and GC/MS showed the essential oil of C. aurantium L. species to be rich in monoterpenes such as α-terpineol, lianolyl acetate, linalool and limonene. The antifungal activity of this oil showed us an inhibition of the germination of mushrooms, in the same way we could note that the biologic activities are generally assigned to the chemotypes high content in oxygenated monoterpene.

Biogenic emissions from Pinus halepensis: a typical species of the Mediterranean area

NASA Astrophysics Data System (ADS)

Simon, V.; Dumergues, L.; Solignac, G.; Torres, L.

2005-03-01

Volatile organic compounds (VOCs) emissions by vegetation present in the Mediterranean area are not well known. They may contribute with anthropogenic VOC emissions to the tropospheric ozone formation that reaches important level in the European Mediterranean region. The present work, carried out as part of the European ESCOMPTE project «fiEld experimentS to COnstrain Models of atmospheric Pollution and Transport of Emissions», adds a new contribution to the inventory of the main natural hydrocarbons sources likely to participate in the ozone production. The corresponding measurement campaign was conducted in La Barben, a site close to Marseilles (France), with the aim to quantify the terpenic emission pattern and the behaviour of Pinus halepensis, an important Mediterranean species slightly studied. The determination of biogenic emissions from P. halepensis was done by the enclosure of an intact branch in a Teflon cuvette. Main emitted monoterpenes were β trans-ocimene and linalool. The total monoterpenic emission rates thus recorded were found to reach maximum values around 30 μg g dry weight-1 h -1. The normalized emission rates calculated at 30 °C and 1000 μmol m -2 s -1 with Guenther's algorithm was 14.76, 8.65 and 4.05 μg g dry weight-1 h -1, respectively, for the total monoterpenes, β trans-ocimene and linalool.

Quantification of Terpenes by 1DGC-MS and 2DGC-TOF-MS

NASA Astrophysics Data System (ADS)

Flores, R. M.; Perlinger, J. A.; Doskey, P. V.

2009-12-01

Biogenic emissions are the primary source of volatile organic compounds in the global troposphere. Deciduous and coniferous forests are the principal emitters of a complex mixture of isoprene (C5H8), monoterpenes (C10H16), and sesquiterpenes (C15H24). Sesquiterpenes are readily oxidized in the atmosphere producing secondary organic aerosols (SOA) with 100% yields. The SOA are hydrophilic and scatter light, and thus, increase albedo and lead to a cooling effect. In addition, both monoterpene and sesquiterpene generated SOA are effective cloud condensation nuclei leading to an increase in the particle number concentration and to the formation of clouds that also increase albedo. To quantify the complex mixture of terpenes and their oxidation products requires development of on-line extraction and comprehensive two-dimensional gas chromatographic techniques. One objective of this work was to compare one-dimensional gas chromatography-mass spectrometry (1DGC-MS) and two-dimensional gas chromatography time-of-flight mass spectrometry (2DGC-TOFMS) for quantifying eight monoterpenes (alpha- and beta-pinene, limonene, 3-carene, linalool, terpinolene, myrcene and ocimene) and eight sesquiterpenes (beta-caryophyllene, humulene, alpha-cedrene, cis-nerolidol, trans-nerolidol, cedrol, camphene and farnesene) in air samples collected in Northern Michigan. Future research involves coupling thermal desorption and supercritical fluid extraction devices to a GC×2GC for routine quantification of the complex mixture of terpenes and their oxidation products in rural and urban air.

Screening, separation, and evaluation of xanthine oxidase inhibitors from Paeonia lactiflora using chromatography combined with a multi-mode microplate reader.

PubMed

Wang, Jing; Shi, Dongfang; Zheng, Meizhu; Ma, Bing; Cui, Jing; Liu, Chunming; Liu, Chengyu

2017-11-01

Natural products have become one of the most important resources for discovering novel xanthine oxidase inhibitors, which are commonly employed in the treatment of hyperuricemia and gout. However, to date, few reports exist regarding the use of monoterpene glycosides as xanthine oxidase inhibitors. Thus, we herein report the use of ultrafiltration coupled with liquid chromatography in the screening of monoterpene glycoside xanthine oxidase inhibitors from the extract of Paeonia lactiflora (P. lactiflora), and both high-performance counter-current chromatography and medium-pressure liquid chromatography were employed to separate the main constituents. Furthermore, the xanthine oxidase inhibitory activities and the mechanisms of inhibition of the isolated compounds were evaluated using a multi-mode microplate reader by Molecular Devices. As a result, three monoterpene glycosides were separated by combined high-performance counter-current chromatography and medium-pressure liquid chromatography in purities of 90.4, 98.0, and 86.3%, as determined by liquid chromatography. These three compounds were identified as albiflorin, paeoniflorin, and 1-O-β-ᴅ-glucopyranosyl-8-O-benzoylpaeonisuffrone by electrospray ionization tandem mass spectrometry, and albiflorin and paeoniflorin were screened as potential xanthine oxidase inhibitors by ultrafiltration with liquid chromatography. The evaluation results of xanthine oxidase inhibitory activity corresponded with the screening results, as only albiflorin and paeoniflorin exhibited xanthine oxidase inhibitory activity. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Do multiple herbivores maintain chemical diversity of Scots pine monoterpenes?

PubMed Central

Iason, Glenn R.; O'Reilly-Wapstra, Julianne M.; Brewer, Mark J.; Summers, Ron W.; Moore, Ben D.

2011-01-01

A central issue in our understanding of the evolution of the diversity of plant secondary metabolites (PSMs) is whether or not compounds are functional, conferring an advantage to the plant, or non-functional. We examine the hypothesis that the diversity of monoterpene PSMs within a plant species (Scots pine Pinus sylvestris) may be explained by different compounds acting as defences against high-impact herbivores operating at different life stages. We also hypothesize that pairwise coevolution, with uncorrelated interactions, is more likely to result in greater PSM diversity, than diffuse coevolution. We tested whether up to 13 different monoterpenes in Scots pine were inhibitory to herbivory by slugs (Arion ater), bank voles (Clethrionomys glareolus), red deer (Cervus elaphus) and capercaillie (Tetrao urogallus), each of which attack trees at a different life stage. Plants containing more α-pinene were avoided by both slugs and capercaillie, which may act as reinforcing selective agents for this dominant defensive compound. Herbivory by red deer and capercaillie were, respectively, weakly negatively associated with δ3-carene, and strongly negatively correlated with the minor compound β-ocimene. Three of the four herbivores are probably contributory selective agents on some of the terpenes, and thus maintain some, but by no means all, of the phytochemical diversity in the species. The correlated defensive function of α-pinene against slugs and capercaillie is consistent with diffuse coevolutionary processes. PMID:21444308

Genetic and metabolite diversity of Sardinian populations of Helichrysum italicum.

PubMed

Melito, Sara; Sias, Angela; Petretto, Giacomo L; Chessa, Mario; Pintore, Giorgio; Porceddu, Andrea

2013-01-01

Helichrysum italicum (Asteraceae) is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia. H. italicum plants were AFLP fingerprinted and the composition of their leaf essential oil characterized by GC-MS. The relationships between the genetic structure of the populations, soil, habitat and climatic variables and the essential oil chemotypes present were evaluated using Bayesian clustering, contingency analyses and AMOVA. The Sardinian germplasm could be partitioned into two AFLP-based clades. Populations collected from the southwestern region constituted a homogeneous group which remained virtually intact even at high levels of K. The second, much larger clade was more diverse. A positive correlation between genetic diversity and elevation suggested the action of natural purifying selection. Four main classes of compounds were identified among the essential oils, namely monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Oxygenated monoterpene levels were significantly correlated with the AFLP-based clade structure, suggesting a correspondence between gene pool and chemical diversity. The results suggest an association between chemotype, genetic diversity and collection location which is relevant for the planning of future collections aimed at identifying valuable sources of essential oil.

Chemical composition and insecticidal activity of Cymbopogon citratus essential oil from Cuba and Brazil against housefly.

PubMed

Pinto, Zeneida Teixeira; Sánchez, Félix Fernández; dos Santos, Arith Ramos; Amaral, Ana Claudia Fernandes; Ferreira, José Luiz Pinto; Escalona-Arranz, Julio César; Queiroz, Margareth Maria de Carvalho

2015-01-01

Essential oil of Cymbopogon citratus collected from Brazil and Cuba was tested to a chemical characterization and then was tested on the post-embryonic development of Musca domestica. The chemical composition analysis by GC-MS of the oils from Brazil/Cuba allowed the identification of 13 and 12 major constituents respectively; nine of them common to both. In the both oils, the main components were the isomers geranial and neral, which together form the compound citral. This corresponds to a total of 97.92%/Brazil and 97.69%/Cuba of the compounds identified. The monoterpene myrcene, observed only in the sample of Cuba, presented a large relative abundance (6.52%). The essential oil of C. citratus (Brazil/Cuba) was dissolved in DMSO and tested at concentrations of 5, 10, 25, 50, 75 and 100% and citral was prepared by mixing 16.8 mg with 960 µL DMSO. Both essential oils and monoterpene citral were applied topically to newly-hatched larvae (1µL/larva). The results showed a lethal concentration (LC50) of 4.25 and 3.24% for the Brazilian and Cuban essential oils, respectively. Mortalities of larval and newly-hatched larvae to adult periods were dose-dependent for the two both oils as for monoterpene citral, reaching 90%. Both essential oils and citral caused morphological changes in adult specimens.

Anthropogenic Sulfur Perturbations on Biogenic Oxidation: SO2 Additions Impact Gas-Phase OH Oxidation Products of α- and β-Pinene.

PubMed

Friedman, Beth; Brophy, Patrick; Brune, William H; Farmer, Delphine K

2016-02-02

In order to probe how anthropogenic pollutants can impact the atmospheric oxidation of biogenic emissions, we investigated how sulfur dioxide (SO2) perturbations impact the oxidation of two monoterpenes, α-and β-pinene. We used chemical ionization mass spectrometry to examine changes in both individual molecules and gas-phase bulk properties of oxidation products as a function of SO2 addition. SO2 perturbations impacted the oxidation systems of α-and β-pinene, leading to an ensemble of products with a lesser degree of oxygenation than unperturbed systems. These changes may be due to shifts in the OH:HO2 ratio from SO2 oxidation and/or to SO3 reacting directly with organic molecules. Van Krevelen diagrams suggest a shift from gas-phase functionalization by alcohol/peroxide groups to functionalization by carboxylic acid or carbonyl groups, consistent with a decreased OH:HO2 ratio. Increasing relative humidity dampens the impact of the perturbation. This decrease in oxygenation may impact secondary organic aerosol formation in regions dominated by biogenic emissions with nearby SO2 sources. We observed sulfur-containing organic compounds following SO2 perturbations of monoterpene oxidation; whether these are the result of photochemistry or an instrumental artifact from ion-molecule clustering remains uncertain. However, our results demonstrate that the two monoterpene isomers produce unique suites of oxidation products.

Sorption of the monoterpenes α-pinene and limonene to carbonaceous geosorbents including biochar.

PubMed

Hale, Sarah E; Endo, Satoshi; Arp, Hans Peter H; Zimmerman, Andrew R; Cornelissen, Gerard

2015-01-01

The sorption of two monoterpenes, α pinene and limonene to the carbonaceous geosorbents graphite, bituminous coal, lignite coke, biochar and Pahokee peat was quantified. Polyethylene (PE) passive samplers were calibrated for the first time for these compounds by determining the PE-water partitioning coefficients and used as a tool to determine sorption to the carbonaceous geosorbents. Log KPE-water values were 3.49±0.58 for α pinene and 4.08±0.27 for limonene. The sorption of limonene to all materials was stronger than that for α pinene (differences of 0.2-1.3 log units between distribution coefficients for the monoterpenes). Placing Kd values in increasing order for α pinene gave biochar≈Pahokee peat≈bituminous coal≈lignite coke

In vitro inhibition of the bovine viral diarrhoea virus by the essential oil of Ocimum basilicum (basil) and monoterpenes.

PubMed

Kubiça, Thaís F; Alves, Sydney H; Weiblen, Rudi; Lovato, Luciane T

2014-01-01

The bovine viral diarrhoea virus (BVDV) is suggested as a model for antiviral studies of the hepatitis C virus (HCV). The antiviral activity of the essential oil of Ocimum basilicum and the monoterpenes camphor, thymol and 1,8-cineole against BVDV was investigated. The cytotoxicities of the compounds were measured by the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) test, and the antiviral activities were tested by the plaque reduction assay. The oil or compounds were added to the assay in three different time points: a) pre-treatment of the virus (virucidal assay); b) pre-treatment of the cells; or c) post-treatment of the cells (after virus inoculation). The percentage of plaques inhibition for each compound was determined based on the number of plaques in the viral control. The results were expressed by CC50 (50% cytotoxic concentration), IC50 (inhibitory concentration for 50% of plaques) and SI (selectivity index = CC50/IC50). Camphor (CC50 = 4420.12 μg mL(-1)) and 1,8-cineole (CC50 = 2996.10 μg mL(-1)) showed the lowest cytotoxicities and the best antiviral activities (camphor SI = 13.88 and 1,8-cineol SI = 9.05) in the virucidal assay. The higher activities achieved by the monoterpenes in the virucidal assay suggest that these compounds act directly on the viral particle.

Formulation of sage essential oil (Salvia officinalis, L.) monoterpenes into chitosan hydrogels and permeation study with GC-MS analysis.

PubMed

Kodadová, Alexandra; Vitková, Zuzana; Herdová, Petra; Ťažký, Anton; Oremusová, Jarmila; Grančai, Daniel; Mikuš, Peter

2015-01-01

This study deals with the formulation of natural drugs into hydrogels. For the first time, compounds from the sage essential oil were formulated into chitosan hydrogels. A sample preparation procedure for hydrophobic volatile analytes present in a hydrophilic water matrix along with an analytical method based on the gas chromatography coupled with the mass spectrometry (GC-MS) was developed and applied for the evaluation of the identity and quantity of essential oil components in the hydrogels and saline samples. The experimental results revealed that the chitosan hydrogels are suitable for the formulation of sage essential oil. The monoterpene release can be effectively controlled by both chitosan and caffeine concentration in the hydrogels. Permeation experiment, based on a hydrogel with the optimized composition [3.5% (w/w) sage essential oil, 2.0% (w/w) caffeine, 2.5% (w/w) chitosan and 0.1% (w/w) Tween-80] in donor compartment, saline solution in acceptor compartment, and semi-permeable cellophane membrane, demonstrated the useful permeation selectivity. Here, (according to lipophilicity) an enhanced permeation of the bicyclic monoterpenes with antiflogistic and antiseptic properties (eucalyptol, camphor and borneol) and, at the same time, suppressed permeation of toxic thujone (not exceeding its permitted applicable concentration) was observed. These properties highlight the pharmaceutical importance of the developed chitosan hydrogel formulating sage essential oil in the dermal applications.

Mountain pine beetle attack associated with low levels of 4-allylanisole in ponderosa pine.

PubMed

Emerick, Jay J; Snyder, Aaron I; Bower, Nathan W; Snyder, Marc A

2008-08-01

Mountain pine beetle (Dendroctonus ponderosae) is the most important insect pest in southern Rocky Mountain ponderosa pine (Pinus ponderosa) forests. Tree mortality is hastened by the various fungal pathogens that are symbiotic with the beetles. The phenylpropanoid 4-allylanisole is an antifungal and semiochemical for some pine beetle species. We analyzed 4-allylanisole and monoterpene profiles in the xylem oleoresin from a total of 107 trees at six sites from two chemotypes of ponderosa pine found in Colorado and New Mexico using gas chromatography-mass spectroscopy (GC-MS). Although monoterpene profiles were essentially the same in attacked and nonattacked trees, significantly lower levels of 4-allylanisole were found in attacked trees compared with trees that showed no evidence of attack for both chemotypes.

Knockdown and larvicidal activity of six monoterpenes against Aedes aegypti (Diptera: Culicidae) and their structure-activity relationships.

PubMed

Lucia, Alejandro; Zerba, Eduardo; Masuh, Hector

2013-12-01

The relationships between physicochemical parameters of majority components of Eucalyptus essential oils and their insecticide effect were evaluated on Aedes aegypti (L.) (Diptera: Culicidae). The octanol-water partition coefficients of the monoterpenes were estimated by the atom/fragment contribution method and the vapor pressures were determined by our laboratory in previous studies. The larvicidal activity (LC50 (ppm)) and knockdown effect (KT50 (min)) of each component was determined. The results show that the toxicity of EOs main components of Eucalyptus on adults and larvae of A. aegypti is strongly related to their physicochemical properties (vapor pressure and Log P). However, the interaction of both variables (vapor pressure * Log P) explains the toxicological phenomenon more precisely. The regression models were expressed as follows: KT 50(min) =  - 10.9 + 3.7 * Log P + 1.9 * 1/Pvapor (R(2) = 0.80; F = 42.5) and LC 50(ppm) =  - 94.3 + 438.6 *  1/Log P + 2.8 *  1/Pvapor (F = 57.8; R(2) = 0.85). The six evaluated components present different functional groups. Therefore, it was considered to evaluate the monoterpenes as a group and separated in two groups: oxygenated monoterpenes (α-terpineol, 4-terpineol, and 1,8-cineole) and terpene hydrocarbons (γ-terpinene, p-cymene, and α-pinene). The results show the regression models for each group as follows: (A) oxygenated terpenes: KT 50(min) = - 515.3 + 1613.2 * 1/Log P + 5, 2 * 1/Pvapor (F = 3176.7 R(2) = 0.99) and LC 50(ppm)  =  - 1679.4 + 5402.1 * 1/Log P + 12.7 *  1/Pvapor (F = 282.9; R(2) = 0.99). (B) Hydrocarbons terpenes: KT 50(min) = 18.2 - 58.3 * 1/Log P + 2.7 * 1/Pvapor (F = 171.7;  R(2) = 0.97) and LC 50(ppm) = - 21.1 + 174.9 * 1/Log P - 14.3 * 1/Pvapor (F = 410.0; R(2) = 0.99). The association between the toxic effect of the evaluated monoterpenes against A. aegypti and the physicochemical properties can be better described when they are separated into functional groups (hydrocarbons vs. oxygenated terpenes).

Online Measurements of Highly Oxidized Organics in the Gas and Particle phase during SOAS and SENEX

NASA Astrophysics Data System (ADS)

Lopez-Hilfiker, F.; Lee, B. H.; Mohr, C.; Ehn, M.; Rubach, F.; Mentel, T. F.; Kleist, E.; Thornton, J. A.

2014-12-01

We present measurements of a large suite of gas and particle phase organic compounds made with a Filter Inlet for Gas and AEROsol (FIGAERO) coupled to a high resolution time of flight chemical ionization mass spectrometer (HR-ToF-CIMS) developed at the University of Washington and with airborne HR-ToF-CIMS measurements. The FIGAERO instrument was deployed on the Jülich Plant Atmosphere Chamber to study α-pinene oxidation, and subsequently at the SMEAR II forest station in Hyytiälä, Finland and the SOAS ground site, in Brent Alabama. During the Southern Atmosphere Study, a gas-phase only version of the HR-ToF-CIMS was deployed on the NOAA WP-3 aircraft as part of SENEX. We focus here on highly oxygenated organic compounds derived from monoterpene oxidation detected both aloft during SENEX and at the ground-based site during SOAS. In both chamber and the atmosphere, many highly oxidized, low volatility compounds were observed in the gas and particles and many of the same compositions detected in the gas-phase were detected in the particles upon temperature programmed thermal desorption. The fraction of a given compound measured in the particle phase follows expected trends with elemental composition such as O/C ratios, but many compounds would not be well described by an absorptive partitioning model assuming unity activity coefficients. The detailed structure in the thermograms reveals a significant contribution from large molecular weight organics and/or oligomers in both chamber and ambient aerosol samples. Approximately 50% of the measured organics in the particle phase are associated with compounds having effective vapour pressures 4 or more orders of magnitude lower than commonly measured monoterpene oxidation products. We discuss the implications of these findings for measurements of gas-particle partitioning and for evaluating the contribution of monoterpene oxidation to organic aerosol formation and growth. We also use the aircraft measurements and a steady state model to estimate the yield of such highly oxidized compounds from monoterpene oxidation.

Seasonal soil VOC exchange rates in a Mediterranean holm oak forest and their responses to drought conditions

NASA Astrophysics Data System (ADS)

Asensio, Dolores; Peñuelas, Josep; Ogaya, Romà; Llusià, Joan

Available information on soil volatile organic compound (VOC) exchange, emissions and uptake, is very scarce. We here describe the amounts and seasonality of soil VOC exchange during a year in a natural Mediterranean holm oak forest growing in Southern Catalonia. We investigated changes in soil VOC dynamics in drought conditions by decreasing the soil moisture to 30% of ambient conditions by artificially excluding rainfall and water runoff, and predicted the response of VOC exchange to the drought forecasted in the Mediterranean region for the next decades by GCM and ecophysiological models. The annual average of the total (detected) soil VOC and total monoterpene exchange rates were 3.2±3.2 and -0.4±0.3 μg m -2 h -1, respectively, in control plots. These values represent 0.003% of the total C emitted by soil at the study site as CO 2 whereas the annual mean of soil monoterpene exchange represents 0.0004% of total C. Total soil VOC exchange rates in control plots showed seasonal variations following changes in soil moisture and phenology. Maximum values were found in spring (17±8 μg m -2 h -1). Although there was no significant global effect of drought treatment on the total soil VOC exchange rates, annual average of total VOC exchange rates in drought plots resulted in an uptake rate (-0.5±1.8 μg m -2 h -1) instead of positive net emission rates. Larger soil VOC and monoterpene exchanges were measured in drought plots than in control plots in summer, which might be mostly attributable to autotrophic (roots) metabolism. The results show that the diversity and magnitude of monoterpene and VOC soil emissions are low compared with plant emissions, that they are driven by soil moisture, that they represent a very small part of the soil-released carbon and that they may be strongly reduced or even reversed into net uptakes by the predicted decreases of soil water availability in the next decades. In all cases, it seems that VOC fluxes in soil might have greater impact on soil ecology than on atmospheric chemistry.

Undisturbed and disturbed above canopy ponderosa pine emissions: PTR-TOF-MS measurements and MEGAN 2.1 model results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaser, L.; Karl, T.; Guenther, A.

2013-01-01

We present the first eddy covariance flux measurements of volatile organic compounds (VOCs) using a proton-transfer-reaction time-of-flight mass-spectrometer (PTR-TOFMS) above a ponderosa pine forest in Colorado, USA. The high mass resolution of the PTR-TOF-MS enabled the identification of chemical sum formulas. During a 30 day measurement period in August and September 2010, 649 different ion mass peaks were detected in the ambient air mass spectrum (including primary ions and mass calibration ompounds). Eddy covariance with the vertical wind speed was calculated for all ion mass peaks. On a typical day, 17 ion mass peaks including protonated parent compounds, their fragmentsmore » and isotopes as well as VOC-H+-water clusters showed a significant flux with daytime average emissions above a reliable flux threshold of 0.1mgcompoundm-2 h-1. These ion mass peaks could be assigned to seven compound classes. The main flux contributions during daytime (10:00-18:00 LT) are attributed to the sum of 2-methyl-3-buten-2-ol (MBO) and isoprene (50 %), methanol (12%), the sum of acetic acid and glycolaldehyde (10%) and the sum of monoterpenes (10 %). The total MBO+isoprene flux was composed of 10% isoprene and 90% MBO. There was good agreement between the light and temperature dependency of the sum of MBO and isoprene observed for this work and those of earlier studies. The above canopy flux measurements of the sum of MBO and isoprene and the sum of 20 monoterpenes were compared to emissions calculated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN 2.1). The best agreement between MEGAN 2.1 and measurements was reached using emission factors determined from site specific leaf cuvette measurements. While the modelled and measured MBO+isoprene fluxes agree well the emissions of the sum of monoterpenes is underestimated by MEGAN 2.1. This is expected as some factors impacting monoterpene emissions, such as physical damage of needles and branches due to storms, are not included in MEGAN 2.1.« less

Biogenic volatile organic compound (BVOC) emissions from forested areas in Turkey: determination of specific emission rates for thirty-one tree species.

PubMed

Aydin, Yagmur Meltem; Yaman, Baris; Koca, Husnu; Dasdemir, Okan; Kara, Melik; Altiok, Hasan; Dumanoglu, Yetkin; Bayram, Abdurrahman; Tolunay, Doganay; Odabasi, Mustafa; Elbir, Tolga

2014-08-15

Normalized biogenic volatile organic compound (BVOC) emission rates for thirty one tree species that cover the 98% of national forested areas in Turkey were determined. Field samplings were performed at fourteen different forested areas in Turkey using a specific dynamic enclosure system. The selected branches of tree species were enclosed in a chamber consisted of a transparent Nalofan bag. The air-flows were sampled from both inlet and outlet of the chamber by Tenax-filled sorbent tubes during photosynthesis of trees under the presence of sunlight. Several environmental parameters (temperature, humidity, photosynthetically active radiation-PAR, and CO2) were continuously monitored inside and outside the enclosure chamber during the samplings. Collected samples were analyzed using a gas chromatography mass spectrometry (GC/MS) system equipped with a thermal desorber (TD). Sixty five BVOCs classified in five major groups (isoprene, monoterpenes, sesquiterpenes, oxygenated sesquiterpenes, and other oxygenated compounds) were analyzed. Emission rates were determined by normalization to standard conditions (1000 μmol/m(2)s PAR and 30 °C temperature for isoprene and 30 °C temperature for the remaining compounds). In agreement with the literature, isoprene was mostly emitted by broad-leaved trees while coniferous species mainly emitted monoterpenes. Several tree species such as Sweet Chestnut, Silver Lime, and European Alder had higher monoterpene emissions although they are broad-leaved species. High isoprene emissions were also observed for a few coniferous species such as Nordmann Fir and Oriental Spruce. The highest normalized total BVOC emission rate of 27.1 μg/gh was observed for Oriental Plane while South European Flowering Ash was the weakest BVOC emitter with a total normalized emission rate of 0.031 μg/gh. Monoterpene emissions of broad-leaved species mainly consisted of sabinene, limonene and trans-beta-ocimene, while alpha-pinene, beta-pinene and beta-myrcene were generally emitted by coniferous species. Oxygenated compounds were the third most prominent BVOC group and sesquiterpenes had slightly lower contributions. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification, functional characterization, and regulation of the enzyme responsible for floral (E)-nerolidol biosynthesis in kiwifruit (Actinidia chinensis).

PubMed

Green, Sol A; Chen, Xiuyin; Nieuwenhuizen, Niels J; Matich, Adam J; Wang, Mindy Y; Bunn, Barry J; Yauk, Yar-Khing; Atkinson, Ross G

2012-03-01

Flowers of the kiwifruit species Actinidia chinensis produce a mixture of sesquiterpenes derived from farnesyl diphosphate (FDP) and monoterpenes derived from geranyl diphosphate (GDP). The tertiary sesquiterpene alcohol (E)-nerolidol was the major emitted volatile detected by headspace analysis. Contrastingly, in solvent extracts of the flowers, unusually high amounts of (E,E)-farnesol were observed, as well as lesser amounts of (E)-nerolidol, various farnesol and farnesal isomers, and linalool. Using a genomics-based approach, a single gene (AcNES1) was identified in an A. chinensis expressed sequence tag library that had significant homology to known floral terpene synthase enzymes. In vitro characterization of recombinant AcNES1 revealed it was an enzyme that could catalyse the conversion of FDP and GDP to the respective (E)-nerolidol and linalool terpene alcohols. Enantiomeric analysis of both AcNES1 products in vitro and floral terpenes in planta showed that (S)-(E)-nerolidol was the predominant enantiomer. Real-time PCR analysis indicated peak expression of AcNES1 correlated with peak (E)-nerolidol, but not linalool accumulation in flowers. This result, together with subcellular protein localization to the cytoplasm, indicated that AcNES1 was acting as a (S)-(E)-nerolidol synthase in A. chinensis flowers. The synthesis of high (E,E)-farnesol levels appears to compete for the available pool of FDP utilized by AcNES1 for sesquiterpene biosynthesis and hence strongly influences the accumulation and emission of (E)-nerolidol in A. chinensis flowers.

Observations of VOC Emissions and Photochemical Products over US Oil- and Gas-Producing Regions Using High-Resolution H3O+ CIMS (PTR-ToF-MS)

NASA Technical Reports Server (NTRS)

Koss, Abigail; Yuan, Bin; Warneke, Carsten; Gilman, Jessica B.; Lerner, Brian M.; Veres, Patrick R.; Peischl, Jeff; Eilerman, Scott; Wild, Rob; Brown, Steven S.;

Oxidative stress and production of bioactive monoterpene indole alkaloids: biotechnological implications.

PubMed

Matsuura, Hélio Nitta; Rau, Mariana Ritter; Fett-Neto, Arthur Germano

2014-02-01

Monoterpene indole alkaloids (MIAs) encompass plant natural products with important pharmacological relevance. They include the anti-tumoral MIAs found in Catharanthus roseus and Camptotheca acuminata. The often low yields of bioactive alkaloids in plants has prompted research to identify the factors regulating MIA production. Oxidative stress is a general response associated with biotic and abiotic stresses leading to several secondary responses, including elicitation of MIA production. These changes in secondary metabolism may take place directly or via second messengers, such as Ca(2+) and reactive oxygen species (ROS). H2O2 is the main ROS that participates in MIA biosynthesis. This review analyzes the links between oxidative stress, elicitation of bioactive MIA production and their potential roles in antioxidant defense, as well as exploring the implications to developing biotechnological strategies relevant for alkaloid supply.

Labdane-type diterpenoids from hairy root cultures of Coleus forskohlii, possible intermediates in the biosynthesis of forskolin.

PubMed

Asada, Yoshihisa; Li, Wei; Terada, Tomohiro; Kuang, Xinzhu; Li, Qin; Yoshikawa, Takafumi; Hamaguchi, Shogo; Namekata, Iyuki; Tanaka, Hikaru; Koike, Kazuo

2012-07-01

Significant attention has been devoted to studying hairy root cultures as a promising strategy for production of various valuable secondary metabolites. These offer many advantages, such as high growth rate, genetic stability and being hormone-free. In this study, a detailed phytochemical investigation of the secondary metabolites of Coleus forskohlii hairy root cultures was undertaken and which resulted in the isolation of 22 compounds, including four forskolin derivatives and a monoterpene. Their structures were elucidated by extensive spectroscopic analyses. These compounds could be classified into four groups viz.: labdane-type diterpenes, monoterpenes, triterpenes and phenylpropanoid dimers. Apart from one compound, all labdane type diterpenes are oxygenated at C-11 as in forskolin and a scheme showing their biosynthetic relationships is proposed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Chemical profile, antiproliferative and antioxidant activities of rhizome oil of Zingiber anamalayanum from Western Ghats in India.

PubMed

Salim, Mohamed; Kabeer, T K Ahmedul; Nair, S Ajikumaran; Dan, Mathew; Sabu, M; Baby, Sabulal

2016-09-01

Volatile oil from fresh rhizomes of Zingiber anamalayanum was isolated by hydrodistillation and characterised by GC-FID and GC-MS. Twenty-one out of 24 constituents comprising 99.47% of the oil were identified. Major components in Z. anamalayanum rhizome oil were δ-2-carene (52.83%), camphene (9.83%), endo-fenchol (9.42%), iso-dihydrocarveol (6.44%) and cis-p-mentha-2,8-dien-1-ol (5.19%). Monoterpene hydrocarbons in the rhizome oil were 65.81%, followed by oxygenated monoterpenes (23.78%) and sesquiterpene hydrocarbons (9.87%). Physical parameters of rhizome oil were [Formula: see text] 1.4031, [Formula: see text] - 16.097(o) (c = 1, CHCl3) and [Formula: see text] 0.9202. Z. anamalayanum rhizome oil showed significant anti-Dalton's Lymphoma Ascitic activity.

The biogenic volatile organic compounds emission inventory in France: application to plant ecosystems in the Berre-Marseilles area (France).

PubMed

Simon, Valérie; Dumergues, Laurent; Ponche, Jean-Luc; Torres, Liberto

2006-12-15

An inventory describing the fluxes of volatile organic compounds (VOCs), isoprene and monoterpenes, and other VOCs (OVOCs) from the biosphere to the atmosphere, has been constructed within the framework of the ESCOMPTE project (fiEld experimentS to COnstrain Models of atmospheric Pollution and Transport of Emissions). The area concerned, located around Berre-Marseilles, is a Mediterranean region frequently subject to high ozone concentrations. The inventory has been developed using a fine scale land use database for the year 1999, forest composition statistics, emission potentials from individual plant species, biomass distribution, temperature and light intensity. The seasonal variations in emission potentials and biomass were also taken into account. Hourly meteorological data for 1999 were calculated from ALADIN data and these were used to predict the hourly isoprene, monoterpene and OVOC fluxes for the area on a 1 kmx1 km spatial grid. Estimates of annual biogenic isoprene, monoterpene and OVOC fluxes for the reference year 1999 were 20.6, 38.9 and 13.3 kt, respectively, Quercus pubescens, Quercus ilex, Pinus halepensis and garrigue vegetation are the dominant emitting species of the area. VOC emissions from vegetation in this region contribute approximately 94% to the NMVOC (non-methane volatile organic compounds) of natural origin and are of the same order of magnitude as NMVOC emissions from anthropogenic sources. These results complete the global ESCOMPTE database needed to make an efficient strategy for tropospheric ozone reduction policy.

Biochemistry of Short-Chain Alkanes (Tissue-Specific Biosynthesis of n-Heptane in Pinus jeffreyi).

PubMed Central

Savage, T. J.; Hamilton, B. S.; Croteau, R.

1996-01-01

Short-chain (C7-C11) alkanes accumulate as the volatile component of oleoresin (pitch) in several pine species native to western North America. To establish the tissue most amenable for use in detailed studies of short-chain alkane biosynthesis, we examined the tissue specificity of alkane accumulation and biosynthesis in Pinus jeffreyi Grev. & Balf. Short-chain alkane accumulation was highly tissue specific in both 2-year-old saplings and mature trees; heart-wood xylem accumulated alkanes up to 7.1 mg g-1 dry weight, whereas needles and other young green tissue contained oleoresin with monoterpenoid, rather than paraffinic, volatiles. These tissue-specific differences in oleoresin composition appear to be a result of tissue-specific rates of alkane and monoterpene biosynthesis; incubation of xylem tissue with [14C]sucrose resulted in accumulation of radiolabel in alkanes but not monoterpenes, whereas incubation of foliar tissue with 14CO2 resulted in the accumulation of radiolabel in monoterpenes but not alkanes. Furthermore, incubation of xylem sections with [14C]acetate resulted in incorporation of radiolabel into alkanes at rates up to 1.7 nmol h-1 g-1 fresh weight, a rate that exceeds most biosynthetic rates reported with other plant systems for the incorporation of this basic precursor into natural products. This suggests that P. jeffreyi may provide a suitable model for elucidating the enzymology and molecular biology of short-chain alkane biosynthesis. PMID:12226177

Ultraviolet-B and photosynthetically active radiation interactively affect yield and pattern of monoterpenes in leaves of peppermint (Mentha x piperita L.).

PubMed

Behn, Helen; Albert, Andreas; Marx, Friedhelm; Noga, Georg; Ulbrich, Andreas

2010-06-23

Solar radiation is a key environmental signal in regulation of plant secondary metabolism. Since metabolic responses to light and ultraviolet (UV) radiation exposure are known to depend on the ratio of spectral ranges (e.g., UV-B/PAR), we examined effects of different UV-B radiation (280-315 nm) and photosynthetically active radiation (PAR, 400-700 nm) levels and ratios on yield and pattern of monoterpenoid essential oil of peppermint. Experiments were performed in exposure chambers, technically equipped for realistic simulation of natural climate and radiation. The experimental design comprised four irradiation regimes created by the combination of two PAR levels including or excluding UV-B radiation. During flowering, the highest essential oil yield was achieved at high PAR (1150 micromol m(-2) s(-1)) and approximate ambient UV-B radiation (0.6 W m(-2)). Regarding the monoterpene pattern, low PAR (550 micromol m(-2) s(-1)) and the absence of UV-B radiation led to reduced menthol and increased menthone contents and thereby to a substantial decrease in oil quality. Essential oil yield could not be correlated with density or diameter of peltate glandular trichomes, the epidermal structures specialized on biosynthesis, and the accumulation of monoterpenes. The present results lead to the conclusion that production of high quality oils (fulfilling the requirements of the Pharmacopoeia Europaea) requires high levels of natural sunlight. In protected cultivation, the use of UV-B transmitting covering materials is therefore highly recommended.

Within-canopy sesquiterpene ozonolysis in Amazonia

NASA Astrophysics Data System (ADS)

Jardine, K.; YañEz Serrano, A.; Arneth, A.; Abrell, L.; Jardine, A.; van Haren, J.; Artaxo, P.; Rizzo, L. V.; Ishida, F. Y.; Karl, T.; Kesselmeier, J.; Saleska, S.; Huxman, T.

2011-10-01

Through rapid reactions with ozone, which can initiate the formation of secondary organic aerosols, the emission of sesquiterpenes from vegetation in Amazonia may have significant impacts on tropospheric chemistry and climate. Little is known, however, about sesquiterpene emissions, transport, and chemistry within plant canopies owing to analytical difficulties stemming from very low ambient concentrations, high reactivities, and sampling losses. Here, we present ambient sesquiterpene concentration measurements obtained during the 2010 dry season within and above a primary tropical forest canopy in Amazonia. We show that by peaking at night instead of during the day, and near the ground instead of within the canopy, sesquiterpene concentrations followed a pattern different from that of monoterpenes, suggesting that unlike monoterpene emissions, which are mainly light dependent, sesquiterpene emissions are mainly temperature dependent. In addition, we observed that sesquiterpene concentrations were inversely related with ozone (with respect to time of day and vertical concentration), suggesting that ambient concentrations are highly sensitive to ozone. These conclusions are supported by experiments in a tropical rain forest mesocosm, where little atmospheric oxidation occurs and sesquiterpene and monoterpene concentrations followed similar diurnal patterns. We estimate that the daytime dry season ozone flux of -0.6 to -1.5 nmol m-2 s-1 due to in-canopy sesquiterpene reactivity could account for 7%-28% of the net ozone flux. Our study provides experimental evidence that a large fraction of total plant sesquiterpene emissions (46%-61% by mass) undergo within-canopy ozonolysis, which may benefit plants by reducing ozone uptake and its associated oxidative damage.

Oxidation of monoterpenes in Protium heptaphyllum oleoresins.

PubMed

Albino, Rayane C; Oliveira, Prissila C; Prosdocimi, Francisco; da Silva, Osman F; Bizzo, Humberto R; Gama, Paola E; Sakuragui, Cássia M; Furtado, Carolina; de Oliveira, Danilo R

2017-04-01

Protium heptaphyllum (Burseraceae) oleoresins are rich in volatile monoterpenes, exhibiting a chemical composition that can be strongly altered with time. The present work aimed to discuss the temporal change of the volatile composition of these oleoresins, and search for related supporting evidence. Samples of P. heptaphyllum oleoresin were collected separately for fresh (n = 10) and aged (n = 8) oleoresins, with the essential oils obtained by hydrodistillation analyzed by GC-FID and GC-MS. Fresh oleoresins were characterized by a high content of terpinolene (28.2-69.7%), whereas aged ones contained large amounts of p-cymene (18.7-43.0%) and p-cymen-8-ol (8.2-31.8%). Multivariate analyses were performed based on the yield and major essential oil components to clearly demonstrate the existence of two subsets (fresh and aged oleoresins). In addition, an analysis of the partial genome sequencing of the species was carried out, producing the largest amount of data for the genus Protium. Subsequently, were searched for nucleotide sequences responsible for the enzymes involved in the biosynthesis of monoterpenes. Two hypotheses were formulated to understand the oxidation process during aging of the oleoresins: (i) a natural chemical oxidation of terpenes and (ii) an oxidation catalyzed by enzymes produced by microorganisms associated with the plant. The results suggested that terpinolene was most likely oxidized to p-cymene, which, in turn, was oxidized into p-cymen-8-ol during natural aging of the exudate due to abiotic factors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetic and Metabolite Diversity of Sardinian Populations of Helichrysum italicum

PubMed Central

Melito, Sara; Sias, Angela; Petretto, Giacomo L.; Chessa, Mario; Pintore, Giorgio; Porceddu, Andrea

2013-01-01

Background Helichrysum italicum (Asteraceae) is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia. Methods H. italicum plants were AFLP fingerprinted and the composition of their leaf essential oil characterized by GC-MS. The relationships between the genetic structure of the populations, soil, habitat and climatic variables and the essential oil chemotypes present were evaluated using Bayesian clustering, contingency analyses and AMOVA. Key results The Sardinian germplasm could be partitioned into two AFLP-based clades. Populations collected from the southwestern region constituted a homogeneous group which remained virtually intact even at high levels of K. The second, much larger clade was more diverse. A positive correlation between genetic diversity and elevation suggested the action of natural purifying selection. Four main classes of compounds were identified among the essential oils, namely monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Oxygenated monoterpene levels were significantly correlated with the AFLP-based clade structure, suggesting a correspondence between gene pool and chemical diversity. Conclusions The results suggest an association between chemotype, genetic diversity and collection location which is relevant for the planning of future collections aimed at identifying valuable sources of essential oil. PMID:24260149

Efficacy of Lippia alba (Mill.) N.E. Brown essential oil and its monoterpene aldehyde constituents against fungi isolated from some edible legume seeds and aflatoxin B1 production.

PubMed

Shukla, Ravindra; Kumar, Ashok; Singh, Priyanka; Dubey, Nawal Kishore

2009-10-31

The present study deals with evaluation of antifungal properties of Lippia alba essential oil (EO) and two of its monoterpene aldehyde constituents against legume-contaminating fungi. Seventeen different fungal species were isolated from 11 varieties of legumes, and aflatoxigenic isolates of Aspergillus flavus were identified. Hydrodistillation method was used to extract the EO from fresh leaves. The GC and GC-MS analysis of EO revealed the monoterpene aldehydes viz. geranial (22.2%) and neral (14.2%) as the major components. The antifungal activity of EO, geranial and neral was evaluated by contact assay on Czapek's-dox agar. The EO (0.25-1 microL/mL) and its two constituents (1 microL/mL) showed remarkable antifungal effects against all the fungal isolates (growth inhibition range 32.1-100%). Their minimal inhibitory (MIC) and fungicidal (MFC) concentrations for A. flavus were lower than those of the systemic fungicide Bavistin. Aflatoxin B(1) (AFB(1)) production by three isolates of A. flavus was strongly inhibited even at the lower fungistatic concentration of EO and its constituents. There was no adverse effect of treatments on seed germination, and rather, there was enhanced seedling growth in the EO-treated seeds. It is concluded that L. alba EO and two of its constituents could be safely used as effective preservative for food legumes against fungal infections and mycotoxins.

Drought stress alters the concentration of wood terpenoids in Scots pine and Norway spruce seedlings.

PubMed

Turtola, Satu; Manninen, Anne-Marja; Rikala, Risto; Kainulainen, Pirjo

2003-09-01

Drought is known to have an impact on the resistance of conifers to various pests, for example, by affecting resin flow in trees. Little is known, however, about the quantitative and qualitative changes in resin when trees are growing in low moisture conditions. We exposed Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings to medium and severe drought stress for two growing seasons and analyzed the monoterpenes and resin acids in the main stem wood after two years of treatment. In addition to secondary chemistry, we measured the level of nutrients in the needles and the growth response of seedlings. After the first year of treatment, drought stress did not affect the growth of seedlings, but in the second year, shoot growth was retarded, especially in Scots pine. In both conifer species, severe drought increased the concentrations of several individual monoterpenes and resin acids. Total monoterpenes and resin acids were 39 and 32% higher in severe drought-treated Scots pine seedlings than in the controls, and 35 and 45% higher in Norway spruce seedlings. In Scots pine needles, the concentrations of nitrogen and phosphorus increased, while magnesium and calcium decreased compared to controls. In Norway spruce needles, nutrient concentrations were not affected. The results suggest that drought stress substantially affects both the growth of conifers and the chemical quality of the wood. We discuss the potential trade-off in growth and defense of small conifer seedlings.

Chemotaxonomic analysis of the aroma compounds in essential oils of two different Ocimum basilicum L. varieties from Iran.

PubMed

Pirmoradi, Mohammad Reza; Moghaddam, Mohammad; Farhadi, Nasrin

2013-07-01

Hydrodistilled essential oils of 21 accessions of Ocimum basilicum L. belonging to two different varieties (var. purpurascens and var. dianatnejadii) from Iran were characterized by GC-FID and GC/MS analyses. The oil yield was found to be between 0.6 and 1.1% (v/w). In total, 49 compounds, accounting for 96.6-99.7% of the oil compositions, were identified. Aromatic compounds, represented mainly by methyl chavicol (33.6-49.1%), and oxygenated monoterpenes, represented by linalool (14.4-39.3%), were the main components in all essential oils. Monoterpene hydrocarbons were present in the essential oils of all accessions of the purpurascens variety, whereas they were completely absent in those of the dianatnejadii variety, indicating that monoterpene hydrocarbons might be considered as marker constituents of the purpurascens variety. The chemotaxonomic value of the essential-oil compositions was discussed according to the results of the cluster analysis (CA). The CA showed a clear separation of the O. basilicum var. purpurascens accessions and the O. basilicum var. dianatnejadii accessions, although the data showed no major chemotype variation between the studied varieties. Indeed, the CA revealed only one principal chemotype (methyl chavicol/linalool) for both varieties. In conclusion, GC/MS analyses in combination with CA showed to be a flexible and reliable method for the characterization of the chemical profiles of different varieties of Ocimum basilicum L. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

Perception of noxious compounds by contact chemoreceptors of the blowfly, Phormia regina: putative role of an odorant-bindingpProtein.

PubMed

Ozaki, Mamiko; Takahara, Teruhiko; Kawahara, Yasuhiro; Wada-Katsumata, Ayako; Seno, Keiji; Amakawa, Taisaku; Yamaoka, Ryohei; Nakamura, Tadashi

2003-05-01

The blowfly, Phormia regina, has sensilla with four contact-chemoreceptor cells and one mechanoreceptor cell on its labellum. Three of the four chemoreceptor cells are called the sugar, the salt and the water receptor cells, respectively. However, the specificity of the remaining chemoreceptor cell, traditionally called the "fifth cell", has not yet been clarified. Referring to behavioral evaluation of the oral toxicity of monoterpenes, we measured the electrophysiological response of the "fifth cell" to these compounds. Of all the monoterpenes examined, D-limonene exhibited the strongest oral toxicity and induced the severest aversive behavior with vomiting and/or excretion in the fly. D-Limonene, when dispersed in an aqueous stimulus solution including dimethyl sulfoxide or an odorant-binding protein (OBP) found in the contact-chemoreceptor sensillum, the chemical sense-related lipophilic ligand-binding protein (CRLBP), evoked impulses from the "fifth cell". Considering the relationship between the aversive effects of monoterpenes and the response of the "fifth cell" to these effects, we propose that the "fifth cell" is a warning cell that has been differentiated as a taste system for detecting and avoiding dangerous foods. Here we suggest that in the insect contact-chemoreceptor sensillum, CRLBP carries lipophilic members of the noxious taste substances to the "fifth cell" through the aqueous sensillum lymph. This insect OBP may functionally be analogous to the von Ebner's grand protein in taste organs of mammals.

Novel pathway of SO2 oxidation in the atmosphere: reactions with monoterpene ozonolysis intermediates and secondary organic aerosol

NASA Astrophysics Data System (ADS)

Ye, Jianhuai; Abbatt, Jonathan P. D.; Chan, Arthur W. H.

2018-04-01

Ozonolysis of monoterpenes is an important source of atmospheric biogenic secondary organic aerosol (BSOA). While enhanced BSOA formation has been associated with sulfate-rich conditions, the underlying mechanisms remain poorly understood. In this work, the interactions between SO2 and reactive intermediates from monoterpene ozonolysis were investigated under different humidity conditions (10 % vs. 50 %). Chamber experiments were conducted with ozonolysis of α-pinene or limonene in the presence of SO2. Limonene SOA formation was enhanced in the presence of SO2, while no significant changes in SOA yields were observed during α-pinene ozonolysis. Under dry conditions, SO2 primarily reacted with stabilized Criegee intermediates (sCIs) produced from ozonolysis, but at 50 % RH heterogeneous uptake of SO2 onto organic aerosol was found to be the dominant sink of SO2, likely owing to reactions between SO2 and organic peroxides. This SO2 loss mechanism to organic peroxides in SOA has not previously been identified in experimental chamber studies. Organosulfates were detected and identified using an electrospray ionization-ion mobility spectrometry-high-resolution time-of-flight mass spectrometer (ESI-IMS-TOF) when SO2 was present in the experiments. Our results demonstrate the synergistic effects between BSOA formation and SO2 oxidation through sCI chemistry and SO2 uptake onto organic aerosol and illustrate the importance of considering the chemistry of organic and sulfur-containing compounds holistically to properly account for their reactive sinks.

Distribution of primary and specialized metabolites in Nigella sativa seeds, a spice with vast traditional and historical uses.

PubMed

Botnick, Ilan; Xue, Wentao; Bar, Einat; Ibdah, Mwafaq; Schwartz, Amnon; Joel, Daniel M; Lev, Efraim; Fait, Aaron; Lewinsohn, Efraim

2012-08-24

Black cumin (Nigella sativa L., Ranunculaceae) is an annual herb commonly used in the Middle East, India and nowadays gaining worldwide acceptance. Historical and traditional uses are extensively documented in ancient texts and historical documents. Black cumin seeds and oil are commonly used as a traditional tonic and remedy for many ailments as well as in confectionery and bakery. Little is known however about the mechanisms that allow the accumulation and localization of its active components in the seed. Chemical and anatomical evidence indicates the presence of active compounds in seed coats. Seed volatiles consist largely of olefinic and oxygenated monoterpenes, mainly p-cymene, thymohydroquinone, thymoquinone, γ-terpinene and α-thujene, with lower levels of sesquiterpenes, mainly longifolene. Monoterpene composition changes during seed maturation. γ-Terpinene and α-thujene are the major monoterpenes accumulated in immature seeds, and the former is gradually replaced by p-cymene, carvacrol, thymo-hydroquinone and thymoquinone upon seed development. These compounds, as well as the indazole alkaloids nigellidine and nigellicine, are almost exclusively accumulated in the seed coat. In contrast, organic and amino acids are primarily accumulated in the inner seed tissues. Sugars and sugar alcohols, as well as the amino alkaloid dopamine and the saponin α-hederin accumulate both in the seed coats and the inner seed tissues at different ratios. Chemical analyses shed light to the ample traditional and historical uses of this plant.

Invasive bark beetle-associated microbes degrade a host defensive monoterpene.

PubMed

Xu, Le-Tian; Lu, Min; Sun, Jiang-Hua

2016-04-01

Conifers respond to herbivore attack with defensive chemicals, which are toxic to both insects and their associated microorganisms. Microorganisms associated with insects have been widely reported to metabolize toxic chemicals, which may help both microorganisms and host insects overcome host conifer defense. Dendroctonus valens LeConte, an introduced exotic pest from North America to China, has killed millions of healthy pines. Alpha-pinene is the most abundant defensive monoterpene in Chinese Pinus tabuliformis. Although microorganisms associated with D. valens have already been investigated, little is known about their bioactivities when encountering host defensive monoterpenes. In this study, we evaluated the influences of different concentrations of α-pinene to D. valens and the three most frequently isolated yeasts and bacteria of D. valens, and further assayed microorganisms' capabilities to degrade α-pinene. Results showed that the gallery lengths and body weight changes of bark beetles were significantly affected by 6 mg/mL and 12 mg/mL of α-pinene applied in media compared to controls. The tolerance of experimental microorganisms to α-pinene varied depending on the microbial species. Two out of three yeast strains and all three bacterial strains degraded 20%-50% of α-pinene compared to controls in 24 h in vitro. The microorganisms capable of α-pinene degradation in vitro and their tolerance to high levels of α-pinene suggested that D. valens-associated microorganisms may help both microorganisms and the bark beetle overcome host α-pinene defense. © 2015 Institute of Zoology, Chinese Academy of Sciences.

In vitro inhibition of the bovine viral diarrhoea virus by the essential oil of Ocimum basilicum (basil) and monoterpenes

PubMed Central

Kubiça, Thaís F.; Alves, Sydney H.; Weiblen, Rudi; Lovato, Luciane T.

2014-01-01

The bovine viral diarrhoea virus (BVDV) is suggested as a model for antiviral studies of the hepatitis C virus (HCV). The antiviral activity of the essential oil of Ocimum basilicum and the monoterpenes camphor, thymol and 1,8-cineole against BVDV was investigated. The cytotoxicities of the compounds were measured by the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) test, and the antiviral activities were tested by the plaque reduction assay. The oil or compounds were added to the assay in three different time points: a) pre-treatment of the virus (virucidal assay); b) pre-treatment of the cells; or c) post-treatment of the cells (after virus inoculation). The percentage of plaques inhibition for each compound was determined based on the number of plaques in the viral control. The results were expressed by CC50 (50% cytotoxic concentration), IC50 (inhibitory concentration for 50% of plaques) and SI (selectivity index = CC50/IC50). Camphor (CC50 = 4420.12 μg mL−1) and 1,8-cineole (CC50 = 2996.10 μg mL−1) showed the lowest cytotoxicities and the best antiviral activities (camphor SI = 13.88 and 1,8-cineol SI = 9.05) in the virucidal assay. The higher activities achieved by the monoterpenes in the virucidal assay suggest that these compounds act directly on the viral particle. PMID:24948933

Expeditious construction of (+)-mintlactone via intramolecular hetero-Pauson-Khand reaction.

PubMed

Gao, Peng; Xu, Peng-Fei; Zhai, Hongbin

2009-03-20

(+)-Mintlactone, a bicyclic monoterpene natural product, has been efficiently assembled from (-)-citronellol in three steps. The synthesis features nitrous acid-induced formal isopropylidene "demethanation" and the molybdenum-mediated intramolecular hetero-Pauson-Khand reaction.

Ecosystem scale VOC exchange measurements at Bosco Fontana (IT) and Hyytiälä (FI)

NASA Astrophysics Data System (ADS)

Schallhart, S.; Rantala, P.; Taipale, R.; Nemitz, E.; Tillmann, R.; Mentel, T. F.; Ruuskanen, T.; Rinne, J.

2013-12-01

The ozone production and destruction mechanisms in the troposphere depend on the abundance of NOx and volatile organic compounds (VOCs). As the latter originate not only from human activities, but to a large extent from vegetation it is important to quantify these biogenic sources as well. The VOC-fluxes were measured in Bosco Fontana forest as a part of an intensive measurement campaign of the Eclaire project, which investigates how climate change alters the threat of air pollution. Measurements were carried out at the Nature Reserve 'Bosco della Fontana' in the Po valley, Italy. The area of the forest is 198 ha and the dominanting tree species are Quercus robur (English oak), Quercus cerris (Turkey oak) and Carpinus betulus (hornbeam). The fluxes were measured on at a height of 32 metres using the eddy covariance method. A PTR-TOF (Ionicon Analytik, Austria) measured volatile organic compounds up to a mass of 300 atomic mass units. The instrument is capable of recording full spectra of VOCs in real-time with a resolution of 10 Hz. In addition to the mass spectrometer a 3D Anemometer was placed next to the inlet. Results will be presented and compared with disjunct eddy covariance measurements (Taipale et al. 2011) from a Pinus sylvestris (Scots Pine) dominated forest in Hyytiälä, Finland. The two forests are characterized by a different emission profile; the Bosco Fontana forest emits large amounts of isoprene, whereas the terpenoid emissions from Hyytiälä forest are dominated by monoterpenes. The magnitude of the emissions differs as emission from Bosco Fontana is much higher. The monoterpene emission from Bosco Fontana is likely to follow different dynamics than that from Hyytiälä as it correlates well with the radiation. This leads to the conclusion, that monoterpenes are released right after they are produced (de novo). In Hyytiälä the emissions are light and temperature dependent, which is caused by de novo and storage emissions. Pines have large monoterpenes storages, which are emitted at high temperatures. The results of both forests are consistent with the cuvette measurements of Ghirardo et al. (2010). This research received funding from the EC Seventh Framework Programme (Collaborative project "ECLAIRE" grant no. 282910) and by the Academy of Finland Center of Excellence program (project number 141135). References.: Ghirardo, A., Koch, K., Taipale, R., Zimmer, I., Schnitzler, J-P. and Rinne, J. Determination of de novo and pool emissions of terpenes from four common boreal/alpine trees by 13CO2 labelling and PTR-MS analysis. Plant, Cell & Environment,33,5,781-792,2010. Taipale, R., Kajos, M.K., Patokoski, J., Rantala, P., Ruuskanen, T.M. and Rinne, J. Role of de novo biosynthesis in ecosystem scale monoterpene emissions from a boreal Scots pine forest. Biogeosciences, 8, 8, 2247-2255, 2011.

[Investigation on emission properties of biogenic VOCs of landscape plants in Shenzhen].

PubMed

Huang, Ai-Kui; Li, Nan; Guenther, Alex; Greenberg, Jim; Baker, Brad; Graessli, Michael; Bai, Jian-Hui

2011-12-01

Isoprene and monoterpene emissions were characterized using flow and enclosure sampling method and GC-MS in USA for 158 species of plants growing in Shenzhen, China. This survey was designed to include all of the dominant plants within the Shenzhen region as well as unique plants such as Cycads. These are the first measurements in a subtropical Asian metropolis. Substantial isoprene emissions were observed from thirty-one species, including Caryota mitis, Adenanthera pavonina var. microsperma, Mangifera indica and Excoecoria agalloch. Monoterpene emissions were observed from fifty-two species, including Passiflora edulis, Bambusa glaucescens cv. silverstripe as well as some primitive and rare Cycadaceae and Cyatheaceae plants. For the first time some of red plants have been measured, most of them have the ability of releasing terpene. These results will be used to develop biogenic emission model estimates for Shenzhen and the surrounding region that can be used as inputs for regional air quality models.

Estimation of terpene content in loblolly pine biomass using a hybrid fast-GC and pyrolysis-molecular beam mass spectrometry method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harman-Ware, Anne E.; Davis, Mark F.; Peter, Gary F.

Terpenes can be used as renewable fuels and chemicals and quantifying their presence in biomass is becoming increasingly important. A novel method was developed to rapidly quantify total diterpenoid resin acids using pyrolysis-molecular beam mass spectrometry (py-MBMS). Pine sapling monoterpenes and diterpenoids were extracted from wood using a 1:1 (v/v) mixture of hexane and acetone and analyses were performed before and after extraction to determine the extraction efficiency of the solvent system. The resulting extract was analyzed for total diterpenoid content using py-MBMS and was combined with total monoterpene content that was determined using a low thermal mass modular acceleratedmore » column heater (LTM MACH) fast-GC/FID to measure the terpene content present in pine saplings. Oleoresin extruded from larger pine trees was used to validate mass balance closure of the terpene content in the extract solvent.« less

Profiles of Volatile Compounds in Black Currant (Ribes nigrum) Cultivars with Special Focus on Influence of Growth Latitude and Weather Conditions.

PubMed

Marsol-Vall, Alexis; Kortesniemi, Maaria Katariina; Karhu, Saila; Kallio, Heikki; Yang, Baoru

2018-06-25

The volatile profile of three blackcurrant (Ribes nigrum L.) cultivars grown in Finland and their response to growth latitude and weather conditions were studied over an eight-year period by headspace solid-phase microextraction (HS-SPME) followed by gas chromatographic-mass spectrometric (GC-MS) analysis. Monoterpene hydrocarbons and oxygenated monoterpenes were the major classes of volatiles. The cultivar 'Melalahti' presented lower content of volatiles compared with 'Ola' and 'Mortti', the two latter showing a very similar composition. Higher contents of volatiles were found in berries cultivated at higher latitude (66° 34' N) than in those from the southern location (60° 23' N). Among the meteorological variables, radiation and temperature during the last month before harvest were negatively linked with the volatile content. Storage time had a negative impact on the amount of blackcurrant volatiles.

Chemical Constituents of Essential Oil from Lippia sidoides Cham. (Verbenaceae) Leaves Cultivated in Hidrolândia, Goiás, Brazil

PubMed Central

de Morais, Sandra Ribeiro; Oliveira, Thiago Levi Silva; Bara, Maria Teresa Freitas; da Conceição, Edemilson Cardoso; Rezende, Maria Helena; Ferri, Pedro Henrique; de Paula, José Realino

2012-01-01

Several studies involving the family Verbenaceae, occurring in the Brazilian Cerrado, have emphasized the popular use of many aromatic species. We highlight the use of Lippia sidoides Cham., known as “alecrim pimenta,” native to northeastern Brazil and northern Minas Gerais. Leaves of this species were collected in antropized Brazilian Cerrado area, in Hidrolândia, Goiás, and their essential oils were extracted by hydrodistillation in a Clevenger-type apparatus and thereafter analyzed GC/MS. Among the compounds identified in this study were the most abundant oxygenated monoterpenes, followed by sesquiterpenes hydrocarbons. The oxygenated monoterpene 1,8-cineole was the major constituent followed by isoborneol and bornyl acetate. The chemical composition of essential oil described in this paper differs from that described in the literature for L. sidoides found in its native environment, where the major constituents are thymol and carvacrol. PMID:22505916

Estimation of terpene content in loblolly pine biomass using a hybrid fast-GC and pyrolysis-molecular beam mass spectrometry method

DOE PAGES

Harman-Ware, Anne E.; Davis, Mark F.; Peter, Gary F.; ...

2017-01-16

Terpenes can be used as renewable fuels and chemicals and quantifying their presence in biomass is becoming increasingly important. A novel method was developed to rapidly quantify total diterpenoid resin acids using pyrolysis-molecular beam mass spectrometry (py-MBMS). Pine sapling monoterpenes and diterpenoids were extracted from wood using a 1:1 (v/v) mixture of hexane and acetone and analyses were performed before and after extraction to determine the extraction efficiency of the solvent system. The resulting extract was analyzed for total diterpenoid content using py-MBMS and was combined with total monoterpene content that was determined using a low thermal mass modular acceleratedmore » column heater (LTM MACH) fast-GC/FID to measure the terpene content present in pine saplings. Oleoresin extruded from larger pine trees was used to validate mass balance closure of the terpene content in the extract solvent.« less

Composition of the essential oils from Peucedanum cervaria and P. alsaticum growing wild in the urban area of Vienna (Austria).

PubMed

Chizzola, Remigius

2012-11-01

The composition of the essential oil from the different above ground plant parts of Peucedanum cervaria and P. alsaticum (Apiaceae) collected in the urban area of Vienna has been studied. P. cervaria fruits and inflorescences had 1.5 and 1.8% essential oil, respectively. All the oils of P. cervaria were dominated by monoterpenes, with the main components being beta-pinene (7-58%), alpha-pinene (7-22%), sabinene (up to 22%), and beta-phellandrene with limonene (6-21%). P. alsaticum fruits afforded 0.3-0.4% essential oil. These oils were made up mainly by alpha-pinene (11-40%), sabinene (16-34%) and beta-phellandrene (12-31%). Stems and leaves produced only very small amounts of essential oil (< 0.05%). Besides monoterpenes, these oils contained also E-nerolidol (5-22%), spathulenol (up to 18%), dodecanal (up to 7.5%) and caryophyllene oxide (up to 7%).

Impact of aromatics and monoterpenes on simulated tropospheric ozone and total OH reactivity

NASA Astrophysics Data System (ADS)

Porter, William C.; Safieddine, Sarah A.; Heald, Colette L.

2017-11-01

The accurate representation of volatile organic compounds (VOCs) in models is an important step towards the goal of understanding and predicting many changes in atmospheric constituents relevant to climate change and human health. While isoprene is the most abundant non-methane VOC, many other compounds play a large role in governing pollutant formation and the overall oxidative capacity of the atmosphere. We quantify the impacts of aromatics and monoterpenes, two classes of VOC not included in the standard gas-phase chemistry of the chemical transport model GEOS-Chem, on atmospheric composition. We find that including these compounds increases mean total summer OH reactivity by an average of 11% over the United States, Europe, and Asia. This increased reactivity results in higher simulated levels of O3, raising maximum daily 8-h average O3 in the summer by up to 14 ppb at some NOx-saturated locations.

Direct observations of Biogenic Volatile Organic Compound (BVOC) Air-Sea Exchange in the remote North Atlantic from the High-Wind Gas-Exchange Study (HiWinGS)

NASA Astrophysics Data System (ADS)

Kim, M.; Yang, M. X.; Blomquist, B.; Huebert, B. J.; Bertram, T. H.

2014-12-01

Biogenic Volatile Organic Compounds (BVOCs) are reactive trace gases that impact both chemistry and climate by regulating oxidant loadings, determining secondary organic aerosol production rates as well as altering particle hygroscopicity. While continental BVOC exchange rates are well studied, global marine flux estimates are poorly constrained. In Fall 2013, a chemical-ionization time-of-flight mass spectrometer (CI-ToF-MS) utilizing benzene cations was deployed as part of the High Wind Gas Exchange Study (HiWinGs) to quantify monoterpenes, isoprene and dimethylsulfide fluxes in the remote North Atlantic. Dimethylsulfide measurements are in strong agreement with those determined by the University of Hawaii's atmospheric pressure ionization mass-spectrometer. In the remote marine boundary layer, positive monoterpene fluxes (i.e. emissions) were observed while isoprene levels rarely exceeded the detection limit.

Controls over hydrocarbon emissions from boreal forest conifers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lerdau, M.; Litvak, M.; Monson, R.

1995-06-01

The emissions of monoterpenes and isoprene were measured from two species of conifers native to the boreal forest of Canada, jack pine, Pinus rigida, and black spruce, Picea Mariana. We examined the effects of phenology and needle age on the emissions of these compounds, and the variations in tissue concentrations of monoterpenes. We measured photosynthetic carbon uptake and hydrocarbon emissions at two sites in northern Saskatchewan under controlled light, temperatures, and CO{sub 2} concentrations, and analyzed carbon uptake rates using an infra-red gas analyzer and hydrocarbon emissions using a solid sorbent/thermal desorption system coupled to a gas chromatograph with amore » mass spectrometer. Our data indicate a strong effect of temperature and seasonality on emissions but only small effects of site conditions. These results suggest that regional models of hydrocarbon emissions from boreal forests should focus on temperature and phenology as the most important controlling variables.« less

Release of wine monoterpenes from natural precursors by glycosidases from Oenococcus oeni

PubMed Central

Michlmayr, Herbert; Nauer, Stefan; Brandes, Walter; Schümann, Christina; Kulbe, Klaus D.; del Hierro, Andrés M.; Eder, Reinhard

2012-01-01

It is now well established that wine-related lactic acid bacteria (LAB), especially Oenococcus oeni, possess glycosidase activities that positively contribute to wine aroma through the hydrolysis of grape-derived aroma precursors. In our recent studies, we have identified and characterised several LAB glycosidases with potential in these terms. Here, we report that both a glucosidase and an arabinosidase from O. oeni can release high amounts of monoterpenes from natural substrates under optimal conditions, indicating that these intracellular enzymes might play a significant role in the hydrolysis of aroma precursors during malolactic fermentation. The enzymes from O. oeni exhibited broad substrate specificities (release of both primary/tertiary terpene alcohols) and were even active in grape juice. Further, a sensory panel clearly preferred enzyme-treated Riesling wines over the controls and affirmed that the glycosidases from O. oeni could improve the typical Riesling aroma.

Estimating terpene and terpenoid emissions from conifer oleoresin composition

NASA Astrophysics Data System (ADS)

Flores, Rosa M.; Doskey, Paul V.

2015-07-01

The following algorithm, which is based on the thermodynamics of nonelectrolyte partitioning, was developed to predict emission rates of terpenes and terpenoids from specific storage sites in conifers: Ei =xoriγoripi∘ where Ei is the emission rate (μg C gdw-1 h-1) and pi∘ is the vapor pressure (mm Hg) of the pure liquid terpene or terpenoid, respectively, and xori and γori are the mole fraction and activity coefficient (on a Raoult's law convention), respectively, of the terpene and terpenoid in the oleoresin. Activity coefficients are calculated with Hansen solubility parameters that account for dispersive, polar, and H-bonding interactions of the solutes with the oleoresin matrix. Estimates of pi∘ at 25 °C and molar enthalpies of vaporization are made with the SIMPOL.1 method and are used to estimate pi∘ at environmentally relevant temperatures. Estimated mixing ratios of terpenes and terpenols were comparatively higher above resin-acid- and monoterpene-rich oleoresins, respectively. The results indicated a greater affinity of terpenes and terpenols for the non-functionalized and carboxylic acid containing matrix through dispersive and H-bonding interactions, which are expressed in the emission algorithm by the activity coefficient. The correlation between measured emission rates of terpenes and terpenoids for Pinus strobus and emission rates predicted with the algorithm were very good (R = 0.95). Standard errors for the range and average of monoterpene emission rates were ±6 - ±86% and ±54%, respectively, and were similar in magnitude to reported standard deviations of monoterpene composition of foliar oils (±38 - ±51% and ±67%, respectively).

Antinociceptive and anticonvulsant effects of the monoterpene linalool oxide.

PubMed

Souto-Maior, Flávia Negromonte; Fonsêca, Diogo Vilar da; Salgado, Paula Regina Rodrigues; Monte, Lucas de Oliveira; de Sousa, Damião Pergentino; de Almeida, Reinaldo Nóbrega

2017-12-01

Linalool oxide (OXL) (a monoterpene) is found in the essential oils of certain aromatic plants, or it is derived from linalool. The motivation for this work is the lack of psychopharmacological studies on this substance. To evaluate OXL's acute toxicity, along with its anticonvulsant and antinociceptive activities in male Swiss mice. OXL (50, 100 and 150 mg/kg, i.p.) was investigated for acute toxicity and in the Rota-rod test. Antinociceptive activity was evaluated by the acetic acid-induced writhing test, and by formalin testing. Anticonvulsant effects were demonstrated by testing for pentylenetetrazol (PTZ)-induced seizures and by Maximum Electroshock headset (MES) test. OXL was administered to the animals intraperitoneally 30 min before for pharmacological tests. OXL showed an LD 50 of ∼721 (681-765) mg/kg. In the Rota-rod test, it was observed that OXL caused no damage to the animal's motor coordination. OXL significantly reduced (p < .001) the number of writhings. OXL also significantly decreased (p < .05, p < .01 or p < .001) paw-licking time in the two phases of the formalin test. OXL significantly reduced (p < .01 or p < .001) the duration of tonic seizures in the MES test, and at the dose 150 mg/kg, significantly increased (p < .01) the latency to first seizure in the PTZ test. The tested doses of OXL were safe, with no motor impairment, and show clear antinociceptive and anticonvulsant potential. Future investigations with this monoterpene may lead to the development of a new molecule with even higher potency and selectivity.

A highly spatially resolved GIS-based model to assess the isoprenoid emissions from key Italian ecosystems

NASA Astrophysics Data System (ADS)

Pacheco, Claudia Kemper; Fares, Silvano; Ciccioli, Paolo

2014-10-01

The amount of Biogenic Volatile Organic Compounds (BVOC) emitted from terrestrial vegetation is of great importance in atmospheric reactivity, particularly for ozone-forming reactions and as condensation nuclei in aerosol formation and growth. This work presents a detailed inventory of isoprenoid emissions from vegetation in Italy using an original approach which combines state of the art models to estimate the species-specific isoprenoid emissions and a Geographic Information System (GIS) where emissions are spatially represented. Isoprenoid species and basal emission factors were obtained by combining results from laboratory experiments with those published in literature. For the first time, our investigation was not only restricted to isoprene and total monoterpenes, but our goal was to provide maps of isoprene and individual monoterpenes at a high-spatial (∼1 km2) and temporal resolution (daily runs, monthly trends in emissions are discussed in the text). Another novelty in our research was the inclusion of the effects of phenology on plant emissions. Our results show that: a) isoprene, a-pinene, sabinene and b-pinene are the most important compounds emitted from vegetation in Italy; b) annual biogenic isoprene and monoterpene fluxes for the year 2006 were ∼31.30 Gg and ∼37.70 Gg, respectively; and c) Quercus pubescens + Quercus petrea + Quercus robur, Quercus ilex, Quercus suber and Fagus sylvatica are the principal isoprenoid emitting species in the country. The high spatial and temporal resolution, combined with the species-specific emission output, makes the model particularly suitable for assessing local budgets, and for modeling photochemical pollution in Italy.

Emissions of Monoterpenes and DMS from Corn and their Influence on Nighttime Chemical Processing of Nitrogen Oxides

NASA Astrophysics Data System (ADS)

Graus, M.; De Gouw, J. A.; Brown, S. S.; Williams, E. J.; Eller, A. S.; Gilman, J. B.; Lerner, B. M.; Fall, R.; Warneke, C.

2012-12-01

In the United States large amounts of corn are grown for the use as animal feed, for the food industry and for the production of fuel ethanol. In 2012 the acreage of corn planted was 390,000 km2 covering over 4.2% of the US land surface. The BioCORN 2011 field experiment took place in summer 2011 to look at ecosystem fluxes of volatile organic compounds (VOCs) from a cornfield in Colorado during the period of rapid biomass increase and the development of flowers and ears. Eddy covariance, soil and leaf cuvette measurements using various instruments including PTR-MS, NI-PT-CIMS and GC-MS were used to determine fluxes of VOCs, CO2 and NOx. Corn plants emit significant amounts of VOCs with methanol being the largest emission and smaller emissions of other VOCs such acetone, acetaldehyde, monoterpene and dimethylsulfide (DMS). During the day VOCs mainly react with hydroxyl radicals and during the night with nitrate radicals (NO3), where emissions from corn may act as a sink for reactive nitrogen. DMS, mainly emitted from oceans and to a lesser extent from terrestrial vegetation, had a diurnal cycle: mixing ratios high during the night, but fluxes high during the day. DMS was found to dominate the reactivity of NO3 followed by monoterpenes and the heterogeneous loss of N2O5, which has implications for the nighttime chemistry. Other results of BioCORN 2011 on VOC emissions from corn and their impact on atmospheric chemistry will be presented and discussed.

Capturing of the monoterpene olefin limonene produced in Saccharomyces cerevisiae.

PubMed

Jongedijk, Esmer; Cankar, Katarina; Ranzijn, Jorn; van der Krol, Sander; Bouwmeester, Harro; Beekwilder, Jules

2015-01-01

Monoterpene olefins such as limonene are plant compounds with applications as flavouring and fragrance agents, as solvents and potentially also in polymer and fuel chemistry. We engineered baker's yeast Saccharomyces cerevisiae to express a (-)-limonene synthase from Perilla frutescens and a (+)-limonene synthase from Citrus limon. Both proteins were expressed either with their native plastid targeting signal or in a truncated form in which the plastidial sorting signal was removed. The yeast host strain for expression was AE9 K197G, which expresses a mutant Erg20 enzyme. This enzyme catalyses the formation of geranyl diphosphate, which is the precursor for monoterpenes. Several methods were tested to capture limonene produced by the yeast. Extraction from the culture medium by pentane, or by the addition of CaCl2 followed by solid-phase micro-extraction, did not lead to detectable limonene, indicating that limonene is rapidly lost from the culture medium. Volatile terpenes such as limonene may also be trapped in a dodecane phase added to the medium during fermentation. This method resulted in recovery of 0.028 mg/l (+)-limonene and 0.060 mg/l (-)-limonene in strains using the truncated Citrus and Perilla synthases, respectively. Trapping the headspace during culture of the limonene synthase-expressing strains resulted in higher titres, at 0.12 mg/l (+)-limonene and 0.49 mg/l (-)-limonene. These results show that the volatile properties of the olefins produced require specific methods for efficient recovery of these molecules from biotechnological production systems. Copyright © 2014 John Wiley & Sons, Ltd.

Assessment of volatile organic compound emissions from ecosystems of China

NASA Astrophysics Data System (ADS)

Klinger, L. F.; Li, Q.-J.; Guenther, A. B.; Greenberg, J. P.; Baker, B.; Bai, J.-H.

2002-11-01

Isoprene, monoterpene, and other volatile organic compound (VOC) emissions from grasslands, shrublands, forests, and peatlands in China were characterized to estimate their regional magnitudes and to compare these emissions with those from landscapes of North America, Europe, and Africa. Ecological and VOC emission sampling was conducted at 52 sites centered in and around major research stations located in seven different regions of China: Inner Mongolia (temperate), Changbai Mountain (boreal-temperate), Beijing Mountain (temperate), Dinghu Mountain (subtropical), Ailao Mountain (subtropical), Kunming (subtropical), and Xishuangbanna (tropical). Transects were used to sample plant species and growth form composition, leafy (green) biomass, and leaf area in forests representing nearly all the major forest types of China. Leafy biomass was determined using generic algorithms based on tree diameter, canopy structure, and absolute cover. Measurements of VOC emissions were made on 386 of the 541 recorded species using a portable photo-ionization detector method. For 105 species, VOC emissions were also measured using a flow-through leaf cuvette sampling/gas chromatography analysis method. Results indicate that isoprene and monoterpene emissions, as well as leafy biomass, vary systematically along gradients of ecological succession in the same manner found in previous studies in the United States, Canada, and Africa. Applying these results to a regional VOC emissions model, we arrive at a value of 21 Tg C for total annual biogenic VOC emissions from China, compared to 5 Tg C of VOCs released annually from anthropogenic sources there. The isoprene and monoterpene emissions are nearly the same as those reported for Europe, which is comparable in size to China.

Photochemical Aging of α-pinene and β-pinene Secondary Organic Aerosol formed from Nitrate Radical Oxidation: New Insights into the Formation and Fates of Highly Oxygenated Gas- and Particle-phase Organic Nitrates

NASA Astrophysics Data System (ADS)

Nah, T.; Sanchez, J.; Boyd, C.; Ng, N. L.

2015-12-01

The nitrate radical (NO3), one of the most important oxidants in the nocturnal atmosphere, can react rapidly with a variety of biogenic volatile organic compounds (BVOCs) to form high mass concentrations of secondary organic aerosol (SOA) and organic nitrates (ON). Despite its critical importance in aerosol formation, the mechanisms and products from the NO3 oxidation of BVOCs have been largely unexplored, and the fates of their SOA and ON after formation are not well characterized. In this work, we studied the formation of SOA and ON from the NO3 oxidation of α-pinene and β-pinene and investigated for the first time how they evolve during dark and photochemical aging through a series of chamber experiments performed at the Georgia Tech Environmental Chamber (GTEC) facility. The α-pinene and β-pinene SOA are characterized using real-time gas- and particle-phase measurements, which are used to propose mechanisms for SOA and organic nitrate formation and aging. Highly oxygenated gas- and particle-phase ON (containing as many as 9 oxygen atoms) are detected during the NO3 reaction. In addition, the β-pinene SOA and α-pinene SOA exhibited drastically different behavior during photochemical aging. Our results indicate that nighttime ON formed by NO3+monoterpene chemistry can serve as either NOx reservoirs or sinks depending on the monoterpene precursor. Results from this study provide fundamental data for evaluating the contributions of NO3+monoterpene reactions to ambient OA measured in the Southeastern U.S.

Dermal exposure to monoterpenes during wood work.

PubMed

Eriksson, Kare; Wiklund, Leif

2004-06-01

The dermal exposure to the suspected allergenic monoterpenes [small alpha]-pinene, [small beta]-pinene and [capital Delta](3)-carene was assessed with a patch sampling technique. The patch used was made of activated charcoal sandwiched between two layers of cotton cloth. Patches were fastened at 12 different spots on a sampling overall and at the front of a cap to estimate the potential exposure of the body. Fastening two patches on a cotton glove, one patch representing the dorsal side and one patch representing the palm of the hand respectively, assessed the exposure on the hands. Sampling was carried out during collecting of pine and spruce boards in sawmills and during sawing of pine wood pieces in joinery shops respectively. The potential dermal exposure of the total body was 29.0-1 890 mg h(-1) with a geometric mean (GM) of 238 mg h(-1) during sawing. During collecting the GM was estimated to 100 mg h(-1) with a range of 12.2-959 mg h(-1). The hands had a mean exposure of 9.24 mg h(-1) during sawing and 3.25 mg h(-1) during collecting respectively. The good correlation between the mass of contamination on the individual body parts and the potential body exposure indicates that sampling can be performed on one body part to give a good estimation of the potential body exposure. Monoterpenes were detected at patches fastened underneath the protective clothing indicating a contamination of the skin of the worker. The patch used may overestimate the dermal exposure.

Algicide Constituents from Swinglea glutinosa

USDA-ARS?s Scientific Manuscript database

Oscillatoria perornata, a cyanobacterium (blue-green alga) common in catfish production ponds in the southeastern United States, produces the monoterpene 2-methylisoborneol (MIB) which is absorbed into catfish flesh and imparts a “musty” taste rendering them unpalatable and unmarketable. Algicides t...

Effects of Acute Ozone Exposure and Methyl Jasmonate Treatment on White Pine Monoterpene and Sesquiterpene Emission Rates

NASA Astrophysics Data System (ADS)

Faiola, C. L.; Wagner, D.; Allwine, E.; Harley, P. C.; Vanreken, T. M.

2010-12-01

Biogenic volatile organic compounds (BVOCs) are produced by plants and include monoterpenes, sesquiterpenes, and their oxygenated derivatives. These BVOCs are one of the principal factors influencing the oxidative capacity of the atmosphere in forested regions, and impact both ozone concentration and secondary organic aerosol formation. Under unstressed conditions, the release of BVOCs to the atmosphere is primarily controlled by the vapor pressure of the relevant compounds within the plant tissue, which is in turn dependent on temperature as well as complex biochemical production processes. However, various natural and anthropogenic stressors can alter both the quantity and composition of the BVOCs emitted by plants. Many potential stressors are expected to become stronger as climate change effects escalate. The impacts of most stressors on BVOC emissions have not been well characterized, particularly in a field setting where changes in BVOC emissions could have influential feedbacks with climate. This study investigated the effects of two stressors on monoterpene and sesquiterpene emission rates at a field site in northern Michigan: acute ozone exposure and treatment with methyl jasmonate, an herbivory proxy. The study included six repetitions of the same experiment, each time using a new set of sub-canopy eastern white pine specimens. For each experiment, dynamic branch enclosures were simultaneously used on three specimens for sample collection: one ozone treatment tree, one methyl jasmonate treatment tree, and one control tree. Sampling lines were placed in each enclosure and VOCs were collected onto cartridges packed with Tenax GR adsorbent. Samples were collected several times per day for at least two days before treatment and for five days after treatment. Cartridges were analyzed via thermodesorption with an Agilent GC/MS/FID. This analysis allowed the identification and quantification of several monoterpene and sesquiterpene species in the samples. Preliminary results indicate that methyl jasmonate may initiate the expression of inducible terpenes not normally expressed under unstressed conditions. Further analysis of results is ongoing. Ultimately, the results of this study will enable improved estimates of the changes in BVOC emissions from white pine forests resulting from the predicted increases in tropospheric ozone and plant herbivory expected to accompany climate change. Implications for potential feedbacks between altered BVOC emissions and climate change will be discussed.

Challenges in modelling isoprene and monoterpene emission dynamics of Arctic plants: a case study from a subarctic tundra heath

NASA Astrophysics Data System (ADS)

Tang, Jing; Schurgers, Guy; Valolahti, Hanna; Faubert, Patrick; Tiiva, Päivi; Michelsen, Anders; Rinnan, Riikka

2016-12-01

The Arctic is warming at twice the global average speed, and the warming-induced increases in biogenic volatile organic compounds (BVOCs) emissions from Arctic plants are expected to be drastic. The current global models' estimations of minimal BVOC emissions from the Arctic are based on very few observations and have been challenged increasingly by field data. This study applied a dynamic ecosystem model, LPJ-GUESS, as a platform to investigate short-term and long-term BVOC emission responses to Arctic climate warming. Field observations in a subarctic tundra heath with long-term (13-year) warming treatments were extensively used for parameterizing and evaluating BVOC-related processes (photosynthesis, emission responses to temperature and vegetation composition). We propose an adjusted temperature (T) response curve for Arctic plants with much stronger T sensitivity than the commonly used algorithms for large-scale modelling. The simulated emission responses to 2 °C warming between the adjusted and original T response curves were evaluated against the observed warming responses (WRs) at short-term scales. Moreover, the model responses to warming by 4 and 8 °C were also investigated as a sensitivity test. The model showed reasonable agreement to the observed vegetation CO2 fluxes in the main growing season as well as day-to-day variability of isoprene and monoterpene emissions. The observed relatively high WRs were better captured by the adjusted T response curve than by the common one. During 1999-2012, the modelled annual mean isoprene and monoterpene emissions were 20 and 8 mg C m-2 yr-1, with an increase by 55 and 57 % for 2 °C summertime warming, respectively. Warming by 4 and 8 °C for the same period further elevated isoprene emission for all years, but the impacts on monoterpene emissions levelled off during the last few years. At hour-day scale, the WRs seem to be strongly impacted by canopy air T, while at the day-year scale, the WRs are a combined effect of plant functional type (PFT) dynamics and instantaneous BVOC responses to warming. The identified challenges in estimating Arctic BVOC emissions are (1) correct leaf T estimation, (2) PFT parameterization accounting for plant emission features as well as physiological responses to warming, and (3) representation of long-term vegetation changes in the past and the future.

Seasonal variation of nitrogen oxides, ozone and biogenic volatile organic compound concentrations and fluxes at Norway spruce forest

NASA Astrophysics Data System (ADS)

Juran, Stanislav; Vecerova, Kristyna; Holisova, Petra; Zapletal, Milos; Pallozzi, Emanuele; Guidolotti, Gabriele; Calfapietra, Carlo; Vecera, Zbynek; Cudlin, Pavel; Urban, Otmar

2015-04-01

Dynamics of nitrogen oxides (NOx) and ozone concentration and their depositions were investigated on the Norway spruce forest at Bily Kriz experimental station at the Silesian Beskydy Mountains (north-eastern part of the Czech Republic). Both NOx and ozone concentration and fluxes were modelled for the whole season and covering thus different climate conditions. Data were recorded for three consecutive years and therefore deeper analyses were performed. During the summer 2014 BVOC field campaign was carried out using proton-transfer-reaction-time-of-flight-mass-spectrometry (PTR-TOF, Ionicon Analytik GmbH, Innsbruck, Austria) and volatile organic compound of biogenic origin (BVOC) were measured at the different levels of tree canopies. By the same time BVOC were trapped into the Tenax tubes (Markes International Ltd., UK) and put afterwards for thermal desorption (Markes Unity System 2, Markes International Ltd., UK) to GS-MS analysis (TSQ Quntum XLS triple Quadrupole, Thermo Scientific, USA). Thus data of different levels of canopies together with different spectra of monoterpenes were obtained. Interesting comparison of both methods will be shown. It was the first BVOC field campaign using PTR technique at any of the forest in the Czech Republic. Highest fluxes and concentrations were recorded around the noon hours, represented particularly by monoterpenes, especially α-pinen and limonene. Other BVOCs than monoterpenes were negligible. Variation of fluxes between different canopies levels was observed, highlighting difference in shaded and sun exposed leaves. Sun leaves emitted up to 2.4 nmol m-2 s-1 of monoterpenes, while shaded leaves emitted only up to 0.6 nmol m-2 s-1 when measured under standard conditions (irradiance 1000 µmol m-2 s-1; temperature 30°C). We discuss here the importance of the most common Norway spruce tree forests in the Czech Republic in bi-directional exchanges of important secondary pollutant such as ozone and nitrogen oxides, their production and deposition and interaction with BVOCs at low nitrogen oxides polluted area. Forests of Beskydy Mountains could play a key role in pollutants removal because of closeness to highest ozone and aerosol polluted area of the Czech Republic - Ostrava region, where heavy industry is located.

Manipulation of GES and ERG20 for geraniol overproduction in Saccharomyces cerevisiae.

PubMed

Jiang, Guo-Zhen; Yao, Ming-Dong; Wang, Ying; Zhou, Liang; Song, Tian-Qing; Liu, Hong; Xiao, Wen-Hai; Yuan, Ying-Jin

2017-05-01

Manipulation of monoterpene synthases to maximize flux towards targeted products from GPP (geranyl diphosphate) is the main challenge for heterologous monoterpene overproduction, in addition to cell toxicity from compounds themselves. In our study, by manipulation of the key enzymes geraniol synthase (GES) and farnesyl diphosphate synthase (Erg20), geraniol (a valuable acyclic monoterpene alcohol) overproduction was achieved in Saccharomyces cerevisiae with truncated 3-hydroxy-3-methylglutaryl-coenzyme reductase (tHMGR) and isopentenyl diphosphate isomerase (IDI1) overexpressed. The expressions of all above engineered genes were under the control of Gal promoter for alleviating product toxicity. Geraniol production varied from trace amount to 43.19mg/L (CrGES, GES from Catharanthus roseus) by screening of nine GESs from diverse species. Further through protein structure analysis and site-directed mutation in CrGES, it was firstly demonstrated that among the high-conserved amino acid residues located in active pocket, Y436 and D501 with strong affinity to diphosphate function group, were critical for the dephosphorylation (the core step for geraniol formation). Moreover, the truncation position of the transit peptide from the N-terminus of CrGES was found to influence protein expression and activity significantly, obtaining a titer of 191.61mg/L geraniol in strain with CrGES truncated at S43 (t3CrGES). Furthermore, directed by surface electrostatics distribution of t3CrGES and Erg20 WW (Erg20 F96W-N127W ), co-expression of the reverse fusion of Erg20 ww /t3CrGES and another copy of Erg20 WW promoted the geraniol titer to 523.96mg/L at shakes flask level, due to enhancing GPP accessibility led by protein interaction of t3CrGES-Erg20 WW and the free Erg20 WW . Eventually, a highest reported titer of 1.68g/L geraniol in eukaryote cells was achieved in 2.0L fed-batch fermentation under carbon restriction strategy. Our research opens large opportunities for other microbial production of monoterpenes. It also sets a good reference for desired compounds overproduction in microorganisms in terms of manipulation of key enzymes by protein engineering and metabolic engineering. Copyright © 2017. Published by Elsevier Inc.

Variation in phenology and monoterpene patterns of defoliated and nondefoliated Douglas-fir (Pseudotsuga menziesii var. glauca).

Treesearch

Rose-Marie Muzika; Judith Engle; Catherine Parks; Boyd Wickman

1993-01-01

Foliage was collected from paired Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) trees characterized as either "resistant" or "susceptible" western spruce budworm (Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae) attack. Resistant trees produced more...

Structure Elucidation of a Natural Product.

ERIC Educational Resources Information Center

Letcher, Roy M.

1983-01-01

Describes an experiment simulating a real-life structure elucidation problem through isolation, characterization, and chemical transformation of an "unknown," naturally occurring monoterpene, with extensive use being made of spectroscopy and aided by biogenetic considerations. Information given to students, procedures, results, and discussion of…

SOA from BVOCs in the Southeastern United States

EPA Science Inventory

Biogenic hydrocarbons contribute to organic aerosol in the southeast United States. In this work, we represent aerosol formation from the oxidation of isoprene and monoterpenes in CMAQ and compare to data from the Southeast Oxidants and Aerosol Study (SOAS). Sensitivity simulatio...

FACTORS CONTROLLING THE EMISSIONS OF MONOTERPENES AND OTHER VOLATILE ORGANIC COMPOUNDS

EPA Science Inventory

Plants contain a number of volatile organic compounds, including isoprene, mono- and sesquiterpenes, alcohols, aldehydes, ketones, and esters. ndividual plant species have unique combinations of these compounds; consequently, the emission pattern for each species is also specific...

Identification, functional characterization, and regulation of the enzyme responsible for floral (E)-nerolidol biosynthesis in kiwifruit (Actinidia chinensis)

PubMed Central

Green, Sol A.; Chen, Xiuyin; Nieuwenhuizen, Niels J.; Matich, Adam J.; Wang, Mindy Y.; Bunn, Barry J.; Yauk, Yar-Khing; Atkinson, Ross G.

2012-01-01

Flowers of the kiwifruit species Actinidia chinensis produce a mixture of sesquiterpenes derived from farnesyl diphosphate (FDP) and monoterpenes derived from geranyl diphosphate (GDP). The tertiary sesquiterpene alcohol (E)-nerolidol was the major emitted volatile detected by headspace analysis. Contrastingly, in solvent extracts of the flowers, unusually high amounts of (E,E)-farnesol were observed, as well as lesser amounts of (E)-nerolidol, various farnesol and farnesal isomers, and linalool. Using a genomics-based approach, a single gene (AcNES1) was identified in an A. chinensis expressed sequence tag library that had significant homology to known floral terpene synthase enzymes. In vitro characterization of recombinant AcNES1 revealed it was an enzyme that could catalyse the conversion of FDP and GDP to the respective (E)-nerolidol and linalool terpene alcohols. Enantiomeric analysis of both AcNES1 products in vitro and floral terpenes in planta showed that (S)-(E)-nerolidol was the predominant enantiomer. Real-time PCR analysis indicated peak expression of AcNES1 correlated with peak (E)-nerolidol, but not linalool accumulation in flowers. This result, together with subcellular protein localization to the cytoplasm, indicated that AcNES1 was acting as a (S)-(E)-nerolidol synthase in A. chinensis flowers. The synthesis of high (E,E)-farnesol levels appears to compete for the available pool of FDP utilized by AcNES1 for sesquiterpene biosynthesis and hence strongly influences the accumulation and emission of (E)-nerolidol in A. chinensis flowers. PMID:22162874

Seasonality of isoprenoid emissions from a primary rainforest in central Amazonia

DOE PAGES

Alves, Eliane G.; Jardine, Kolby; Tota, Julio; ...

2016-03-23

Tropical rainforests are an important source of isoprenoid and other volatile organic compound (VOC) emissions to the atmosphere. The seasonal variation of these compounds is however still poorly understood. In this study, vertical profiles of mixing ratios of isoprene, total monoterpenes and total sesquiterpenes, were measured within and above the canopy, in a primary rainforest in central Amazonia, using a proton transfer reaction – mass spectrometer (PTR-MS). Fluxes of these compounds from the canopy into the atmosphere were estimated from PTR-MS measurements by using an inverse Lagrangian transport model. Measurements were carried out continuously from September 2010 to January 2011,more » encompassing the dry and wet seasons. Mixing ratios were higher during the dry (isoprene – 2.68 ± 0.9 ppbv, total monoterpenes – 0.67 ± 0.3 ppbv; total sesquiterpenes – 0.09 ± 0.07 ppbv) than the wet season (isoprene – 1.66 ± 0.9 ppbv, total monoterpenes – 0.47 ± 0.2 ppbv; total sesquiterpenes – 0.03 ± 0.02 ppbv) for all compounds. Ambient air temperature and photosynthetically active radiation (PAR) behaved similarly. Daytime isoprene and total monoterpene mixing ratios were highest within the canopy, rather than near the ground or above the canopy. By comparison, daytime total sesquiterpene mixing ratios were highest near the ground. Daytime fluxes varied significantly between seasons for all compounds. The maximums for isoprene (2.53 ± 0.5 µmol m -2 h -1) and total monoterpenes (1.77 ± 0.05 µmol m -2 h -1) were observed in the late dry season, whereas the maximum for total sesquiterpenes was found during the dry-to-wet transition season (0.77 ± 0.1 µmol m -2 h -1). These flux estimates suggest that the canopy is the main source of isoprenoids emitted into the atmosphere for all seasons. However, uncertainties in turbulence parameterization near the ground could affect estimates of fluxes that come from the ground. Leaf phenology seemed to be an important driver of seasonal variation of isoprenoid emissions. Although remote sensing observations of changes in leaf area index were used to estimate leaf phenology, MEGAN 2.1 did not fully capture the behavior of seasonal emissions observed in this study. This could be a result of very local effects on the observed emissions, but also suggest that other parameters need to be better determined in biogenic volatile organic compound (BVOC) models. Our results support established findings that seasonality of isoprenoids are driven by seasonal changes in light, temperature and leaf phenology. However, they suggest that leaf phenology and its role on isoprenoid production and emission from tropical plant species needs to be better understood in order to develop mechanistic explanations for seasonal variation in emissions. This also may reduce the uncertainties of model estimates associated with the responses to environmental factors. Therefore, this study strongly encourages long-term measurements of isoprenoid emissions, environmental factors and leaf phenology from leaf to ecosystem scale, with the purpose of improving BVOC model approaches that can characterize seasonality of isoprenoid emissions from tropical rainforests.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alves, Eliane G.; Jardine, Kolby; Tota, Julio

Tropical rainforests are an important source of isoprenoid and other volatile organic compound (VOC) emissions to the atmosphere. The seasonal variation of these compounds is however still poorly understood. In this study, vertical profiles of mixing ratios of isoprene, total monoterpenes and total sesquiterpenes, were measured within and above the canopy, in a primary rainforest in central Amazonia, using a proton transfer reaction – mass spectrometer (PTR-MS). Fluxes of these compounds from the canopy into the atmosphere were estimated from PTR-MS measurements by using an inverse Lagrangian transport model. Measurements were carried out continuously from September 2010 to January 2011,more » encompassing the dry and wet seasons. Mixing ratios were higher during the dry (isoprene – 2.68 ± 0.9 ppbv, total monoterpenes – 0.67 ± 0.3 ppbv; total sesquiterpenes – 0.09 ± 0.07 ppbv) than the wet season (isoprene – 1.66 ± 0.9 ppbv, total monoterpenes – 0.47 ± 0.2 ppbv; total sesquiterpenes – 0.03 ± 0.02 ppbv) for all compounds. Ambient air temperature and photosynthetically active radiation (PAR) behaved similarly. Daytime isoprene and total monoterpene mixing ratios were highest within the canopy, rather than near the ground or above the canopy. By comparison, daytime total sesquiterpene mixing ratios were highest near the ground. Daytime fluxes varied significantly between seasons for all compounds. The maximums for isoprene (2.53 ± 0.5 µmol m -2 h -1) and total monoterpenes (1.77 ± 0.05 µmol m -2 h -1) were observed in the late dry season, whereas the maximum for total sesquiterpenes was found during the dry-to-wet transition season (0.77 ± 0.1 µmol m -2 h -1). These flux estimates suggest that the canopy is the main source of isoprenoids emitted into the atmosphere for all seasons. However, uncertainties in turbulence parameterization near the ground could affect estimates of fluxes that come from the ground. Leaf phenology seemed to be an important driver of seasonal variation of isoprenoid emissions. Although remote sensing observations of changes in leaf area index were used to estimate leaf phenology, MEGAN 2.1 did not fully capture the behavior of seasonal emissions observed in this study. This could be a result of very local effects on the observed emissions, but also suggest that other parameters need to be better determined in biogenic volatile organic compound (BVOC) models. Our results support established findings that seasonality of isoprenoids are driven by seasonal changes in light, temperature and leaf phenology. However, they suggest that leaf phenology and its role on isoprenoid production and emission from tropical plant species needs to be better understood in order to develop mechanistic explanations for seasonal variation in emissions. This also may reduce the uncertainties of model estimates associated with the responses to environmental factors. Therefore, this study strongly encourages long-term measurements of isoprenoid emissions, environmental factors and leaf phenology from leaf to ecosystem scale, with the purpose of improving BVOC model approaches that can characterize seasonality of isoprenoid emissions from tropical rainforests.« less

Seasonality of isoprenoid emissions from a primary rainforest in central Amazonia

NASA Astrophysics Data System (ADS)

Alves, Eliane G.; Jardine, Kolby; Tota, Julio; Jardine, Angela; Yãnez-Serrano, Ana Maria; Karl, Thomas; Tavares, Julia; Nelson, Bruce; Gu, Dasa; Stavrakou, Trissevgeni; Martin, Scot; Artaxo, Paulo; Manzi, Antonio; Guenther, Alex

2016-03-01

Tropical rainforests are an important source of isoprenoid and other volatile organic compound (VOC) emissions to the atmosphere. The seasonal variation of these compounds is however still poorly understood. In this study, vertical profiles of mixing ratios of isoprene, total monoterpenes and total sesquiterpenes, were measured within and above the canopy, in a primary rainforest in central Amazonia, using a proton transfer reaction - mass spectrometer (PTR-MS). Fluxes of these compounds from the canopy into the atmosphere were estimated from PTR-MS measurements by using an inverse Lagrangian transport model. Measurements were carried out continuously from September 2010 to January 2011, encompassing the dry and wet seasons. Mixing ratios were higher during the dry (isoprene - 2.68 ± 0.9 ppbv, total monoterpenes - 0.67 ± 0.3 ppbv; total sesquiterpenes - 0.09 ± 0.07 ppbv) than the wet season (isoprene - 1.66 ± 0.9 ppbv, total monoterpenes - 0.47 ± 0.2 ppbv; total sesquiterpenes - 0.03 ± 0.02 ppbv) for all compounds. Ambient air temperature and photosynthetically active radiation (PAR) behaved similarly. Daytime isoprene and total monoterpene mixing ratios were highest within the canopy, rather than near the ground or above the canopy. By comparison, daytime total sesquiterpene mixing ratios were highest near the ground. Daytime fluxes varied significantly between seasons for all compounds. The maximums for isoprene (2.53 ± 0.5 µmol m-2 h-1) and total monoterpenes (1.77 ± 0.05 µmol m-2 h-1) were observed in the late dry season, whereas the maximum for total sesquiterpenes was found during the dry-to-wet transition season (0.77 ± 0.1 µmol m-2 h-1). These flux estimates suggest that the canopy is the main source of isoprenoids emitted into the atmosphere for all seasons. However, uncertainties in turbulence parameterization near the ground could affect estimates of fluxes that come from the ground. Leaf phenology seemed to be an important driver of seasonal variation of isoprenoid emissions. Although remote sensing observations of changes in leaf area index were used to estimate leaf phenology, MEGAN 2.1 did not fully capture the behavior of seasonal emissions observed in this study. This could be a result of very local effects on the observed emissions, but also suggest that other parameters need to be better determined in biogenic volatile organic compound (BVOC) models. Our results support established findings that seasonality of isoprenoids are driven by seasonal changes in light, temperature and leaf phenology. However, they suggest that leaf phenology and its role on isoprenoid production and emission from tropical plant species needs to be better understood in order to develop mechanistic explanations for seasonal variation in emissions. This also may reduce the uncertainties of model estimates associated with the responses to environmental factors. Therefore, this study strongly encourages long-term measurements of isoprenoid emissions, environmental factors and leaf phenology from leaf to ecosystem scale, with the purpose of improving BVOC model approaches that can characterize seasonality of isoprenoid emissions from tropical rainforests.

Seasonality of isoprenoid emissions from a primary rainforest in central Amazonia

NASA Astrophysics Data System (ADS)

Alves, E. G.; Jardine, K.; Tota, J.; Jardine, A.; Yáñez-Serrano, A. M.; Karl, T.; Tavares, J.; Nelson, B.; Gu, D.; Stavrakou, T.; Martin, S.; Manzi, A.; Guenther, A.

2015-10-01

Tropical rainforests are an important source of isoprenoid and other Volatile Organic Compound (VOC) emissions to the atmosphere. The seasonal variation of these compounds is however still poorly understood. In this study, profiles were collected of the vertical profile of mixing ratios of isoprene, total monoterpenes and total sesquiterpenes, within and above the canopy, in a primary rainforest in central Amazonia, using a Proton Transfer Reaction-Mass Spectrometer (PTR-MS). Fluxes of these compounds from the canopy into the atmosphere were estimated from PTR-MS measurements by using an inverse Lagrangian transport model. Measurements were carried out continuously from September 2010 to January 2011, encompassing the dry and wet seasons. Mixing ratios were higher during the dry (isoprene - 2.68 ± 0.9 ppbv, total monoterpenes - 0.67 ± 0.3 ppbv; total sesquiterpenes - 0.09 ± 0.07 ppbv) than the wet season (isoprene - 1.66 ± 0.9 ppbv, total monoterpenes - 0.47 ± 0.2 ppbv; total sesquiterpenes - 0.03 ± 0.02 ppbv) for all compounds. Ambient air temperature and photosynthetically active radiation (PAR) behaved similarly. Daytime isoprene and total monoterpene mixing ratios were highest within the canopy, rather than near the ground or above the canopy. By comparison, daytime total sesquiterpene mixing ratios were highest near the ground. Daytime fluxes varied significantly between seasons for all compounds. The maximums for isoprene (2.53 ± 0.5 μmol m-2 h-1) and total monoterpenes (1.77 ± 0.05 μmol m-2 h-1) were observed in the late dry season, whereas the maximum for total sesquiterpenes was found during the dry-to-wet transition season (0.77 ± 0.1 μmol m-2 h-1). These flux estimates suggest that the canopy is the main source of isoprenoids to the atmosphere for all seasons. However, uncertainties in turbulence parameterization near the ground could affect estimates of fluxes that come from the ground. Leaf phenology seemed to be an important driver of seasonal variation of isoprenoid emissions. Although remote sensing observations of changes in leaf area index were used to estimate leaf phenology, MEGAN 2.1 did not fully capture the behavior of seasonal emissions observed in this study. This could be a result of very local effects on the observed emissions, but also suggest that other parameters need to be better determined in Biogenic Volatile Organic Compound (BVOC) models. Our results support established findings that seasonality of isoprenoids are driven by seasonal changes in light, temperature and leaf phenology. However, they suggest that leaf phenology and its role on isoprenoid production and emission from tropical plant species needs to be better understood in order to develop mechanistic explanations for seasonal variation in emissions. This also may reduce the uncertainties of model estimates associated with the responses to environmental factors. Therefore, this study strongly encourages long-term measurements of isoprenoid emissions, environmental factors and leaf phenology from leaf to ecosystem scale, with the purpose of improving BVOC model approaches that can characterize seasonality of isoprenoid emissions from tropical rainforests.

Identity, regulation, and activity of inducible diterpenoid phytoalexins in maize

USDA-ARS?s Scientific Manuscript database

Phytoalexins constitute a broad category of pathogen and insect-inducible biochemicals that locally protect plant tissues. Due to their agronomic significance, maize and rice have been extensively investigated for their terpenoid-based defenses which include insect-inducible monoterpene and sesquite...

Towards mechanistic representations of SOA from BVOC + NO3 reactions

EPA Science Inventory

Monoterpene reaction with nitrate radicals is a significant source of organic aerosol in the southeast United States. This source of organic aerosol represents an anthropogenic control on biogenic organic aerosol since nitrate radicals result from NOx emissions and are generally ...

PHOTOCHEMISTRY OF SOME NATURALLY EMITTED HYDROCARBONS

EPA Science Inventory

Six C10H16 monoterpenes, p-cymene, and isoprene, all known or thought to be emitted to the atmosphere by vegetation, were irradiated in the presence of NOx. The terpenes studied included one acyclic triolefin (myrcene), two monocyclic diolefins (d-limonene, terpinolene), and thre...

Understanding pathways to organic aerosol: How the sweat and communications of plants influence our air quality

EPA Science Inventory

Isoprene and monoterpenes are major contributors to organic aerosol in in the southeastern U.S. This work presents results from 4 years of work improving the CMAQ model representation of aerosol from these precursors.

Monoterpenes are the largest source of summertime organic aerosol in the southeastern United States

EPA Science Inventory

The chemical complexity of atmospheric organic aerosol (OA) has caused substantial uncertainties in understanding its origins and environmental impacts. Here, we provide constraints on OA origins through compositional characterization with molecular-level details. Our results sug...

The Terpene Synthase Gene Family of Carrot (Daucus carota L.): Identification of QTLs and Candidate Genes Associated with Terpenoid Volatile Compounds

PubMed Central

Keilwagen, Jens; Lehnert, Heike; Berner, Thomas; Budahn, Holger; Nothnagel, Thomas; Ulrich, Detlef; Dunemann, Frank

2017-01-01

Terpenes are an important group of secondary metabolites in carrots influencing taste and flavor, and some of them might also play a role as bioactive substances with an impact on human physiology and health. Understanding the genetic and molecular basis of terpene synthases (TPS) involved in the biosynthesis of volatile terpenoids will provide insights for improving breeding strategies aimed at quality traits and for developing specific carrot chemotypes possibly useful for pharmaceutical applications. Hence, a combination of terpene metabolite profiling, genotyping-by-sequencing (GBS), and genome-wide association study (GWAS) was used in this work to get insights into the genetic control of terpene biosynthesis in carrots and to identify several TPS candidate genes that might be involved in the production of specific monoterpenes. In a panel of 85 carrot cultivars and accessions, metabolite profiling was used to identify 31 terpenoid volatile organic compounds (VOCs) in carrot leaves and roots, and a GBS approach was used to provide dense genome-wide marker coverage (>168,000 SNPs). Based on this data, a total of 30 quantitative trait loci (QTLs) was identified for 15 terpenoid volatiles. Most QTLs were detected for the monoterpene compounds ocimene, sabinene, β-pinene, borneol and bornyl acetate. We identified four genomic regions on three different carrot chromosomes by GWAS which are both associated with high significance (LOD ≥ 5.91) to distinct monoterpenes and to TPS candidate genes, which have been identified by homology-based gene prediction utilizing RNA-seq data. In total, 65 TPS candidate gene models in carrot were identified and assigned to known plant TPS subfamilies with the exception of TPS-d and TPS-h. TPS-b was identified as largest subfamily with 32 TPS candidate genes. PMID:29170675

Effect of vegetation removal and water table drawdown on the non-methane biogenic volatile organic compound emissions in boreal peatland microcosms

NASA Astrophysics Data System (ADS)

Faubert, Patrick; Tiiva, Päivi; Rinnan, Åsmund; Räty, Sanna; Holopainen, Jarmo K.; Holopainen, Toini; Rinnan, Riikka

2010-11-01

Biogenic volatile organic compound (BVOC) emissions are important in the global atmospheric chemistry and their feedbacks to global warming are uncertain. Global warming is expected to trigger vegetation changes and water table drawdown in boreal peatlands, such changes have only been investigated on isoprene emission but never on other BVOCs. We aimed at distinguishing the BVOCs released from vascular plants, mosses and peat in hummocks (dry microsites) and hollows (wet microsites) of boreal peatland microcosms maintained in growth chambers. We also assessed the effect of water table drawdown (-20 cm) on the BVOC emissions in hollow microcosms. BVOC emissions were measured from peat samples underneath the moss surface after the 7-week-long experiment to investigate whether the potential effects of vegetation and water table drawdown were shown. BVOCs were sampled using a conventional chamber method, collected on adsorbent and analyzed with GC-MS. In hummock microcosms, vascular plants increased the monoterpene emissions compared with the treatment where all above-ground vegetation was removed while no effect was detected on the sesquiterpenes, other reactive VOCs (ORVOCs) and other VOCs. Peat layer from underneath the surface with intact vegetation had the highest sesquiterpene emissions. In hollow microcosms, intact vegetation had the highest sesquiterpene emissions. Water table drawdown decreased monoterpene and other VOC emissions. Specific compounds could be closely associated to the natural/lowered water tables. Peat layer from underneath the surface of hollows with intact vegetation had the highest emissions of monoterpenes, sesquiterpenes and ORVOCs whereas water table drawdown decreased those emissions. The results suggest that global warming would change the BVOC emission mixtures from boreal peatlands following changes in vegetation composition and water table drawdown.

Cloning and Functional Characterization of a β-Pinene Synthase from Artemisia annua That Shows a Circadian Pattern of Expression1

PubMed Central

Lu, Shan; Xu, Ran; Jia, Jun-Wei; Pang, Jihai; Matsuda, Seiichi P.T.; Chen, Xiao-Ya

2002-01-01

Artemisia annua plants produce a broad range of volatile compounds, including monoterpenes, which contribute to the characteristic fragrance of this medicinal species. A cDNA clone, QH6, contained an open reading frame encoding a 582-amino acid protein that showed high sequence identity to plant monoterpene synthases. The prokaryotically expressed QH6 fusion protein converted geranyl diphosphate to (−)-β-pinene and (−)-α-pinene in a 94:6 ratio. QH6 was predominantly expressed in juvenile leaves 2 weeks postsprouting. QH6 transcript levels were transiently reduced following mechanical wounding or fungal elicitor treatment, suggesting that this gene is not directly involved in defense reaction induced by either of these treatments. Under a photoperiod of 12 h/12 h (light/dark), the abundance of QH6 transcripts fluctuated in a diurnal pattern that ebbed around 3 h before daybreak (9th h in the dark phase) and peaked after 9 h in light (9th h in the light phase). The contents of (−)-β-pinene in juvenile leaves and in emitted volatiles also varied in a diurnal rhythm, correlating strongly with mRNA accumulation. When A. annua was entrained by constant light or constant dark conditions, QH6 transcript accumulation continued to fluctuate with circadian rhythms. Under constant light, advanced cycles of fluctuation of QH6 transcript levels were observed, and under constant dark, the cycle was delayed. However, the original diurnal pattern could be regained when the plants were returned to the normal light/dark (12 h/12 h) photoperiod. This is the first report that monoterpene biosynthesis is transcriptionally regulated in a circadian pattern. PMID:12226526

Methyl Jasmonate-Induced Monoterpenes in Scots Pine and Norway Spruce Tissues Affect Pine Weevil Orientation.

PubMed

Lundborg, Lina; Nordlander, Göran; Björklund, Niklas; Nordenhem, Henrik; Borg-Karlson, Anna-Karin

2016-12-01

In large parts of Europe, insecticide-free measures for protecting conifer plants are desired to suppress damage by the pine weevil Hylobius abietis (L.). Treatment with methyl jasmonate (MeJA), a chemical elicitor already used in crop production, may enhance expression of chemical defenses in seedlings in conifer regenerations. However, in a previous experiment, MeJA treatment resulted in substantially better field protection for Scots pine (Pinus sylvestris L.) than for Norway spruce (Picea abies (L.) Karst.). Hypothesizing that the variations may be at least due partly to volatiles released by MeJA-treated seedlings and their effects on pine weevil orientation, we examined tissue extracts of seedlings (from the same batches as previously used) by two-dimensional GC-MS. We found that the MeJA treatment increased contents of the monoterpene (-)-β-pinene in phloem (the weevil's main target tissue) of both tree species, however, the (-)-β-pinene/(-)-α-pinene ratio increased more in the phloem of P. sylvestris. We also tested the attractiveness of individual monoterpenes found in conifer tissues (needles and phloem) for pine weevils using an arena with traps baited with single-substance dispensers and pine twigs. Trap catches were reduced when the pine material was combined with a dispenser releasing (-)-β-pinene, (+)-3-carene, (-)-bornyl acetate or 1,8-cineole. However, (-)-α-pinene did not have this effect. Thus, the greater field protection of MeJA-treated P. sylvestris seedlings may be due to the selective induction of increases in contents of the deterrent (-)-β-pinene, in contrast to strong increases in both non-deterrent (-)-α-pinene and the deterrent (-)-β-pinene in P. abies seedlings.

S-Carvone Suppresses Cellulase-Induced Capsidiol Production in Nicotiana tabacum by Interfering with Protein Isoprenylation1[C][W

PubMed Central

Huchelmann, Alexandre; Gastaldo, Clément; Veinante, Mickaël; Zeng, Ying; Heintz, Dimitri; Tritsch, Denis; Schaller, Hubert; Rohmer, Michel; Bach, Thomas J.; Hemmerlin, Andréa

2014-01-01

S-Carvone has been described as a negative regulator of mevalonic acid (MVA) production by interfering with 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMGR) activity, a key player in isoprenoid biosynthesis. The impact of this monoterpene on the production of capsidiol in Nicotiana tabacum, an assumed MVA-derived sesquiterpenoid phytoalexin produced in response to elicitation by cellulase, was investigated. As expected, capsidiol production, as well as early stages of elicitation such as hydrogen peroxide production or stimulation of 5-epi-aristolochene synthase activity, were repressed. Despite the lack of capsidiol synthesis, apparent HMGR activity was boosted. Feeding experiments using (1-13C)Glc followed by analysis of labeling patterns by 13C-NMR, confirmed an MVA-dependent biosynthesis; however, treatments with fosmidomycin, an inhibitor of the MVA-independent 2-C-methyl-d-erythritol 4-phosphate (MEP) isoprenoid pathway, unexpectedly down-regulated the biosynthesis of this sesquiterpene as well. We postulated that S-carvone does not directly inhibit the production of MVA by inactivating HMGR, but possibly targets an MEP-derived isoprenoid involved in the early steps of the elicitation process. A new model is proposed in which the monoterpene blocks an MEP pathway–dependent protein geranylgeranylation necessary for the signaling cascade. The production of capsidiol was inhibited when plants were treated with some inhibitors of protein prenylation or by further monoterpenes. Moreover, S-carvone hindered isoprenylation of a prenylable GFP indicator protein expressed in N. tabacum cell lines, which can be chemically complemented with geranylgeraniol. The model was further validated using N. tabacum cell extracts or recombinant N. tabacum protein prenyltransferases expressed in Escherichia coli. Our study endorsed a reevaluation of the effect of S-carvone on plant isoprenoid metabolism. PMID:24367019

New foliage growth is a significant, unaccounted source for volatiles in boreal evergreen forests

NASA Astrophysics Data System (ADS)

Aalto, J.; Kolari, P.; Hari, P.; Kerminen, V.-M.; Schiestl-Aalto, P.; Aaltonen, H.; Levula, J.; Siivola, E.; Kulmala, M.; Bäck, J.

2013-11-01

Estimates of volatile organic compound (VOC) emissions from forests are based on the assumption that foliage has a steady emission potential over its lifetime, and that emissions are mainly modified by short term variations in light and temperature. However, in many field studies this has been challenged, and high emissions and atmospheric concentrations have been measured during periods of low biological activity such as in springtime. We conducted measurements during three years, using an online gas-exchange monitoring system to observe volatile organic emissions from a mature (1 yr old) and a growing Scots pine shoot. The emission rates of organic vapours (monoterpenes, methyl butenol (MBO), acetone and methanol) from vegetative buds of Scots pine during the dehardening and rapid shoot growth stages were one to two orders of magnitude higher than those from mature foliage. The normally assumed temperature dependency was not sufficient to explain the variations in emission rates during spring. The diurnal emission pattern of growing shoots differed from the diurnal cycle in temperature as well as from the diurnal emission pattern of mature shoots, which may be related to processes involved in shoot or needle elongation. Our findings imply that global estimations of monoterpene emission rates from forests are in need of revision, and that the physiological state of the plants should be taken into account when emissions of the reactive gases such as monoterpenes are estimated. The significant interannual variation in emission rates, related to changes in plant metabolic activity, has important implications to the aerosol precursor concentrations and chemical reactions in atmosphere, and potentially offers an explanation for the frequent aerosol formation events in spring.

The essential oil of bergamot enhances the levels of amino acid neurotransmitters in the hippocampus of rat: implication of monoterpene hydrocarbons.

PubMed

Morrone, Luigi A; Rombolà, Laura; Pelle, Cinzia; Corasaniti, Maria T; Zappettini, Simona; Paudice, Paolo; Bonanno, Giambattista; Bagetta, Giacinto

2007-04-01

The effects of bergamot essential oil (BEO) on the release of amino acid neurotransmitters in rat hippocampus have been studied by in vivo microdialysis and by in vitro superfusion of isolated nerve terminals. Intraperitoneal administration of BEO (100microl/kg) significantly elevated the extracellular concentration of aspartate, glycine and taurine in a Ca(2+)-dependent manner. A dose-relation study generated a bell-shaped curve. When perfused into the hippocampus via the dialysis probe (20microl/20min), BEO produced a significant increase of extracellular aspartate, glycine, taurine as well as of GABA and glutamate. The augmentation of all amino acids was Ca(2+)-independent. Focally injected 1:1 diluted BEO preferentially caused extracellular increase of glutamate. Interestingly, this release appeared to be strictly Ca(2+)-dependent. BEO concentration-dependently enhanced the release of [(3)H]D-aspartate from superfused hippocampal synaptosomes. Similar results were obtained by monitoring the BEO-evoked release of endogenous glutamate. At relatively high concentrations, the BEO-induced [(3)H]d-aspartate release was almost entirely prevented by the glutamate transporter blocker dl-threo-beta-benzyloxyaspartic acid (DL-TBOA) and was Ca(2+)-independent. At relatively low concentrations the release of [(3)H]D-aspartate was only in part ( approximately 50%) DL-TBOA-sensitive and Ca(2+)-independent; the remaining portion of release was dependent on extracellular Ca(2+). Interestingly, the monoterpene hydrocarbon-free fraction of the essential oil appeared to be inactive while the bergapten-free fraction superimposed the releasing effect of BEO supporting the deduction that psoralens may not be implicated. To conclude, BEO contains into its volatile fraction still unidentified monoterpene hydrocarbons able to stimulate glutamate release by transporter reversal and/or by exocytosis, depending on the dose administered.

Comparing the variation of needle and wood terpenoids in Scots pine provenances.

PubMed

Manninen, A M; Tarhanen, S; Vuorinen, M; Kainulaine, P

2002-01-01

We determined variation in both the concentration and composition of terpenoids in needles and wood within nine Scots pine (Pinus sylvestris) provenances. Seedlings of different provenances representing a 1200-km N-S transect from Estonia to northern Finland were cultivated in Suonenjoki nursery field, central Finland, for seven years. Growth of seedlings and the number of vertical resin ducts in wood were also determined. alpha-Pinene and 3-carene were the major monoterpenes both in the needles and wood. The total monoterpene concentration was about five times higher in the needles than in the wood. A strong positive correlation was found between proportional quantities of several terpenes of the needles and wood, particularly for 3-carene, sabinene, and terpinolene. The needles contained both labdane-type and tricyclic resin acids, whereas the wood contained only tricyclic ones. The wood had a four times higher tricyclic resin acid concentration than the needles. The highest total monoterpene concentration in the needles and in the wood occurred in the most northern Muonio provenance and in the most southern Saaremaa provenance plants, respectively. The amount of high 3-carene genotype trees decreased among the northern provenances. The wood of the most northern Muonio provenance showed the lowest total resin acid concentration, but provenance did not affect total tricyclic resin acids in the needles. Korpilahti provenance trees from central Finland had the best growth in height. In addition, Korpilahti and Ruokolahti provenance trees showed largest radial growth of stem and smallest number of vertical resin ducts. The results suggest that especially the proportional quantity of 3-carene in the needles could be used in estimating the amount of this compound in the wood and vice versa.

Secondary metabolite concentrations and terpene emissions of Scots pine xylem after long-term forest fertilization.

PubMed

Turtola, S; Manninen, A M; Holopainen, J K; Levula, T; Raitio, H; Kainulainen, P

2002-01-01

Secondary compounds are known to be associated with the resistance of conifer xylem against insects and fungi. The effects of long-term forest fertilization with nitrogen (N) or with N, calcium (Ca), and phosphorus (P) on secondary compounds in the xylem of 50-yr-old Scots pine (Pinus sylvestris L.) trees were examined. Xylem samples were collected from trees growing in three locations in southern Finland: Vilppula, Padasjoki, and Punkaharju. Forests were fertilized every fifth (Vilppula and Padasjoki) or tenth (Punkaharju) year since the 1950s. We compared concentrations of individual and total monoterpenes and resin acids in the heartwood and sapwood of Scots pine. Terpene emissions were analyzed from the sapwood and total phenolics from the heartwood. Fertilization did not have any significant effect on the concentrations and emissions of xylem monoterpenes. Concentrations of several individual terpenes in sapwood were positively correlated with the corresponding terpene emission. The concentrations of individual resin acids (i.e., abietic and dehydroabietic) decreased significantly in Punkaharju, but increased in the sapwood of N-fertilized trees compared with control ones at Padasjoki and Vilppula. The concentrations of resin acids in the heartwood were not significantly affected by fertilization. Both fertilization treatments decreased the total phenolic concentrations in the heartwood of trees growing in Padasjoki. There was a significant positive correlation between the total phenolics and total resin acid concentration. Overall, resin acids and phenolics seemed be more responsive than monoterpenes to N treatment. These results suggest that forest fertilization might cause slight changes in secondary compound concentrations of xylem, and thus might have significance in the decay resistance of wood.

Engineering d-limonene synthase down-regulation in orange fruit induces resistance against the fungus Phyllosticta citricarpa through enhanced accumulation of monoterpene alcohols and activation of defence.

PubMed

Rodríguez, Ana; Kava, Vanessa; Latorre-García, Lorena; da Silva, Geraldo J; G Pereira, Rosana; Glienke, Chirlei; Ferreira-Maba, Lisandra S; Vicent, Antonio; Shimada, Takehiko; Peña, Leandro

2018-03-24

Terpene volatiles play an important role in the interactions between specialized pathogens and fruits. Citrus black spot (CBS), caused by the fungus Phyllosticta citricarpa, is associated with crop losses in different citrus-growing areas worldwide. The pathogen may infect the fruit for 20-24 weeks after petal fall, but the typical hard spot symptoms appear when the fruit have almost reached maturity, caused by fungal colonization and the induction of cell lysis around essential oil cavities. d-Limonene represents approximately 95% of the total oil gland content in mature orange fruit. Herein, we investigated whether orange fruit with reduced d-limonene content in peel oil glands via an antisense (AS) approach may affect fruit interaction with P. citricarpa relative to empty vector (EV) controls. AS fruit showed enhanced resistance to the fungus relative to EV fruit. Because of the reduced d-limonene content, an over-accumulation of linalool and other monoterpene alcohols was found in AS relative to EV fruit. A global gene expression analysis at 2 h and 8 days after inoculation with P. citricarpa revealed the activation of defence responses in AS fruit via the up-regulation of different pathogenesis-related (PR) protein genes, probably as a result of enhanced constitutive accumulation of linalool and other alcohols. When assayed in vitro and in vivo, monoterpene alcohols at the concentrations present in AS fruit showed strong antifungal activity. We show here that terpene engineering in fruit peels could be a promising method for the development of new strategies to obtain resistance to fruit diseases. © 2018 BSPP and John Wiley & Sons Ltd.

Unexpected Irregular Monoterpene "Yomogi Alcohol" in the Volatiles of the Lathyrus L. species (Leguminosae) of Cyprus.

PubMed

Polatoğlu, Kaan; Arsal, Seniha; Demirci, Betül; Can Başer, Kemal Hüsnü

2016-01-01

Lathyrus species including L. ochrus and L. sativus are known for their food, feed and horticultural uses. Despite their widespread uses and cultivation, there is limited information on their chemistry. Previously, only the essential oil composition of L. rotundifolius, L. vernus and volatiles of L. odoratus have been reported. In the present research, volatiles of seven Lathyrus L. species, namely, L. aphaca, L. ochrus, L. cicera, L. sativus, L. gorgonei, L. saxatilis and L. blepharicarpos var. cyprius were analyzed by SPME GC-MS for the first time. Plant materials were collected from five different locations in Cyprus (February-March 2012). The main components of L. aphaca volatiles from four locations were yomogi alcohol 26.1-16.5%, camphor 21.6-10.1%, tetradecane 14.3-0%; L. cicera from five locations were yomogi alcohol 20.3-3.0%, camphor 18.7-2.0%; L. gorgonei from two locations were yomogi alcohol 24.5-13.1%, camphor 17.1-9.0% and L. sativus was yomogi alcohol 11.4%, camphor 9.0%. Yomogi alcohol was not present as the major compound in L. ochrus (2-methyl butanoic acid 7.2%), L. saxatilis (hexanal 7.7%) and L. blepharicarpos var. cyprius ((Z)-3-hexenal 8.6%) volatiles. The volatiles of the Lathyrus species were also compared with each other quantitative and qualitatively using AHC analysis to find out differences among the species. The irregular monoterpene yomogi alcohol is reported from the Lathyrus and the Leguminosae family for the first time. The existence of yomogi alcohol in Lathyrus volatiles points out that the irregular monoterpenes are not restricted solely to Asteraceae family.

Isolation and characterization of terpene synthases in cotton (Gossypium hirsutum).

PubMed

Yang, Chang-Qing; Wu, Xiu-Ming; Ruan, Ju-Xin; Hu, Wen-Li; Mao, Yin-Bo; Chen, Xiao-Ya; Wang, Ling-Jian

2013-12-01

Cotton plants accumulate gossypol and related sesquiterpene aldehydes, which function as phytoalexins against pathogens and feeding deterrents to herbivorous insects. However, to date little is known about the biosynthesis of volatile terpenes in this crop. Herein is reported that 5 monoterpenes and 11 sesquiterpenes from extracts of a glanded cotton cultivar, Gossypium hirsutum cv. CCRI12, were detected by gas chromatography-mass spectrometry (GC-MS). By EST data mining combined with Rapid Amplification of cDNA Ends (RACE), full-length cDNAs of three terpene synthases (TPSs), GhTPS1, GhTPS2 and GhTPS3 were isolated. By in vitro assays of the recombinant proteins, it was found that GhTPS1 and GhTPS2 are sesquiterpene synthases: the former converted farnesyl pyrophosphate (FPP) into β-caryophyllene and α-humulene in a ratio of 2:1, whereas the latter produced several sesquiterpenes with guaia-1(10),11-diene as the major product. By contrast, GhTPS3 is a monoterpene synthase, which produced α-pinene, β-pinene, β-phellandrene and trace amounts of other monoterpenes from geranyl pyrophosphate (GPP). The TPS activities were also supported by Virus Induced Gene Silencing (VIGS) in the cotton plant. GhTPS1 and GhTPS3 were highly expressed in the cotton plant overall, whereas GhTPS2 was expressed only in leaves. When stimulated by mechanical wounding, Verticillium dahliae (Vde) elicitor or methyl jasmonate (MeJA), production of terpenes and expression of the corresponding synthase genes were induced. These data demonstrate that the three genes account for the biosynthesis of volatile terpenes of cotton, at least of this Upland cotton. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biogenic VOC oxidation and organic aerosol formation in an urban nocturnal boundary layer: aircraft vertical profiles in Houston, TX

NASA Astrophysics Data System (ADS)

Brown, S. S.; Dubé, W. P.; Bahreini, R.; Middlebrook, A. M.; Brock, C. A.; Warneke, C.; de Gouw, J. A.; Washenfelder, R. A.; Atlas, E.; Peischl, J.; Ryerson, T. B.; Holloway, J. S.; Schwarz, J. P.; Spackman, R.; Trainer, M.; Parrish, D. D.; Fehshenfeld, F. C.; Ravishankara, A. R.

2013-11-01

Organic compounds are a large component of aerosol mass, but organic aerosol (OA) sources remain poorly characterized. Recent model studies have suggested nighttime oxidation of biogenic hydrocarbons as a potentially large OA source, but analysis of field measurements to test these predictions is sparse. We present nighttime vertical profiles of nitrogen oxides, ozone, VOCs and aerosol composition measured during low approaches of the NOAA P-3 aircraft to airfields in Houston, TX. This region has large emissions of both biogenic hydrocarbons and nitrogen oxides. The latter category serves as a source of the nitrate radical, NO3, a key nighttime oxidant. Biogenic VOCs (BVOC) and urban pollutants were concentrated within the nocturnal boundary layer (NBL), which varied in depth from 100-400 m. Despite concentrated NOx at low altitude, ozone was never titrated to zero, resulting in rapid NO3 radical production rates of 0.2-2.7 ppbv h-1 within the NBL. Monoterpenes and isoprene were frequently present within the NBL and underwent rapid oxidation (up to 1 ppbv h-1), mainly by NO3 and to a lesser extent O3. Concurrent enhancement in organic and nitrate aerosol on several profiles was consistent with primary emissions and with secondary production from nighttime BVOC oxidation, with the latter equivalent to or slightly larger than the former. Some profiles may have been influenced by biomass burning sources as well, making quantitative attribution of organic aerosol sources difficult. Ratios of organic aerosol to CO within the NBL ranged from 14 to 38 μg m-3 OA/ppmv CO. A box model simulation incorporating monoterpene emissions, oxidant formation rates and monoterpene SOA yields suggested overnight OA production of 0.5 to 9 μg m-3.

Biogenic VOC oxidation and organic aerosol formation in an urban nocturnal boundary layer: aircraft vertical profiles in Houston, TX

NASA Astrophysics Data System (ADS)

Brown, S. S.; Dubé, W. P.; Bahreini, R.; Middlebrook, A. M.; Brock, C. A.; Warneke, C.; de Gouw, J. A.; Washenfelder, R. A.; Atlas, E.; Peischl, J.; Ryerson, T. B.; Holloway, J. S.; Schwarz, J. P.; Spackman, R.; Trainer, M.; Parrish, D. D.; Fehshenfeld, F. C.; Ravishankara, A. R.

2013-05-01

Organic compounds are a large component of aerosol mass, but organic aerosol (OA) sources remain poorly characterized. Recent model studies have suggested nighttime oxidation of biogenic hydrocarbons as a potentially large OA source, but analysis of field measurements to test these predictions is sparse. We present nighttime vertical profiles of nitrogen oxides, ozone, VOCs and aerosol composition measured during low approaches of the NOAA P-3 aircraft to airfields in Houston, TX. This region has large emissions of both biogenic hydrocarbons and nitrogen oxides. The latter serves as a source of the nitrate radical, NO3, a key nighttime oxidant. Biogenic VOCs (BVOC) and urban pollutants were concentrated within the nocturnal boundary layer (NBL), which varied in depth from 100-400 m. Despite concentrated NOx at low altitude, ozone was never titrated to zero, resulting in rapid NO3 radical production rates of 0.2-2.7ppbv h-1 within the NBL. Monoterpenes and isoprene were frequently present within the NBL and underwent rapid oxidation (up to 1ppbv h-1), mainly by NO3 and to a lesser extent O3. Concurrent enhancement in organic and nitrate aerosol on several profiles was consistent with primary emissions and with secondary production from nighttime BVOC oxidation, with the latter equivalent to or slightly larger than the former. Ratios of organic aerosol to CO within the NBL ranged from 14 to 38 μg m-3 OA/ppmv CO. A box model simulation incorporating monoterpene emissions, oxidant formation rates and monoterpene SOA yields suggested overnight OA production of 0.5 to 9 μg m-3.

Nitrate radical oxidation of γ-terpinene: hydroxy nitrate, total organic nitrate, and secondary organic aerosol yields

NASA Astrophysics Data System (ADS)

Slade, Jonathan H.; de Perre, Chloé; Lee, Linda; Shepson, Paul B.

2017-07-01

Polyolefinic monoterpenes represent a potentially important but understudied source of organic nitrates (ONs) and secondary organic aerosol (SOA) following oxidation due to their high reactivity and propensity for multi-stage chemistry. Recent modeling work suggests that the oxidation of polyolefinic γ-terpinene can be the dominant source of nighttime ON in a mixed forest environment. However, the ON yields, aerosol partitioning behavior, and SOA yields from γ-terpinene oxidation by the nitrate radical (NO3), an important nighttime oxidant, have not been determined experimentally. In this work, we present a comprehensive experimental investigation of the total (gas + particle) ON, hydroxy nitrate, and SOA yields following γ-terpinene oxidation by NO3. Under dry conditions, the hydroxy nitrate yield = 4(+1/-3) %, total ON yield = 14(+3/-2) %, and SOA yield ≤ 10 % under atmospherically relevant particle mass loadings, similar to those for α-pinene + NO3. Using a chemical box model, we show that the measured concentrations of NO2 and γ-terpinene hydroxy nitrates can be reliably simulated from α-pinene + NO3 chemistry. This suggests that NO3 addition to either of the two internal double bonds of γ-terpinene primarily decomposes forming a relatively volatile keto-aldehyde, reconciling the small SOA yield observed here and for other internal olefinic terpenes. Based on aerosol partitioning analysis and identification of speciated particle-phase ON applying high-resolution liquid chromatography-mass spectrometry, we estimate that a significant fraction of the particle-phase ON has the hydroxy nitrate moiety. This work greatly contributes to our understanding of ON and SOA formation from polyolefin monoterpene oxidation, which could be important in the northern continental US and the Midwest, where polyolefinic monoterpene emissions are greatest.

Dynamic control of ERG20 expression combined with minimized endogenous downstream metabolism contributes to the improvement of geraniol production in Saccharomyces cerevisiae.

PubMed

Zhao, Jianzhi; Li, Chen; Zhang, Yan; Shen, Yu; Hou, Jin; Bao, Xiaoming

2017-01-31

Microbial production of monoterpenes provides a promising substitute for traditional chemical-based methods, but their production is lagging compared with sesquiterpenes. Geraniol, a valuable monoterpene alcohol, is widely used in cosmetic, perfume, pharmaceutical and it is also a potential gasoline alternative. Previously, we constructed a geraniol production strain by engineering the mevalonate pathway together with the expression of a high-activity geraniol synthase. In this study, we further improved the geraniol production through reducing the endogenous metabolism of geraniol and controlling the precursor geranyl diphosphate flux distribution. The deletion of OYE2 (encoding an NADPH oxidoreductase) or ATF1 (encoding an alcohol acetyltransferase) both involving endogenous conversion of geraniol to other terpenoids, improved geraniol production by 1.7-fold or 1.6-fold in batch fermentation, respectively. In addition, we found that direct down-regulation of ERG20 expression, the branch point regulating geranyl diphosphate flux, does not improve geraniol production. Therefore, we explored dynamic control of ERG20 expression to redistribute the precursor geranyl diphosphate flux and achieved a 3.4-fold increase in geraniol production after optimizing carbon source feeding. Furthermore, the combination of dynamic control of ERG20 expression and OYE2 deletion in LEU2 prototrophic strain increased geraniol production up to 1.69 g/L with pure ethanol feeding in fed-batch fermentation, which is the highest reported production in engineered yeast. An efficient geraniol production platform was established by reducing the endogenous metabolism of geraniol and by controlling the flux distribution of the precursor geranyl diphosphate. The present work also provides a production basis to synthesis geraniol-derived chemicals, such as monoterpene indole alkaloids.

Divergent Regulation of Terpenoid Metabolism in the Trichomes of Wild and Cultivated Tomato Species1[W][OA

PubMed Central

Besser, Katrin; Harper, Andrea; Welsby, Nicholas; Schauvinhold, Ines; Slocombe, Stephen; Li, Yi; Dixon, Richard A.; Broun, Pierre

2009-01-01

The diversification of chemical production in glandular trichomes is important in the development of resistance against pathogens and pests in two species of tomato. We have used genetic and genomic approaches to uncover some of the biochemical and molecular mechanisms that underlie the divergence in trichome metabolism between the wild species Solanum habrochaites LA1777 and its cultivated relative, Solanum lycopersicum. LA1777 produces high amounts of insecticidal sesquiterpene carboxylic acids (SCAs), whereas cultivated tomatoes lack SCAs and are more susceptible to pests. We show that trichomes of the two species have nearly opposite terpenoid profiles, consisting mainly of monoterpenes and low levels of sesquiterpenes in S. lycopersicum and mainly of SCAs and very low monoterpene levels in LA1777. The accumulation patterns of these terpenoids are different during development, in contrast to the developmental expression profiles of terpenoid pathway genes, which are similar in the two species, but they do not correlate in either case with terpenoid accumulation. However, our data suggest that the accumulation of monoterpenes in S. lycopersicum and major sesquiterpenes in LA1777 are linked both genetically and biochemically. Metabolite analyses after targeted gene silencing, inhibitor treatments, and precursor feeding all show that sesquiterpene biosynthesis relies mainly on products from the plastidic 2-C-methyl-d-erythritol-4-phosphate pathway in LA1777 but less so in the cultivated species. Furthermore, two classes of sesquiterpenes produced by the wild species may be synthesized from distinct pools of precursors via cytosolic and plastidial cyclases. However, highly trichome-expressed sesquiterpene cyclase-like enzymes were ruled out as being involved in the production of major LA1777 sesquiterpenes. PMID:18997116

Observation of nighttime new particle formation over the French Landes forest.

PubMed

Kammer, J; Perraudin, E; Flaud, P-M; Lamaud, E; Bonnefond, J M; Villenave, E

2018-04-15

Improving the understanding of processes related to atmospheric particle sources is essential to better assess future climate. Especially, how biogenic volatile organic compounds (BVOCs) are involved in new particle formation (NPF) is still unclear, highlighting the need for field studies in sites that have not yet been explored. Weakly anthropised, mostly composed of maritime pines (known as strong monoterpene emitters), vast and under the influence of sea spray inputs, the Landes forest (located in the southwestern part of France) is a suitable ecosystem to explore these questions. The aim of the present work was to investigate for the first time NPF in the Landes forest, and to identify the conditions for NPF. During a field campaign conducted in July 2015, clear NPF was observed during nighttime, at a high frequency rate (37.5%), whereas only two daytime episodes were observed. Growth rates during NPF events were in the range 9.0-15.7nmh -1 , and nucleation rates (J 10 ) in the range 0.8-8 particles cm 3 s -1 , typically in the range of reported values from rural sites. Nocturnal NPF started at sunset, lagging the reductions of temperature and ozone concentration as well as the increase of relative humidity, atmospheric stability and monoterpene concentration. We established that NPF occurred during more stratified atmosphere episodes, reflecting that NPF is more influenced by local processes at the Landes forest site (Bilos). Concentration of the sum of monoterpenes, here mainly α- and β-pinene, was observed to be maximal during NPF episodes. On the contrary, ozone concentration was lower, which may indicate a larger consumption during nights where NPF episodes occur. Results strongly suggest the contribution of BVOC oxidation to nocturnal NPF, in both nucleation and the growth stages. Copyright © 2017 Elsevier B.V. All rights reserved.

Biochemical Characterization and Homology Modeling of Methylbutenol Synthase and Implications for Understanding Hemiterpene Synthase Evolution in Plants*

PubMed Central

Gray, Dennis W.; Breneman, Steven R.; Topper, Lauren A.; Sharkey, Thomas D.

2011-01-01

2-Methyl-3-buten-2-ol (MBO) is a five-carbon alcohol produced and emitted in large quantities by many species of pine native to western North America. MBO is structurally and biosynthetically related to isoprene and can have an important impact on regional atmospheric chemistry. The gene for MBO synthase was identified from Pinus sabiniana, and the protein encoded was functionally characterized. MBO synthase is a bifunctional enzyme that produces both MBO and isoprene in a ratio of ∼90:1. Divalent cations are required for activity, whereas monovalent cations are not. MBO production is enhanced by K+, whereas isoprene production is inhibited by K+ such that, at physiologically relevant [K+], little or no isoprene emission should be detected from MBO-emitting trees. The Km of MBO synthase for dimethylallyl diphosphate (20 mm) is comparable with that observed for angiosperm isoprene synthases and 3 orders of magnitude higher than that observed for monoterpene and sesquiterpene synthases. Phylogenetic analysis showed that MBO synthase falls into the TPS-d1 group (gymnosperm monoterpene synthases) and is most closely related to linalool synthase from Picea abies. Structural modeling showed that up to three phenylalanine residues restrict the size of the active site and may be responsible for making this a hemiterpene synthase rather than a monoterpene synthase. One of these residues is homologous to a Phe residue found in the active site of isoprene synthases. The remaining two Phe residues do not have homologs in isoprene synthases but occupy the same space as a second Phe residue that closes off the isoprene synthase active site. PMID:21504898

[Gas chromatography for analysis of essential oils. Characteristics of essential oil of Dracocephalum species and the influence of extraction method on its composition].

PubMed

Lemberkovics, Eva; Kakasy, András Zoltán; Héthelyi, B Eva; Simándi, Béla; Böszörményi, Andrea; Balázs, Andrea; Szoke, Eva

2007-01-01

In this work the essential oil composition of some less known Dracocephalum species was studied and compared the effectiveness, selectivity and influence of different extraction methods (hydrodistillation, Soxhlet extraction with organic solvents and supercritical fluid extraction) on essential oils. For investigations in Hungary and Transylvania cultivated plant material was used. The analysis of essential oils was carried out by GC and GC-MS methods. The components were identified by standard addition, retention factors and mass spectra. The percentile evaluation of each volatile constituents was made on basis of GC-FID chromatograms. The accuracy of measurements was characterized by relative standard deviation. In the essential oil of D. renati Emb. (studied firstly by us) 18.3% of limonene was measured and carvone, citrals and linalyl acetate monoterpenes, methyl chavicol and some sesquiterpene (e.g. bicyclovetivenol) determined in lower quantities. We established that more than 50% of essential oil of D. grandiflorum L. was formed by sesquiterpenes (beta-caryophyllene and- oxide, beta-bourbonene, beta-cubebene, aromadendrene) and the essential oil of D. ruyschiana L. contained pinocamphone isomers in more than 60%. The oxygenated acyclic monoterpenes, the characteristic constituents of Moldavian dragonhead were present in some tenth percent only in D. renati oil. We found significant differences in the composition of the SFE extract and traditional essential oil of D. moldavica L. The supercritical fractions collected at the beginning of the extraction process were richer in valuable ester component (geranyl acetate) than the essential oil obtained by hydrodistillation. The fractions collected at the end of supercritical were poor in oxygenated monoterpenes but rich in minor compounds of traditional oil, e.g. palmitic acid.

ESTIMATES OF ISOPRENE AND MONOTERPENE EMISSION RATES IN PLANTS

EPA Science Inventory

A range of plant species, including crops, shrubs, herbs, and trees, was surveyed to determine the magnitude of isoprene emissions. In studies to determine if plants emitted isoprene, greenhouse-grown plants were encapsulated in impermeable plastic bags and kept in a growth chamb...

Modeling the current and future role of particulate organic nitrates in the southeastern United States

EPA Science Inventory

Organic nitrates are an important aerosol constituent in locations where biogenic hydrocarbon emissions mix with anthropogenic NOx sources. While regional and global chemical transport models may include a representation of organic aerosol from monoterpene reactions with nitrate ...

Relative Configuration of Natural Products Using NMR Chemical Shifts

USDA-ARS?s Scientific Manuscript database

By comparing calculated with experimental NMR chemical shifts, we were able to determine the relative configurations of three monoterpene diastereomers produced by the walkingstick Anisomorpha buprestoides. The combined RMSDs of both 1H and 13C quantum chemically calculated shifts were able to predi...

Heliotropium bacciferum Forssk. (Boraginaceae) extracts: chemical constituents, antioxidant activity and cytotoxic effect in human cancer cell lines.

PubMed

Aïssaoui, Hanane; Mencherini, Teresa; Esposito, Tiziana; De Tommasi, Nunziatina; Gazzerro, Patrizia; Benayache, Samir; Benayache, Fadila; Mekkiou, Ratiba

2018-02-12

Heliotropium bacciferum (Boraginaceae) is a perennial herb, growing in the Bechar region of Algeria, where it is traditionally used for skin diseases and tonsillitis. Herein, we report the isolation and characterization of sixteen secondary metabolites from the aerial part extracts. They include a sterol (1), megastigman type nor-isoprenoids (2, 3, 4, 6, 8, 10), C-11 terpene lactones (5 and 9), and a monoterpene (7) from the chloroform extract (HB-C); monoterpene glucoside (14), and phenolic compounds (11-13, 15, 16) from the methanol one (HB-M). Their structures were elucidated by spectroscopic methods including 1D and 2D NMR experiments, and ESIMS analysis. HB-M showed a significant and concentration dependent scavenging activity in vitro against the radicals DPPH and ABTS, related to the phenol derivatives (11-13, and 15-16), and HB-C inhibited the growth of colon cancer cell lines, mainly for the presence of the antiproliferative C-11 terpene lactones (5 and 9).

Strategies for engineering plant natural products: the iridoid-derived monoterpene indole alkaloids of Catharanthus roseus.

PubMed

O'Connor, Sarah E

2012-01-01

The manipulation of pathways to make unnatural variants of natural compounds, a process often termed combinatorial biosynthesis, has been robustly successful in prokaryotic systems. The development of approaches to generate new-to-nature compounds from plant-based pathways is, in comparison, much less advanced. Success will depend on the specific chemistry of the pathway, as well as on the suitability of the plant system for transformation and genetic manipulation. As plant pathways are elucidated, and can be heterologously expressed in hosts that are more amenable to genetic manipulation, biosynthetic production of new-to-nature compounds from plant pathways will become more widespread. In this chapter, some of the key strategies that have been developed for metabolic engineering of plant pathways, namely directed biosynthesis, mutasynthesis, and pathway incorporation of engineered enzymes are highlighted. The iridoid-derived monoterpene indole alkaloids from C. roseus, which are the focus of this chapter, provide an excellent system for developing these strategies. Copyright © 2012 Elsevier Inc. All rights reserved.

Antifungal Monoterpene Derivatives from the Plant Endophytic Fungus Pestalotiopsis foedan.

PubMed

Xu, Dan; Zhang, Bing-Yang; Yang, Xiao-Long

2016-10-01

A new monoterpene lactone, (1R,4R,5R,8S)-8-hydroxy-4,8-dimethyl-2-oxabicyclo[3.3.1]nonan-3-one (1), along with one related known compound, (2R)-2-[(1R)-4-methylcyclohex-3-en-1-yl]propanoic acid (2), were isolated from the liquid culture of the plant endophytic fungus Pestalotiopsis foedan obtained from the branch of Bruguiera sexangula. The structure and absolute configuration of 1 were determined on the basis of extensive analysis of NMR spectra combined with computational methods via calculation of the optical rotation (OR) and 13 C-NMR. Both compounds exhibited strong antifungal activities against Botrytis cinerea and Phytophthora nicotianae with MIC values of 3.1 and 6.3 μg/ml, respectively, which are comparable to those of the known antifungal drug ketoconazole. Compound 2 also showed modest antifungal activity against Candida albicans with a MIC value of 50 μg/ml. © 2016 Wiley-VHCA AG, Zürich.

Inhibition of β-Secretase Activity by Monoterpenes, Sesquiterpenes, and C13 Norisoprenoids.

PubMed

Marumoto, Shinsuke; Okuno, Yoshiharu; Miyazawa, Mitsuo

2017-08-01

Inhibition of β-secretase (BACE1) is currently regarded as the leading treatment strategy for Alzheimer's disease. In the present study, we aimed to screen the in vitro inhibitory activity of 80 types of aroma compounds (monoterpenes, sesquiterpenes, and C 13 norisoprenoids), including plant-based types, at a 200-μM concentration against a recombinant human BACE1. The results showed that the most potent inhibitor of BACE1 was geranyl acetone followed by (+)-camphor, (-)-fenchone, (+)-fenchone, and (-)-camphor with the half-maximal inhibitory concentration (IC 50 ) values of 51.9 ± 3.9, 95.9 ± 11.0, 106.3 ± 14.9, 117.0 ± 18.6, and 134.1 ± 16.4 μM, respectively. Furthermore, the mechanism of inhibition of BACE1 by geranyl acetone was analyzed using Dixon kinetics plus Cornish-Bowden plots, which revealed mixed-type mode. Therefore aroma compounds may be used as potential lead molecules for designing anti-BACE1 agents.

Jasmonate induction of the monoterpene linalool confers resistance to rice bacterial blight and its biosynthesis is regulated by JAZ protein in rice.

PubMed

Taniguchi, Shiduku; Hosokawa-Shinonaga, Yumi; Tamaoki, Daisuke; Yamada, Shoko; Akimitsu, Kazuya; Gomi, Kenji

2014-02-01

Jasmonic acid (JA) is involved in the regulation of host immunity in plants. Recently, we demonstrated that JA signalling has an important role in resistance to rice bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) in rice. Here, we report that many volatile compounds accumulate in response to exogenous application of JA, including the monoterpene linalool. Expression of linalool synthase was up-regulated by JA. Vapour treatment with linalool induced resistance to Xoo, and transgenic rice plants overexpressing linalool synthase were more resistance to Xoo, presumably due to the up-regulation of defence-related genes in the absence of any treatment. JA-induced accumulation of linalool was regulated by OsJAZ8, a rice jasmonate ZIM-domain protein involving the JA signalling pathway at the transcriptional level, suggesting that linalool plays an important role in JA-induced resistance to Xoo in rice. © 2013 John Wiley & Sons Ltd.

Monoterpenes from Larval Frass of Two Cerambycids as Chemical Cues for a Parasitoid, Dastarcus helophoroides

PubMed Central

Wei, Jian-Rong; Lu, Xi-Ping; Jiang, Li

2013-01-01

Anopiophora glabripennis (Motsch.) (Coleoptera: Cerambycidae) is a destructive woodborer, attacking many species of deciduous hardwood trees. Apriona swainsoni (Hope) (Coleoptera: Cerambycidae) is a woodborer of Sophora japonica L. (Angiospermae: Fabaceae). Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae) is an important natural enemy of both Cerambycid species in China. Kairomones for two populations of D. helophoroides that parasitize A. glabripennis and A. swainsoni respectively were studied. Based on identification and quantification of volatiles from larval frass produced by A. glabripennis and A. swainsoni, monoterpenes were selected to test their kairomonal activity to both populations of D. helophoroides adults using a Y-tube olfactometer. The results indicated that (S)-(-)-limonene served as a kairomone for the population of D. helophoroides parasitized A. glabripennis. α-pinene, (IR)-(+)-αpinene and (+)-β-pinene were attractive to the population of D. helophoroides parasitized A. swainsoni. The results provide information about the co-evolution of D. helophoroides, its host, and host-food trees. PMID:23906184

Resistance to pathogens in terpene down-regulated orange fruits inversely correlates with the accumulation of D-limonene in peel oil glands.

PubMed

Rodríguez, Ana; Shimada, Takehiko; Cervera, Magdalena; Redondo, Ana; Alquézar, Berta; Rodrigo, María Jesús; Zacarías, Lorenzo; Palou, Lluís; López, María M; Peña, Leandro

2015-01-01

Volatile organic compounds (VOCs) are secondary metabolites acting as a language for the communication of plants with the environment. In orange fruits, the monoterpene D-limonene accumulates at very high levels in oil glands from the peel. Drastic down-regulation of D-limonene synthase gene expression in the peel of transgenic oranges harboring a D-limonene synthase transgene in antisense (AS) configuration altered the monoterpene profile in oil glands, mainly resulting in reduced accumulation of D-limonene. This led to fruit resistance against Penicillium digitatum (Pd), Xanthomonas citri subsp. citri (Xcc) and other specialized pathogens. Here, we analyze resistance to pathogens in independent AS and empty vector (EV) lines, which have low, medium or high D-limonene concentrations and show that the level of resistance is inversely related to the accumulation of D-limonene in orange peels, thus explaining the need of high D-limonene accumulation in mature oranges in nature for the efficient attraction of specialized microorganism frugivores.

Resistance to pathogens in terpene down-regulated orange fruits inversely correlates with the accumulation of D-limonene in peel oil glands

PubMed Central

Rodríguez, Ana; Shimada, Takehiko; Cervera, Magdalena; Redondo, Ana; Alquézar, Berta; Rodrigo, María Jesús; Zacarías, Lorenzo; Palou, Lluís; López, María M; Peña, Leandro

2015-01-01

Volatile organic compounds (VOCs) are secondary metabolites acting as a language for the communication of plants with the environment. In orange fruits, the monoterpene D-limonene accumulates at very high levels in oil glands from the peel. Drastic down-regulation of D-limonene synthase gene expression in the peel of transgenic oranges harboring a D-limonene synthase transgene in antisense (AS) configuration altered the monoterpene profile in oil glands, mainly resulting in reduced accumulation of D-limonene. This led to fruit resistance against Penicillium digitatum (Pd), Xanthomonas citri subsp. citri (Xcc) and other specialized pathogens. Here, we analyze resistance to pathogens in independent AS and empty vector (EV) lines, which have low, medium or high D-limonene concentrations and show that the level of resistance is inversely related to the accumulation of D-limonene in orange peels, thus explaining the need of high D-limonene accumulation in mature oranges in nature for the efficient attraction of specialized microorganism frugivores. PMID:26023857

Impact of elevated CO2 and O3 concentrations on biogenic volatile organic compounds emissions from Ginkgo biloba.

PubMed

Li, Dewen; Chen, Ying; Shi, Yi; He, Xingyuan; Chen, Xin

2009-04-01

In natural environment with ambient air, ginkgo trees emitted volatile organic compounds 0.18 microg g(-1) h(-1) in July, and 0.92 microg g(-1) h(-1) in September. Isoprene and limonene were the most abundant detected compounds. In September, alpha-pinene accounted for 22.5% of the total. Elevated CO(2) concentration in OTCs increased isoprene emission significantly in July (p<0.05) and September (p<0.05), while the total monoterpenes emission was enhanced in July and decreased in September by elevated CO(2). Exposed to elevated O(3) increased the isoprene and monoterpenes emissions in July and September, and the total volatile organic compounds emission rates were 0.48 microg g(-1) h(-1) (in July) and 2.24 microg g(-1) h(-1) (in September), respectively. The combination of elevated CO(2) and O(3) did not have any effect on biogenic volatile organic compounds emissions, except increases of isoprene and Delta3-carene in September.

Intense Vibronic Modulation of the Chiral Photoelectron Angular Distribution Generated by Photoionization of Limonene Enantiomers with Circularly Polarized Synchrotron Radiation.

PubMed

Rafiee Fanood, Mohammad M; Ganjitabar, Hassan; Garcia, Gustavo A; Nahon, Laurent; Turchini, Stefano; Powis, Ivan

2018-04-17

Photoionization of the chiral monoterpene limonene has been investigated using polarized synchrotron radiation between the adiabatic ionization threshold, 8.505 and 23.5 eV. A rich vibrational structure is seen in the threshold photoelectron spectrum and is interpreted using a variety of computational methods. The corresponding photoelectron circular dichroism-measured in the photoelectron angular distribution as a forward-backward asymmetry with respect to the photon direction-was found to be strongly dependent on the vibronic structure appearing in the photoelectron spectra, with the observed asymmetry even switching direction in between the major vibrational peaks. This effect can be ultimately attributed to the sensitivity of this dichroism to small phase shifts between adjacent partial waves of the outgoing photoelectron. These observations have implications for potential applications of this chiroptical technique, where the enantioselective analysis of monoterpene components is of particular interest. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Juniperus phoenicea var. turbinata (Guss.) Parl. Leaf Essential Oil Variability in the Balkans.

PubMed

Rajčević, Nemanja F; Labus, Marina G; Dodoš, Tanja Z; Novaković, Jelica J; Marin, Petar D

2018-06-15

In the present work leaf essential oil from 97 individuals of Juniperus phoenicea var. turbinata (GUSS.) PARL. from the Balkan Peninsula was analysed. The essential oil was dominated by monoterpene hydrocarbons (45.5 - 71.8%), of which α-pinene was the most abundant in almost all of the samples (38.2 - 55.8%). Several other monoterpenes and sesquiterpenes were also present in relatively high abundances in samples such as myrcene, δ-3-carene, ß-phellandrene, α-terpinyl acetate, (E)-caryophyllene and germacrene D. Multivariate statistical analysis suggested the existence of three possible chemotypes based on the abundance of the four components. Even though the intrapopulation variability was high, discriminant analysis (DA) was able to separate populations. DA showed high separation between western and eastern populations but also grouped geographically closer populations along the west Balkan shoreline. The potential influence of the climate on the composition of the essential oil was also studied. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

High-performance liquid chromatographic enantioseparation of monoterpene-based 2-amino carboxylic acids on macrocyclic glycopeptide-based phases.

PubMed

Sipos, László; Ilisz, István; Pataj, Zoltán; Szakonyi, Zsolt; Fülöp, Ferenc; Armstrong, Daniel W; Péter, Antal

2010-10-29

The enantiomers of five monoterpene-based 2-amino carboxylic acids were directly separated on chiral stationary phases containing macrocyclic glycopeptide antibiotics such as teicoplanin (Astec Chirobiotic T and T2) and teicoplanin aglycone (Chirobiotic TAG) as chiral selectors. The effects of pH, the mobile phase composition, the structure of the analyte and temperature on the separations were investigated. Experiments were performed at constant mobile phase compositions in the temperature range 10-40°C to study the effects of temperature and thermodynamic parameters on separations. Apparent thermodynamic parameters and T(iso) values were calculated from plots of ln k or ln α versus 1/T. Some mechanistic aspects of the chiral recognition process are discussed with respect to the structures of the analytes. It was found that the enantioseparations were in most cases enthalpy driven. The sequence of elution of the enantiomers was determined in all cases. Copyright © 2010 Elsevier B.V. All rights reserved.

Chemical Composition and Antioxidant Activity of Essential Oils from Cinnamodendron dinisii Schwacke and Siparuna guianensis Aublet

PubMed Central

Andrade, Milene Aparecida; Cardoso, Maria das Graças; de Andrade, Juliana; Silva, Lucilene Fernandes; Teixeira, Maria Luisa; Resende, Juliana Maria Valério; Figueiredo, Ana Cristina da Silva; Barroso, José Gonçalves

2013-01-01

The objectives of this study were to chemically characterize and evaluate the antioxidant activity of essential oils Cinnamodendron dinisii Schwacke (pepper) and Siparuna guianensis Aublet (negramina). The essential oil was isolated by hydrodistillation using a Clevenger modified apparatus, and the identification and quantification of constituents, through GC/MS and GC-FID analysis. The antioxidant activity was evaluated using β-carotene/linoleic acid system and the DPPH radical sequestering method. In chromatographic analysis, the majority constituents found in the essential oil of C. dinisii were bicyclic monoterpenes, α-pinene (35.41%), β-pinene (17.81%), sabinene (12.01%) and sesquiterpene bicyclogermacrene (7.59%). In the essential oil of the fresh leaves of Siparuna guianensis Aublet, acyclic monoterpene, β-myrcene (13.14%), and sesquiterpenes, germacrene-D (8.68%) and bicyclogermacrene (16.71%) were identified. The antioxidant activity was low by the β-carotene/linoleic acid test and was not evidenced by the DPPH test, for both oils evaluated. PMID:26784471

Variability of antioxidant and antibacterial effects of essential oils and acetonic extracts of two edible halophytes: Crithmum maritimum L. and Inula crithmoїdes L.

PubMed

Jallali, Ines; Zaouali, Yosr; Missaoui, Ibtissem; Smeoui, Abderrazek; Abdelly, Chedly; Ksouri, Riadh

2014-02-15

This work aimed to assess the richness of the food halophytes Crithmum maritimum and Inula crithmoїdes on phenolics and essential oils (EOs) and to evaluate the antioxidant and antibacterial potential of these metabolites. Results displayed that extract of I. crithmoїdes possesses considerable contents of phenolic compounds (14.1mg GAE.g⁻¹ DW) related to important antioxidant activities (IC₅₀ = 13 μg ml⁻¹ for the DPPH test) as compared to C. maritimum. C. maritimum EOs composition is dominated by oxygenated monoterpenes, while I. crithmoїdes one is mainly consisted by monoterpene hydrocarbons. EOs have low antioxidant activity as compared to acetone extracts; nevertheless, they show best antimicrobial activity. A significant variability is also depicted between the provenances of each species and depended on the chemical nature of antioxidant and antibacterial molecules as well as the used tests. Copyright © 2013 Elsevier Ltd. All rights reserved.

The in vitro and in vivo antiviral properties of combined monoterpene alcohols against West Nile virus infection.

PubMed

Pliego Zamora, Adriana; Edmonds, Judith H; Reynolds, Maxwell J; Khromykh, Alexander A; Ralph, Stephen J

2016-08-01

West Nile Virus (WNV) is a mosquito-borne flavivirus that can cause neuroinvasive disease in humans and animals for which no therapies are currently available. We studied an established combination of monoterpene alcohols (CMA) derived from Melaleuca alternifolia, against WNV infection. The in vitro results show that CMA exhibits virucidal activity, as well as reduces the viral titres and percentage of infected cells. The antiviral mechanism of action of CMA was studied. We found that CMA did not alter the intracellular pH, neither induced apoptosis, but did induce cell cycle arrest in the G0/G1-phase although that was not the antiviral mechanism. Furthermore, we tested CMA in vivo using IRF 3(-)(/)(-)/7(-/-)mice and it was found that CMA treatment significantly delayed morbidity due to WNV infection, reduced the loss of body weight and reduced the viral titres in brain. These findings suggest that CMA could be a therapeutic agent against WNV infection. Copyright © 2016 Elsevier Inc. All rights reserved.

A chemometrics as a powerful tool in the elucidation of the role of metals in the biosynthesis of volatile organic compounds in Hungarian thyme samples.

PubMed

Arsenijević, Jelena; Marković, Jelena; Soštarić, Ivan; Ražić, Slavica

2013-10-01

The volatile fraction of the leaves of Thymus pannonicus All. (Lamiaceae) was analyzed by headspace extraction followed by GC-FID and GC-MS analysis. The different headspace profiles were recognized, with citral and with monoterpene hydrocarbons as dominant compounds. In addition, the determination of Cr, Co, Ni, Mo, Cu, Zn, Mn, Fe, Mg, Ca, K and Na was conducted by spectroscopic techniques (FAAS, GFAAS and ICP-OES). In order to evaluate the relationship between volatile organic compounds and metals, a chemometrics approach was applied. The data obtained by analysis of the headspace and elemental content were subjected to correlation analysis, factor analysis, principal component analysis and cluster analysis. A number of significant correlations of metals with plant volatiles were found. Correlation of Zn with citral, Mn with oxygenated monoterpenes and Mg with β-bourbonene, could be explained by involvement of metals in the biosynthesis of volatile organic compounds. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Evolutionary Engineering Improves Tolerance for Replacement Jet Fuels in Saccharomyces cerevisiae

PubMed Central

Brennan, Timothy C. R.; Williams, Thomas C.; Schulz, Benjamin L.; Palfreyman, Robin W.; Nielsen, Lars K.

2015-01-01

Monoterpenes are liquid hydrocarbons with applications ranging from flavor and fragrance to replacement jet fuel. Their toxicity, however, presents a major challenge for microbial synthesis. Here we evolved limonene-tolerant Saccharomyces cerevisiae strains and sequenced six strains across the 200-generation evolutionary time course. Mutations were found in the tricalbin proteins Tcb2p and Tcb3p. Genomic reconstruction in the parent strain showed that truncation of a single protein (tTcb3p1-989), but not its complete deletion, was sufficient to recover the evolved phenotype improving limonene fitness 9-fold. tTcb3p1-989 increased tolerance toward two other monoterpenes (β-pinene and myrcene) 11- and 8-fold, respectively, and tolerance toward the biojet fuel blend AMJ-700t (10% cymene, 50% limonene, 40% farnesene) 4-fold. tTcb3p1-989 is the first example of successful engineering of phase tolerance and creates opportunities for production of the highly toxic C10 alkenes in yeast. PMID:25746998

Geraniol induces cooperative interaction of apoptosis and autophagy to elicit cell death in PC-3 prostate cancer cells.

PubMed

Kim, Su-Hwa; Park, Eun-Jung; Lee, Chae Ryun; Chun, Jung Nyeo; Cho, Nam-Hyuk; Kim, In-Gyu; Lee, Sanghoon; Kim, Tae Woo; Park, Hyun Ho; So, Insuk; Jeon, Ju-Hong

2012-05-01

Geraniol, an acyclic dietary monoterpene, suppresses prostate cancer growth and enhances docetaxel chemosensitivity in cultured cell or xenograft tumor models. However, the mechanisms of the geraniol action against prostate cancer are largely unknown. In this study, we investigated the cellular and molecular mechanisms of geraniol-induced cell death in PC-3 prostate cancer cells. Among the examined structurally and functionally similar monoterpenes, geraniol potently induced apoptosis and autophagy. Although independent processes, apoptosis and autophagy acted as cooperative partners to elicit geraniol-induced cell death in PC-3 cells. At a molecular level, geraniol inhibited AKT signaling and activated AMPK signaling, resulting in mTOR inhibition. Combined treatment of AKT inhibitor and AMPK activator markedly suppressed cell growth compared to either treatment alone. Our findings provide insight into future investigations that are aimed at elucidating the role of apoptosis and autophagy in prostate cancer therapy and at developing anticancer strategies co-targeting AKT and AMPK.

Chemical compositions and antioxidant/antimicrobial activities of various samples prepared from Schinus terebinthifolius leaves cultivated in Egypt.

PubMed

El-Massry, Khaled F; El-Ghorab, Ahmed H; Shaaban, Hamdy A; Shibamoto, Takayuki

2009-06-24

Essential oil, dichloromethane extract, and ethanol extract were prepared from fresh Schinus terebinthifolius leaves cultivated in Egypt. The essential oil was analyzed by gas chromatography and gas chromatography/mass spectrometry. The essential oil comprised 4.97% monoterpenes, 56.96% sesquiterpenes, 34.37% oxygenated monoterpenes, and 3.32% oxygenated sesquiterpenes. The major compounds in the essential oil were cis-beta-terpineol (GC peak area%, 17.87%), (E)-caryophyllene (17.56%), beta-cedrene (9.76%), and citronellal (7.03%). The major phenolic compounds identified in the ethanol extract were caffeic acid (5.07 mg/100 mg extract), coumaric acid (1.64 mg), and syringic acid (1.59 mg). The antioxidant activity of ethanol extract, which was comparable with that of butylhydroquinone, was superior to essential oil and dichloromethane extract in 2,2-diphenylpicrylhydrazyl and beta-carotene/bleaching assays. The dichloromethane extract exhibited the greatest antimicrobial activity against 6 strains, followed by the ethanol extract and the essential oil.

Borneol, a Bicyclic Monoterpene Alcohol, Reduces Nociceptive Behavior and Inflammatory Response in Mice

PubMed Central

Almeida, Jackson Roberto Guedes da Silva; Souza, Grasielly Rocha; Silva, Juliane Cabral; Saraiva, Sarah Raquel Gomes de Lima; Júnior, Raimundo Gonçalves de Oliveira; Quintans, Jullyana de Souza Siqueira; Barreto, Rosana de Souza Siqueira; Bonjardim, Leonardo Rigoldi; Cavalcanti, Sócrates Cabral de Holanda; Junior, Lucindo José Quintans

2013-01-01

Borneol, a bicyclic monoterpene, has been evaluated for antinociceptive and anti-inflammatory activities. Antinociceptive and anti-inflammatory activities were studied by measuring nociception by acetic acid, formalin, hot plate, and grip strength tests, while inflammation was prompted by carrageenan-induced peritonitis. The rotarod test was used to evaluate motor coordination. Borneol produced a significant (P < 0.01) reduction of the nociceptive behavior at the early and late phases of paw licking and reduced the writhing reflex in mice (formalin and writhing tests, resp.). When the hot plate test was conducted, borneol (in higher dose) produced an inhibition (P < 0.05) of the nociceptive behavior. Such results were unlikely to be provoked by motor abnormality. Additionally, borneol-treated mice reduced the carrageenan-induced leukocytes migration to the peritoneal cavity. Together, our results suggest that borneol possess significant central and peripheral antinociceptive activity; it has also anti-inflammatory activity. In addition, borneol did not impair motor coordination. PMID:23710149

Lavandula luisieri essential oil as a source of antifungal drugs.

PubMed

Zuzarte, M; Gonçalves, M J; Cruz, M T; Cavaleiro, C; Canhoto, J; Vaz, S; Pinto, E; Salgueiro, L

2012-12-01

This work reports the antifungal activity of Lavandula luisieri essential oils against yeast, dermatophyte and Aspergillus strains responsible for human infections and food contamination. The oil's cytotoxicity and its effect on the yeast-mycelium transition in Candida albicans, an important virulence factor, were also evaluated. Analyses by GC and GC/MS showed a peculiar composition of irregular monoterpenes. Significant differences between the samples occurred in the amounts of 1,8-cineole, fenchone and trans-α-necrodyl acetate. The oil with higher amounts of irregular monoterpenes was the most effective. The influence of the oils on the dimorphic transition in C. albicans was also studied through the germ tube inhibition assay. Filamentation was completely inhibited at concentrations sixteen times lower than the minimal inhibitory concentration. The results support the use of L. luiseiri essential oils in the development of new phytopharmaceuticals and food preservatives and emphasise its antifungal properties at concentrations not cytotoxic or with very low detrimental effects on mammalian cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

Eucalyptus oil-loaded microcapsules grafted to cotton fabrics for acaricidal effect against Dermatophagoides farinae.

PubMed

Kim, Joo Ran

2017-05-01

The purpose of this study was to develop acaricidal cotton fabrics grafted with eucalyptus oil-loaded microcapsules (EOMCs) produced from green resources. EOMCs showed a broad size distribution between 0.5 and 6.5 μm, and had the average diameter 1.8 μm. EOMCs exhibited nonporous spherical shapes and individually remained on cotton fibres. Through AATCC mortality tests against house dust mites (HDMs) (Dermatophagoides farinae), the treated cotton fabric containing EOMCs resulted in 98.7% mortality. Acaricidal efficiency was due to the large amount of oxygenated monoterpene, 1,8-eucalyptol (75.8%) and hydroxylated monoterpenes such as α-terpineol (3.6%), terpinen-4-ol (0.4%) and linalool (0.3%) found in eucalyptus oil. These compounds are effective in enhancing penetration into HDMs. EOMCs produced from safe and natural sources can serve as a replacement for synthetic acaricides in controlling the population of HDM, leading to positive impacts on the human health and environment.

Maize terpene volatiles serve as precursors to an array of defensive phytoalexins following insect and pathogen attack

USDA-ARS?s Scientific Manuscript database

Phytoalexins are inducible biochemicals that locally protect plant tissues against biotic attack. Due to their agronomic significance, maize and rice have been extensively investigated for their terpenoid-based defenses which include insect-inducible monoterpene and sesquiterpene vol...

Maize terpene volatiles serve as precursors to an array of defensive phytoalexins following insect and pathogen attack

USDA-ARS?s Scientific Manuscript database

Phytoalexins are inducible biochemicals that locally protect plant tissues against biotic attack. Due to their agronomic significance, maize and rice have been extensively investigated for their terpenoid-based defenses which include insect-inducible monoterpene and sesquiterpene volatiles. ...

NATURAL VOLATILE ORGANIC COMPOUND EMISSION RATE ESTIMATES FOR U.S. WOODLAND LANDSCAPES

EPA Science Inventory

Volatile organic compound (VOC) emission rate factors are estimated for 49 tree genera based on a review of foliar emission rate measurements. oliar VOC emissions are grouped into three categories: isoprene, monoterpenes and other VOC'S. ypical emission rates at a leaf temperatur...

Organic Nitrate Chemistry and Its Implications for Nitrogen Budgets in an Isoprene- and Monoterpene-Rich Atmosphere: Constraints From Aircraft (SEAC4RS) and Ground-Based (SOAS) Observations in the Southeast US

NASA Technical Reports Server (NTRS)

Fisher, Jenny; Jacob, D. J.; Travis, K. R.; Kim, P. S.; Marais, E. A.; Miller, C. Chan; Yu, K.; Zhu, L.; Yantosca, R. M.; Sulprizio, M. P.;

Functional Characterization of a 28-Kilobase Catabolic Island from Pseudomonas sp. Strain M1 Involved in Biotransformation of β-Myrcene and Related Plant-Derived Volatiles

PubMed Central

Soares-Castro, Pedro; Montenegro-Silva, Pedro; Heipieper, Hermann J.

2017-01-01

ABSTRACT Pseudomonas sp. strain M1 is able to mineralize highly hydrophobic and recalcitrant compounds, such as benzene, phenol, and their methylated/halogenated derivatives, as well as the backbone of several monoterpenes. The ability to use such a spectrum of compounds as the sole carbon source is, most probably, associated with a genetic background evolved under different environmental constraints. The outstanding performance of strain M1 regarding β-myrcene catabolism was elucidated in this work, with a focus on the biocatalytical potential of the β-myrcene-associated core code, comprised in a 28-kb genomic island (GI), predicted to be organized in 8 transcriptional units. Functional characterization of this locus with promoter probes and analytical approaches validated the genetic organization predicted in silico and associated the β-myrcene-induced promoter activity to the production of β-myrcene derivatives. Notably, by using a whole-genome mutagenesis strategy, different genotypes of the 28-kb GI were generated, resulting in the identification of a novel putative β-myrcene hydroxylase, responsible for the initial oxidation of β-myrcene into myrcen-8-ol, and a sensor-like regulatory protein, whose inactivation abolished the myr+ trait of M1 cells. Moreover, it was demonstrated that the range of monoterpene substrates of the M1 enzymatic repertoire, besides β-myrcene, also includes other acyclic (e.g., β-linalool) and cyclic [e.g., R-(+)-limonene and (−)-β-pinene] molecules. Our findings are the cornerstone for following metabolic engineering approaches and hint at a major role of the 28-kb GI in the biotransformation of a broad monoterpene backbone spectrum for its future biotechnological applications. IMPORTANCE Information regarding microbial systems able to biotransform monoterpenes, especially β-myrcene, is limited and focused mainly on nonsystematic metabolite identification. Complete and detailed knowledge at the genetic, protein, metabolite, and regulatory levels is essential in order to set a model organism or a catabolic system as a biotechnology tool. Moreover, molecular characterization of reported systems is scarce, almost nonexistent, limiting advances in the development of optimized cell factories with strategies based on the new generation of metabolic engineering platforms. This study provides new insights into the intricate molecular functionalities associated with β-myrcene catabolism in Pseudomonas, envisaging the production of a molecular knowledge base about the underlying catalytic and regulatory mechanisms of plant-derived volatile catabolic pathways. PMID:28213543

Measurement of monoterpenes and sesquiterpenes in serum, plasma, and rumen fluid from sheep

USDA-ARS?s Scientific Manuscript database

Studies involving the consumption, metabolism, and elimination of terpenes by small ruminants consuming terpene-laden shrubs as well as those exploring the potential for natural products as rumen modifiers could benefit from a procedure that measures terpenes in both blood and rumen fluid and that i...

Pheromones in White Pine Cone Beetle, Conophthorus coniperdu (Schwarz) (Coleoptera: Scolytidae)

Treesearch

Goran Birgersson; Gary L. DeBarr; Peter de Groot; Mark J. Dalusky; Harold D. Pierce; John H. Borden; Holger Meyer; Wittko Francke; Karl E. Espelie; C. Wayne Berisford

1995-01-01

Female white pine cone beetles, Conophrhorus coniperda, attacking second-year cones of eastern white pine, Pinus strobus L., produced a sex-specific pheromone that attracted conspecific males in laboratory bioassays and to field traps. Beetle response was enhanced by host monoterpenes. The female-produced compound was identified in...

Multi-Season Monoterpene and Sesquiterpene Analysis of Pinus taeda Needle Tissue

EPA Science Inventory

Pinus taeda (Loblolly pine) is one of the worlds most important timber crop and accounts for a significant portion of the southeastern U.S. landcover. Biogenic voltile organic compound (BVOC) content was extracted from the tissue material of P. taeda needles and analyzed over a m...

[Regulation of terpene metabolism]. [Mentha piperita, Mentha spicata

DOE Office of Scientific and Technical Information (OSTI.GOV)

Croteau, R.

1989-01-01

Progress in understanding of the metabolism of monoterpenes by peppermint and spearmint is recorded including the actions of two key enzymes, geranyl pyrophosphate:limonene cyclase and a UDP-glucose dependent glucosyl transferase; concerning the ultrastructure of oil gland senescence; enzyme subcellular localization; regulation of metabolism; and tissue culture systems.

Large Drought-Induced Variations in Oak Leaf Volatile Organic Compound Emissions during PINOT NOIR 2012

EPA Science Inventory

Leaf-level isoprene and monoterpene emissions were collected and analyzed from five of the most abundant oak (Quercus) species in Central Missouri’s Ozarks Region in 2012 during PINOT NOIR (Particle Investigations at a Northern Ozarks Tower ‐ NOx, Oxidants, Isoprene Research). Ju...

The terpene synthase gene family in Tripterygium wilfordii harbors a labdane-type diterpene synthase among the monoterpene synthase TPS-b subfamily.

PubMed

Hansen, Nikolaj L; Heskes, Allison M; Hamberger, Britta; Olsen, Carl E; Hallström, Björn M; Andersen-Ranberg, Johan; Hamberger, Björn

2017-02-01

Tripterygium wilfordii (Celastraceae) is a medicinal plant with anti-inflammatory and immunosuppressive properties. Identification of a vast array of unusual sesquiterpenoids, diterpenoids and triterpenoids in T. wilfordii has spurred investigations of their pharmacological properties. The tri-epoxide lactone triptolide was the first of many diterpenoids identified, attracting interest due to the spectrum of bioactivities. To probe the genetic underpinning of diterpenoid diversity, an expansion of the class II diterpene synthase (diTPS) family was recently identified in a leaf transcriptome. Following detection of triptolide and simple diterpene scaffolds in the root, we sequenced and mined the root transcriptome. This allowed identification of the root-specific complement of TPSs and an expansion in the class I diTPS family. Functional characterization of the class II diTPSs established their activities in the formation of four C-20 diphosphate intermediates, precursors of both generalized and specialized metabolism and a novel scaffold for Celastraceae. Functional pairs of the class I and II enzymes resulted in formation of three scaffolds, accounting for some of the terpenoid diversity found in T. wilfordii. The absence of activity-forming abietane-type diterpenes encouraged further testing of TPSs outside the canonical class I diTPS family. TwTPS27, close relative of mono-TPSs, was found to couple with TwTPS9, converting normal-copalyl diphosphate to miltiradiene. The phylogenetic distance to established diTPSs indicates neo-functionalization of TwTPS27 into a diTPS, a function not previously observed in the TPS-b subfamily. This example of evolutionary convergence expands the functionality of TPSs in the TPS-b family and may contribute miltiradiene to the diterpenoids of T. wilfordii. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

Caledonian scots pine: origins and genetic structure

Treesearch

Bohun B Kinloch; R. D. Westfall; G. I. Forrest

1986-01-01

Monoterpene and isozyme loci, used as markers to study the genetic structure of Scots pine (Pinus sylvestris L.) native to Scotland, showed that the endemic populations are not genetically impoverished, in spite of severe contraction in range and numbers as a result of both natural and anthropogenic causes. On the contrary, variability in the relict...

Pinus ponderosa: a taxonomic review with five subspecies in the United States

Treesearch

Robert Z. Callaham

2013-01-01

Various forms of Pinus ponderosa Douglas ex C. Lawson are found from British Columbia southward and eastward through 16 states and, perhaps, into Mexico. The status of many names previously associated with this species, but excluded here, has been clarified. Accumulated evidence based on variation in morphology and xylem monoterpenes,...

Deployment of deer-resistant western redcedar (Thuja plicata)

Treesearch

John Russell

2008-01-01

Protecting planted western redcedar (Thuja plicata) seedlings from deer browse in the Pacific Northwest and British Columbia is estimated to cost up to CAN$ 25 million annually. Recent studies linking deer browse and needle monoterpenes has resulted in the initiation of a breeding program for deer-resistant western redcedar at Cowichan Lake Research...

Oligomeric secoiridoid glucosides from Jasminum abyssinicum.

PubMed

Gallo, Francesca Romana; Palazzino, Giovanna; Federici, Elena; Iurilli, Raffaella; Monache, Franco Delle; Chifundera, Kusamba; Galeffi, Corrado

2006-03-01

From the root bark of Jasminum abyssinicum (Oleaceae) collected in Congo was isolated tree oligomeric secoiridoid glucosides named craigosides A-C. The three compounds are esters of a cyclopentanoid monoterpene with an iridane skeleton, esterified with three, two and two, respectively, units of oleoside 11-methyl ester. The structures were elucidated by spectroscopic methods and chemical correlations.

Wood and Chemistry – or How to Combine Bob Heath's Two Passions into Entomology Research

USDA-ARS?s Scientific Manuscript database

Plants generally produce complex mixtures of terpenoids that may differ greatly among species. Terpenoids, such C10 monoterpenes and C15 sesquiterpenes, are known to play an important role in the biology and ecology of plants, directly or indirectly influencing their interactions with their biotic e...

ß-Phellandrene: Kairomone for Pine Engraver, Ips pini (Say) (Coleoptera: Scolytidae)

Treesearch

Daniel R. Miller; John H. Borden

1990-01-01

The responses of Ips pini (Scolytidae) to multiple-funnel traps baited with the pheromone, ipsdienol, and various monoterpenes were determined in stands of lodgepole pine in southern and central British Columbia. Ips pini was attracted to both ipsdienol and ß-phellandrene, demonstrating that ß-phellandrene is a kairomone for this...

A novel Arometic compound acts synergistically with a naturally occurring monoterpene to elicit strong behavioral responses in Asian citrus psyllid

USDA-ARS?s Scientific Manuscript database

Inscent, Inc. has developed methodologies for rapidly screening potential ligands of chemosensory proteins (CSPs) isolated from the antennae of target insects. These novel ligands, referred to as Arometics, mimic naturally-occurring odorants and may function as super-stimuli because of their strong ...

Applying photosynthesis research to increase crop yields

Treesearch

Clayton C. Black; Shi-Jean S. Sung; Kristina Toderich; Pavel Yu Voronin

2010-01-01

This account is dedicated to Dr. Guivi Sanadze for his career long devotion to science and in recognition of his discovery of isoprene emission by trees during photosynthesis. Investigations on the emission of isoprene and other monoterpenes now have been extended globally to encompass other terrestrial vegetation, algae, waters, and marine life in the world's...

Canopy Level Emissions of 2-methyl-3-buten-2-ol, monoterpenes, and sesquiterpenes from a Pinus taeda Experimental Plantation

EPA Science Inventory

Emissions of biogenic volatile organic compounds (BVOC) observed during 2007 from a Pinus taeda experimental plantation in Central North Carolina are compared with model estimates from MEGAN 2.1. Relaxed Eddy Accumulation (REA) estimates of 2-methyl-3-buten-2-ol (MBO) fluxes are ...

ESTIMATES OF REGIONAL NATURAL VOLATILE ORGANIC COMPOUND FLUXES FROM ENCLOSURE AND AMBIENT MEASUREMENTS

EPA Science Inventory

The paper discusses results of an investigation at two forested sites in the Southeastern United States. A variety of VOC compounds including methanol, 2-methyl-3-buten-2-ol, 6-methyl-5-hepten-
2-one, isoprene, and 15 monoterpenes were emitted from vegetation at these sites. D...

[Regulation of terpene metabolism]. Annual progress report, March 15, 1988--March 14, 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Croteau, R.

1989-12-31

Progress in understanding of the metabolism of monoterpenes by peppermint and spearmint is recorded including the actions of two key enzymes, geranyl pyrophosphate:limonene cyclase and a UDP-glucose dependent glucosyl transferase; concerning the ultrastructure of oil gland senescence; enzyme subcellular localization; regulation of metabolism; and tissue culture systems.

IDENTIFICATION AND QUANTIFICATION OF AEROSOL POLAR OXYGENATED COMPOUNDS BEARING CARBOXYLIC OR HYDROXYL GROUPS. 2. ORGANIC TRACER COMPOUNDS FROM MONOTERPENES

EPA Science Inventory

A comparison was made of polar organic compounds found in the field with those produced in secondary organic aerosol from laboratory irradiations of natural hydrocarbons and oxides of nitrogen. The field samples comprised atmospheric particulate matter (PM_2.5) collect...

Enhancing monoterpene alcohols in sweet potato shochu using the diglycoside-specific β-primeverosidase.

PubMed

Sato, Yuichiro; Han, Jinshun; Fukuda, Hisashi; Mikami, Shigeaki

2018-02-01

Monoterpene alcohols (MTAs) are characteristic flavour-imparting compounds in sweet potato shochu (Japanese distilled spirit) that are liberated following hydrolysis by specific enzymes during fermentation. In the present study, we evaluated the effect of an exogenously added diglycoside-specific β-glycosidase (β-primeverosidase) on aroma formation during shochu brewing using various sweet potato species to address whether MTAs are predominantly present as diglycosidic precursors in raw materials. The results showed that the amount of MTAs produced from enzyme-treated mash was dramatically increased by 2- to 9-fold compared with untreated controls, and the increase varied with sweet potato species. In addition, levels of methyl salicylate, 1-octene-3-ol and ethyl benzoate were also elevated by enzyme treatment. These results indicate that a large amount of MTAs and other volatile aroma compounds are stored in the form of disaccharide β-glycosides such as β-primeverosides in sweet potato. This enzyme may therefore be useful for controlling aroma formation during shochu manufacturing, and may ultimately contribute to diversifying shochu quality. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Rice terpene synthase 24 (OsTPS24) encodes a jasmonate-responsive monoterpene synthase that produces an antibacterial γ-terpinene against rice pathogen.

PubMed

Yoshitomi, Kayo; Taniguchi, Shiduku; Tanaka, Keiichiro; Uji, Yuya; Akimitsu, Kazuya; Gomi, Kenji

2016-02-01

Rice is one of the most important crops worldwide and is widely used as a model plant for molecular studies of monocotyledonous species. The plant hormone jasmonic acid (JA) is involved in rice-pathogen interactions. In addition, volatile compounds, including terpenes, whose production is induced by JA, are known to be involved in the rice defense system. In this study, we analyzed the JA-induced terpene synthase OsTPS24 in rice. We found that OsTPS24 was localized in chloroplasts and produced a monoterpene, γ-terpinene. The amount of γ-terpinene increased after JA treatment. γ-Terpinene had significant antibacterial activity against Xanthomonas oryzae pv. oryzae (Xoo); however, it did not show significant antifungal activity against Magnaporthe oryzae. The antibacterial activity of the γ-terpinene against Xoo was caused by damage to bacterial cell membranes. These results suggest that γ-terpinene plays an important role in JA-induced resistance against Xoo, and that it functions as an antibacterial compound in rice. Copyright © 2015 Elsevier GmbH. All rights reserved.

Cytotoxic halogenated monoterpenes from Plocamium cartilagineum.

PubMed

Sabry, Omar M M; Goeger, Douglas E; Valeriote, Frederick A; Gerwick, William H

2017-02-01

As a result of our efforts to identify bioactive agents from marine algae, we have isolated and identified one new halogenated monoterpene 1 [(-)-(5E,7Z)-348-trichloro-7-dichloromethyl-3-methyl-157-octatriene] in addition to three known compounds (2, 3 and 4) from the red alga Plocamium cartilagineum collected by hand from the eastern coast of South Africa. Compound 1 was found to be active as a cytotoxic agent in human lung cancer (NCI-H460) and mouse neuro-2a cell lines (IC 50 4 μg/mL). Two of these compounds (3 and 4) were found to have cytotoxic activity in other cell line assays, especially against human leukaemia and human colon cancers (IC 50 1.3 μg/mL). None of these metabolites were active as sodium channel blockers or activators. All structures were determined by spectroscopic methods (UV, IR, LRMS, HRMS, 1D NMR and 2D NMR). 1D and 2D NOE experiments were carried out on these compounds to confirm the geometry of the double bonds.

Chemical composition and biological activities of leaf and fruit essential oils from Eucalyptus camaldulensis.

PubMed

Dogan, Gulden; Kara, Nazan; Bagci, Eyup; Gur, Seher

2017-10-26

The chemical composition of the essential oils from the leaves and fruit of Eucalyptus camaldulensis grown in Mersin, Turkey was analyzed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques. The biological activities (antibacterial and antifungal) were examined using the agar well diffusion method. The main leaf oil constituents were p-cymene (42.1%), eucalyptol (1,8-cineole) (14.1%), α-pinene (12.7%) and α-terpinol (10.7%). The main constituents of the fruit oil were eucalyptol (1,8-cineole) (34.5%), p-cymene (30.0%), α-terpinol (15.1%) and α-pinene (9.0%). Our results showed that both types of oils are rich in terms of monoterpene hydrocarbons and oxygenated monoterpenes. The leaf and fruit essential oils of E. camaldulensis significantly inhibited the growth of Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Streptococcus sp.) bacteria (p<0.05). The oils also showed fungicidal activity against Candida tropicalis and C. globrata. Leaf essential oils showed more activity than fruit essential oils, probably due to the higher p-cymene concentration in leaves.

Biomimetic synthesis, antimicrobial, antileishmanial and antimalarial activities of euglobals and their analogues.

PubMed

Bharate, Sandip B; Bhutani, Kamlesh K; Khan, Shabana I; Tekwani, Babu L; Jacob, Melissa R; Khan, Ikhlas A; Singh, Inder Pal

2006-03-15

In the present communication, naturally occurring phloroglucinol-monoterpene adducts, euglobals G1-G4 (3b/a and 4a/b) and 16 new analogues (13a/b-18a/b and 19-22) were synthesized by biomimetic approach. These synthetic compounds differ from natural euglobals in the nature of monoterpene and acyl functionality. All of these compounds were evaluated for their antibacterial, antifungal, antileishmanial and antimalarial activities. Analogue 17b possessed good antibacterial activity against methicillin-resistant Staphylococcus aureus, while analogues 19-22 possessed potent antifungal activity against Candida glabrata with IC50s ranging from 1.5 to 2.5 microg/mL. Euglobals along with all synthesized analogues exhibited antileishmanial activity. Amongst these, euglobal G2 (3a), G3 (4a) and analogues 13a and 14a showed potent antileishmanial activity with IC50s ranging from 2.8 to 3.9 microg/mL. Analogue 16a possessed antimalarial activity against chloroquine sensitive D6 clone of Plasmodium falciparum. None of the compounds showed toxicity against mammalian kidney fibroblasts (vero cells) upto the concentration of 4.76 microg/ml.

Laboratory and field studies of biogenic volatile organic compound emissions from Sitka spruce (Picea sitchensis Bong.) in the United Kingdom

NASA Astrophysics Data System (ADS)

Street, Rachel A.; Duckham, S. Craig; Hewitt, C. Nicholas

1996-10-01

Isoprene and monoterpene emission rates were measured from Sitka spruce (Picea sitchensis Bong.) with a dynamic flow-through branch enclosure, both in the laboratory and in the field in the United Kingdom. In the laboratory, emission rates of isoprene comprised over 94% of the identified VOC species, and were exponentially related to temperature over a period of 1 day. This exponential relationship broke down at ˜33°C. Field measurements were taken on five sampling days in 1992 and 1993, in Grizedale Forest, Cumbria. Total emission rates were in the range 36-3771 ng g-1 h-1. Relative emissions were more variable than suggested by laboratory measurements, with monoterpenes contributing at least 64% to the total emissions in most cases. There was a significant variation in the basal emission rate both across the growing season and between different ages of vegetation, the causes of which are as yet unknown. Total emission rates, in July 1993, were estimated to be between 0.01 and 0.27% of assimilated carbon.

Anaerobic utilization of essential oils by denitrifying bacteria.

PubMed

Harder, J; Heyen, U; Probian, C; Foss, S

2000-01-01

Plant volatile organic compounds are a major carbon source in nature. We studied the degradability of these substances by anaerobic microorganisms in enrichment cultures with representative essential oils as organic substrates and nitrate as electron acceptor. Lemon and pine needle oil supported microbial growth in the presence of pure oil, whereas parsley seed, camphor, sage, fennel, and mint oil supported growth only when the essential oils were dissolved in an overlying phase of 2,2,4,4,6,8,8-heptamethylnonane. Thyme oil did not support denitrification. Analyses of the microbially degraded oils revealed the disappearance of monoterpenes, of several monoterpenoids, and of methoxy-propenyl-benzenes, including apiole and myristicin. Most-probable-number determinations for denitrifying communities in sewage sludge and forest soil yielded 10(6) to 10(7) monoterpene-utilizing cells ml(-1), representing 0.7 to 100% of the total cultivable nitrate-reducing microorganisms. The utilization of essential oils together with the common occurrence of this metabolic trait are indications for an environmentally important, but currently unexplored anaerobic turnover of plant volatile organic compounds in soil.

Secondary Organic Aerosol Formation and Organic Nitrate Yield from NO 3 Oxidation of Biogenic Hydrocarbons

DOE PAGES

Fry, Juliane L.; Draper, Danielle C.; Barsanti, Kelley C.; ...

2014-09-17

Here, the secondary organic aerosol (SOA) mass yields from NO 3 oxidation of a series of biogenic volatile organic compounds (BVOCs), consisting of five monoterpenes and one sesquiterpene (α-pinene, β-pinene, Δ-3-carene, limonene, sabinene, and β-caryophyllene), were investigated in a series of continuous flow experiments in a 10 m 3 indoor Teflon chamber. By making in situ measurements of the nitrate radical and employing a kinetics box model, we generate time-dependent yield curves as a function of reacted BVOC. SOA yields varied dramatically among the different BVOCs, from zero for α-pinene to 38–65% for Δ-3-carene and 86% for β-caryophyllene at massmore » loading of 10 μg m –3, suggesting that model mechanisms that treat all NO 3 + monoterpene reactions equally will lead to errors in predicted SOA depending on each location’s mix of BVOC emissions. In most cases, organonitrate is a dominant component of the aerosol produced, but in the case of α-pinene, little organonitrate and no aerosol is formed.« less

Effects of seasonal changes in feeding management under part-time grazing on terpene concentrations of ewes' milk.

PubMed

Abilleira, Eunate; Virto, Mailo; Nájera, Ana Isabel; Albisu, Marta; Pérez-Elortondo, Francisco José; Ruiz de Gordoa, Juan Carlos; de Renobales, Mertxe; Barron, Luis Javier R

2011-05-01

Terpene composition of ewes' raw milk from nine commercial flocks was analysed from February to July. Ewes' diet consisted of concentrate and conserved forage in winter (indoor feeding) and part-time grazing from spring (transition and outdoor feeding). Regardless of the feeding, limonene and β-phellandrene were the most abundant monoterpenes and β-caryophyllene showed the highest concentrations among sesquiterpenes. Terpene content increased in the milks of commercial flocks when animals were reared under grazing management. Monoterpenes were detected in the milks of all the commercial flocks throughout the season, whereas sesquiterpenes were only detected in the milks from flocks grazing on non-cultivated community-owned grasslands in which a higher biodiversity of plant species grew. These preliminary results indicated that β-caryophyllene could be a potential pasture-diet marker in the case of milks from animals grazing a higher biodiversity of plant species but in-depth studies including information on terpene composition of plants ingested by the animals are necessary to evaluate the suitability of β-caryophyllene or another terpenoid compound as pasture biomarker.

Evaluation of seasonal chemical composition, antibacterial, antioxidant and anticholinesterase activity of essential oil from Eugenia brasiliensis Lam.

PubMed

Siebert, Diogo Alexandre; Tenfen, Adrielli; Yamanaka, Celina Noriko; de Cordova, Caio Maurício Mendes; Scharf, Dilamara Riva; Simionatto, Edésio Luiz; Alberton, Michele Debiasi

2015-02-01

This study describes the seasonal composition and the antibacterial, antioxidant and anticholinesterase activity of the essential oil from Eugenia brasiliensis leaves. Analysis by using GC allowed the identification of 40 compounds. It was observed that the monoterpenes varied more (42%) than the sesquiterpenes (14%), and that the monoterpene hydrocarbons suffered the greatest variation throughout the year (64%). Major compounds were spathulenol in the spring (16.02 ± 0.44%) and summer (18.17 ± 0.41%), τ-cadinol in the autumn (12.83 ± 0.03%) and α-pinene (15.94 ± 0.58%) in the winter. Essential oils were tested for their antibacterial activity, and the best result was obtained from the autumn oil, with MIC = 500 μg mL(- 1) against Staphylococcus saprophyticus and Pseudomonas aeruginosa. Antioxidant activity was evaluated using DPPH, lipid peroxidation and iron-reducing power assays, as well as the anticholinesterase activity. Both tests showed a weak performance of the essential oils.

Composition and antimicrobial activities of Lippia multiflora Moldenke, Mentha x piperita L. and Ocimum basilicum L. essential oils and their major monoterpene alcohols alone and in combination.

PubMed

Bassolé, Imaël Henri Nestor; Lamien-Meda, Aline; Bayala, Balé; Tirogo, Souleymane; Franz, Chlodwig; Novak, Johannes; Nebié, Roger Charles; Dicko, Mamoudou Hama

2010-11-03

Essential oils from leaves of Lippia multiflora, Mentha x piperita and Ocimum basilicum from Burkina Faso were analysed by GC-FID and GC-MS. Major components were p-cymene, thymol, b-caryophyllene, carvacrol and carvone for L. multiflora, menthol and iso-menthone for M. x piperita and, linalool and eugenol for O. basilicum. The essential oils and their major monoterpene alcohols were tested against nine bacterial strains using the disc diffusion and broth microdilution methods. The essential oils with high phenolic contents were the most effective antimicrobials. The checkerboard method was used to quantify the efficacy of paired combinations of essential oils and their major components. The best synergetic effects among essential oils and major components were obtained with combinations involving O. basilicum essential oil and eugenol, respectively. As phenolic components are characterized by a strong spicy aroma, this study suggests that the selection of certain combinations of EOs could help to reduce the amount of essential oils and consequently reduce any adverse sensory impact in food.

Chemical composition and antibacterial activity of essential oil from fruit of Micromelum integerrimum (Buch.-Ham. ex DC.) Wight & Arn. ex M. Roem.

PubMed

Kotoky, Rumi; Bordoloi, Manobjyoti; Yadav, Archana; Tamuli, Kashyap J; Saikia, Surovi; Dutta, Partha P; Khound, Prodip P; Saikia, Siddhartha P

2018-06-13

The essential oil extracted from fruit of Micromelum integrrimum were evaluated through gas chromatography and gas chromatography-mass spectroscopy. 52 compounds were identified from the fruit oil representing 99.98% of the oil. The major components of the total fruit oil are monoterpene hydrocarbons (72.23%), oxygenated monoterpenes (14.78%) and sesquiterpene (11.54%) which were predominated by terpinolene (32.21%), α-pinene (17.24%), β-pinene (17.24%), and camphene (4.05%). Moreover, other components that present in 1.45% were aromatic compounds, fatty acid, etc. The essential oil exhibited broad spectrum antimicrobial activity which is concentration dependent and 100 μL of the fruit oil showed the inhibition zones ranging from 7-16 mm. Fruit oil exhibited strong inhibition activity compared to standard anti-bacterial drug neomycin B (22 mm) against Bacillus subtilis MTCC 441 and Bacillus spizizenii ATCC 6633. This is the first hand report on the chemical profiles and promising anti-microbial activity of Micromelum integrrimum fruit essential oil towards Basillus Sp.

Secondary Organic Aerosol Formation and Organic Nitrate Yield from NO3 Oxidation of Biogenic Hydrocarbons

PubMed Central

2014-01-01

The secondary organic aerosol (SOA) mass yields from NO3 oxidation of a series of biogenic volatile organic compounds (BVOCs), consisting of five monoterpenes and one sesquiterpene (α-pinene, β-pinene, Δ-3-carene, limonene, sabinene, and β-caryophyllene), were investigated in a series of continuous flow experiments in a 10 m3 indoor Teflon chamber. By making in situ measurements of the nitrate radical and employing a kinetics box model, we generate time-dependent yield curves as a function of reacted BVOC. SOA yields varied dramatically among the different BVOCs, from zero for α-pinene to 38–65% for Δ-3-carene and 86% for β-caryophyllene at mass loading of 10 μg m–3, suggesting that model mechanisms that treat all NO3 + monoterpene reactions equally will lead to errors in predicted SOA depending on each location’s mix of BVOC emissions. In most cases, organonitrate is a dominant component of the aerosol produced, but in the case of α-pinene, little organonitrate and no aerosol is formed. PMID:25229208

Effect of geraniol on rat cardiomyocytes and its potential use as a cardioprotective natural compound.

PubMed

Crespo, R; Wei, K; Rodenak-Kladniew, B; Mercola, M; Ruiz-Lozano, P; Hurtado, C

2017-03-01

Reactive oxygen species (ROS) are generated in the ischaemic myocardium especially during early reperfusion and affect myocardial function and viability. Monoterpenes have been proposed to play beneficial roles in diverse physiological systems; however, the mechanisms of action remain largely unknown. This study aims to assess the effect of monoterpene geraniol (GOH) on neonatal rat ventricular cardiomyocytes (NRVCs) subjected to oxidative stress. We used an in vitro model of hypoxia-reoxygenation. Cardioprotective (AMPK) and cardiotoxic (ERK1/2, ROS) signaling indicators were measured. Assays were performed by fluorogenic probes, MTT assays and Western-blots. We determined that the addition of GOH (5-200μM) to cultured normoxic and hypoxic-NRVCs diminished the endogenous production of ROS in stressed cardiomyocytes. We observed that GOH treatment increased pAMPK levels and decreased pERK1/2 levels in cultured NRVCs. This report suggests that GOH is a candidate cardioprotective natural compound that operates by blunting the oxidative stress signaling that is normally induced by hypoxia-reoxygenation. Copyright © 2017 Elsevier Inc. All rights reserved.

Evolution of Volatile Emission in Rhus coriaria Organs During Different Stages of Growth and Evaluation of the Essential Oil Composition.

PubMed

Reidel, Rose Vanessa Bandeira; Cioni, Pier Luigi; Majo, Luigi; Pistelli, Luisa

2017-11-01

Rhus coriaria, also known as Sumac, has been traditionally used in many countries as spice, condiment, dying agent, and medicinal herb. The chemical composition of essential oils (EOs) and the volatile emissions from different organs of this species collected in Sicily (Italy) were analyzed by gas chromatography-flame ionization detection and gas chromatography/mass spectrometry. Monoterpene and sesquiterpene hydrocarbons were the most abundant class in the volatile emissions with β-caryophyllene and α-pinene were the main constituents in the majority of the examined samples. The EO composition was characterized by high amount of monoterpene and sesquiterpene hydrocarbons together with diterpenes. The main compounds in the EO obtained from the leaves and both stages of fruit maturation were cembrene and β-caryophyllene, while α-pinene and tridecanoic acid were the key compounds in the flower EO. All the data were submitted to multivariate statistical analysis showing many differences among the different plant parts and their ontogenetic stages. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Phytochemical variation among the traditional Chinese medicine Mu Dan Pi from Paeonia suffruticosa (tree peony).

PubMed

Li, Shan-Shan; Wu, Qian; Yin, Dan-Dan; Feng, Cheng-Yong; Liu, Zheng-An; Wang, Liang-Sheng

2018-02-01

Mu Dan Pi is a traditional Chinese medicine used to treat inflammation, cancer, allergies, diabetes, angiocardiopathy, and neurodegenerative diseases. In this study, the metabolome variation within Mu Dan Pi collected from 372 tree peony cultivars was systematically investigated. In total, 42 metabolites were identified, comprising of 14 monoterpene glucosides, 11 tannins, 8 paeonols, 6 flavonoids, and 3 phenols. All cultivars revealed similar metabolite profiles, however, they were further classified into seven groups on the basis of their varying metabolite contents by hierarchical cluster analysis. Traditional cultivars for Mu Dan Pi were found to have very low metabolite contents, falling into clusters I and II. Cultivars with the highest amounts of metabolites were grouped in clusters VI and VII. Five potential cultivars, namely, 'Bai Yuan Qi Guan', 'Cao Zhou Hong', 'Da Zong Zi', 'Sheng Dan Lu', and 'Cheng Xin', with high contents of monoterpene glycosides, tannins, and paeonols, were further screened. Interestingly, the majority of investigated cultivars had relatively higher metabolite contents compared to the traditional medicinal tree peony cultivars. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of soil application of humic acid on nutrients uptake, essential oil and chemical compositions of garden thyme (Thymus vulgaris L.) under greenhouse conditions.

PubMed

Noroozisharaf, Alireza; Kaviani, Maryam

2018-05-01

Humic acid is natural biological organic, which has a high effect on plant growth and quality. However, the mechanisms of the promoting effect of humic acid on the volatile composition were rarely reported. In this study, the effects of soil application of humic acid on the chemical composition and nutrients uptake of Thymus vulgaris were investigated. Treatments comprised 0, 50, 75 and 100 g m -2 . Essential oil was extracted by hydrodistillation and analyzed using GC-MS and GC-FID. Essential oil content was enhanced by increase of the humic acid level and its content ranged from 0.8% (control) to 2.0% (75 g m -2 ). Thirty-two volatile compounds were identified and these compounds were considerably affected by humic acid. The highest percentage of thymol (74.15%), carvacrol (6.20%), p -cymene (4.24%), borneol (3.42%), trans -caryophyllene (1.70%) and cis -sabinene hydrate (1.35%) as major compounds were observed in T. vulgaris under 100 g m -2 humic acid. There was a linear relationship ( R 2  = 97%) between humic acid levels and thymol as a major compound. The oils were dominated by oxygenated monoterpenes followed by monoterpene hydrocarbons and sesquiterpene hydrocarbons. Based on the path coefficient analysis, the highest direct effects on essential oil content were observed in monoterpene esters (3.465) and oxygenated sesquiterpenes (3.146). The humic acid application also enhanced the uptake of N, P, K, Mg and Fe in garden thyme. The highest N (2.42%), P (0.75%), K (2.63%), Mg (0.23%) and Fe (1436.58 ppm) were observed in medium supplemented with 100 g m -2 humic acid. In all, the utilization of humic acid could positively change nutrients uptake, essential oil content and its major constituents in T. vulgaris .

Leaf level emissions of volatile organic compounds (VOC) from some Amazonian and Mediterranean plants

NASA Astrophysics Data System (ADS)

Bracho-Nunez, A.; Knothe, , N. M.; Welter, S.; Staudt, M.; Costa, W. R.; Liberato, M. A. R.; Piedade, M. T. F.; Kesselmeier, J.

2013-09-01

Emission inventories defining regional and global biogenic volatile organic compounds (VOC) emission strengths are needed to determine the impact of VOC on atmospheric chemistry (oxidative capacity) and physics (secondary organic aerosol formation and effects). The aim of this work was to contribute with measurements of tree species from the poorly described tropical vegetation in direct comparison with the quite well-investigated, highly heterogeneous emissions from Mediterranean vegetation. VOC emission from sixteen plant species from the Mediterranean area were compared with twelve plant species from different environments of the Amazon basin by an emission screening at leaf level using branch enclosures. Analysis of the volatile organics was performed online by a proton-transfer-reaction mass spectrometer (PTR-MS) and offline by collection on adsorbent tubes and subsequent gas chromatographic analysis. Isoprene was the most dominant compound emitted followed by monoterpenes, methanol and acetone. The average loss rates of VOC carbon in relation to the net CO2 assimilation were found below 4% and indicating normal unstressed plant behavior. Most of the Mediterranean species emitted a large variety of monoterpenes, whereas only five tropical species were identified as monoterpene emitters exhibiting a quite conservative emission pattern (α-pinene < limonene < sabinene < ß-pinene). Mediterranean plants showed additional emissions of sesquiterpenes. In the case of Amazonian plants no sesquiterpenes were detected. However, missing of sesquiterpenes may also be due to a lack of sensitivity of the measuring systems. Furthermore, our screening activities cover only 1% of tree species of such tropical areas as estimated based on recent biodiversity reports. Methanol emissions, an indicator of growth, were found to be common in most of the tropical and Mediterranean species. A few species from both ecosystems showed acetone emissions. The observed heterogeneous emissions, including reactive VOC species which are not easily detected by flux measurements, give reason to perform more screening at leaf level and, whenever possible, within the forests under ambient conditions.

Parameterized isoprene and monoterpene emissions from the boreal forest floor: Implementation into a 1D chemistry-transport model and investigation of the influence on atmospheric chemistry

NASA Astrophysics Data System (ADS)

Mogensen, Ditte; Aaltonen, Hermanni; Aalto, Juho; Bäck, Jaana; Kieloaho, Antti-Jussi; Gierens, Rosa; Smolander, Sampo; Kulmala, Markku; Boy, Michael

2015-04-01

Volatile organic compounds (VOCs) are emitted from the biosphere and can work as precursor gases for aerosol particles that can affect the climate (e.g. Makkonen et al., ACP, 2012). VOC emissions from needles and leaves have gained the most attention, however other parts of the ecosystem also have the ability to emit a vast amount of VOCs. This, often neglected, source can be important e.g. at periods where leaves are absent. Both sources and drivers related to forest floor emission of VOCs are currently limited. It is thought that the sources are mainly due to degradation of organic matter (Isidorov and Jdanova, Chemosphere, 2002), living roots (Asensio et al., Soil Biol. Biochem., 2008) and ground vegetation. The drivers are biotic (e.g. microbes) and abiotic (e.g. temperature and moisture). However, the relative importance of the sources and the drivers individually are currently poorly understood. Further, the relative importance of these factors is highly dependent on the tree species occupying the area of interest. The emission of isoprene and monoterpenes where measured from the boreal forest floor at the SMEAR II station in Southern Finland (Hari and Kulmala, Boreal Env. Res., 2005) during the snow-free period in 2010-2012. We used a dynamic method with 3 automated chambers analyzed by Proton Transfer Reaction - Mass Spectrometer (Aaltonen et al., Plant Soil, 2013). Using this data, we have developed empirical parameterizations for the emission of isoprene and monoterpenes from the forest floor. These parameterizations depends on abiotic factors, however, since the parameterizations are based on field measurements, biotic features are captured. Further, we have used the 1D chemistry-transport model SOSAA (Boy et al., ACP, 2011) to test the seasonal relative importance of inclusion of these parameterizations of the forest floor compared to the canopy crown emissions, on the atmospheric reactivity throughout the canopy.

Leaf level emissions of volatile organic compounds (VOC) from some Amazonian and Mediterranean plants

NASA Astrophysics Data System (ADS)

Bracho-Nunez, A.; Knothe, N. M.; Welter, S.; Staudt, M.; Costa, W. R.; Liberato, M. A. R.; Piedade, M. T. F.; Kesselmeier, J.

2012-11-01

As volatile organic compounds (VOCs) significantly affect atmospheric chemistry (oxidative capacity) and physics (secondary organic aerosol formation and effects), emission inventories defining regional and global biogenic VOC emission strengths are important. The aim of this work was to achieve a description of VOC emissions from poorly described tropical vegetation to be compared with the quite well investigated and highly heterogeneous emissions from Mediterranean vegetation. For this task, common plant species of both ecosystems were investigated. Sixteen plant species from the Mediterranean area, which is known for its special diversity in VOC emitting plant species, were chosen. In contrast, little information is currently available regarding emissions of VOCs from tropical tree species at the leaf level. Twelve plant species from different environments of the Amazon basin, i.e. Terra firme, Várzea and Igapó, were screened for emission of VOCs at leaf level with a branch enclosure system. Analysis of the volatile organics was performed online by a proton-transfer-reaction mass spectrometer (PTR-MS) and offline by collection on adsorbent tubes and subsequent gas chromatographic analysis. Isoprene was quantitatively the most dominant compound emitted followed by monoterpenes, methanol and acetone. Most of the Mediterranean species emitted a variety of monoterpenes, whereas only five tropical species were monoterpene emitters exhibiting a quite conservative emission pattern (α-pinene > limonene > sabinene > β-pinene). Mediterranean plants showed additional emissions of sesquiterpenes, whereas in the case of plants from the Amazon region no sesquiterpenes were detected probably due to a lack of sensitivity in the measuring systems. On the other hand methanol emissions, an indicator of growth, were common in most of the tropical and Mediterranean species. A few species from both ecosystems showed acetone emissions. The observed heterogeneous emissions including reactive VOC species which are not easily detected by flux measurements, give reason to perform more screening at leaf level and, whenever possible, within the forests under ambient conditions.

Composition and Biological Activity of Picea pungens and Picea orientalis Seed and Cone Essential Oils.

PubMed

Wajs-Bonikowska, Anna; Szoka, Łukasz; Karna, Ewa; Wiktorowska-Owczarek, Anna; Sienkiewicz, Monika

2017-03-01

The increasing consumption of natural products lead us to discover and study new plant materials, such as conifer seeds and cones, which could be easily available from the forest industry as a waste material, for their potential uses. The chemical composition of the essential oils of Picea pungens and Picea orientalis was fully characterized by GC and GC/MS methods. Seed and cone oils of both tree species were composed mainly of monoterpene hydrocarbons, among which limonene, α- and β-pinene were the major, but in different proportions in the examined conifer essential oils. The levorotary form of chiral monoterpene molecules was predominant over the dextrorotary form. The composition of oils from P. pungens seeds and cones was similar, while the hydrodistilled oils of P. orientalis seeds and cones differed from each other, mainly by a higher amount of oxygenated derivatives of monoterpenes and by other higher molar mass terpenes in seed oil. The essential oils showed mild antimicrobial action, however P. orientalis cone oil exhibited stronger antimicrobial properties against tested bacterial species than those of P. pungens. Effects of the tested cone essential oils on human skin fibroblasts and microvascular endothelial cells (HMEC-1) were similar: in a concentration of 0 - 0.075 μl/ml the oils were rather safe for human skin fibroblasts and 0 - 0.005 μl/ml for HMEC-1 cells. IC 50 value of Picea pungens oils was 0.115 μl/ml, while that of Picea orientalis was 0.105 μl/ml. The value of IC 50 of both oils were 0.035 μl/ml for HMEC-1 cells. The strongest effect on cell viability had the oil from Picea orientalis cones, while on DNA synthesis the oil from Picea pungens cones. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Housefly (Musca domestica L.) control potential of Cymbopogon citratus Stapf. (Poales: Poaceae) essential oil and monoterpenes (citral and 1,8-cineole).

PubMed

Kumar, Peeyush; Mishra, Sapna; Malik, Anushree; Satya, Santosh

2013-01-01

In spite of being a major vector for several domestic, medical, and veterinary pests, the control aspect of the common housefly, Musca domestica L. (Diptera: Muscidae) is often neglected. In the present study, the essential oil of Cymbopogon citratus and its major components were evaluated for control of housefly. The chemical composition analysis of C. citratus oil by gas chromatographic mass spectrometry (GC-MS) revealed citral (47 %) and 1,8-cineole (7.5 %) as principal components. The analysis of oil vapor by solid phase microextraction (SPME/GC-MS) showed increase in citral (74.9 %) and 1,8-cineole (8.6 %) content. Assay of oil against housefly larvae and pupae through contact toxicity assay showed lethal concentration (LC)(50) value of 0.41 μl/cm(2) and of percentage inhibition rate (PIR) of 77.3 %, respectively. Fumigation assay was comparatively more effective with LC(50) of 48.6 μl/L against housefly larvae, and a PIR value of 100 % against housefly pupae. The monoterpenes, citral, and 1,8-cineole, when assessed for their insecticidal activity against housefly larvae, showed LC(50) of 0.002 and 0.01 μl/cm(2) (contact toxicity assay) and LC(50) of 3.3 and 2.4 μl/L (fumigation assay). For pupicidal assay, both citral and 1,8-cineole had a PIR value of 100 %. High efficacy of citral and 1,8-cineole against housefly, established them to be an active insecticidal agent of C. citratus oil. The study demonstrates potentiality of C. citratus oil as an excellent insecticide for housefly control, and the results open up the opportunity of oil/monoterpenes being developed into an eco-friendly, economical, and acceptable product.

[Cloning and expression regulation of 1-deoxy-D-xylulose-5-phosphate reductoisomerase cDNA from Alpinia officinarum].

PubMed

Zhang, Chun-Rong; Yang, Quan; Chen, Hu-Biao; Pang, Yu-Xin; Tang, Xiao-Min; Cheng, Xuan-Xuan; Wu, Wen-Ya; Chen, Shi-Min

2012-11-01

The rhizome of Alpinia officinarum is a widely used Chinese herbal medicine. The essential oil in A. officinarum rhizome is mainly composed of 1, 8-cineole and other monoterpenes, as the major bioactive ingredients. In plants, monoterpenes are synthesized through the methylerythritol phosphate (MEP) pathway in the plastids, and 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) is an enzyme catalyzing a committed step of the MEP pathway. In the present study, the full-length cDNA encoding DXR was cloned from the rhizome of A. officinarum, using homology-based RT-PCR and rapid amplification of cDNA ends (RACE) techniques. The new cDNA was designated as AoDXR and submitted to GenBank to be assigned with an accession number HQ874658. The full-length cDNA of AoDXR was 1 670 bp containing a 1 419 bp open reading frame encoding a polypeptide of 472 amino acids with a calculated molecular mass of 51.48 kDa and an isoelectric point of 6.15. Bioinformatic analyses revealed that AoDXR showed extensive homology with DXRs from other plant species and contained a conserved plastids transit peptide, a Pro-rich region and two highly conserved NADPH-binding motifs in its N-terminal region characterized by all plant DXRs. The phylogenetic analysis revealed that AoDXR belonged to angiosperm DXRs. The structural modeling of AoDXR showed that AoDXR had the typical V-shaped structure of DXR proteins. The tissue expression pattern analysis indicated that AoDXR expressed strongly in leaves, weak in rhizomes of A. officinarum. Exogenous methyl jasmonate (MeJA) could enhance the expression of AoDXR and the production of 1, 8-cineole in A. officinarum rhizomes. The cloning and characterization of AoDXR will be helpful to reveal the molecular regulation mechanism of monoterpene biosynthesis in A. officinarum and provides a candidate gene for metabolic engineering in improving the medicinal quality of A. officinarum rhizome.

Plasticity and evolution of (+)-3-carene synthase and (-)-sabinene synthase functions of a sitka spruce monoterpene synthase gene family associated with weevil resistance.

PubMed

Roach, Christopher R; Hall, Dawn E; Zerbe, Philipp; Bohlmann, Jörg

2014-08-22

The monoterpene (+)-3-carene is associated with resistance of Sitka spruce against white pine weevil, a major North American forest insect pest of pine and spruce. High and low levels of (+)-3-carene in, respectively, resistant and susceptible Sitka spruce genotypes are due to variation of (+)-3-carene synthase gene copy number, transcript and protein expression levels, enzyme product profiles, and enzyme catalytic efficiency. A family of multiproduct (+)-3-carene synthase-like genes of Sitka spruce include the three (+)-3-carene synthases, PsTPS-3car1, PsTPS-3car2, PsTPS-3car3, and the (-)-sabinene synthase PsTPS-sab. Of these, PsTPS-3car2 is responsible for the relatively higher levels of (+)-3-carene in weevil-resistant trees. Here, we identified features of the PsTPS-3car1, PsTPS-3car2, PsTPS-3car3, and PsTPS-sab proteins that determine different product profiles. A series of domain swap and site-directed mutations, supported by structural comparisons, identified the amino acid in position 596 as critical for product profiles dominated by (+)-3-carene in PsTPS-3car1, PsTPS-3car2, and PsTPS-3car3, or (-)-sabinene in PsTPS-sab. A leucine in this position promotes formation of (+)-3-carene, whereas phenylalanine promotes (-)-sabinene. Homology modeling predicts that position 596 directs product profiles through differential stabilization of the reaction intermediate. Kinetic analysis revealed position 596 also plays a role in catalytic efficiency. Mutations of position 596 with different side chain properties resulted in a series of enzymes with different product profiles, further highlighting the inherent plasticity and potential for evolution of alternative product profiles of these monoterpene synthases of conifer defense against insects. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

A UPLC-MS/MS method for simultaneous quantitation of three monoterpene glycosides and four alkaloids in rat plasma: application to a comparative pharmacokinetic study of Huo Luo Xiao Ling Dan and single herb extract.

PubMed

Ai, Yu; Wu, Yun; Wang, Fenrong; Ma, Wen; Bian, Qiaoxia; Lee, David Y-W; Dai, Ronghua

2015-03-01

The objective of this study was to develop a sensitive and reliable ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for simultaneous quantitation of three monoterpene glycosides (paeoniflorin, alibiflorin and oxypaeoniflorin) and four alkaloids (tetrahydropalmatine, corydaline, dehydrocorydaline and berberine), the main active ingredients of Radix Paeoniae Rubra extract (RPE) and Corydalis yanhusuo extract (CYE) in Huo Luo Xiao Ling Dan (HLXLD), and to compare the pharmacokinetics of these active ingredients in normal and arthritic rats orally administrated with HLXLD or RPE/CYE alone. The analytes and internal standard (IS) (geniposide) were separated on a XBridge C18 column (150 × 4.6 mm, 3.5 µm) using gradient elution with the mobile phase consisting of methanol and 0.01% formic acid in water at a flow rate of 0.6 ml/min. The detection of the analytes was performed on Acquity UPLC-MS/MS system with an electrospray ionization and multiple reaction monitoring mode via polarity switching between negative (for monoterpene glycosides) and positive (for alkaloids) ionization mode. The lower limits of quantification were 2.5, 1, 0.5, 0.2, 0.2, 0.02 and 0.01 ng/ml for paeoniflorin, alibiflorin, oxypaeoniflorin, tetrahydropalmatine, corydaline, dehydrocorydaline and berberine, respectively. Intra-day and inter-day precision and accuracy of analytes were well within acceptance criteria (15%). The mean extraction recoveries of analytes and IS from rat plasma were all more than 83.1%. The validated method has been successfully applied to determination of the analytes. Results showed that there were remarkable differences in pharmacokinetic properties of the analytes between herbal formula and single herb group, normal and arthritic group. Copyright © 2015 John Wiley & Sons, Ltd.