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

Geraniol promotes functional recovery and attenuates neuropathic pain in rats with spinal cord injury.

PubMed

Lv, Yan; Zhang, Liang; Li, Na; Mai, Naiken; Zhang, Yu; Pan, Shuyi

2017-12-01

Geraniol, a plant-derived monoterpene, has been extensively studied and showed a wide variety of beneficial effects. The aim of this study was to investigate the therapeutic effect of geraniol on functional recovery and neuropathic pain in rats with spinal cord injury (SCI). Rats received a clip-compression SCI and were treated with geraniol 6 h following SCI. Treatment of SCI rats with geraniol markedly improved locomotor function, and reduced sensitivity to the mechanical allodynia and thermal hyperalgesia. Treatment of SCI rats with geraniol increased NeuN-positive cells, suppressed expression of glial fibrillary acidic protein, and reduced activity of caspase-3 in the injured region. Treatment of SCI rats with geraniol reduced levels of malondialdehyde and 3-nitrotyrosine, upregulated protein expression of nuclear factor-erythroid 2-related factor 2 and heme oxygenase 1, and suppressed expression of inducible nitric oxide synthase in the injured region. In addition, treatment of SCI rats with geraniol downregulated protein expression of N-methyl-d-aspartate receptor 1 and reduced the number of CD68-positive cells and protein levels of TNF-α in the injured region. In conclusion, geraniol significantly promoted the recovery of neuronal function and attenuated neuropathic pain after SCI.

40 CFR 180.1251 - Geraniol; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Geraniol; exemption from the... Exemptions From Tolerances § 180.1251 Geraniol; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of the biochemical pesticide geraniol...

40 CFR 180.1251 - Geraniol; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Geraniol; exemption from the... Exemptions From Tolerances § 180.1251 Geraniol; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of the biochemical pesticide geraniol...

40 CFR 180.1251 - Geraniol; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Geraniol; exemption from the... Exemptions From Tolerances § 180.1251 Geraniol; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of the biochemical pesticide geraniol...

40 CFR 180.1251 - Geraniol; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Geraniol; exemption from the... Exemptions From Tolerances § 180.1251 Geraniol; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of the biochemical pesticide geraniol...

40 CFR 180.1251 - Geraniol; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Geraniol; exemption from the... Exemptions From Tolerances § 180.1251 Geraniol; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of the biochemical pesticide geraniol...

Functional characterization of a geraniol synthase-encoding gene from Camptotheca acuminata and its application in production of geraniol in Escherichia coli.

PubMed

Chen, Fei; Li, Wei; Jiang, Liangzhen; Pu, Xiang; Yang, Yun; Zhang, Guolin; Luo, Yinggang

2016-09-01

Geraniol synthase (GES) catalyzes the conversion of geranyl diphosphate (GPP) into geraniol, an acyclic monoterpene alcohol that has been widely used in many industries. Here we report the functional characterization of CaGES from Camptotheca acuminata, a camptothecin-producing plant, and its application in production of geraniol in Escherichia coli. The full-length cDNA of CaGES was obtained from overlap extension PCR amplification. The intact and N-terminus-truncated CaGESs were overexpressed in E. coli and purified to homogeneity. Recombinant CaGES showed the conversion activity from GPP to geraniol. To produce geraniol in E. coli using tCaGES, the biosynthetic precursor GPP should be supplied and transferred to the catalytic pocket of tCaGES. Thus, ispA(S80F), a mutant of farnesyl diphosphate (FPP) synthase, was prepared to produce GPP via the head-to-tail condensation of isoprenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). A slight increase of geraniol production was observed in the fermentation broth of the recombinant E. coli harboring tCaGES and ispA(S80F). To enhance the supply of IPP and DMAPP, the encoding genes involved in the whole mevalonic acid biosynthetic pathway were introduced to the E. coli harboring tCaGES and the ispA(S80F) and a significant increase of geraniol yield was observed. The geraniol production was enhanced to 5.85 ± 0.46 mg L(-1) when another copy of ispA(S80F) was introduced to the above recombinant strain. The following optimization of medium composition, fermentation time, and addition of metal ions led to the geraniol production of 48.5 ± 0.9 mg L(-1). The present study will be helpful to uncover the biosynthetic enigma of camptothecin and tCaGES will be an alternative to selectively produce geraniol in E. coli with other metabolic engineering approaches.

Utilization of alkaline phosphatase PhoA in the bioproduction of geraniol by metabolically engineered Escherichia coli.

PubMed

Liu, Wei; Zhang, Rubing; Tian, Ning; Xu, Xin; Cao, Yujing; Xian, Mo; Liu, Huizhou

2015-01-01

Geraniol is a valuable acyclic monoterpene alcohol and has many applications in the perfume industries, pharmacy and others. It has been hypothesized that phosphatases can convert geranyl diphosphate (GPP) into geraniol. However, whether and which phosphatases can transform GPP to geraniol has remained unanswered up till now. In this paper, the catalysis abilities of 4 different types of phosphatases were studied with GPP as substrate in vitro. They are bifunctional diacylglycerol diphosphate phosphatase (DPP1) and lipid phosphate phosphatase (LPP1) from Saccharomyces cerevisiae, ADP-ribose pyrophosphatase (NudF) and alkaline phosphatase (PhoA) from Escherichia coli. The results show that just PhoA from E. coli can convert GPP into geraniol. Moreover, in order to confirm the ability of PhoA in vivo, the heterologous mevalonate pathway and geranyl diphosphate synthase gene from Abies grandis were co-overexpressed in E. coli with PhoA gene and 5.3 ± 0.2 mg/l geraniol was produced from glucose in flask-culture. Finally, we also evaluated the fed-batch fermentation of this engineered E. coli and a maximum concentration of 99.3 mg/l geraniol was produced while the conversion efficiency of glucose to geranoid (gram to gram) was 0.51%. Our results offer a new option for geraniol biosynthesis and promote the industrial bio-production of geraniol.

Utilization of alkaline phosphatase PhoA in the bioproduction of geraniol by metabolically engineered Escherichia coli

PubMed Central

Liu, Wei; Zhang, Rubing; Tian, Ning; Xu, Xin; Cao, Yujing; Xian, Mo; Liu, Huizhou

2015-01-01

Geraniol is a valuable acyclic monoterpene alcohol and has many applications in the perfume industries, pharmacy and others. It has been hypothesized that phosphatases can convert geranyl diphosphate (GPP) into geraniol. However, whether and which phosphatases can transform GPP to geraniol has remained unanswered up till now. In this paper, the catalysis abilities of 4 different types of phosphatases were studied with GPP as substrate in vitro. They are bifunctional diacylglycerol diphosphate phosphatase (DPP1) and lipid phosphate phosphatase (LPP1) from Saccharomyces cerevisiae, ADP-ribose pyrophosphatase (NudF) and alkaline phosphatase (PhoA) from Escherichia coli. The results show that just PhoA from E. coli can convert GPP into geraniol. Moreover, in order to confirm the ability of PhoA in vivo, the heterologous mevalonate pathway and geranyl diphosphate synthase gene from Abies grandis were co-overexpressed in E. coli with PhoA gene and 5.3 ± 0.2 mg/l geraniol was produced from glucose in flask-culture. Finally, we also evaluated the fed-batch fermentation of this engineered E. coli and a maximum concentration of 99.3 mg/l geraniol was produced while the conversion efficiency of glucose to geranoid (gram to gram) was 0.51%. Our results offer a new option for geraniol biosynthesis and promote the industrial bio-production of geraniol. PMID:26091008

Geraniol-a flavoring agent with multifunctional effects in protecting the gastric and duodenal mucosa.

PubMed

de Carvalho, Katharinne Ingrid Moraes; Bonamin, Flavia; Dos Santos, Raquel Cássia; Périco, Larissa Lucena; Beserra, Fernando Pereira; de Sousa, Damião Pergentino; Filho, José Maria Barbosa; da Rocha, Lucia Regina Machado; Hiruma-Lima, Clelia Akiko

2014-04-01

Geraniol is an acyclic monoterpene alcohol commonly used as a flavoring agent. The present study was undertaken to investigate antiulcerogenic effects of geraniol and to determine the possible mechanisms involved in this action. In the model of the ethanol-induced ulcer, treatment of rats with geraniol by oral route significantly inhibited gastric lesions by 70 % (7.50 mg/kg) to 99 % (200 mg/kg). Analysis of the gastric tissue of rats treated with geraniol (7.50 mg/kg) revealed that total glutathione content levels (GSH) increased and levels of myeloperoxidase (MPO) decreased in the gastric mucosa. Oral treatment with geraniol significantly decreased the number of ulcerative lesions induced by ischemia/reperfusion injury by 71 % and the duodenal ulcers induced by cysteamine by 68 %. The action of geraniol was mediated by the activation of defensive mucosa-protective factors such as the nitric oxide (NO) pathway, endogenous prostaglandins, increased mucus production, increased sulfhydryl compounds, antioxidant properties and the stimulation of calcitonin gene-related peptide (CGRP) release through the activation of transient receptor potential vanilloid (TRPV). The multifaceted gastroprotective mechanisms of geraniol represent a promising option for the treatment of gastric and duodenal mucosa injury.

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.

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.

Geraniol, a natural monoterpene, ameliorates hyperglycemia by attenuating the key enzymes of carbohydrate metabolism in streptozotocin-induced diabetic rats.

PubMed

Babukumar, Sukumar; Vinothkumar, Veerasamy; Sankaranarayanan, Chandrasekaran; Srinivasan, Subramani

2017-12-01

Geraniol, an acyclic monoterpene alcohol is found in medicinal plants, is used traditionally for several medical purposes including diabetes. The present study evaluates the antihyperglycemic potential of geraniol on key enzymes of carbohydrate metabolism in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in experimental rats, by a single intraperitoneal (i.p) injection of STZ [40 mg/kg body weight (b.w.)]. Different doses of geraniol (100, 200 and 400 mg/kg b.w.) and glyclazide (5 mg/kg b.w.) were administrated orally to diabetic rats for 45 days. Body weight, food intake, plasma glucose, insulin, blood haemoglobin (Hb), glycosylated haemoglobin (HbA 1c ), hepatic glucose metabolic enzymes and glycogen were examined. The LD 50 value of geraniol is 3600 mg/kg b.w. at oral administration in rats. Administration of geraniol in a dose-dependent manner (100, 200, 400 mg/kg b.w.) and glyclazide (5 mg/kg b.w.) for 45 days significantly improved the levels of insulin, Hb and decreased plasma glucose, HbA 1C in diabetic-treated rats. Geraniol at its effective dose (200 mg/kg b.w.) ameliorated the altered activities of carbohydrate metabolic enzymes near normal effects compared with two other doses (100 and 400 mg/kg b.w.). Geraniol treatment to diabetic rats improved hepatic glycogen content suggesting its anti-hyperglycemic potential. Geraniol supplement was found to preserve the normal histological appearance of hepatic cells and pancreatic β-cells in diabetic rats. The present findings suggest that geraniol can potentially ameliorate key enzymes of glucose metabolism in experimental diabetes even though clinical studies used to evaluate this possibility are warranted.

Geraniol blocks calcium and potassium channels in the mammalian myocardium: useful effects to treat arrhythmias.

PubMed

de Menezes-Filho, José Evaldo Rodrigues; Gondim, Antônio Nei Santana; Cruz, Jader Santos; de Souza, Américo Azevedo; Santos, José Nilson Andrade Dos; Conde-Garcia, Eduardo Antônio; de Sousa, Damião Pergentino; Santos, Michel Santana; de Oliveira, Evaleide Diniz; de Vasconcelos, Carla Maria Lins

2014-12-01

Geraniol is a monoterpene present in several essential oils, and it is known to have a plethora of pharmacological activities. In this study, we explored the contractile and electrophysiological properties of geraniol and its antiarrhythmic effects in the heart. The geraniol effects on atrial contractility, L-type Ca(2+) current, K(+) currents, action potential (AP) parameters, ECG profile and on the arrhythmia induced by ouabain were evaluated. In the atrium, geraniol reduced the contractile force (~98%, EC = 1,510 ± 160 μM) and diminished the positive inotropism of CaCl2 and BAY K8644. In cardiomyocytes, the IC a,L was reduced by 50.7% (n = 5) after perfusion with 300 μM geraniol. Moreover, geraniol prolonged the AP duration (APD) measured at 50% (n = 5) after repolarization, without changing the resting potential. The increased APD could be attributed to the blockade of the transient outward K(+) current (Ito ) (59.7%, n = 4), the non-inactivation K(+) current (Iss ) (39.2%, n = 4) and the inward rectifier K(+) current (IK 1 ) (33.7%, n = 4). In isolated hearts, geraniol increased PRi and QTi without affecting the QRS complex (n = 6), and it reduced both the left ventricular pressure (83%) and heart rate (16.5%). Geraniol delayed the time to onset of ouabain-induced arrhythmias by 128%, preventing 30% of the increase in resting tension (n = 6). Geraniol exerts its negative inotropic and chronotropic responses in the heart by decreasing both L-type Ca(2+) and voltage-gated K(+) currents, ultimately acting against ouabain-induced arrhythmias. © 2014 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

Effect of treatment with geraniol on ovalbumin-induced allergic asthma in mice.

PubMed

Xue, Zheng; Zhang, Xin-Guang; Wu, Jie; Xu, Wan-Chao; Li, Li-Qing; Liu, Fei; Yu, Jian-Er

2016-06-01

Asthma, a complex highly prevalent airway disease, is a major public health problem for which current treatment options are inadequate. To evaluate the antiasthma activity of geraniol and investigate its underlying molecular mechanisms. In a standard experimental asthma model, Balb/c mice were sensitized with ovalbumin, treated with geraniol (100 or 200 mg/kg) or a vehicle control, during ovalbumin challenge. Treatment of ovalbumin-sensitized/challenged mice with geraniol significantly decreased airway hyperresponsiveness to inhaled methacholine. Geraniol treatment reduced eotaxin levels in bronchoalveolar lavage fluid and attenuated infiltration of eosinophils induced by ovalbumin. Geraniol treatment reduced TH2 cytokines (including interleukins 4, 5, and 13), increased TH1 cytokine interferon γ in bronchoalveolar lavage fluid, and reduced ovalbumin-specific IgE in serum. In addition, treatment of ovalbumin-sensitized/challenged mice with geraniol enhanced T-bet (TH1 response) messenger RNA expression and reduced GATA-3 (TH2 response) messenger RNA expression in lungs. Furthermore, treatment of ovalbumin -sensitized/challenged mice with geraniol further enhanced Nrf2 protein expression and activated Nrf2-directed antioxidant pathways, such as glutamate-cysteine ligase, superoxide dismutase, and glutathione S-transferase, and enhanced formation of reduced glutathione and reduced formation of malondialdehyde in lungs. Geraniol attenuated important features of allergic asthma in mice, possibly through the modulation of TH1/TH2 balance and activation the of Nrf2/antioxidant response element pathway. Copyright © 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Aqueous 2% geraniol as a mosquito repellent failed against Aedes aegypti on ponies.

PubMed

Reeves, Will K; Miller, Myrna M

2010-09-01

Organic insect repellents are of interest to many agricultural producers and animal owners. Geraniol, a plant-derived alcohol, is naturally produced by a wide range of plants and is a US Environmental Protection Agency minimum risk pesticide. Previous studies have shown various concentrations of geraniol repel or kill mosquitoes; however, geraniol might cause allergic contact dermatitis in humans or animals. We tested a commercially available 2% aqueous solution of geraniol on ponies as a mosquito repellent. Five trials were conducted on ponies treated with a 60-ml aerosol mist (30 ml per side) of 2% geraniol or as untreated controls. Animals were observed 3 h postapplication to check for skin irritation. Aedes aegypti, in feeding tubes, were held on the ponies for 7 min. The average percent of biting on control animals was 56%, with a range of 16-90%, and the average for the treatments was 13%, with a range of 0-86%. Based on statistical models, there was no significant difference (P = 0.081) in the percent bites between treated and untreated animals after 3 h. Based on our data, 2% geraniol was not an adequate mosquito repellent for horses. We did not observe any skin irritation on the animals treated with 2% geraniol.

The Effect of Geraniol on Liver Regeneration Αfter Hepatectomy in Rats

PubMed Central

CANBEK, MEDIHA; UYANOGLU, MUSTAFA; CANBEK, SELCUK; CEYHAN, EMRE; OZEN, AHMET; DURMUS, BASAK; TURGAK, OZGE

2017-01-01

Geraniol is a monoterpenoid alcohol that has a hepatoprotective effect. We investigated the regenerative effects of geraniol in rats after a 70% partial hepatectomy (PH). Using Wistar albino rats, nine groups were created: Group I was the control group, while the remaining groups received a single intraperitoneal dose of saline, Silymarin, or geraniol after PH. A 70% PH was performed on all groups except for groups II and III. Blood serum samples were obtained for alanine amino transferase (ALT) analysis. Then liver tissues were harvested for histological and real-time polymerase chain reaction (PCR) analyses. Tumor necrosis factor-α (TNFα) and interleukin 6 (IL6) gene expression were examined 24 and 48 h after PH. ALT levels were found to be statistically significantly increased in all PH-treated groups. TNFα and IL6 gene expression levels were elevated in geraniol-treated groups. Histological evaluation revealed a hepatoprotective effect for geraniol-treated groups. Our results suggest that geraniol plays a significant role during liver regeneration, which involves the elevated expression of TNFα and IL6 48 h after PH. PMID:28358702

Engineering the Autotroph Methanococcus maripaludis for Geraniol Production.

PubMed

Lyu, Zhe; Jain, Rachit; Smith, Peyton; Fetchko, Travis; Yan, Yajun; Whitman, William B

2016-07-15

The rapid autotrophic growth of the methanogenic archaeon Methanococcus maripaludis on H2 and CO2 makes it an attractive microbial chassis to inexpensively produce biochemicals. To explore this potential, a synthetic gene encoding geraniol synthase (GES) derived from Ocimum basilicum was cloned into a M. maripaludis expression vector under selection for puromycin resistance. Recombinant expression of GES in M. maripaludis during autotrophic growth on H2/CO2 or formate yielded geraniol at 2.8 and 4.0 mg g(-1) of dry weight, respectively. The yield of geraniol decreased 2-3-fold when organic carbon sources were added to stimulate heterotrophic growth. In the absence of puromycin, geraniol production during autotrophic growth on formate increased to 4.6 mg g(-1) of dry weight. A conceptual model centered on the autotrophic acetyl coenzyme A biosynthetic pathway identified strategies to divert more autotrophic carbon flux to geraniol production.

Characterization of two geraniol synthases from Valeriana officinalis and Lippia dulcis: similar activity but difference in subcellular localization.

PubMed

Dong, Lemeng; Miettinen, Karel; Goedbloed, Miriam; Verstappen, Francel W A; Voster, Alessandra; Jongsma, Maarten A; Memelink, Johan; van der Krol, Sander; Bouwmeester, Harro J

2013-11-01

Two geraniol synthases (GES), from Valeriana officinalis (VoGES) and Lippia dulcis (LdGES), were isolated and were shown to have geraniol biosynthetic activity with Km values of 32 µM and 51 µM for GPP, respectively, upon expression in Escherichia coli. The in planta enzymatic activity and sub-cellular localization of VoGES and LdGES were characterized in stable transformed tobacco and using transient expression in Nicotiana benthamiana. Transgenic tobacco expressing VoGES or LdGES accumulate geraniol, oxidized geraniol compounds like geranial, geranic acid and hexose conjugates of these compounds to similar levels. Geraniol emission of leaves was lower than that of flowers, which could be related to higher levels of competing geraniol-conjugating activities in leaves. GFP-fusions of the two GES proteins show that VoGES resides (as expected) predominantly in the plastids, while LdGES import into to the plastid is clearly impaired compared to that of VoGES, resulting in both cytosolic and plastidic localization. Geraniol production by VoGES and LdGES in N. benthamiana was nonetheless very similar. Expression of a truncated version of VoGES or LdGES (cytosolic targeting) resulted in the accumulation of 30% less geraniol glycosides than with the plastid targeted VoGES and LdGES, suggesting that the substrate geranyl diphosphate is readily available, both in the plastids as well as in the cytosol. The potential role of GES in the engineering of the TIA pathway in heterologous hosts is discussed. © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Geraniol improves endothelial function by inhibiting NOX-2 derived oxidative stress in high fat diet fed mice

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

Wang, Xiaoyu; Zhao, Shiqi; Su, Mengqi

Endothelial dysfunction occurs in obese patients and high-fat diet (HFD) fed experimental animals. While geraniol has been reported to ameliorate inflammation and oxidative stress, inhibit tumor cell proliferation, and improve atherosclerosis, its direct effect on endothelial function remains uncharacterized. The present study therefore investigated the effect of geraniol on endothelial function in HFD mice and its underlying mechanisms. C57 BL/6 mice were fed an HFD (n = 40) or a normal diet (n = 20) for 8 weeks. HFD fed mice then were randomized to intraperitoneal treatment with geraniol (n = 20) or vehicle (n = 20) for another 6 weeks. Acetylcholine (Ach)-induced endothelial dependent vasorelaxation was measuredmore » on wire myography; reactive oxygen species (ROS) generation was assessed by fluorescence imaging, and NADPH oxidases (NOXs) and adhesive molecules VCAM-1 and ICAM-1 protein expression by western blotting. Geraniol improved endothelial function in HFD fed mice, as evidenced by its: 1. restoring endothelial dependent vasorelaxation induced by Ach, and reversing increased VCAM-1 and ICAM-1 expression; 2. attenuating HFD induced increased serum TBARS and aortic ROS generation; and 3. downregulating aortic NOX-2 expression in both HFD fed mice and in palmitic acid treated endothelial cells. Geraniol therefore protects against endothelial dysfunction induced by HFD through reducing NOX-2 associated ROS generation. -- Highlights: •Geraniol improved endothelial dependent relaxation in high fat diet fed mice. •Geraniol alleviated vascular injury in high fat diet fed mice. •Geraniol inhibited ROS generation through downregulating NOX-2 expression.« less

Oral administration of geraniol ameliorates acute experimental murine colitis by inhibiting pro-inflammatory cytokines and NF-κB signaling.

PubMed

Medicherla, Kanakaraju; Sahu, Bidya Dhar; Kuncha, Madhusudana; Kumar, Jerald Mahesh; Sudhakar, Godi; Sistla, Ramakrishna

2015-09-01

Ulcerative colitis is associated with a considerable reduction in the quality of life of patients. The use of phyto-ingredients is becoming an increasingly attractive approach for the management of colitis. Geraniol is a monoterpene with anti-inflammatory and antioxidative properties. In this study, we investigated the therapeutic potential of geraniol as a complementary and alternative medicine against dextran sulphate sodium (DSS)-induced ulcerative colitis in mice. Disease activity indices (DAI) comprising body weight loss, presence of occult blood and stool consistency were assessed for evaluation of colitis symptoms. Intestinal damage was assessed by evaluating colon length and its histology. Pre-treatment with geraniol significantly reduced the DAI score, improved stool consistency (without occult blood) and increased the colon length. The amount of pro-inflammatory cytokines, specifically TNF-α, IL-1β and IL-6 and the activity of myeloperoxidase in colon tissue were significantly decreased in geraniol pre-treated mice. Western blot analyses revealed that geraniol interfered with NF-κB signaling by inhibiting NF-κB (p65)-DNA binding, and IκBα phosphorylation, degradation and subsequent increase in nuclear translocation. Moreover, the expressions of downstream target pro-inflammatory enzymes such as iNOS and COX-2 were significantly reduced by geraniol. Pre-treatment with geraniol also restored the DSS-induced decline in antioxidant parameters such as reduced glutathione and superoxide dismutase activity and attenuated the increase in lipid peroxidation marker, thiobarbituric acid reactive substances and nitrative stress marker, nitrites in colon tissue. Thus, our results suggest that geraniol is a potential therapeutic agent for inflammatory bowel disease.

Assessment of Cultivation Factors that Affect Biomass and Geraniol Production in Transgenic Tobacco Cell Suspension Cultures

PubMed Central

Vasilev, Nikolay; Schmitz, Christian; Grömping, Ulrike; Fischer, Rainer; Schillberg, Stefan

2014-01-01

A large-scale statistical experimental design was used to determine essential cultivation parameters that affect biomass accumulation and geraniol production in transgenic tobacco (Nicotiana tabacum cv. Samsun NN) cell suspension cultures. The carbohydrate source played a major role in determining the geraniol yield and factors such as filling volume, inoculum size and light were less important. Sucrose, filling volume and inoculum size had a positive effect on geraniol yield by boosting growth of plant cell cultures whereas illumination of the cultures stimulated the geraniol biosynthesis. We also found that the carbohydrates sucrose and mannitol showed polarizing effects on biomass and geraniol accumulation. Factors such as shaking frequency, the presence of conditioned medium and solubilizers had minor influence on both plant cell growth and geraniol content. When cells were cultivated under the screened conditions for all the investigated factors, the cultures produced ∼5.2 mg/l geraniol after 12 days of cultivation in shaking flasks which is comparable to the yield obtained in microbial expression systems. Our data suggest that industrial experimental designs based on orthogonal arrays are suitable for the selection of initial cultivation parameters prior to the essential medium optimization steps. Such designs are particularly beneficial in the early optimization steps when many factors must be screened, increasing the statistical power of the experiments without increasing the demand on time and resources. PMID:25117009

Transcriptional and posttranscriptional inhibition of HMGCR and PC biosynthesis by geraniol in 2 Hep-G2 cell proliferation linked pathways.

PubMed

Crespo, Rosana; Montero Villegas, Sandra; Abba, Martín C; de Bravo, Margarita G; Polo, Mónica P

2013-06-01

Geraniol, present in the essential oils of many aromatic plants, has in vitro and in vivo antitumor activity against several cell lines. We investigated the effects of geraniol on lipid metabolic pathways involved in Hep-G2 cell proliferation and found that geraniol inhibits the mevalonate pathway, phosphatidylcholine biosynthesis, cell growth, and cell cycle progression (with an arrest occurring at the G0/G1 interphase) and increases apoptosis. The expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), the rate-limiting step in cholesterol synthesis, was inhibited at the transcriptional and posttranscriptional levels, as assessed by real-time RT-PCR, Western blots, and [(14)C]HMG-CoA-conversion radioactivity assays. That geraniol decreased cholesterogenesis but increased the incorporation of [(14)C]acetate into other nonsaponifiable metabolites indicated the existence of a second control point between squalene and cholesterol involved in redirecting the flow of cholesterol-derived carbon toward other metabolites of the mevalonate pathway. That exogenous mevalonate failed to restore growth in geraniol-inhibited cells suggests that, in addition to the inhibition of HMGCR, other dose-dependent actions exist through which geraniol can impact the mevalonate pathway and consequently inhibit cell proliferation. These results suggest that geraniol, a nontoxic compound found in many fruits and herbs, exhibits notable potential as a natural agent for combatting cancer and (or) cardiovascular diseases.

Precursor feeding studies and molecular characterization of geraniol synthase establish the limiting role of geraniol in monoterpene indole alkaloid biosynthesis in Catharanthus roseus leaves.

PubMed

Kumar, Krishna; Kumar, Sarma Rajeev; Dwivedi, Varun; Rai, Avanish; Shukla, Ashutosh K; Shanker, Karuna; Nagegowda, Dinesh A

2015-10-01

The monoterpene indole alkaloids (MIAs) are generally derived from strictosidine, which is formed by condensation of the terpene moiety secologanin and the indole moiety tryptamine. There are conflicting reports on the limitation of either terpene or indole moiety in the production of MIAs in Catharanthus roseus cell cultures. Formation of geraniol by geraniol synthase (GES) is the first step in secologanin biosynthesis. In this study, feeding of C. roseus leaves with geraniol, but not tryptophan (precursor for tryptamine), increased the accumulation of the MIAs catharanthine and vindoline, indicating the limitation of geraniol in MIA biosynthesis. This was further validated by molecular and in planta characterization of C. roseus GES (CrGES). CrGES transcripts exhibited leaf and shoot specific expression and were induced by methyl jasmonate. Virus-induced gene silencing (VIGS) of CrGES significantly reduced the MIA content, which was restored to near-WT levels upon geraniol feeding. Moreover, over-expression of CrGES in C. roseus leaves increased MIA content. Further, CrGES exhibited correlation with MIA levels in leaves of different C. roseus cultivars and has significantly lower expression relative to other pathway genes. These results demonstrated that the transcriptional regulation of CrGES and thus, the in planta geraniol availability plays crucial role in MIA biosynthesis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Assessment of cultivation factors that affect biomass and geraniol production in transgenic tobacco cell suspension cultures.

PubMed

Vasilev, Nikolay; Schmitz, Christian; Grömping, Ulrike; Fischer, Rainer; Schillberg, Stefan

2014-01-01

A large-scale statistical experimental design was used to determine essential cultivation parameters that affect biomass accumulation and geraniol production in transgenic tobacco (Nicotiana tabacum cv. Samsun NN) cell suspension cultures. The carbohydrate source played a major role in determining the geraniol yield and factors such as filling volume, inoculum size and light were less important. Sucrose, filling volume and inoculum size had a positive effect on geraniol yield by boosting growth of plant cell cultures whereas illumination of the cultures stimulated the geraniol biosynthesis. We also found that the carbohydrates sucrose and mannitol showed polarizing effects on biomass and geraniol accumulation. Factors such as shaking frequency, the presence of conditioned medium and solubilizers had minor influence on both plant cell growth and geraniol content. When cells were cultivated under the screened conditions for all the investigated factors, the cultures produced ∼ 5.2 mg/l geraniol after 12 days of cultivation in shaking flasks which is comparable to the yield obtained in microbial expression systems. Our data suggest that industrial experimental designs based on orthogonal arrays are suitable for the selection of initial cultivation parameters prior to the essential medium optimization steps. Such designs are particularly beneficial in the early optimization steps when many factors must be screened, increasing the statistical power of the experiments without increasing the demand on time and resources.

Enhancement of geraniol resistance of Escherichia coli by MarA overexpression.

PubMed

Shah, Asad Ali; Wang, Chonglong; Chung, Young-Ryun; Kim, Jae-Yean; Choi, Eui-Sung; Kim, Seon-Won

2013-03-01

Improvement of a microorganism's tolerance against organic solvents is required for a microbial factory producing terpenoid based biofuels. The bacterial genes, marA, imp, cls and cti have been found to increase organic solvent tolerance. Thus, the tolerance against the following terpenoids (isopentenol, geraniol, myrcene, and farnesol) was studied with overexpression of marA, imp, cls and cti genes in Escherichia coli. The marA overexpression significantly enhanced the tolerance of E. coli against geraniol, whereas there was no tolerance improvement against the terpenoids by overexpression of cls and cti genes. The imp overexpression even yielded sensitive phenotype to the tested solvents. The colony forming efficiency of the marA overexpressing E. coli was increased by 10(4)-fold in plate overlay of geraniol compared to that of wild type E. coli and a two-fold decrease of intracellular geraniol accumulation was also observed in liquid culture of geraniol. Single knock-out mutations of marA, or one of the following genes (acrA, acrB and tolC) encoding AcrAB-TolC efflux pump made E. coli hypersensitive to geraniol. The geraniol tolerance conferred by marA overexpression was attributed to the AcrAB-TolC efflux pump that is activated by MarA. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Metabolic flux phenotype of tobacco hairy roots engineered for increased geraniol production.

PubMed

Masakapalli, Shyam K; Ritala, Anneli; Dong, Lemeng; van der Krol, Alexander R; Oksman-Caldentey, Kirsi-Marja; Ratcliffe, R George; Sweetlove, Lee J

2014-03-01

The goal of this study was to characterise the metabolic flux phenotype of transgenic tobacco (Nicotiana tabacum) hairy roots engineered for increased biosynthesis of geraniol, an intermediate of the terpenoid indole alkaloid pathway. Steady state, stable isotope labelling was used to determine flux maps of central carbon metabolism for transgenic lines over-expressing (i) plastid-targeted geraniol synthase (pGES) from Valeriana officinalis, and (ii) pGES in combination with plastid-targeted geranyl pyrophosphate synthase from Arabidopsis thaliana (pGES+pGPPS), as well as for wild type and control-vector-transformed roots. Fluxes were constrained by the redistribution of label from [1-¹³C]-, [2-¹³C]- or [¹³C6]glucose into amino acids, sugars and organic acids at isotopic steady state, and by biomass output fluxes determined from the fractionation of [U-¹⁴C]glucose into insoluble polymers. No significant differences in growth and biomass composition were observed between the lines. The pGES line accumulated significant amounts of geraniol/geraniol glycosides (151±24 ng/mg dry weight) and the de novo synthesis of geraniol in pGES was confirmed by ¹³C labelling analysis. The pGES+pGPPS also accumulated geraniol and geraniol glycosides, but to lower levels than the pGES line. Although there was a distinct impact of the transgenes at the level of geraniol synthesis, other network fluxes were unaffected, reflecting the capacity of central metabolism to meet the relatively modest demand for increased precursors in the transgenic lines. It is concluded that re-engineering of the terpenoid indole alkaloid pathway will only require simultaneous manipulation of the steps producing the pathway precursors that originate in central metabolism in tissues engineered to produce at least an order of magnitude more geraniol than has been achieved so far. Copyright © 2013 Elsevier Ltd. All rights reserved.

Geraniol alleviates diabetic cardiac complications: Effect on cardiac ischemia and oxidative stress.

PubMed

El-Bassossy, Hany M; Ghaleb, Hanna; Elberry, Ahmed A; Balamash, Khadijah S; Ghareib, Salah A; Azhar, Ahmad; Banjar, Zainy

2017-04-01

The present study was planned to assess the possible protective effect of geraniol on cardiovascular complications in an animal model with diabetes. Diabetes was induced in rats by a single streptozotocin injection. In the treated group, geraniol (150mgkg -1 day -1 ) was administered orally starting from the 15th day after induction of diabetes, and ending after 7 weeks; diabetic control rats were given vehicle for the same period. At the end of the study, cardiac contractility was assessed by using a Millar microtip catheter in anesthetised rats, and cardiac conductivity determined by a surface ECG. Serum levels of glucose, cholesterol, triglyceride and adiponectin as well as urine 8-isoprostane were determined. In addition, cardiac superoxide dismutase (SOD) and catalase activity were measured. Geraniol administration significantly alleviated the attenuated cardiac systolic function associated with diabetes as indicated by inhibiting the decrease in the rate of rise (dP/dt max ) in ventricular pressure and the increase in systolic duration observed in diabetic rats. In addition, geraniol alleviated impaired diastolic function as shown by inhibiting the decrease in the rate of fall (dP/dt min ) in ventricular pressure and increased isovolumic relaxation constant (Tau) observed in diabetic rats. ECG recordings showed that geraniol prevented any increase in QTc and T-peak-T-end intervals, and markers of LV ischemia and arrhythmogenesis, seen in diabetic animals. Geraniol suppressed the exaggerated oxidative stress as evidenced by preventing the increase in 8-isoprotane. In diabetic heart tissue, geraniol prevented the inhibition in catalase activity but did not affect the heart SOD. Geraniol partially reduced hyperglycemia, prevented the hypercholesterolemia, but did not affect the serum level of adiponectin in diabetic animals. Results obtained in this study suggest that geraniol provides a potent protective effect against cardiac dysfunction induced by diabetes. This ameliorative effect could be attributed to its suppression of oxidative stress. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

The Effect of Geraniol on Liver Regeneration After Hepatectomy in Rats.

PubMed

Canbek, Mediha; Uyanoglu, Mustafa; Canbek, Selcuk; Ceyhan, Emre; Ozen, Ahmet; Durmus, Basak; Turgak, Ozge

2017-01-01

Geraniol is a monoterpenoid alcohol that has a hepatoprotective effect. We investigated the regenerative effects of geraniol in rats after a 70% partial hepatectomy (PH). Using Wistar albino rats, nine groups were created: Group I was the control group, while the remaining groups received a single intraperitoneal dose of saline, Silymarin, or geraniol after PH. A 70% PH was performed on all groups except for groups II and III. Blood serum samples were obtained for alanine amino transferase (ALT) analysis. Then liver tissues were harvested for histological and real-time polymerase chain reaction (PCR) analyses. Tumor necrosis factor-α (TNFα) and interleukin 6 (IL6) gene expression were examined 24 and 48 h after PH. ALT levels were found to be statistically significantly increased in all PH-treated groups. TNFα and IL6 gene expression levels were elevated in geraniol-treated groups. Histological evaluation revealed a hepatoprotective effect for geraniol-treated groups. Our results suggest that geraniol plays a significant role during liver regeneration, which involves the elevated expression of TNFα and IL6 48 h after PH. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Geraniol and simvastatin show a synergistic effect on a human hepatocarcinoma cell line.

PubMed

Polo, M P; Crespo, R; de Bravo, M G

2011-08-01

Simvastatin is a competitive inhibitor of 3-hydroxymethylglutaryl coenzyme A reductase activity, whereas geraniol is a monoterpene with multiple pharmacologic effects on mevalonate metabolism. Both of them inhibit growth and proliferation of many cell lines. The present study was designed to determine the action of geraniol, in combination with simvastatin, by assessing their effects in vitro on human hepatocarcinoma cell line (Hep G2). The treatment of Hep G2 cells with concentrations of simvastatin or geraniol that did not inhibit cell proliferation (5 µmol·l⁻¹ of simvastatin and 50 µmol·l⁻¹ of geraniol) resulted in a significant inhibition of cell proliferation. We also examined the effect of simvastatin, geraniol and the combination of both on the biosynthesis of lipids from [¹⁴C]-acetate. Our results demonstrate that the combination of simvastatin and geraniol synergistically inhibited cholesterol biosynthesis and proliferation of Hep G2 cell line, contributing to a better understanding of the action of a component of essential oils targeting a complex metabolic pathway, which would improve the use of drugs or their combination in the fight against cancer and/or cardiovascular diseases. Copyright © 2011 John Wiley & Sons, Ltd.

Genetic analysis of geraniol metabolism during fermentation.

PubMed

Steyer, Damien; Erny, Claude; Claudel, Patricia; Riveill, Geneviève; Karst, Francis; Legras, Jean-Luc

2013-04-01

Geraniol produced by grape is the main precursor of terpenols which play a key role in the floral aroma of white wines. We investigated the fate of geraniol during wine fermentation by Saccharomyces cerevisiae. The volatile compounds produced during fermentation of a medium enriched with geraniol were extracted by Stir-bar sorptive extraction and analysed by GC-MS. We were able to detect and quantify geranyl acetate but also citronellyl- and neryl-acetate. The presence of these compounds partly explains the disparition of geraniol. The amounts of terpenyl esters are strain dependant. We demonstrated both by gene overexpression and gene-deletion the involvement of ATF1 enzyme but not ATF2 in the acetylation of terpenols. The affinity of ATF1 enzyme for several terpenols and for isoamyl alcohol was compared. We also demonstrated that OYE2 is the enzyme involved in geraniol to citronellol reduction. Fermenting strain deleted from OYE2 gene produces far less citronellol than wild type strain. Moreover lab strain over-expressing OYE2 allows 87% geraniol to citronellol reduction in bioconversion experiment compared to about 50% conversion with control strain. Copyright © 2012 Elsevier Ltd. All rights reserved.

Geraniol attenuates hydrogen peroxide-induced liver fatty acid alterations in male rats.

PubMed

Ozkaya, Ahmet; Sahin, Zafer; Gorgulu, Ahmet Orhan; Yuce, Abdurrauf; Celik, Sait

2017-01-01

Hydrogen peroxide (H 2 O 2 ) is an oxidant agent and this molecule naturally occurs in the body as a product of aerobic metabolism. Geraniol is a plant-derived natural antioxidant. The aim of this study was to determine the role of geraniol on hepatic fatty acids alterations following H 2 O 2 -induced oxidative stress in male rats. After randomization, male Wistar rats were divided into four groups ( n = 7 each group). Geraniol (50 mg/kg, dissolved in corn oil) and H 2 O 2 (16 mg/kg, dissolved in distilled water) were administered by an intraperitoneal injection. Administrations were performed during 30 days with 1-day interval. Administration of H 2 O 2 resulted with a significant increase in malondialdehyde (MDA) and a significant decrease in glutathione (GSH) peroxidase glutathione level; geraniol restored its effects on liver. However, hepatic catalase (CAT) activities were significantly higher in H 2 O 2 , geraniol, and geraniol+H 2 O 2 groups than control group. The ratio of hepatic total saturated fatty acids increased in H 2 O 2 -treated animals compared with control. In addition, hepatic total unsaturated fatty acids reduced in H 2 O 2 group compared with control. The percentages of both hepatic total saturated and unsaturated fatty acids were not different between geraniol+H 2 O 2 and control groups. H 2 O 2 -induced oxidative stress may affect fatty acid composition in liver and body. Geraniol can partly restore oxidative hepatic damage because it cannot completely reverse the H 2 O 2 -induced increase in hepatic CAT activities. Moreover, this natural compound can regulate hepatic total saturated and unsaturated fatty acids percentages against H 2 O 2 -induced alterations.

Geraniol ameliorates TNBS-induced colitis: Involvement of Wnt/β-catenin, p38MAPK, NFκB, and PPARγ signaling pathways.

PubMed

Soubh, Ayman A; Abdallah, Dalaal M; El-Abhar, Hanan S

2015-09-01

Geraniol, a natural component of plant essential oils, exhibits potent chemopreventive effects in the colon; however, its possible role/mechanisms in experimental colitis have not been elucidated, which is the aim of this study. To fulfill this goal, rats were treated for 11days with geraniol and/or sulfasalazine using a TNBS-induced colitis model. Geraniol significantly hindered the colitis-clinical signs (weight loss, colon edema,ulcerative area, colon/spleen mass indices) and opposed the altered oxidative/nitrosative stress. It restored the depleted total antioxidant capacity and lessened the elevated levels of nitric oxide and lipid peroxide. TNBS induced apoptosis and inflammatory cell infiltration, whereas geraniol curtailed these effects by diminishing the levels of caspase-3, intercellular adhesion molecule-1, and myeloperoxidase. The anti-inflammatory effect was documented by inhibiting the colon contents of prostaglandin E2 and interleukin-1β. In order to delve into the anti-colitic signaling pathways, geraniol inhibited the content/expression of glycogen synthase kinase (GSK)-3β, β-catenin, p38 mitogen activated protein kinase (p38MAPK), and nuclear factor kappa B (NFκB), but upregulated that of peroxisome proliferator activated receptor γ (PPARγ). These effects were comparable to those of sulfasalazine, the standard drug, whereas its combination with geraniol mediated effects that surpassed either treatment alone. Geraniol in the current study improved experimental colitis partly via its antioxidant, anti-inflammatory, and immunosuppressive potentials, possibly by modulating the Wnt/GSK-3β/β-catenin, p38MAPK, NFκB, and PPARγ signaling pathways. The study also revealed that geraniol represents a valuable asset against colitis alone or in combination with the conventional anti-colitic therapies. Copyright © 2015 Elsevier Inc. All rights reserved.

Protective effect of geraniol inhibits inflammatory response, oxidative stress and apoptosis in traumatic injury of the spinal cord through modulation of NF-κB and p38 MAPK.

PubMed

Wang, Jiansheng; Su, Baishan; Zhu, Hongbin; Chen, Chao; Zhao, Gang

2016-12-01

Geraniol is a type of monoterpenoid with a rose scent and a slightly sweet flavor. It is found in the volatile oil of various plants, and has anti-inflammatory and anti-oxidant effects. The present study aimed to investigate the protective effect of geraniol in inhibiting the inflammatory response, oxidative stress and apoptosis in traumatic spinal cord injury (SCI), as well as to analyze the mechanism underlying its effect. Adult male Sprague-Dawley rats were induced to traumatic SCI through a surgical procedure and were defined as the SCI model group. SCI or normal rats were then administered 250 mg/kg/day geraniol for 4 weeks. The Basso, Beattie and Bresnahan (BBB) test and the spinal cord water content were used to analyze the effect of geraniol against traumatic SCI in rats. The inflammatory response, oxidative stress, and caspase-9 and -3 activities were measured using commercial ELISA kits. In addition, the associated mechanism was analyzed, using western blot analysis to determine the protein expression levels of nuclear factor (NF)-κB and p38 mitogen-activated protein kinase (MAPK). The results of the present study demonstrated that BBB scores were significantly increased and the spinal cord water content was significantly inhibited in SCI rats after 3 weeks of geraniol treatment. Furthermore, the inflammatory response, oxidative stress, and the caspase-9 and -3 activities were significantly suppressed upon treatment with geraniol. Finally, the mechanism of geraniol against traumatic SCI downregulated the NF-κB and p38 MAPK pathways in SCI rats. Therefore, the protective effect of geraniol is suggested to inhibit the inflammatory response, oxidative stress and apoptosis in traumatic SCI through the modulation of NF-κB and p38 MAPK.

Treatment with geraniol ameliorates methionine-choline-deficient diet-induced non-alcoholic steatohepatitis in rats.

PubMed

Chen, Jun; Fan, Xiaoxia; Zhou, Lin; Gao, Xiaogang

2016-07-01

Non-alcoholic steatohepatitis (NASH) is one of the most common causes of chronic liver disease and is considered to be a causative factor of cryptogenic cirrhosis and hepatocellular carcinoma. The aim of this work was to investigate whether treatment with geraniol (a monoterpene) attenuated NASH induced by methionine-choline-deficient (MCD) diet in rats. Rats were fed with MCD diet to induce NASH and treated with geraniol (200 mg/kg/day) for 10 weeks. Treatment with geraniol reduced histological scores, fibrosis, and apoptosis in livers, lowered activities of alanine aminotransferase and aspartate aminotransferase in serum, and attenuated hepatic fat accumulation in rats fed with MCD diet. Treatment with geraniol preserved hepatic mitochondrial function, evidenced by reduced mitochondrial reactive oxygen species formation, enhanced adenosine triphosphate formation and membrane integrity, restored mitochondrial electron transport chain enzyme activity, and increased mitochondrial DNA content in rats fed with MCD diet. Treatment with geraniol reduced uncoupling protein 2 protein expression, and enhanced protein expression of prohibitin, mRNA expression of peroxisome proliferator-activated receptor α, and activity of mitochondrial carnitine palmitoyl transferase-I in livers of rats fed with MCD diet. Treatment with geraniol abated oxidative stress, evidenced by reduced malondialdehyde and 3-nitrotyrosine formation, enhanced activity of glutathione S-epoxide transferase, and down-regulated expression of inducible nitric oxide synthase and cytochrome P450 2E1 in livers of rats fed with MCD diet. Treatment with geraniol reduced myeloperoxidase activity and protein expression of tumor necrosis factor alpha and IL-6 in livers of rats fed with MCD diet. Treatment with geraniol attenuated MCD-induced NASH in rats. © 2015 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

A domain swapping approach to elucidate differential regiospecific hydroxylation by geraniol and linalool synthases from perilla.

PubMed

Sato-Masumoto, Naoko; Ito, Michiho

2014-06-01

Geraniol and linalool are acyclic monoterpenes found in plant essential oils that have attracted much attention for their commercial use and in pharmaceutical studies. They are synthesized from geranyl diphosphate (GDP) by geraniol and linalool synthases, respectively. Both synthases are very similar at the amino acid level and share the same substrate; however, the position of the GDP to which they introduce hydroxyl groups is different. In this study, the mechanisms underlying the regiospecific hydroxylation of geraniol and linalool synthases were investigated using a domain swapping approach and site-directed mutagenesis in perilla. Sequences of the synthases were divided into ten domains (domains I to IV-4), and each corresponding domain was exchanged between both enzymes. It was shown that different regions were important for the formation of geraniol and linalool, namely, domains IV-1 and -4 for geraniol, and domains III-b, III-d, and IV-4 for linalool. These results suggested that the conformation of carbocation intermediates and their electron localization were seemingly to be different between geraniol and linalool synthases. Further, five amino acids in domain IV-4 were apparently indispensable for the formation of geraniol and linalool. According to three-dimensional structural models of the synthases, these five residues seemed to be responsible for the different spatial arrangement of the amino acid at H524 in the case of geraniol synthase, while N526 is the corresponding residue in linalool synthase. These results suggested that the side-chains of these five amino acids, in combination with several relevant domains, localized the positive charge in the carbocation intermediate to determine the position of the introduced hydroxyl group. Copyright © 2014 Elsevier Ltd. All rights reserved.

Protective effect of Geraniol on the transgenic Drosophila model of Parkinson's disease.

PubMed

Siddique, Yasir Hasan; Naz, Falaq; Jyoti, Smita; Ali, Fahad; Fatima, Ambreen; Rahul; Khanam, Saba

2016-04-01

The role of Geraniol was studied on the transgenic Drosophila model flies expressing normal human alpha synuclein (h-αS) in the neurons. Geraniol at final concentration of 10, 20 and 40μM were mixed in the diet and the flies were allowed to feed on it for 24 days. The effect of geraniol was studied on the climbing ability, activity pattern, lipid peroxidation, protein carbonyl, glutathione, dopamine content, and glutathione-S-transferase activity in the brains of transgenic Drosophila. The exposure of PD model flies to 10, 20 and 40μM of geraniol results in a significant delay in the loss of climbing ability (p<0.05), improved activity pattern reduced the oxidative stress (p<0.05) in the brains of transgenic Drosophila as compared to unexposed PD model flies. The results suggest that geraniol is potent in reducing the PD symptoms in transgenic Drosophila model of Parkinson's disease. Copyright © 2016 Elsevier B.V. All rights reserved.

Geraniol rescues inflammation in cellular and animal models of mevalonate kinase deficiency.

PubMed

Marcuzzi, Annalisa; Crovella, Sergio; Pontillo, Alessandra

2011-01-01

The inhibition of the mevalonate pathway through genetic defects such as mevalonate kinase deficiency (MKD) or pharmacological drugs such as aminobisphosphonates causes a shortage of intermediate compounds, in particular geranylgeranyl-pyrophosphate (GGPP), which is associated with the consequent augmented IL-1β release in monocytes. Considering that, due to its biochemical structure, isoprenoid geraniol enters the mevalonate pathway and may revert the genetic or pharmacological inhibition, the present study tested isoprenoid geraniol in cellular and animal MKD models obtained through the use of aminobisphosphonate pamidronate. The effect of natural isoprenoid geraniol on bacterial induced-inflammation was evaluated in a monocytic cell line (Raw 264.7) and in Balb/c mice treated with pamidronate. Geraniol diminished the levels of inflammatory markers induced by pamidronate stimuli in vitro and in vivo. Geraniol may be proposed as a novel therapeutic approach for the orphan disease MKD, and may also be considered for the evaluation of possible inflammatory side-effects of aminobisphosphonates.

Geraniol hydroxylase and hydroxygeraniol oxidase activities of the CYP76 family of cytochrome P450 enzymes and potential for engineering the early steps of the (seco)iridoid pathway.

PubMed

Höfer, René; Dong, Lemeng; André, François; Ginglinger, Jean-François; Lugan, Raphael; Gavira, Carole; Grec, Sebastien; Lang, Gerhard; Memelink, Johan; Van der Krol, Sander; Bouwmeester, Harro; Werck-Reichhart, Danièle

2013-11-01

The geraniol-derived (seco)iridoid skeleton is a precursor for a large group of bioactive compounds with diverse therapeutic applications, including the widely used anticancer molecule vinblastine. Despite of this economic prospect, the pathway leading to iridoid biosynthesis from geraniol is still unclear. The first geraniol hydroxylation step has been reported to be catalyzed by cytochrome P450 enzymes such as CYP76B6 from Catharanthus roseus and CYP76C1 from Arabidopsis thaliana. In the present study, an extended functional analysis of CYP76 family members was carried-out to identify the most effective enzyme to be used for pathway reconstruction. This disproved CYP76C1 activity and led to the characterization of CYP76C4 from A. thaliana as a geraniol 9- or 8-hydroxylase. CYP76B6 emerged as a highly specialized multifunctional enzyme catalyzing two sequential oxidation steps leading to the formation of 8-oxogeraniol from geraniol. This dual function was confirmed in planta using a leaf-disc assay. The first step, geraniol hydroxylation, was very efficient and fast enough to outcompete geraniol conjugation in plant tissues. When the enzyme was expressed in leaf tissues, 8-oxogeraniol was converted into further oxidized and/or reduced compounds in the absence of the next enzyme of the iridoid pathway. Copyright © 2013 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Evaluation of tobacco (Nicotiana tabacum L. cv. Petit Havana SR1) hairy roots for the production of geraniol, the first committed step in terpenoid indole alkaloid pathway.

PubMed

Ritala, Anneli; Dong, Lemeng; Imseng, Nicole; Seppänen-Laakso, Tuulikki; Vasilev, Nikolay; van der Krol, Sander; Rischer, Heiko; Maaheimo, Hannu; Virkki, Arho; Brändli, Johanna; Schillberg, Stefan; Eibl, Regine; Bouwmeester, Harro; Oksman-Caldentey, Kirsi-Marja

2014-04-20

The terpenoid indole alkaloids are one of the major classes of plant-derived natural products and are well known for their many applications in the pharmaceutical, fragrance and cosmetics industries. Hairy root cultures are useful for the production of plant secondary metabolites because of their genetic and biochemical stability and their rapid growth in hormone-free media. Tobacco (Nicotiana tabacum L. cv. Petit Havana SR1) hairy roots, which do not produce geraniol naturally, were engineered to express a plastid-targeted geraniol synthase gene originally isolated from Valeriana officinalis L. (VoGES). A SPME-GC-MS screening tool was developed for the rapid evaluation of production clones. The GC-MS analysis revealed that the free geraniol content in 20 hairy root clones expressing VoGES was an average of 13.7 μg/g dry weight (DW) and a maximum of 31.3 μg/g DW. More detailed metabolic analysis revealed that geraniol derivatives were present in six major glycoside forms, namely the hexose and/or pentose conjugates of geraniol and hydroxygeraniol, resulting in total geraniol levels of up to 204.3 μg/g DW following deglycosylation. A benchtop-scale process was developed in a 20-L wave-mixed bioreactor eventually yielding hundreds of grams of biomass and milligram quantities of geraniol per cultivation bag. Copyright © 2014 Elsevier B.V. All rights reserved.

Geraniol suppresses prostate cancer growth through down-regulation of E2F8.

PubMed

Lee, Sanghoon; Park, Yu Rang; Kim, Su-Hwa; Park, Eun-Jung; Kang, Min Ji; So, Insuk; Chun, Jung Nyeo; Jeon, Ju-Hong

2016-10-01

Geraniol, an acyclic dietary monoterpene, has been found to suppress cancer survival and growth. However, the molecular mechanism underlying the antitumor action of geraniol has not been investigated at the genome-wide level. In this study, we analyzed the microarray data obtained from geraniol-treated prostate cancer cells. Geraniol potently altered a gene expression profile and primarily down-regulated cell cycle-related gene signatures, compared to linalool, another structurally similar monoterpene that induces no apparent phenotypic changes. Master regulator analysis using the prostate cancer-specific regulatory interactome identified that the transcription factor E2F8 as a specific target molecule regulates geraniol-specific cell cycle signatures. Subsequent experiments confirmed that geraniol down-regulated E2F8 expression and the knockdown of E2F8 was sufficient to suppress cell growth by inducing G 2 /M arrest. Epidemiological analysis showed that E2F8 is up-regulated in metastatic prostate cancer and associated with poor prognosis. These results indicate that E2F8 is a crucial transcription regulator controlling cell cycle and survival in prostate cancer cells. Therefore, our study provides insight into the role of E2F8 in prostate cancer biology and therapeutics. © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Geraniol improves the impaired vascular reactivity in diabetes and metabolic syndrome through calcium channel blocking effect.

PubMed

El-Bassossy, Hany M; Elberry, Ahmed A; Ghareib, Salah A

2016-08-01

The aim of the present study is to investigate the effect and possible mechanism of action of geraniol on the impaired vascular reactivity of aortic rings isolated from diabetes or metabolic syndrome (MS) -induced rats. Male Wistar rats were divided into control, type 1 diabetes and metabolic syndrome (MS) groups. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50mg/kg) and left for 10weeks to develop vascular complications. MS was induced by adding 10% fructose and 3% salt to water and diet for 12weeks. The present study investigated the effect of in vitro incubation with geraniol (10-300μM) on the vasoconstrictor response to phenylephrine (PE) and the vasodilator response to acetylcholine (ACh) as well as its effect on aortae incubated with methylglyoxal (MG) as an advanced glycation end product (AGE). To investigate the mechanism of action of geraniol, different blockers are used, including Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME, 100μM), tetraethylammonium chloride (TEA, 10mM), and indomethacin (INDO, 5μM). Moreover, the effect of calcium chloride (CaCl2) on aortic rings precontracted with PE or potassium chloride (KCl) was examined. Thirty minutes incubation with geraniol alleviated the exaggerated vasoconstriction in aortae isolated from diabetic or MS animals or in vitro exposed to MG in a concentration-dependent manner. In addition, geraniol improved the vasodilatation response of diabetic or MS aortae or aortae exposed to MG. In search for the mechanism; geraniol produced concentration-dependent relaxation of both PE and KCl-precontracted aorta. Geraniol relaxation was not affected by L-NAME, INDO or TEA. However, geraniol significantly inhibited voltage dependent and receptor mediated Ca(2+)-induced contraction activated by KCl or PE respectively. In conclusion, geraniol ameliorates impaired vascular reactivity in experimentally induced diabetes and MS. The effect may be partially attributed to an endothelium-independent pathway involving blockage of both voltage dependent and receptor operated calcium channel. Copyright © 2016 Elsevier Inc. All rights reserved.

Preventive Effect of Geraniol on Diethylnitrosamine-Induced Hepatocarcinogenesis in Rats.

PubMed

Sawada, Shintaro; Okano, Jun-Ichi; Imamoto, Ryu; Yasunaka, Yuki; Abe, Ryo; Koda, Masahiko; Murawaki, Yoshikazu; Isomoto, Hajime

2016-03-01

Geraniol is a plant-derived phytochemical possessing anti-cancer action. The anti-carcinogenic effect of geraniol was investigated in the diethylnitrosamine (DEN)-induced hepatocarcinogenic rat model. Male Wistar rats were intraperitoneally injected with 300 μL of phosphate-buffered saline (PBS) (G1; n = 4) or DEN (100 mg/kg body weight) dissolved in PBS (G2; n = 8) every 2 weeks on experimental weeks 2, 4 and 6. The rats were treated with a low concentration (0.07%) of geraniol (G3; n = 9) and high concentration (0.35%) of geraniol (G4; n = 7) for 12 weeks. To evaluate the effects of geraniol on the DEN-induced hepatocarcinogenesis, we compared the relative liver weight, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels and expression levels of proliferating cell nuclear antigen (PCNA) and glutathione S transferase-P (GST-P) by immunohistochemical analyses among each group. Relative liver weight was significantly higher in G2 than in G1 (P < 0.01). Both serum AST and ALT levels were significantly higher in G2 than in G3 and in G4 (P < 0.05). Serum ALP levels did not show a significant difference among each group. Percentages of both PCNA- and GST-P- positive area were significantly decreased in G3 and in G4 compared to in G2 (P < 0.001, respectively), suggesting anti-hepatocarcinogenic effects of geraniol. Geraniol is a promising compound useful for suppression of hepatocellular carcinoma. The mechanisms of action are required to be clarified in the future intensive study.

Aqueous 2% Geraniol as a mosquito repellent failed against Aedes Aegypti on ponies

USDA-ARS?s Scientific Manuscript database

Organic insect repellents are of interest to many agricultural producers and animal owners. Geraniol, a plant-derived alcohol is naturally produced by a wide range of plants and is an EPA “minimum risk pesticide”. Previous studies have shown various concentrations of geraniol to repel or kill mosqui...

Inhibitory effects of citronellol and geraniol on nitric oxide and prostaglandin E₂production in macrophages.

PubMed

Su, Yu-Wen; Chao, Shiou-Huei; Lee, Meng-Hwan; Ou, Tsang-Yow; Tsai, Ying-Chieh

2010-10-01

Geranium oil has been used traditionally for diarrhea, dermatitis, and intestinal inflammation in East Asia. The aim of this study was to determine the effects of geranium oil's characteristic components, citronellol and geraniol, on lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin E(2) (PGE(2)) production in RAW 264.7 macrophages. Citronellol and geraniol suppressed NO and PGE(2) production in a dose-dependent manner. The inhibitory efficacy of geraniol was concomitant with decreases in protein and mRNA expression levels of inducible nitric oxide synthase (iNOS), whereas citronellol inhibited only iNOS enzymatic activity. By adding citronellol and geraniol, the LPS-induced cyclooxygenase-2 (COX-2) protein and mRNA expression levels were significantly attenuated, whereas cytosolic degradation of I κB α and upregulation of NF-κB p65 in the nucleus were reversed. These results suggested that citronellol and geraniol exhibit anti-inflammatory activities, supporting their common use and demonstrating their therapeutic potential for inflammation-associated disorders. © Georg Thieme Verlag KG Stuttgart · New York.

Geraniol encapsulated in chitosan/gum arabic nanoparticles: a promising system for pest management in sustainable agriculture.

PubMed

de Oliveira, Jhones Luiz; Campos, Estefania Vangelie Ramos; Pereira, Anderson E S; Nunes, Lucas E S; da Silva, Camila C L; Pasquoto, Tatiane; Lima, Renata; Smaniotto, Giovani; Polanczyk, Ricardo Antonio; Fraceto, Leonardo F

2018-05-07

The nanoencapsulation of botanical compounds (such as geraniol) is an important strategy that can be used to increase the stability and efficiency of these substances in integrated pest management. In this study, chitosan/gum arabic nanoparticles containing geraniol were prepared and characterized. In addition, evaluation was made of the biological activity of geraniol encapsulated in chitosan/gum arabic nanoparticles towards whitefly (Bemisia tabaci). The optimized formulation showed a high encapsulation efficiency (>90%) and remained stable for about 120 days. The formulation protected the geraniol against degradation by UV radiation, and the in vitro release was according to a diffusion mechanism that was influenced by temperature. An attraction effect was observed for Bemisia tabaci, indicating the potential of this type of system for use in pest management, especially in trap devices.

Protective effect of geraniol inhibits inflammatory response, oxidative stress and apoptosis in traumatic injury of the spinal cord through modulation of NF-κB and p38 MAPK

PubMed Central

Wang, Jiansheng; Su, Baishan; Zhu, Hongbin; Chen, Chao; Zhao, Gang

2016-01-01

Geraniol is a type of monoterpenoid with a rose scent and a slightly sweet flavor. It is found in the volatile oil of various plants, and has anti-inflammatory and anti-oxidant effects. The present study aimed to investigate the protective effect of geraniol in inhibiting the inflammatory response, oxidative stress and apoptosis in traumatic spinal cord injury (SCI), as well as to analyze the mechanism underlying its effect. Adult male Sprague-Dawley rats were induced to traumatic SCI through a surgical procedure and were defined as the SCI model group. SCI or normal rats were then administered 250 mg/kg/day geraniol for 4 weeks. The Basso, Beattie and Bresnahan (BBB) test and the spinal cord water content were used to analyze the effect of geraniol against traumatic SCI in rats. The inflammatory response, oxidative stress, and caspase-9 and −3 activities were measured using commercial ELISA kits. In addition, the associated mechanism was analyzed, using western blot analysis to determine the protein expression levels of nuclear factor (NF)-κB and p38 mitogen-activated protein kinase (MAPK). The results of the present study demonstrated that BBB scores were significantly increased and the spinal cord water content was significantly inhibited in SCI rats after 3 weeks of geraniol treatment. Furthermore, the inflammatory response, oxidative stress, and the caspase-9 and −3 activities were significantly suppressed upon treatment with geraniol. Finally, the mechanism of geraniol against traumatic SCI downregulated the NF-κB and p38 MAPK pathways in SCI rats. Therefore, the protective effect of geraniol is suggested to inhibit the inflammatory response, oxidative stress and apoptosis in traumatic SCI through the modulation of NF-κB and p38 MAPK. PMID:28105094

A homomeric geranyl diphosphate synthase-encoding gene from Camptotheca acuminata and its combinatorial optimization for production of geraniol in Escherichia coli.

PubMed

Yang, Lixia; Jiang, Liangzhen; Li, Wei; Yang, Yun; Zhang, Guolin; Luo, Yinggang

2017-10-01

Geranyl diphosphate (GPP), the unique precursor for all monoterpenoids, is biosynthesized from isopentenyl diphosphate and dimethylallyl diphosphate via the head-to-tail condensation reaction catalyzed by GPP synthase (GPPS). Herein a homomeric GPPS from Camptotheca acuminata, a camptothecin-producing plant, was obtained from 5'- and 3'-rapid amplification of cDNA ends and subsequent overlap extension and convenient PCR amplifications. The truncate CaGPPS was introduced to replace ispA of pBbA5c-MevT(CO)-MBIS(CO, ispA), a de novo biosynthetic construct for farnesyl diphosphate generation, and overexpressed in Escherichia coli, together with the truncate geraniol synthase-encoding gene from C. acuminata (tCaGES), to confirm CaGPPS-catalyzed reaction in vivo. A 24.0 ± 1.3 mg L -1 of geraniol was produced in the recombinant E. coli. The production of GPP was also validated by the direct UPLC-HRMS E analyses. The tCaGPPS and tCaGES genes with different copy numbers were introduced into E. coli to balance their catalytic potential for high-yield geraniol production. A 1.6-fold increase of geraniol production was obtained when four copies of tCaGPPS and one copy of tCaGES were introduced into E. coli. The following fermentation conditions optimization, including removal of organic layers and addition of new n-decane, led to a 74.6 ± 6.5 mg L -1 of geraniol production. The present study suggested that the gene copy number optimization, i.e., the ratio of tCaGPPS and tCaGES, plays an important role in geraniol production in the recombinant E. coli. The removal and addition of organic solvent are very useful for sustainable high-yield production of geraniol in the recombinant E. coli in view of that the solubility of geraniol is limited in the fermentation broth and/or n-decane.

Geraniol and Geranial Dehydrogenases Induced in Anaerobic Monoterpene Degradation by Castellaniella defragrans

PubMed Central

Lüddeke, Frauke; Wülfing, Annika; Timke, Markus; Germer, Frauke; Weber, Johanna; Dikfidan, Aytac; Rahnfeld, Tobias; Linder, Dietmar; Meyerdierks, Anke

2012-01-01

Castellaniella defragrans is a Betaproteobacterium capable of coupling the oxidation of monoterpenes with denitrification. Geraniol dehydrogenase (GeDH) activity was induced during growth with limonene in comparison to growth with acetate. The N-terminal sequence of the purified enzyme directed the cloning of the corresponding open reading frame (ORF), the first bacterial gene for a GeDH (geoA, for geraniol oxidation pathway). The C. defragrans geraniol dehydrogenase is a homodimeric enzyme that affiliates with the zinc-containing benzyl alcohol dehydrogenases in the superfamily of medium-chain-length dehydrogenases/reductases (MDR). The purified enzyme most efficiently catalyzes the oxidation of perillyl alcohol (kcat/Km = 2.02 × 106 M−1 s−1), followed by geraniol (kcat/Km = 1.57 × 106 M−1 s−1). Apparent Km values of <10 μM are consistent with an in vivo toxicity of geraniol above 5 μM. In the genetic vicinity of geoA is a putative aldehyde dehydrogenase that was named geoB and identified as a highly abundant protein during growth with phellandrene. Extracts of Escherichia coli expressing geoB demonstrated in vitro a geranial dehydrogenase (GaDH) activity. GaDH activity was independent of coenzyme A. The irreversible formation of geranic acid allows for a metabolic flux from β-myrcene via linalool, geraniol, and geranial to geranic acid. PMID:22286981

Cymbopogon martinii essential oil and geraniol at noncytotoxic concentrations exerted immunomodulatory/anti-inflammatory effects in human monocytes.

PubMed

Murbach Teles Andrade, Bruna Fernanda; Conti, Bruno José; Santiago, Karina Basso; Fernandes Júnior, Ary; Sforcin, José Maurício

2014-10-01

In traditional medicine, plants have formed the basis of sophisticated systems that have been in existence for thousands of years and still provide mankind with new remedies. Cymbopogon martinii, known as palmarosa, has been used in aromatherapy as a skin tonic due to its antimicrobial properties. It has also used in Ayurvedic medicine for skin problems and to relieve nerve pain. The immunomodulatory action of C. martinii essential oil (EO) and geraniol was evaluated regarding the production of pro- and anti-inflammatory cytokines (tumour necrosis factor (TNF)-α and IL-10, respectively) by human monocytes in vitro. Monocyte cultures were incubated with EO or geraniol. After 18 h, cytotoxicity assays were performed using 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide method, and cytokine production was determined by ELISA. The variables showed no cytotoxic effects on monocytes. TNF-α production was not affected by C. martinii and geraniol, and only the concentration of 5 μg/ml of C. martinii stimulated its production. On the other hand, all concentrations of C. martinii and geraniol increased IL-10 production by human monocytes. Data showed that noncytotoxic concentrations of EO and geraniol exerted an anti-inflammatory action by increasing IL-10 production; moreover, geraniol seemed to be probably responsible for EO immunomodulatory activity in our assay condition. © 2014 Royal Pharmaceutical Society.

Geraniol and geranial dehydrogenases induced in anaerobic monoterpene degradation by Castellaniella defragrans.

PubMed

Lüddeke, Frauke; Wülfing, Annika; Timke, Markus; Germer, Frauke; Weber, Johanna; Dikfidan, Aytac; Rahnfeld, Tobias; Linder, Dietmar; Meyerdierks, Anke; Harder, Jens

2012-04-01

Castellaniella defragrans is a Betaproteobacterium capable of coupling the oxidation of monoterpenes with denitrification. Geraniol dehydrogenase (GeDH) activity was induced during growth with limonene in comparison to growth with acetate. The N-terminal sequence of the purified enzyme directed the cloning of the corresponding open reading frame (ORF), the first bacterial gene for a GeDH (geoA, for geraniol oxidation pathway). The C. defragrans geraniol dehydrogenase is a homodimeric enzyme that affiliates with the zinc-containing benzyl alcohol dehydrogenases in the superfamily of medium-chain-length dehydrogenases/reductases (MDR). The purified enzyme most efficiently catalyzes the oxidation of perillyl alcohol (k(cat)/K(m) = 2.02 × 10(6) M(-1) s(-1)), followed by geraniol (k(cat)/K(m) = 1.57 × 10(6) M(-1) s(-1)). Apparent K(m) values of <10 μM are consistent with an in vivo toxicity of geraniol above 5 μM. In the genetic vicinity of geoA is a putative aldehyde dehydrogenase that was named geoB and identified as a highly abundant protein during growth with phellandrene. Extracts of Escherichia coli expressing geoB demonstrated in vitro a geranial dehydrogenase (GaDH) activity. GaDH activity was independent of coenzyme A. The irreversible formation of geranic acid allows for a metabolic flux from β-myrcene via linalool, geraniol, and geranial to geranic acid.

Cytochrome P450-mediated activation of the fragrance compound geraniol forms potent contact allergens

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

Hagvall, Lina; Baron, Jens Malte; Boerje, Anna

2008-12-01

Contact sensitization is caused by low molecular weight compounds which penetrate the skin and bind to protein. In many cases, these compounds are activated to reactive species, either by autoxidation on exposure to air or by metabolic activation in the skin. Geraniol, a widely used fragrance chemical, is considered to be a weak allergen, although its chemical structure does not indicate it to be a contact sensitizer. We have shown that geraniol autoxidizes and forms allergenic oxidation products. In the literature, it is suggested but not shown that geraniol could be metabolically activated to geranial. Previously, a skin-like CYP cocktailmore » consisting of cutaneous CYP isoenzymes, was developed as a model system to study cutaneous metabolism. In the present study, we used this system to investigate CYP-mediated activation of geraniol. In incubations with the skin-like CYP cocktail, geranial, neral, 2,3-epoxygeraniol, 6,7-epoxygeraniol and 6,7-epoxygeranial were identified. Geranial was the main metabolite formed followed by 6,7-epoxygeraniol. The allergenic activities of the identified metabolites were determined in the murine local lymph node assay (LLNA). Geranial, neral and 6,7-epoxygeraniol were shown to be moderate sensitizers, and 6,7-epoxygeranial a strong sensitizer. Of the isoenzymes studied, CYP2B6, CYP1A1 and CYP3A5 showed high activities. It is likely that CYP1A1 and CYP3A5 are mainly responsible for the metabolic activation of geraniol in the skin, as they are expressed constitutively at significantly higher levels than CYP2B6. Thus, geraniol is activated through both autoxidation and metabolism. The allergens geranial and neral are formed via both oxidation mechanisms, thereby playing a large role in the sensitization to geraniol.« less

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

Cytochrome P450-mediated activation of the fragrance compound geraniol forms potent contact allergens.

PubMed

Hagvall, Lina; Baron, Jens Malte; Börje, Anna; Weidolf, Lars; Merk, Hans; Karlberg, Ann-Therese

2008-12-01

Contact sensitization is caused by low molecular weight compounds which penetrate the skin and bind to protein. In many cases, these compounds are activated to reactive species, either by autoxidation on exposure to air or by metabolic activation in the skin. Geraniol, a widely used fragrance chemical, is considered to be a weak allergen, although its chemical structure does not indicate it to be a contact sensitizer. We have shown that geraniol autoxidizes and forms allergenic oxidation products. In the literature, it is suggested but not shown that geraniol could be metabolically activated to geranial. Previously, a skin-like CYP cocktail consisting of cutaneous CYP isoenzymes, was developed as a model system to study cutaneous metabolism. In the present study, we used this system to investigate CYP-mediated activation of geraniol. In incubations with the skin-like CYP cocktail, geranial, neral, 2,3-epoxygeraniol, 6,7-epoxygeraniol and 6,7-epoxygeranial were identified. Geranial was the main metabolite formed followed by 6,7-epoxygeraniol. The allergenic activities of the identified metabolites were determined in the murine local lymph node assay (LLNA). Geranial, neral and 6,7-epoxygeraniol were shown to be moderate sensitizers, and 6,7-epoxygeranial a strong sensitizer. Of the isoenzymes studied, CYP2B6, CYP1A1 and CYP3A5 showed high activities. It is likely that CYP1A1 and CYP3A5 are mainly responsible for the metabolic activation of geraniol in the skin, as they are expressed constitutively at significantly higher levels than CYP2B6. Thus, geraniol is activated through both autoxidation and metabolism. The allergens geranial and neral are formed via both oxidation mechanisms, thereby playing a large role in the sensitization to geraniol.

Monoterpenoid biosynthesis in Saccharomyces cerevisiae.

PubMed

Oswald, Marilyne; Fischer, Marc; Dirninger, Nicole; Karst, Francis

2007-05-01

Plant monoterpenoids belong to a large family of plant secondary metabolites with valuable applications in cosmetics and medicine. Their usual low levels and difficult purification justify the need for alternative fermentative processes for large-scale production. Geranyl diphosphate is the universal precursor of monoterpenoids. In yeast it occurs exclusively as an intermediate of farnesyl diphosphate synthesis. In the present study we investigated the potential use of Saccharomyces cerevisiae as an alternative engineering tool. The expression of geraniol synthase of Ocimum basilicum in yeast allowed a strong and specific excretion of geraniol to the growth medium, in contrast to mutants defective in farnesyl diphosphate synthase which excreted geraniol and linalool in similar amounts. A further increase of geraniol synthesis was obtained using yeast mutants defective in farnesyl diphosphate synthase. We also showed that geraniol synthase expression affects the general ergosterol pathway, but in a manner dependent on the genetic background of the strain.

Role of geraniol against lead acetate-mediated hepatic damage and their interaction with liver carboxylesterase activity in rats.

PubMed

Ozkaya, Ahmet; Sahin, Zafer; Kuzu, Muslum; Saglam, Yavuz Selim; Ozkaraca, Mustafa; Uckun, Mirac; Yologlu, Ertan; Comakli, Veysel; Demirdag, Ramazan; Yologlu, Semra

2018-02-01

In this study, the effect of geraniol (50 mg/kg for 30 d), a natural antioxidant and repellent/antifeedant monoterpene, in a rat model of lead acetate-induced (500 ppm for 30 d) liver damage was evaluated. Hepatic malondialdehyde increased in the lead acetate group. Reduced glutathione unchanged, but glutathione S-transferase, glutathione reductase, as well as carboxylesterase activities decreased in geraniol, lead acetate and geraniol + lead acetate groups. 8-OhDG immunoreactivity, mononuclear cell infiltrations and hepatic lead concentration were lower in the geraniol + lead acetate group than the lead acetate group. Serum aspartate aminotransferase and alanine aminotransferase activities increased in the Pb acetate group. In conclusion, lead acetate causes oxidative and toxic damage in the liver and this effect can reduce with geraniol treatment. However, we first observed that lead acetate, as well as geraniol, can affect liver carboxylesterase activity.

Effect of Inhaling Cymbopogon martinii Essential Oil and Geraniol on Serum Biochemistry Parameters and Oxidative Stress in Rats.

PubMed

Andrade, Bruna Fernanda Murbach Teles; Braga, Camila Pereira; Dos Santos, Klinsmann Carolo; Barbosa, Lidiane Nunes; Rall, Vera Lúcia Mores; Sforcin, José Maurício; Fernandes, Ana Angélica Henrique; Fernandes Júnior, Ary

2014-01-01

The effects of the inhalation of Cymbopogon martinii essential oil (EO) and geraniol on Wistar rats were evaluated for biochemical parameters and hepatic oxidative stress. Wistar rats were divided into three groups (n = 8): G1 was control group, treated with saline solution; G2 received geraniol; and G3 received C. martinii EO by inhalation during 30 days. No significant differences were observed in glycemia and triacylglycerol levels; G2 and G3 decreased (P < 0.05) total cholesterol level. There were no differences in serum protein, urea, aspartate aminotransferase activity, and total hepatic protein. Creatinine levels increased in G2 but decreased in G3. Alanine aminotransferase activity and lipid hydroperoxide were higher in G2 than in G3. Catalase and superoxide dismutase activities were higher in G3. C. martinii EO and geraniol increased glutathione peroxidase. Oxidative stress caused by geraniol may have triggered some degree of hepatic toxicity, as verified by the increase in serum creatinine and alanine aminotransferase. Therefore, the beneficial effects of EO on oxidative stress can prevent the toxicity in the liver. This proves possible interactions between geraniol and numerous chemical compounds present in C. martinii EO.

In vitro human skin penetration of geraniol and citronellol.

PubMed

Gilpin, Sarah; Hui, Xiaoying; Maibach, Howard

2010-01-01

Geraniol and citronellol are commonly used fragrance components in consumer products. Both are listed as alleged fragrance allergens that should be declared in the European Union when used in cosmetics and consumer products. Such allergenic potential is determined largely by effects on the skin once these materials penetrate and elicit an immune response. Few data demonstrate their penetration abilities or their effects on percutaneous absorption. We wanted to determine the effects of these materials on skin absorption. Skin penetration characterization via flow-through diffusion study serves as a reasonable model for determining dermal dosing for fragrance materials. Such characterization can be used for more accurate safety exposure calculations and regulatory determinations. Extensive comparisons to in vivo data in humans or closely related animals will be required before accepting flow-through diffusion methods as in vivo alternatives by industry and regulatory bodies. To evaluate the penetration abilities of geraniol and citronellol when they are used in a typical vehicle in consumer products. In vitro skin penetration of radiolabeled geraniol and citronellol was studied under occlusion in human cadaver skin, using flow-through diffusion cells for scintillation counting to determine the percentage of dose absorbed. For comparison, two doses of each material were used: 2% and 5% in 3:1 diethyl phthalate/ethanol. After 24 hours, geraniol and citronellol had relatively low skin absorption rates; 3.8% +/- 2.1% of 2% citronellol, 4.7% +/- 1.9% of 5% citronellol, 3.5% +/- 1.9% of 2% geraniol, and 7.3% +/- 1.1% of 5% geraniol were recovered from skin and receptor fluid compartments. These materials showed good mass-balance recovery. The majority of the dose was recovered in the skin washes (a minimum of 64.7% +/- 4.6% recovered for 2% citronellol and a maximum of 79.3% +/- 3.9% recovered for 5% geraniol). Receptor fluid collection points over time showed a linear increase in the amounts of citronellol and geraniol that penetrated the skin, although overall absorption values were quite small. In vitro results indicate that geraniol and citronellol have low potentials for skin penetration, which has implications for their ability to induce allergenicity and for more predictive toxicologic profiling of these materials. In vivo studies should be done to correlate the in vitro results.

Anti-Trichomonas vaginalis properties of the oil of Amomum tsao-ko and its major component, geraniol.

PubMed

Dai, Min; Peng, Cheng; Peng, Fu; Xie, Chengbin; Wang, Pinjia; Sun, Fenghui

2016-01-01

Trichomonosis, caused by the flagellate protozoan Trichomonas vaginalis, is the most common non-viral sexually transmitted disease (STD) and 5-nitroimidazole drugs are used for the treatment. However, a growing number of T. vaginalis isolates are resistant to these drugs, which make it becomes an urgent issue. The current study was designed to evaluate the anti-T. vaginalis activity of the essential oil from A. tsao-ko used in traditional Chinese medicine and as a spice and its main component, geraniol. The anti-T. vaginalis activities of A. tsao-ko essential oil and geraniol were evaluated by the minimum lethal concentration (MLC) and 50% inhibitory concentration (IC50) in vitro. The morphological changes of T. vaginalis were observed by transmission electron microscopy (TEM). Additionally, sub-MLC concentration treatment with sub-MLC A. tsao-ko essential oil and geraniol was also performed. This study shows that MLC/IC50 of A. tsao-ko essential oil was 44.97 µg/ml/22.49 µg/ml for T. vaginalis isolate Tv1, and 89.93 µg/ml/44.97 µg/ml for T. vaginalis isolate Tv2. Those of geraniol were 342.96 µg/ml/171.48 µg/ml, respectively. After A. tsao-ko essential oil or geraniol treatment, obvious similar morphological changes of T. vaginalis were observed by TEM: the nuclear membrane was damaged, nuclei were dissolved, and the chromatin was accumulated; in the cytoplasm, numerous vacuoles appeared, rough endoplasmic reticulum dilated, the number of ribosomes were reduced, organelles disintegrated, the cell membrane was partially damaged, with cytoplasmic leakage, and cell disintegration was observed. The action time did not increase the effect of A. tsao-ko essential oil or geraniol against T. vaginalis, as no significant difference was observed after sub-MLC concentration treatment for 1, 3, and 5 h with A. tsao-ko essential oil and geraniol. The study describes the first report on the activity and morphological changes of A. tsao-ko essential oil and geraniol against T. vaginalis. The results obtained herein presented new opportunities for antitrichomonal drugs.

Geraniol and beta-ionone inhibit proliferation, cell cycle progression, and cyclin-dependent kinase 2 activity in MCF-7 breast cancer cells independent of effects on HMG-CoA reductase activity.

PubMed

Duncan, Robin E; Lau, Dominic; El-Sohemy, Ahmed; Archer, Michael C

2004-11-01

3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase catalyzes the formation of mevalonate, a precursor of cholesterol that is also required for cell proliferation. Mevalonate depletion results in a G1 phase cell cycle arrest that is mediated in part by impaired activity of cyclin-dependent kinase (CDK) 2, and decreased expression of positive regulators of G1 to S phase progression. Inhibition of mevalonate synthesis may, therefore, be a useful strategy to impair the growth of malignant cells. Plant isoprenoids, including beta-ionone and geraniol, have previously been shown to inhibit rodent mammary tumor development, and rodent and avian hepatic HMG-CoA reductase activity. We hypothesized that the putative anti-proliferative and cell cycle inhibitory effects of beta-ionone and geraniol on MCF-7 human breast cancer cells in culture are mediated by mevalonate depletion resulting from inhibition of HMG-CoA reductase activity. Flow cytometric analysis showed a G1 arrest in isoprenoid-treated MCF-7 cells, and also a G2/M arrest at higher concentrations of isoprenoids. These compounds minimally affected the growth of MCF-10F normal breast epithelial cells. Both beta-ionone and geraniol inhibited CDK 2 activity and dose-dependently decreased the expression of cyclins D1, E, and A, and CDK 2 and 4, without changing the expression of p21cip1 or p27kip1. Although both beta-ionone and geraniol also inhibited MCF-7 proliferation, only geraniol inhibited HMG-CoA reductase activity. While these effects were significantly correlated (r2=0.89, P <0.01), they were not causally related, since exogenous mevalonate did not restore growth in geraniol-inhibited cells. These findings indicate that mechanisms other than impaired mevalonate synthesis mediate the anti-proliferative and cell cycle regulatory effects of beta-ionone and geraniol in human breast cancer cells.

In vitro larvicidal activity of geraniol and citronellal against Contracaecum sp (Nematoda: Anisakidae).

PubMed

Barros, L A; Yamanaka, A R; Silva, L E; Vanzeler, M L A; Braum, D T; Bonaldo, J

2009-10-01

Human infection with fish parasites can result from the ingestion of incompletely cooked or raw fish, giving origin to parasitic diseases such as anisakiasis, caused by parasites of the Anisakidae family. The present study assessed the in vitro larvicidal effect of two monoterpene compounds, geraniol and citronellal, against Contracaecum sp (Nematoda: Anisakidae). Four hundred live larvae of Contracaecum sp obtained from 'traíra' fish (Hoplias malabaricus, Bloch, 1974) were analyzed on 40 Petri dishes (10 larvae each) with the compounds to be tested. The final concentrations tested for each compound were 250, 125, 62.5, and 31.2 microg/mL and the evaluation was carried out at five different times (2, 4, 8, 24, and 48 h). The larvicidal action of geraniol and citronellal was statistically superior (P < 0.005) to the control (1% ethanol) at concentrations of 250 and 31.2 microg/mL (geraniol) and 250, 125, and 62.5 microg/mL (citronellal). However, no larvicidal activity was observed at concentrations of 125 and 62.5 microg/mL for geraniol and 31.2 microg/mL for citronellal. When the larvicidal action of geraniol was compared to that of citronellal, the former was found to be statistically superior (P < 0.05) to the latter at concentrations of 250 and 31.2 microg/mL. On the other hand, citronellal was statistically superior (P < 0.005) to geraniol at concentrations of 125 and 62.5 microg/mL. The larval mortality rate in terms of time (hours) was higher for geraniol with the passing of time at the 250 microg/mL concentration. At this concentration (in 48 h) the best larvicidal effect was observed with 90% lethality. The larvae were considered to be dead using no motility and loss of structural integrity as parameters. The data indicate that natural terpene compounds should be more explored for antihelminthic activity and can be useful for other studies about anisakiasis treatment.

Geraniol as a novel antivirulence agent against bacillary dysentery-causing Shigella sonnei.

PubMed

Mirza, Zainulabedeen R M H; Hasan, Thaer; Seidel, Veronique; Yu, Jun

2018-01-01

Antimicrobial resistance has emerged as a major challenge to modern medicine and it has become urgent to seek alternative approaches to treat infections caused by fast-evolving multi-resistant clones of bacillary dysentery-causing Shigella sonnei. Here, we show that geraniol, a natural substance present in the essential oils of plants such as rose and lemongrass, can reduce S. sonnei proliferation inside host cells and protect Galleria mellonella larvae from killing by S. sonnei infection. We present evidence that geraniol competitively inhibits the catalytic activity of the master virulence regulator, DsbA, a periplasmic disulphide bond oxidoreductase required for Shigella survival in the host cell cytosol. Our observations suggest that geraniol holds a great therapeutic potential that should be further exploited.

Analysis of the enzymatic formation of citral in the glands of sweet basil.

PubMed

Iijima, Yoko; Wang, Guodong; Fridman, Eyal; Pichersky, Eran

2006-04-15

Basil glands of the Sweet Dani cultivar contain high levels of citral, a mixture of geranial and its cis-isomer neral, as well as low levels of geraniol and nerol. We have previously reported the identification of a cDNA from Sweet Dani that encodes an enzyme responsible for the formation of geraniol from geranyl diphosphate in the glands, and that these glands cannot synthesize nerol directly from geranyl diphosphate. Here, we report the identification of two basil cDNAs encoding NADP+-dependent dehydrogenases that can use geraniol as the substrate. One cDNA, designated CAD1, represents a gene whose expression is highly specific to gland cells of all three basil cultivars examined, regardless of their citral content, and encodes an enzyme with high sequence similarity to known cinnamyl alcohol dehydrogenases (CADs). The enzyme encoded by CAD1 reversibly oxidizes geraniol to produce geranial (which reversibly isomerizes to neral via keto-enol tautomerization) at half the efficiency compared with its activity with cinnamyl alcohol. CAD1 does not use nerol and neral as substrates. A second cDNA, designated GEDH1, encodes an enzyme with sequence similarity to CAD1 that is capable of reversibly oxidizing geraniol and nerol in equal efficiency, and prolonged incubation of geraniol with GEDH1 in vitro produces not only geranial and neral, but also nerol. GEDH1 is also active, although at a lower efficiency, with cinnamyl alcohol. However, GEDH1 is expressed at low levels in glands of all cultivars compared with its expression in leaves. These and additional data presented indicate that basil glands may contain additional dehydrogenases capable of oxidizing geraniol.

Geraniol dehydrogenase, the key enzyme in biosynthesis of the alarm pheromone, from the astigmatid mite Carpoglyphus lactis (Acari: Carpoglyphidae).

PubMed

Noge, Koji; Kato, Makiko; Mori, Naoki; Kataoka, Michihiko; Tanaka, Chihiro; Yamasue, Yuji; Nishida, Ritsuo; Kuwahara, Yasumasa

2008-06-01

Geraniol dehydrogenase (GeDH), which plays an important role in the biosynthesis of neral, an alarm pheromone, was purified from the astigmatid mite Carpoglyphus lactis. The enzyme was obtained in an apparently homogeneous and active form after 1879-fold purification through seven steps of chromatography. Car. lactis GeDH was determined to be a monomer in its active form with a relative molecular mass of 42 800, which is a unique subunit structure in comparison with already established alcohol dehydrogenases. Car. lactis GeDH oxidized geraniol into geranial in the presence of NAD+. NADP+ was ineffective as a cofactor, suggesting that Car. lactis GeDH is an NAD+-dependent alcohol dehydrogenase. The optimal pH and temperature for geraniol oxidation were determined to be pH 9.0 and 25 degrees C, respectively. The Km values for geraniol and NAD+ were 51.0 microm and 59.5 microm, respectively. Car. lactis GeDH was shown to selectively oxidize geraniol, whereas its geometrical isomer, nerol, was inert as a substrate. The high specificity for geraniol suggests that Car. lactis GeDH specializes in the alarm pheromone biosynthesis of Car. lactis. Car. lactis GeDH is composed of 378 amino acids. Structurally, Car. lactis GeDH showed homology with zinc-dependent alcohol dehydrogenases found in mammals and a mosquito (36.6-37.6% identical), and the enzyme was considered to be a member of the medium-chain dehydrogenase/reductase family, in view of the highly conserved sequences of zinc-binding and NAD+-binding sites. Phylogenetic analyses indicate that Car. lactis GeDH could be categorized as a new class, different from other established alcohol dehydrogenases.

Investigating the antifungal activity and mechanism(s) of geraniol against Candida albicans strains.

PubMed

Leite, Maria Clerya Alvino; de Brito Bezerra, André Parente; de Sousa, Janiere Pereira; de Oliveira Lima, Edeltrudes

2015-04-01

Candida albicans can be a yeast that is a commensal on the human body but can cause opportunistic or pathogenic infections. Candida infections may create serious health problems and as a result has initiated a search for new drugs with an antifungal action. Geraniol is an acyclic monoterpene alcohol with known pharmacological properties, including antimicrobial activity. The aim of this work was to evaluate the antifungal activity and mechanism(s) of geraniol against C. albicans strains. The minimum inhibitory concentration (MIC) was determined through broth microdilution techniques. We investigated possible geraniol activity on the fungal cell wall (sorbitol protect effect), cell membrane (geraniol to ergosterol binding), the time-kill curve, and its biological activity on the yeast's morphology. Amphotericin B was used as control, and all tests were performed in duplicate. The MIC of geraniol was 16 μg/ml (for 90% of isolates) but its probable mechanism of action did not involve the cell wall and ergosterol binding. In the morphological interference assay, we observed that the product inhibited pseudohyphae and chlamydoconidia formation. Time-dependent kill curve assay demonstrated that the fungicidal activity for MIC × 2 started at 2 h for the ATCC 76485 strain, and at 4 h for the LM-70 strain. Geraniol showed in vitro antifungal potential against strains of C. albicans but did not involve action on the cell wall or ergosterol. This study contributes to the development of new antifungal drugs, especially against Candida spp. © The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Quantitative risk assessment of the aggregate dermal exposure to the sensitizing fragrance geraniol in personal care products and household cleaning agents.

PubMed

Nijkamp, M M; Bokkers, B G H; Bakker, M I; Ezendam, J; Delmaar, J E

2015-10-01

A quantitative risk assessment was performed to establish if consumers are at risk for being dermally sensitized by the fragrance geraniol. Aggregate dermal exposure to geraniol was estimated using the Probabilistic Aggregate Consumer Exposure Model, containing data on the use of personal care products and household cleaning agents. Consumer exposure to geraniol via personal care products appeared to be higher than via household cleaning agents. The hands were the body parts receiving the highest exposure to geraniol. Dermal sensitization studies were assessed to derive the point of departure needed for the estimation of the Acceptable Exposure Level (AEL). Two concentrations were derived, one based on human studies and the other from dose-response analysis of the available murine local lymph node assay data. The aggregate dermal exposure assessment resulted in body part specific median exposures up to 0.041 μg/cm(2) (highest exposure 102 μg/cm(2)) for hands. Comparing the exposure to the lowest AEL (55 μg/cm(2)), shows that a range of 0.02-0.86% of the population may have an aggregated exposure which exceeds the AEL. Furthermore, it is demonstrated that personal care products contribute more to the consumer's geraniol exposure compared to household cleaning agents. Copyright © 2015 Elsevier Inc. All rights reserved.

Health impact assessment of a skin sensitizer: Analysis of potential policy measures aimed at reducing geraniol concentrations in personal care products and household cleaning products.

PubMed

Jongeneel, W P; Delmaar, J E; Bokkers, B G H

2018-06-08

A methodology to assess the health impact of skin sensitizers is introduced, which consists of the comparison of the probabilistic aggregated exposure with a probabilistic (individual) human sensitization or elicitation induction dose. The health impact of potential policy measures aimed at reducing the concentration of a fragrance allergen, geraniol, in consumer products is analysed in a simulated population derived from multiple product use surveys. Our analysis shows that current dermal exposure to geraniol from personal care and household cleaning products lead to new cases of contact allergy and induce clinical symptoms for those already sensitized. We estimate that this exposure results yearly in 34 new cases of geraniol contact allergy per million consumers in Western and Northern Europe, mainly due to exposure to household cleaning products. About twice as many consumers (60 per million) are projected to suffer from clinical symptoms due to re-exposure to geraniol. Policy measures restricting geraniol concentrations to <0.01% will noticeably reduce new cases of sensitization and decrease the number of people with clinical symptoms as well as the frequency of occurrence of these clinical symptoms. The estimated numbers should be interpreted with caution and provide only a rough indication of the health impact. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Geraniol improves endothelial function by inhibiting NOX-2 derived oxidative stress in high fat diet fed mice.

PubMed

Wang, Xiaoyu; Zhao, Shiqi; Su, Mengqi; Sun, Li; Zhang, Song; Wang, Dingyu; Liu, Zhaorui; Yuan, Yue; Liu, Yang; Li, Yue

2016-05-20

Endothelial dysfunction occurs in obese patients and high-fat diet (HFD) fed experimental animals. While geraniol has been reported to ameliorate inflammation and oxidative stress, inhibit tumor cell proliferation, and improve atherosclerosis, its direct effect on endothelial function remains uncharacterized. The present study therefore investigated the effect of geraniol on endothelial function in HFD mice and its underlying mechanisms. C57 BL/6 mice were fed an HFD (n = 40) or a normal diet (n = 20) for 8 weeks. HFD fed mice then were randomized to intraperitoneal treatment with geraniol (n = 20) or vehicle (n = 20) for another 6 weeks. Acetylcholine (Ach)-induced endothelial dependent vasorelaxation was measured on wire myography; reactive oxygen species (ROS) generation was assessed by fluorescence imaging, and NADPH oxidases (NOXs) and adhesive molecules VCAM-1 and ICAM-1 protein expression by western blotting. Geraniol improved endothelial function in HFD fed mice, as evidenced by its: 1. restoring endothelial dependent vasorelaxation induced by Ach, and reversing increased VCAM-1 and ICAM-1 expression; 2. attenuating HFD induced increased serum TBARS and aortic ROS generation; and 3. downregulating aortic NOX-2 expression in both HFD fed mice and in palmitic acid treated endothelial cells. Geraniol therefore protects against endothelial dysfunction induced by HFD through reducing NOX-2 associated ROS generation. Copyright © 2016 Elsevier Inc. All rights reserved.

An in vitro antibacterial study of savory essential oil and geraniol in combination with standard antimicrobials.

PubMed

Miladinović, Dragoljub L; Ilić, Budimir S; Kocić, Branislava D; Miladinović, Marija D

2014-11-01

The chemical composition and antibacterial activity of Satureja kitaibelii Wierzb. ex Heuff. (savory) essential oil were examined, as well as the association between it and standard antimicrobials: tetracycline and chloramphenicol. The antibacterial activities of geraniol, the main constituent of S. kitaibelii oil, individually and in combination with standard antimicrobials were also determined. The interactions of the essential oil and geraniol with antimicrobials toward five selected strains were evaluated using the microdilution checkerboard assay in combination with chemometric methods. Oxygenated monoterpenes were the most abundant compound class in the oil (59.7%), with geraniol (50.4%) as the major compound. The essential oil exhibited in vitro antibacterial activity against all tested bacterial strains, but the activities were lower than those of the standard antimicrobials. The combinations savory oil-chloramphenicol, savory oil-tetracycline and geraniol-chloramphenicol produced predominantly synergistic interactions (FIC indices in the range 0.21-0.87) and substantial reductions in the MIC values of antimicrobials against Gram-negative bacteria, the pharmacological treatment of which is very difficult nowadays. In the PCA and HCA analyses these combinations form a separate group.

Mechanism of Air Oxidation of the Fragrance Terpene Geraniol.

PubMed

Bäcktorp, Carina; Hagvall, Lina; Börje, Anna; Karlberg, Ann-Therese; Norrby, Per-Ola; Nyman, Gunnar

2008-01-01

The fragrance terpene geraniol autoxidizes upon air exposure and forms a mixture of oxidation products, some of which are skin sensitizers. Reactions of geraniol with O2 have been studied with DFT (B3LYP) and the computational results compared to experimentally observed product ratios. The oxidation is initiated by hydrogen abstraction, forming an allylic radical which combines with an O2 molecule to yield an intermediate peroxyl radical. In the subsequent step, geraniol differs from previously studied cases, in which the radical chain reaction is propagated through intermolecular hydrogen abstraction. The hydroxy-substituted allylic peroxyl radical prefers an intramolecular rearrangement, producing observable aldehydes and the hydroperoxyl radical, which in turn can propagate the radical reaction. Secondary oxidation products like epoxides and formates were also considered, and plausible reaction pathways for formation are proposed.

Transcription factor CitERF71 activates the terpene synthase gene CitTPS16 involved in the synthesis of E-geraniol in sweet orange fruit.

PubMed

Li, Xiang; Xu, Yaying; Shen, Shuling; Yin, Xueren; Klee, Harry; Zhang, Bo; Chen, Kunsong; Hancock, Robert

2017-10-13

The unique flavor of Citrus fruit depends on complex combinations of soluble sugars, organic acids, and volatile compounds. The monoterpene E-geraniol is an important volatile, contributing to flavor in sweet orange (Citrus sinensis Osbeck). Moreover, antifungal activity of E-geraniol has also been observed. However, the terpene synthase (TPS) responsible for its synthesis has not been identified in sweet orange. Terpene synthase 16 (CitTPS16) was shown to catalyze synthesis of E-geraniol in vitro, and transient overexpression of CitTPS16 in fruits and leaves of Newhall sweet orange resulted in E-geraniol accumulation in vivo. Having identified the responsible enzyme, we next examined transcriptional regulation of CitTPS16 in the fruit. Among cloned members of the AP2/ERF transcription factor gene family, CitERF71 showed a similar expression pattern to CitTPS16. Moreover, CitERF71 was able to activate the CitTPS16 promoter based on results from transient dual-luciferase assays and yeast one-hybrid assays. EMSAs showed that CitERF71 directly binds to ACCCGCC and GGCGGG motifs in the CitTPS16 promoter. These results indicate an important role for CitERF71 in transcriptional regulation of CitTP16 and, therefore, in controlling production of E-geraniol in Citrus fruit. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Alarm Pheromone Activity of Nymph-specific Geraniol in Chrysanthemum Lace Bug Corythucha marmorata against Adults and Nymphs.

PubMed

Watanabe, Kisaki; Shimizu, Nobuhiro

2015-09-01

The exotic insect pest Corythucha marmorata (Uhler) is increasingly spreading in Japan using the weed Solidago canadensis L. as a major host plant. The nymphs form colonies on the backs of leaves where they crowd together; however, aggregation does not occur in the adults. When an individual nymph is crushed using a needle tip and further the needle tip covered with the nymph's bodily fluids is moved slowly toward the center of the crowd, the surrounding nymphs display an escape behavior and their aggregation is disrupted. We detected geraniol as a nymph-specific volatile component. Bioassay results indicated that geraniol was effective as an alarm pheromone on second to fifth instar nymphs. Furthermore, we found that male and female adults responded sensitively to the alarm pheromone produced by nymphs. These results suggest that although the adult insects do not secrete geraniol, they can detect it produced by nymphs, thereby retaining the ability to escape from danger while suppressing the cost of geraniol production. The present study is the first to demonstrate that an alarm pheromone secreted by nymphs is also effective in adults among Tingidae.

Essential oil of Cymbopogon citratus (lemongrass) and geraniol, but not citral, promote gastric healing activity in mice.

PubMed

Venzon, Larissa; Mariano, Luísa Nathália Bolda; Somensi, Lincon Bordignon; Boeing, Thaise; de Souza, Priscila; Wagner, Theodoro Marcel; Andrade, Sérgio Faloni de; Nesello, Luciane Angela Nottar; da Silva, Luísa Mota

2018-02-01

Cymbopogon citratus, popularly known as lemongrass, is used for the treatment of gastric, nervous and hypertensive disorders, in addition to its use in the food and pharmaceutical industries. This study evaluated the gastroprotective and gastric healing effect of essential oil of C. citratus (EOCC), citral and geraniol at doses of 1-100 mg/kg (p.o) on acute ethanol-induced ulcer and chronic acetic acid-induced ulcer. Histological and histochemical evaluation was also performed, as well as the in vitro evaluation of the effects of these phytochemicals on H + /K + -ATPase activity. In the ethanol-induced gastric ulcer, the minimum effective oral dose of EOCC, citral and geraniol were 10, 100 and 3 mg/kg, reducing the ulcer area by 51.67%, 96.57% and 55.74%, respectively, compared to vehicle group (25.82 ± 3.59 mm 2 ). Moreover, EOCC (10 mg/kg, p.o) and geraniol (3 mg/kg), but not citral (100 mg/kg), accelerated the gastric healing process by 34.52 and 80.57%, compared to acetic-acid ulcerated group treated with vehicle (36.04 ± 1.03 mm 2 ). These healing effects were confirmed histologically by the contraction of the ulcer base and by the enhancement on mucin staining in slices of ulcer site from mice treated with EOCC or geraniol. Interestingly, EOCC and citral at 100 μg/ml inhibited the H + / K + -ATPase activity by 28.26% and 44.36%, whereas geraniol did not change this parameter. Together, these findings confirm the gastroprotective and healing gastric ulcer effects of essential oil from aerial parts of C. citratus and added the information that geraniol, but not citral, promotes healing effects on installed ulcers. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Antifungal activity of geraniol and citronellol, two monoterpenes alcohols, against Trichophyton rubrum involves inhibition of ergosterol biosynthesis.

PubMed

Pereira, Fillipe de Oliveira; Mendes, Juliana Moura; Lima, Igara Oliveira; Mota, Kelly Samara de Lira; Oliveira, Wylly Araújo de; Lima, Edeltrudes de Oliveira

2015-02-01

Trichophyton rubrum is the most common fungus causing chronic dermatophytosis in humans. Antifungal activity of promising agents is of great interest. Geraniol and citronellol are monoterpenes with antimicrobial properties. This study aimed to investigate the inhibitory effects and possible mechanism of antifungal activity of geraniol and citronellol against strains of T. rubrum. The minimum inhibitory concentration (MIC) of each drug against 14 strains was determined by broth microdilution. The effects of the drugs on dry mycelial weight, conidial germination, infectivity on human nail fragments, and morphogenesis of T. rubrum were analyzed. The effects on the cell wall (test with sorbitol) and cell membrane (release of intracellular material and ergosterol biosynthesis) were investigated. MIC values of geraniol ranged between 16 and 256 µg/mL while citronellol showed MIC values from 8 to 1024 µg/mL. The drugs (MIC and 2 × MIC) inhibited the mycelial growth, conidia germination, and fungal growth on nail fragments. The drugs (half of MIC) induced the formation of wide, short, and crooked hyphae in T. rubrum morphology. With sorbitol, geraniol MIC was increased by 64-fold and citronellol by 32-fold. The drugs caused leakage of intracellular material and inhibited ergosterol biosynthesis. The results suggest that the drugs damage cell wall and cell membrane of T. rubrum through a mechanism that seems to involve the inhibition of the ergosterol biosynthesis. This study confirms that geraniol and citronellol can be regarded as potential drugs for controlling T. rubrum growth, with great potential against agents of dermatophytosis.

Liquid-phase hydrogenation of citral over Pt/SiO{sub 2} catalysts. 2. Hydrogenation of reaction intermediate compounds

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

Singh, U.K.; Sysak, M.N.; Vannice, M.A.

2000-04-01

Liquid-phase hydrogenation of the four principal reaction intermediates formed during citral hydrogenation, i.e., nerol, geraniol, citronellal, and citronellol, was studied at 298 and 373 K under 20 atm H{sub 2} at concentrations of 0.5 to 1.0 M in hexane. A decrease in the initial reaction rate as temperature increased from 298 to 373 K was exhibited during the hydrogenation of all four compounds, just as reported earlier for citral; however, the decrease in rate at 373 K was only one-half for citronellal whereas it was orders of magnitude greater for nerol and geraniol. Furthermore, simultaneous hydrogenation of citronellal and geraniolmore » at 298 K resulted in a continuous decrease in the rate of citronellal disappearance in contrast to the nearly constant rate of disappearance observed during hydrogenation of citronellal alone. Competitive hydrogenation of citral with either geraniol or citronellal showed that geraniol hydrogenation to citronellol is kinetically insignificant during citral hydrogenation at 373 K. The initial activity for hydrogenation of the intermediates at 298 K follows the following trend: geraniol > nerol < citronellol < E-citral, citronellal > Z-citral. Based on the relative hydrogenation rates of the intermediate alone versus its hydrogenation in the presence of other reactants, the relative size of the adsorption equilibrium constants for the various organic compounds appears to be as follows: citral > citronellal > geraniol, nerol > citronellol > 3,7-dimethyloctanol. This study indicates that activation of the C{double_bond}O bond should be performed at higher reaction temperatures to maximize selectivity to the unsaturated alcohols.« less

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.

Late-stage divergent synthesis and antifouling activity of geraniol-butenolide hybrid molecules.

PubMed

Takamura, Hiroyoshi; Ohashi, Takumi; Kikuchi, Takahiro; Endo, Noriyuki; Fukuda, Yuji; Kadota, Isao

2017-07-05

Hybrid molecules consisting of geraniol and butenolide were designed and synthesized by the late-stage divergent strategy. In the synthetic route, ring-closing metathesis was utilized for the construction of a butenolide moiety. A biological evaluation of the eight synthetic hybrid compounds revealed that these molecules exhibit antifouling activity against the cypris larvae of the barnacle Balanus (Amphibalanus) amphitrite with EC 50 values of 0.30-1.31 μg mL -1 . These results show that hybridization of the geraniol and butenolide structural motifs resulted in the enhancement of the antifouling activity.

Neuroprotective effect of geraniol and curcumin in an acrylamide model of neurotoxicity in Drosophila melanogaster: relevance to neuropathy.

PubMed

Prasad, Sathya N; Muralidhara

2014-01-01

Chronic exposure of acrylamide (ACR) leads to neuronal damage in both experimental animals and humans. The primary focus of this study was to assess the ameliorative effect of geraniol, (a natural monoterpene) against ACR-induced oxidative stress, mitochondrial dysfunction and neurotoxicity in a Drosophila model and compare its efficacy to that of curcumin, a spice active principle with pleiotropic biological activity. Adult male flies (8-10 days) were exposed (7 days) to ACR (5 mM) with or without geraniol and curcumin (5-10 μM) in the medium. Both phytoconstituents significantly reduced the incidence of ACR-induced mortality, rescued the locomotor phenotype and alleviated the enhanced levels of oxidative stress markers in head/body regions. The levels of reduced glutathione (GSH) and total thiols (TSH) resulting from ACR exposure was also restored with concomitant elevation in the activities of detoxifying enzymes. Interestingly, ACR induced mitochondrial dysfunctions (MTT reduction, activities of SDH and citrate synthase enzymes) were alleviated by both phytoconstituents. While ACR elevated the activity of acetylcholinesterase in head/body regions, marked diminution in enzyme activity ensued with co-exposure to phytoconstituents suggesting their potency to mitigate cholinergic function. Furthermore, phytoconstituents also restored the dopamine levels in head/body regions. The neuroprotective effect of geraniol was comparable to curcumin in terms of phenotypic and biochemical markers. Based on our evidences in fly model we hypothesise that geraniol possess significant neuromodulatory propensity and may be exploited for therapeutic application in human pathophysiology associated with neuropathy. However, the precise mechanism/s by which geraniol offers neuroprotection needs to be investigated in appropriate neuronal cell models. Copyright © 2013 Elsevier Ltd. All rights reserved.

Determining the Effects of Geraniol on Liver Regeneration Via the Nuclear Factor kB Pathway After Partial Hepatectomy.

PubMed

Ceyhan, Emre; Canbek, Mediha

2017-05-01

Context • Nuclear factor kB (NF-κB) is a dimeric transcription factor that is involved in the regulation of regenerative and apoptosic genes and plays a key role in liver regeneration after a partial hepatectomy (PH). Complementary medicine is used to treat various diseases and can be obtained from a large number of plants that are found in nature. One such plant is geraniol, and no studies have yet occurred assessing its in vivo effects on liver regeneration. Objective • The current study intended to assess the effects of geraniol on liver regeneration after a 70% PH in rats. Design • The research team studied geraniol in a rat model in vivo. Setting • The study took place in the medical and surgical experimental research center at Eskisehir Osmangazi University (Eskisehir, Turkey). Animals • The animals were Wistar albino male rats. Intervention • The rats were divided into 8 groups with 6 rats in each group. Two groups were the sham control groups. The other 6 groups received an injection of a single dose of saline, the negative control; silymarin, the negative control; or geraniol, the intervention. The injections were given intraperitoneally immediately after PH. A laparotomy was performed on the rats all of those groups at either 24 h or 48 h after the PH. Outcome Measures • Using the reverse transcription (RT)- polymerase chain reaction (PCR) method (RT-PCR) and Western blot analysis, the NF-κB, tumor necrosis factor α, and interleukin 6 gene expression and protein levels were measured. Moreover, the levels of the heat shock proteins (HSPs) HSP27 and HSP60 were examined by Western blot. Results • The data showed that geraniol had a significant role (P < .05) in increasing the process of liver regeneration when given intraperitoneally, and it protected the liver as assessed by histology and the HSP levels. In rats receiving 100 mg/kg geraniol intraperitoneally, the agent induced hepatic regeneration 24 h and 48 h after PH (70%).

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.

Anti-Candida activity of geraniol involves disruption of cell membrane integrity and function.

PubMed

Sharma, Y; Khan, L A; Manzoor, N

2016-09-01

Candidiasis is a major problem in immunocompromised patients. Candida, an opportunistic fungal pathogen, is a major health concern today as conventional drugs are highly toxic with undesirable side effects. Their fungistatic nature is responsible for drug resistance in continuously evolving strains. Geraniol, an acyclic monoterpene alcohol, is a component of several plant essential oils. In the present study, an attempt has been made to understand the antifungal activity of geraniol at the cell membrane level in three Candida species. With an MIC of 30-130μg/mL, this natural compound was fungicidal at concentrations 2×MIC. There was complete suppression of fungal growth at MIC values (growth curves) and encouragingly geraniol is non-toxic even at the concentrations approaching 5×MIC (hemolysis assay). Exposed cells showed altered morphology, wherein the cells appeared either broken or shrivelled up (SEM studies). Significant reduction was seen in ergosterol levels at sub-MIC and glucose-induced H(+) efflux at concentrations>MIC values. Our results suggest that geraniol disrupts cell membrane integrity by interfering with ergosterol biosynthesis and inhibiting the very crucial PM-ATPase. It may hence be used in the management and treatment of both superficial and invasive candidiasis but further studies are required to elaborate its mode of action. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

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.

Regulation of the Mevalonate Pathway for the Prevention of Breast Cancer

DTIC Science & Technology

2003-08-01

eicosapentaenoic acid (EPA) as well as the dietary isoprenoid geraniol that inhibit cell proliferation, are inhibitors of HMG-CoA reductase activity in...breast cancer cells. The inhibitory effects of EPA and geraniol on cell proliferation, however, are independent of mevalonate. DHA, on the other hand

Reduction of mosquito biting pressure by timed-release 0.3% aerosolized geraniol

USDA-ARS?s Scientific Manuscript database

We conducted a study to determine the degree of personal protection provided by the Terminix® ALLCLEAR® Mosquito Mister – Lantern Edition. This outdoor unit was operated to disperse an aerosolized aqueous 0.3% geraniol emulsion in timed-release intervals of 5.0, 7.5, and 10.0 min. Human volunteers ...

Neurophysiological Study of Vector Responses to Repellents.

DTIC Science & Technology

1979-08-01

The Al sensilla responded weakly or not at all to oviposition site attractants and the repellent series. Citronellol and geraniol induced a decrease...612 - 0/++ -- ++/0 + + 0 SRI-C6 - 0/-- - /++ ++ 0 0 2504-5 0/- 0 0 0 0 Citronellol 0/++ 0 - 0 Geraniol 0 - - 0 0 Naphthalene 0 0 0 0 Juglone + + +4

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

Study of β-cyclodextrin inclusion complexes with volatile molecules geraniol and α-terpineol enantiomers in solid state and in solution

NASA Astrophysics Data System (ADS)

Ceborska, Magdalena; Szwed, Kamila; Asztemborska, Monika; Wszelaka-Rylik, Małgorzata; Kicińska, Ewa; Suwińska, Kinga

2015-11-01

Geraniol and α-terpineol are insoluble in water volatile compounds. α-Terpineol is a potentially important agent for medical applications. Formation of molecular complexes with β-cyclodextrin would lead to the increase of water solubility and bioavailability. β-Cyclodextrin forms 2:2 inclusion complexes with both enantiomers of α-terpineol and their precursor geraniol. Solid state complexes are thoroughly characterized by single X-ray crystallography and their stability over vast range of temperatures is proven by TG analysis. Intermolecular host-guest, host-host and guest-guest interactions give good insight into the nature of formed inclusion complexes. Stability constants of the complexes in solution are determined by HPLC.

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.

Geraniol Restores Antibiotic Activities against Multidrug-Resistant Isolates from Gram-Negative Species▿ †

PubMed Central

Lorenzi, Vannina; Muselli, Alain; Bernardini, Antoine François; Berti, Liliane; Pagès, Jean-Marie; Amaral, Leonard; Bolla, Jean-Michel

2009-01-01

The essential oil of Helichrysum italicum significantly reduces the multidrug resistance of Enterobacter aerogenes, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. Combinations of the two most active fractions of the essential oil with each other or with phenylalanine arginine β-naphthylamide yield synergistic activity. Geraniol, a component of one fraction, significantly increased the efficacy of β-lactams, quinolones, and chloramphenicol. PMID:19258278

Infrared Laser Optoacoustic Detection Of Gases And Vapours

NASA Astrophysics Data System (ADS)

Johnson, S. A.; Cummins, P. G.; Bone, S. A.; Davies, P. B.

1988-10-01

Mid-infrared laser optoacoustic spectroscopy has been used to detect a variety of gases and vapours. Performance was calibrated using the signal from a known concentration of ethene, and then the method applied to the perfume alcohol geraniol. Detection limits were found to be 1 ppb for ethene and 70 ppb for geraniol on their strongest absorption lines for a few seconds measurement time.

Geraniol attenuates 4NQO-induced tongue carcinogenesis through downregulating the activation of NF-κB in rats.

PubMed

Madankumar, Arumugam; Tamilarasi, Sasivarnam; Premkumar, Thandavamoorthy; Gopikrishnan, Mani; Nagabhishek, Natesh; Devaki, Thiruvengadam

2017-10-01

Geraniol, an acyclic monoterpene found in lemon grass and aromatic herb oil, has been shown to exert antitumor and antioxidant activities against various cancer types. The objective of this study was to investigate the potential chemoprotective role of geraniol against 4-nitroquinoline-1-oxide (4NQO)-induced oral carcinogenesis in male Wistar rats and furthermore to study anti-inflammatory mechanisms of action through possible NF-κB signaling. 4NQO was administered to rats at the dose of 50 ppm through drinking water to induce tongue cancer in 20 weeks. 4NQO provoked inflammation by upregulating the expressions of the p65 subunit nuclear factor kappa-β (NF-κB) in the nucleus, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). Additionally, staining for immature and mature mast cells in cancer niche by toluidine blue staining and alcian blue-safranin staining showed more accumulation. Co-treatment of geraniol 200 mg/kg b.w. showed a significant decrease in the level of p65 NF-κB in the nucleus, and this might be due to the inhibition of NF-κB activation/translocation into nucleus, which was further confirmed by decreased immature and mature mast cell density and the expression of inflammatory downstream mediators such as TNF-α, IL-1β, COX-2, and iNOS. Collectively, our results suggested that geraniol as a potential anti-inflammatory agent having the capability to obstruct 4NQO initiated NF-κB activation and modulated the expression of inflammatory mediators.

Cytotoxic and genotoxic potential of geraniol in peripheral blood mononuclear cells and human hepatoma cell line (HepG2).

PubMed

Queiroz, T B; Santos, G F; Ventura, S C; Hiruma-Lima, C A; Gaivão, I O M; Maistro, E L

2017-09-27

Geraniol is an acyclic monoterpene alcohol present in the essential oil of many aromatic plants and is one of the most frequently used molecules by the flavor and fragrance industries. The literature also reports its therapeutic potential, highlighting itself especially as a likely molecule for the development of drugs against cancer. In view of these considerations, this study was designed to evaluate the cytotoxic and genotoxic potential of geraniol, in an in vitro protocol, using two types of human cells: one without the ability to metabolize (peripheral blood mononuclear cells - PBMC), and the other with this capability (human hepatoma cell line - HepG2) through the comet assay and the micronucleus test. Four concentrations (10, 25, 50, and 100 µg/mL) were selected for the genotoxic assessment for PBMC and three (1.25, 2.5, and 5 µg/mL) for HepG2 cells based on cytotoxicity tests (MTT assay). Results showed that geraniol did not present genotoxic or clastogenic/aneugenic effects on both cell types under the conditions studied. However, caution is advised in the use of this substance by humans, since a significant reduction in viability of HepG2 and a marked decrease in cell viability on normal PBMC were verified.

Two types of alcohol dehydrogenase from Perilla can form citral and perillaldehyde.

PubMed

Sato-Masumoto, Naoko; Ito, Michiho

2014-08-01

Studies on the biosynthesis of oil compounds in Perilla will help in understanding regulatory systems of secondary metabolites and in elucidating reaction mechanisms for natural product synthesis. In this study, two types of alcohol dehydrogenases, an aldo-keto reductase (AKR) and a geraniol dehydrogenase (GeDH), which are thought to participate in the biosynthesis of perilla essential oil components, such as citral and perillaldehyde, were isolated from three pure lines of perilla. These enzymes shared high amino acid sequence identity within the genus Perilla, and were expressed regardless of oil type. The overall reaction from geranyl diphosphate to citral was performed in vitro using geraniol synthase and GeDH to form a large proportion of citral and relatively little geraniol as reaction products. The biosynthetic pathway from geranyl diphosphate to citral, the main compound of citral-type perilla essential oil, was established in this study. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inhibitory effect of Rosa damascena Mill flower essential oil, geraniol and citronellol on rat ileum contraction.

PubMed

Sadraei, H; Asghari, G; Emami, S

2013-01-01

Flower of Rosa damascena Mill is widely used in Iran for gastrointestinal (GI) disorders. However, its pharmacological action on ileum contraction has not been studied. In this research we have investigated ileum motility effect of essential oil of flower petals of R. damascena growing in Kashan, Iran, and two of its constituents. The essential oils obtained by hydrodistillation were investigated by a combination of GC and GC/MS. More than 34 compounds have been identified. The main constituents of the essential oil were β-citronellol (23%), nonadecane (16%), geraniol (16%) and heneicosane (5%). A portion of rat isolated ileum was suspended under 1g tension in Tyrode's solution at 37°C and gassed with O2. Effect of the R. damascena essential oil (2.5-160 μg/ml), geraniol (0.2-3.2 μg/ml) and citronellol (0.8-6.4 μg/ml) were studied on ileum contractions induced by KCl, acetylcholine (ACh) and electrical field stimulation (EFS) and compared with standard drugs atropine and loperamide. The contractile response of EFS was mediated mainly through the intramural nerve plexuses, because its response was inhibited by loperamide and partially reduced by atropine. The essential oil concentration dependently inhibited the response to KCl (IC50=67 ± 8.4μg/ml) and EFS (IC50=47 ± 10.6 μg/ml). Geraniol (IC50=1.7 ± 0.15 μg/ml for KCl) and citronellol (IC50=2.9 ± 0.3 μg/ml for KCl) also had inhibitory effect of ileum contraction and both were more potent than the essential oil. It was concluded that R. damascena essential oil mainly had an inhibitory effect on ileum contractions and geraniol and citronellol had a major role in inhibitory effect of the essential.

Green tea flavour determinants and their changes over manufacturing processes.

PubMed

Han, Zhuo-Xiao; Rana, Mohammad M; Liu, Guo-Feng; Gao, Ming-Jun; Li, Da-Xiang; Wu, Fu-Guang; Li, Xin-Bao; Wan, Xiao-Chun; Wei, Shu

2016-12-01

Flavour determinants in tea infusions and their changes during manufacturing processes were studied using Camellia sinensis cultivars 'Bai-Sang Cha' ('BAS') possessing significant floral scents and 'Fuding-Dabai Cha' ('FUD') with common green tea odour. Metabolite profiling based on odour activity threshold revealed that 'BAS' contained higher levels of the active odorants β-ionone, linalool and its two oxides, geraniol, epoxylinalool, decanal and taste determinant catechins than 'FUD' (p<0.05). Enhanced transcription of some terpenoid and catechin biosynthetic genes in 'BAS' suggested genetically enhanced production of those flavour compounds. Due to manufacturing processes, the levels of linalool and geraniol decreased whereas those of β-ionone, linalool oxides, indole and cis-jasmone increased. Compared with pan-fire treatment, steam treatment reduced the levels of catechins and proportion of geraniol, linalool and its derivatives, consequently, reducing catechin-related astringency and monoterpenol-related floral scent. Our study suggests that flavour determinant targeted modulation could be made through genotype and manufacturing improvements. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fractionation of Java Citronella Oil and Citronellal Purification by Batch Vacuum Fractional Distillation

NASA Astrophysics Data System (ADS)

Eden, W. T.; Alighiri, D.; Cahyono, E.; Supardi, K. I.; Wijayati, N.

2018-04-01

The aim of this work was to assess the performance of a vacuum fractionating column for the fractionation of Java Citronella Oil (Cymbopogon winterianus) and citronellal purification during batch mode operation at vacuum -76 cmHg and reflux ratios 5:1. Based on GC-MS analysis of Java Citronella Oil is known that citronellal, citronellol, and geraniol has yielded 21,59%; 7,43%; and 34,27%, respectively. Fractional distillation under reduced pressure and continued redistilled are needed to isolate the component of Java Citronella Oil. Redistilled can improve the purity, then distillate collected while the temperature changed. In the first distillate yielded citronellal with a purity of 75.67%. The first distillate obtained residue rhodinol product will then be carried back to separation into citronellol and geraniol. The purity of citronellol reached 80,65% purity, whereas geraniol reached 76.63% purity. Citronellal Purification resulting citronellal to 95.10% purity and p-menthane-3,8-diol reached 75.95% purity.

Chemical Diversity in Basil (Ocimum sp.) Germplasm

PubMed Central

da Costa, Andréa Santos; Arrigoni-Blank, Maria de Fátima; de Carvalho Filho, José Luiz Sandes; de Santana, Aléa Dayane Dantas; Santos, Darlisson de Alexandria; Alves, Péricles Barreto; Blank, Arie Fitzgerald

2015-01-01

The present study aimed to chemically characterize 31 accessions and seven cultivars of basil. The percentage composition of the essential oils of the accessions and cultivars was based on the 14 most abundant constituents: 1,8-cineole, linalool, methyl chavicol, neral, nerol, geraniol, geranial, methyl cinnamate, β-bourbonene, methyl eugenol, α-trans-bergamotene, germacrene-D, epi-α-cadinol, and δ-cadinene. The genetic materials were classified into eight clusters according to the chemical composition of the essential oils: Cluster 1—mostly linalool and 1,8-cineole; Cluster 2—mostly linalool, geraniol, and α-trans-bergamotene; Cluster 3—mostly linalool, methyl chavicol, methyl cinnamate, and β-bourbonene; Cluster 4—mostly linalool, methyl chavicol, epi-α-cadinol, and α-trans-bergamotene; Cluster 5—mainly linalool, methyl eugenol, α-trans-bergamotene, and epi-α-cadinol; Cluster 6—mainly linalool, geraniol, and epi-α-cadinol; Cluster 7—mostly linalool and methyl chavicol; Cluster 8—mainly geranial and neral. PMID:25629084

Protective activity of geranium oil and its component, geraniol, in combination with vaginal washing against vaginal candidiasis in mice.

PubMed

Maruyama, Naho; Takizawa, Toshio; Ishibashi, Hiroko; Hisajima, Tatsuya; Inouye, Shigeharu; Yamaguchi, Hideyo; Abe, Shigeru

2008-08-01

In order to evaluate an effective administration method of essential oils for vaginal candidiasis, efficacy of vaginal application of essential oils against murine experimental candidiasis was investigated. The effect on vaginal inflammation and Candida growth form was also studied. Vaginal candidiasis was established by intravaginal infection of C. albicans to estradiol-treated mice. These mice intravaginally received essential oils such as geranium and tea tree singly or in combination with vaginal washing. Vaginal administration of clotrimazole significantly decreased the number of viable C. albicans cells in the vaginal cavity by itself. In contrast, these essential oils did not lower the cell number. When application of geranium oil or geraniol was combined with vaginal washing, the cell number was decreased significantly. The myeloperoxidase activity assay exhibited the possibility that essential oils worked not only to reduce the viable cell number of C. albicans, but also to improve vaginal inflammation. The smear of vaginal washing suspension suggested that more yeast-form cells appeared in vaginal smears of these oil-treated mice than in control mice. In vitro study showed that a very low concentration (25 microg/ml) of geranium oil and geraniol inhibited mycelial growth, but not yeast growth. Based on these findings, it is estimated that vaginal application of geranium oil or its main component, geraniol, suppressed Candida cell growth in the vagina and its local inflammation when combined with vaginal washing.

Multivariate optimization of a headspace solid-phase microextraction method followed by gas chromatography with mass spectrometry for the determination of terpenes in Nicotiana langsdorffii.

PubMed

Ardini, Francisco; Carro, Marina Di; Abelmoschi, Maria Luisa; Grotti, Marco; Magi, Emanuele

2014-07-01

A simple and sensitive procedure based on headspace solid-phase microextraction and gas chromatography with mass spectrometry was developed for the determination of five terpenes (α-pinene, limonene, linalool, α-terpineol, and geraniol) in the leaves of Nicotiana langsdorffii. The microextraction conditions (extraction temperature, equilibration time, and extraction time) were optimized by means of a Doehlert design. The experimental design showed that, for α-pinene and limonene, a low temperature and a long extraction time were needed for optimal extraction, while linalool, α-terpineol, and geraniol required a high temperature and a long extraction time. The chosen compromise conditions were temperature 60°C, equilibration time 15 min and extraction time 50 min. The main analytical figures of the optimized method were evaluated; LODs ranged from 0.07 ng/g (α-pinene) to 8.0 ng/g (geraniol), while intraday and interday repeatability were in the range 10-17% and 9-13%, respectively. Finally, the procedure was applied to in vitro wild-type and transgenic specimens of N. langsdorffii subjected to abiotic stresses (chemical and heat stress). With the exception of geraniol (75-374 ng/g), low concentration levels of terpenes were measured (ng/g level or lower); some interesting variations in terpene concentration induced by abiotic stress were observed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Effect of Citrus Essential Oils and Their Constituents on Growth of Xanthomonas citri subsp. citri.

PubMed

Mirzaei-Najafgholi, Hossein; Tarighi, Saeed; Golmohammadi, Morteza; Taheri, Parissa

2017-04-14

Citrus bacterial canker (CBC) caused by Xanthomonas citri subsp. citri ( Xcc ), is the most devastating of the citrus diseases worldwide. During our study, we found that Essential oils (EOs) of some citrus cultivars are effective on Xcc . Therefore, it prompted us to determine the plant metabolites responsible for the antibacterial properties. We obtained EOs from some locally cultivated citrus by using a Clevenger apparatus and their major constituents were identified by gas chromatography/mass spectrometry (GC-MS). The effect of Citrus aurantium , C. aurantifolia , Fortunella sp. EOs and their major constituents were evaluated against Xcc -KVXCC1 using a disk diffusion assay. Minimal inhibitory and bactericidal concentration of the EOs and their constituents were determined using the broth microdilution method. C. aurantium , C. aurantifolia Eos, and their major constituents including citral, linalool, citronellal, geraniol, α-terpineol, and linalyl acetate indicated antibacterial effects against Xcc . The C. aurantifolia EO and citral showed the highest antibacterial activity among the tested EOs and constituents with inhibition zones of 15 ± 0.33 mm and 16.67 ± 0.88 mm, respectively. Synergistic effects of the constituents were observed between α-terpineol-citral, citral-citronellal, citral-geraniol, and citronellal-geraniol by using a microdilution checkerboard assay. Transmission electron microscopy revealed that exposure of Xcc cells to citral caused cell wall damage and altered cytoplasmic density. We introduced C. aurantifolia and C. aurantium EOs, and their constituents citral, α-terpineol, citronellal, geraniol, and linalool as possible control agents for CBC.

Selective oxidation of rhodinol to citral using H{sub 2}O{sub 2}-platinum black system under microwave irradiation

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

Chong, D. J. W.; Latip, J.; Hasbullah, S. A.

2014-09-03

The oxidation method utilising H{sub 2}O{sub 2}-Pt black system was successfully adapted in the oxidation of rhodinol which is a mixture form of geraniol and citronellol. This green oxidation found to be selectively converted geraniol to citral using conventional method. The implementation of microwave irradiation (175 Watt, 90°C, 30 mins) and a higher molar of H{sub 2}O{sub 2} further improved the conversion rate (72.6%) and selectivity (81%) as compared to the conventional method.

Selective oxidation of rhodinol to citral using H2O2-platinum black system under microwave irradiation

NASA Astrophysics Data System (ADS)

Chong, D. J. W.; Latip, J.; Hasbullah, S. A.; Sastrohamidjojo, H.

2014-09-01

The oxidation method utilising H2O2-Pt black system was successfully adapted in the oxidation of rhodinol which is a mixture form of geraniol and citronellol. This green oxidation found to be selectively converted geraniol to citral using conventional method. The implementation of microwave irradiation (175 Watt, 90°C, 30 mins) and a higher molar of H2O2 further improved the conversion rate (72.6%) and selectivity (81%) as compared to the conventional method.

Evaluation of anti-Candida potential of geranium oil constituents against clinical isolates of Candida albicans differentially sensitive to fluconazole: inhibition of growth, dimorphism and sensitization.

PubMed

Zore, Gajanan B; Thakre, Archana D; Rathod, V; Karuppayil, S Mohan

2011-07-01

Fluconazole (FLC) susceptibility of isolates of Candida spp., (n = 42) and efficacy as well as mechanism of anti-Candida activity of three constituents of geranium oil is evaluated in this study. No fluconazole resistance was observed among the clinical isolates tested, however 22% were susceptible-dose-dependent (S-DD) [minimal inhibitory concentration (MIC) ≥ 16 μg ml(-1)] and a standard strain of C. albicans ATCC 10231 was resistant (≥ 64 μg ml(-1)). Geraniol and geranyl acetate were equally effective, fungicidal at 0.064% v/v concentrations i.e. MICs (561 μg ml(-1) and 584 μg ml(-1) respectively) and killed 99.9% inoculum within 15 and 30 min of exposures respectively. Citronellol was least effective and fungistatic. C. albicans dimorphism (Y → H) was highly sensitive to geranium oil constituents tested (IC50 approximately 0.008% v/v). Geraniol, geranyl acetate and citronellol brought down MICs of FLC by 16-, 32- and 64-fold respectively in a FLC-resistant strain. Citronellol and geraniol arrested cells in G1 phase while geranyl acetate in G2-M phase of cell cycle at MIC(50). In vitro cytotoxicity study revealed that geraniol, geranyl acetate and citronellol were non-toxic to HeLa cells at MICs of the C. albicans growth. Our results indicate that two of the three geranium oil constituents tested exhibit excellent anti-Candida activity and significant synergistic activity with fluconazole. © 2010 Blackwell Verlag GmbH.

Geraniol modulates tongue and hepatic phase I and phase II conjugation activities and may contribute directly to the chemopreventive activity against experimental oral carcinogenesis.

PubMed

Madankumar, Arumugam; Jayakumar, Subramaniyan; Gokuladhas, Krishnan; Rajan, Balan; Raghunandhakumar, Subramanian; Asokkumar, Selvamani; Devaki, Thiruvengadam

2013-04-05

Xenobiotic metabolizing enzymes are chief determinants in both the susceptibility to mutagenic effect of chemical carcinogens and in the response of tumors to chemotherapy. The present study was aimed to analyze the effect of geraniol administration on the activity of phase I and phase II carcinogen metabolizing enzymes through the nuclear factor erythroid 2-related factor-2 (Nrf2) activation against 4-niroquinoline-1-oxide (4NQO) induced oral carcinogenesis. The well-known chemical carcinogen 4NQO (50 ppm) was used to induce oral carcinogenesis through drinking water for 4, 12, and 20 weeks. The degree of cancer progression at each stage was confirmed by histological examination. At the end of the experimental period, 100% tumor formation was observed in the oral cavity of 4NQO induced animals with significant (P<0.05) alteration in the status of tumor markers, tongue and liver phase I and phase II drug metabolizing enzymes indicating progression of disease. Oral administration of geraniol at the dose of 200 mg/kg b.wt., thrice a week to 4NQO induced animals was able to inhibit tumor formation and thereby delayed the progression of oral carcinogenesis by modulating tongue and liver phase I and phase II drug metabolizing enzymes, as substantiated further by the histological and transmission electron microscopic studies. Our results demonstrate that geraniol exerts its chemopreventive potential by altering activities of phases I and II drug metabolizing enzymes to achieve minimum bioactivation of carcinogen and maximum detoxification. Copyright © 2013 Elsevier B.V. All rights reserved.

Synthesis of Geraniol Esters in a Continuous-Flow Packed-Bed Reactor of Immobilized Lipase: Optimization of Process Parameters and Kinetic Modeling.

PubMed

Salvi, Harshada M; Kamble, Manoj P; Yadav, Ganapati D

2018-02-01

With increasing demand for perfumes, flavors, beverages, and pharmaceuticals, the various associated industries are resorting to different approaches to enhance yields of desired compounds. The use of fixed-bed biocatalytic reactors in some of the processes for making fine chemicals will be of great value because the reaction times could be reduced substantially as well as high conversion and yields obtained. In the current study, a continuous-flow packed-bed reactor of immobilized Candida antarctica lipase B (Novozym 435) was employed for synthesis of various geraniol esters. Optimization of process parameters such as biocatalyst screening, effect of solvent, mole ratio, temperature and acyl donors was studied in a continuous-flow packed-bed reactor. Maximum conversion of ~ 87% of geranyl propionate was achieved in 15 min residence time at 70 °C using geraniol and propionic acid with a 1:1 mol ratio. Novozym 435 was found to be the most active and stable biocatalyst among all tested. Ternary complex mechanism with propionic acid inhibition was found to fit the data.

The Role of Leaf Volatiles of Ludwigia octovalvis (Jacq.) Raven in the Attraction of Altica cyanea (Weber) (Coleoptera: Chrysomelidae).

PubMed

Mitra, Saubhik; Karmakar, Amarnath; Mukherjee, Abhishek; Barik, Anandamay

2017-07-01

Larvae and adults of Altica cyanea (Weber) (Coleoptera: Chrysomelidae) feed on the rice-field weed Ludwigia octovalvis (Jacq.) Raven (Onagraceae), commonly known as willow primrose, which is considered a biocontrol agent of the weed. Volatile organic compounds from undamaged plants, plants after 4, 12, and 36 h of continuous feeding by A. cyanea larvae or adult females and after mechanical damaging were identified by GC-MS and GC-FID analyses. Twenty nine compounds were identified from undamaged plants. 2Z-Penten-1-ol, geraniol, and 1-tridecanol were present in all plants damaged by larvae. In contrast, feeding by adults caused the release of 2Z-penten-1-ol only after 12 and 36 h; whereas geraniol and 1-tridecanol appeared only after 36 h. Farnesyl acetone was detected after 12 and 36 h of feeding by larvae and after 36 h of feeding by adults. Farnesene was detected after 36 h of feeding by larvae and adults. Linalool was unique after 36 h of feeding by larvae. In Y-shaped glass tube olfactometer bioassays, A. cyanea females were attracted to volatiles after 36 h of feeding by larvae or adults compared to volatiles released by undamaged plants. The insects were attracted to five synthetic compounds: 3-hexanol, α-pinene, linalool oxide, geraniol, and phytol. Synthetic blends were more attractive than individual compounds. Compared to undamaged plants, volatiles released by plants, damaged by conspecific individuals, were more attractive to A. cyanea females, due to elevated emissions of 3-hexanol, α-pinene, linalool oxide, geraniol, and phytol.

Toxicity of β-citronellol, geraniol and linalool from Pelargonium roseum essential oil against the West Nile and filariasis vector Culex pipiens (Diptera: Culicidae).

PubMed

Tabari, Mohaddeseh Abouhosseini; Youssefi, Mohammad Reza; Esfandiari, Aryan; Benelli, Giovanni

2017-10-01

Insect vectors are responsible for spreading devastating parasites and pathogens. A large number of botanicals have been suggested for eco-friendly control programs against mosquito vectors, and some of them are aromatic plants. Pelargonium roseum, a species belonging to the Geraniaceae family, due to its pleasant rose-like odor may represent a suitable candidate as mosquito repellent and/or larvicide. In this research, we evaluated the toxicity of the essential oil from P. roseum and its major constituents against the West Nile and filariasis vector Culex pipiens. The chemical composition of P. roseum essential oil was analyzed by gas chromatography-mass spectroscopy. Major constituents were citronellol (35.9%), geraniol (18.5%), and linalool (5.72%). The bioactivity of P. roseum essential oil and its three major compounds on larvae and egg rafts of Cx. pipiens was evaluated. The essential oil had a significant toxic effect on larvae and egg rafts of Cx. pipiens, with 50% lethal concentration (LC 50 ) values of 5.49 and 0.45μg/mL, respectively. Major constituents, geraniol, citronellol and linalool resulted in LC 50 values of 6.86, 7.64 and 14.87μg/mL on larvae, and 0.8, 0.67 and 1.27μg/mL on egg rafts. Essential oil and two of its constituents, citronellol and geraniol showed moderate knock-down on Cx. pipiens adults. Overall, the present investigation revealed that the major components of P. roseum and specially the whole essential oil could be helpful in developing novel and safe mosquito control tools and also offer an environmentally safe and cheap tool for reducing Cx. pipiens mosquito populations. Copyright © 2017. Published by Elsevier Ltd.

Preparation and Characterization of Nanoparticle β-Cyclodextrin:Geraniol Inclusion Complexes.

PubMed

Hadian, Zahra; Maleki, Majedeh; Abdi, Khosro; Atyabi, Fatemeh; Mohammadi, Abdoreza; Khaksar, Ramin

2018-01-01

The aim of the present study was to formulate β-cyclodextrin (β-CD) nanoparticles loaded with geraniol (GR) essential oil (EO) with appropriate physicochemical properties. Complexation of GR with β-CD was optimized by evaluation of four formulations, using the co-precipitation method, and the encapsulation efficiency (EE), loading, size, particle size distribution (PDI) and zeta potential were investigated. Further characterization was performed with nuclear magnetic resonance spectroscopy ( 1 H NMR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and infra-red (IR) spectroscopy analysis. Results showed that the physicochemical properties of the nanoparticles were affected by GR content in formulations that yielded nanoscale-size particles ranging from 111 to 258 nm. The highest encapsulation efficiency (79.4 ± 5.4%) was obtained when the molar ratio of EO to β-CD was 0.44: 0.13 with negative zeta potential (-21.1 ± 0.5 mV). The 1 H-NMR spectrum confirmed the formation structure of the EO and β-CD nanoparticle complex. Complexation with geraniol resulted in changes of IR profile, NMR chemical shifts, DSC properties, and SEM of β-cyclodextrin. Inclusion complex of essential oil with β-cyclodextrin was considered as promising bioactive materials for designing functional food.

Preparation and Characterization of Nanoparticle β-Cyclodextrin:Geraniol Inclusion Complexes

PubMed Central

Hadian, Zahra; Maleki, Majedeh; Abdi, Khosro; Atyabi, Fatemeh; Mohammadi, Abdoreza; Khaksar, Ramin

2018-01-01

The aim of the present study was to formulate β-cyclodextrin (β-CD) nanoparticles loaded with geraniol (GR) essential oil (EO) with appropriate physicochemical properties. Complexation of GR with β-CD was optimized by evaluation of four formulations, using the co-precipitation method, and the encapsulation efficiency (EE), loading, size, particle size distribution (PDI) and zeta potential were investigated. Further characterization was performed with nuclear magnetic resonance spectroscopy (1H NMR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and infra-red (IR) spectroscopy analysis. Results showed that the physicochemical properties of the nanoparticles were affected by GR content in formulations that yielded nanoscale-size particles ranging from 111 to 258 nm. The highest encapsulation efficiency (79.4 ± 5.4%) was obtained when the molar ratio of EO to β-CD was 0.44: 0.13 with negative zeta potential (-21.1 ± 0.5 mV). The 1H-NMR spectrum confirmed the formation structure of the EO and β-CD nanoparticle complex. Complexation with geraniol resulted in changes of IR profile, NMR chemical shifts, DSC properties, and SEM of β-cyclodextrin. Inclusion complex of essential oil with β-cyclodextrin was considered as promising bioactive materials for designing functional food.

Specificity of Ocimum basilicum geraniol synthase modified by its expression in different heterologous systems.

PubMed

Fischer, Marc J C; Meyer, Sophie; Claudel, Patricia; Perrin, Mireille; Ginglinger, Jean François; Gertz, Claude; Masson, Jean E; Werck-Reinhardt, Danièle; Hugueney, Philippe; Karst, Francis

2013-01-10

Numerous aromatic plant species produce high levels of monoterpenols, using geranyl diphosphate (GPP) as a precursor. Sweet basil (Ocimum basilicum) geraniol synthase (GES) was used to evaluate the monoterpenol profiles arising from heterologous expressions in various plant models. Grapevine (Vitis vinifera) calli were transformed using Agrobacterium tumefasciens and the plants were regenerated. Thale cress (Arabidopsis thaliana) was transformed using the floral dip method. Tobacco (Nicotiana benthamiana) leaves were agro-infiltrated for transient expression. Although, as expected, geraniol was the main product detected in the leaves, different minor products were observed in these plants (V. vinifera: citronellol and nerol; N. benthamiana: linalool and nerol; A. thaliana: none). O. basilicum GES expression was also carried out with microbial system yeasts (Saccharomyces cerevisiae) and Escherichia coli. These results suggest that the functional properties of a monoterpenol synthase depend not only on the enzyme's amino-acidic sequence, but also on the cellular background. They also suggest that some plant species or microbial expression systems could induce the simultaneous formation of several carbocations, and could thus have a natural tendency to produce a wider spectrum of monoterpenols. Copyright © 2012 Elsevier B.V. All rights reserved.

Dose-Dependent Behavioral Response of the Mosquito Aedes albopictus to Floral Odorous Compounds

PubMed Central

Hao, Huiling; Sun, Jingcheng; Dai, Jianqing

2013-01-01

The value of using plant volatiles as attractants for trapping and spatial repellents to protect hosts against mosquitoes has been widely recognized. The current study characterized behavioral responses of Aedes albopictus (Skuse) (Diptera: Culicidae) to different concentrations, ranging from 6 to 96%, of several common floral odorous compounds, including linalool, geraniol, citronellal, eugenol, anisaldehyde, and citral, using a wind tunnel olfactometer system. The results indicated that female mosquitoes reacted differently to different concentrations of the tested compounds, and the reactions also were different when those chemicals were tested alone or in the presence of human host odor. When tested alone, anisaldehyde was attractive at all tested concentrations, eugenol was attractive only at concentrations of 48–96%, while citronellal, linalool, citral, and geraniol were attractive at lower concentrations and repellent at higher concentrations. When tested in the presence of a human host, all compounds except for anisaldehyde at all tested concentrations showed host-seeking inhibition to certain degrees. Based on the results, it was concluded that anisaldehyde was effective in attracting Ae. albopictus when used alone but could also remarkably inhibit the host-seeking ability at a concentration of 96%, while citral, geraniol, linalool, citronellal, and eugenol are suitable as spatial repellents. PMID:24779928

Monoterpene biosynthesis potential of plant subcellular compartments.

PubMed

Dong, Lemeng; Jongedijk, Esmer; Bouwmeester, Harro; Van Der Krol, Alexander

2016-01-01

Subcellular monoterpene biosynthesis capacity based on local geranyl diphosphate (GDP) availability or locally boosted GDP production was determined for plastids, cytosol and mitochondria. A geraniol synthase (GES) was targeted to plastids, cytosol, or mitochondria. Transient expression in Nicotiana benthamiana indicated local GDP availability for each compartment but resulted in different product levels. A GDP synthase from Picea abies (PaGDPS1) was shown to boost GDP production. PaGDPS1 was also targeted to plastids, cytosol or mitochondria and PaGDPS1 and GES were coexpressed in all possible combinations. Geraniol and geraniol-derived products were analyzed by GC-MS and LC-MS, respectively. GES product levels were highest for plastid-targeted GES, followed by mitochondrial- and then cytosolic-targeted GES. For each compartment local boosting of GDP biosynthesis increased GES product levels. GDP exchange between compartments is not equal: while no GDP is exchanged from the cytosol to the plastids, 100% of GDP in mitochondria can be exchanged to plastids, while only 7% of GDP from plastids is available for mitochondria. This suggests a direct exchange mechanism for GDP between plastids and mitochondria. Cytosolic PaGDPS1 competes with plastidial GES activity, suggesting an effective drain of isopentenyl diphosphate from the plastids to the cytosol. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Workers make the queens in melipona bees: identification of geraniol as a caste determining compound from labial glands of nurse bees.

PubMed

Jarau, Stefan; van Veen, Johan W; Twele, Robert; Reichle, Christian; Gonzales, Eduardo Herrera; Aguilar, Ingrid; Francke, Wittko; Ayasse, Manfred

2010-06-01

Reproductive division of labor in advanced eusocial honey bees and stingless bees is based on the ability of totipotent female larvae to develop into either workers or queens. In nearly all species, caste is determined by larval nutrition. However, the mechanism that triggers queen development in Melipona bees is still unresolved. Several hypotheses have been proposed, ranging from the proximate (a genetic determination of caste development) to the ultimate (a model in which larvae have complete control over their own caste fate). Here, we showed that the addition of geraniol, the main compound in labial gland secretions of nurse workers, to the larval food significantly increases the number of larvae that develop into queens. Interestingly, the proportion of queens in treated brood exactly matched the value (25%) predicted by the two-locus, two-allele model of genetic queen determination, in which only females that are heterozygous at both loci are capable of developing into queens. We conclude that labial gland secretions, added to the food of some cells by nurse bees, trigger queen development, provided that the larvae are genetically predisposed towards this developmental pathway. In Melipona beecheii, geraniol acts as a primer pheromone representing the first caste determination substance identified to date.

Assessment of geraniol-incorporated polymers to control Aedes albopictus (Diptera: culicidae)

PubMed Central

Chuaycharoensuk, T.; Manguin, S.; Duvallet, G.; Chareonviriyaphap, T.

2012-01-01

Effective control of mosquito borne diseases has proven extremely difficult with both vector and pathogen remaining entrenched and expanding in many disease endemic areas. When lacking an effective vaccine, vector control methods targeting both larval habitats and adult mosquito populations remain the primary strategy for reducing risk. Aedes albopictus from Thailand was used as a reference baseline for evaluation of natural insecticides incorporated in polymer disks and pellets and tested both in laboratory and field conditions. In laboratory and field tests, the highest larval mortality was obtained with disks or pellets containing IKHC (Insect Killer Highly Concentrate) from Fulltec AG Company. This product is reputed to contain geraniol as an active ingredient. With pellets, high mortality of Ae. albopictus larvae (92%) was observed in presence of 1 g of pellets per 500 ml of water at day 1st, and the mortality was 100% at day 1st for larvae in presence of 5 or 10 g of pellets. Fulltec AG Company has not accepted to give us the exact composition of their IKHC product. Therefore, we cannot recommend it, but the principle of using monoterpenes like geraniol, incorporated into polymer disks or pellets as natural larvicide needs more attention as it could be considered as a powerful alternative in mosquito vector control. PMID:22910616

Design and development of aqueous nanoformulations for mosquito control.

PubMed

Montefuscoli, Antonela Rita; Werdin González, Jorge Omar; Palma, Santiago Daniel; Ferrero, Adriana Alicia; Fernández Band, Beatriz

2014-02-01

Microemulsions (ME) are thermodynamically stable isotropic mixtures of oil, water, and surfactant; they would also be attractive as potential insecticidal products due to the high bioviability of the active ingredient, attributable to the small sizes of the oil drops. A laboratory study was conducted in order to compare the biological effect of oil in water (o/w) geranium essential oil (EO) and geraniol MEs and emulsions, against Culex pipiens pipiens mosquito larvae. The systems were based on three nonionic surfactants (Cremophor EL, Brij 35, Tween 80). The MEs showed dispersed phase diameters in the range of 8 to 14 nm and had low PDI values (<0.2). The MEs were analyzed by TEM, indicating that they had nearly spherical morphology. The microemulsified systems based on geranium EO and those of geraniol produced a notable increase of the larvicidal activity when compared with the respectably emulsions, concluding that the biological effect is related with the diameter of the dispersed phase. The smallest drops achieved the highest larvicidal activity, being the aqueous nanoformulations based on geraniol most effective than those of geranium EO. However, geranium microemulsions are preferred due to their residual toxicological profiles. The results indicate that these novel systems could be used in integrated pest management program for the C. pipiens pipiens.

Structural and kinetic studies of a novel nerol dehydrogenase from Persicaria minor, a nerol-specific enzyme for citral biosynthesis.

PubMed

Tan, Cheng Seng; Hassan, Maizom; Mohamed Hussein, Zeti Azura; Ismail, Ismanizan; Ho, Kok Lian; Ng, Chyan Leong; Zainal, Zamri

2018-02-01

Geraniol degradation pathway has long been elucidated in microorganisms through bioconversion studies, yet weakly characterised in plants; enzyme with specific nerol-oxidising activity has not been reported. A novel cDNA encodes nerol dehydrogenase (PmNeDH) was isolated from Persicaria minor. The recombinant PmNeDH (rPmNeDH) is a homodimeric enzyme that belongs to MDR (medium-chain dehydrogenases/reductases) superfamily that catalyses the first oxidative step of geraniol degradation pathway in citral biosynthesis. Kinetic analysis revealed that rPmNeDH has a high specificity for allylic primary alcohols with backbone ≤10 carbons. rPmNeDH has ∼3 fold higher affinity towards nerol (cis-3,7-dimethyl-2,6-octadien-1-ol) than its trans-isomer, geraniol. To our knowledge, this is the first alcohol dehydrogenase with higher preference towards nerol, suggesting that nerol can be effective substrate for citral biosynthesis in P. minor. The rPmNeDH crystal structure (1.54 Å) showed high similarity with enzyme structures from MDR superfamily. Structure guided mutation was conducted to describe the relationships between substrate specificity and residue substitutions in the active site. Kinetics analyses of wild-type rPmNeDH and several active site mutants demonstrated that the substrate specificity of rPmNeDH can be altered by changing any selected active site residues (Asp 280 , Leu 294 and Ala 303 ). Interestingly, the L294F, A303F and A303G mutants were able to revamp the substrate preference towards geraniol. Furthermore, mutant that exhibited a broader substrate range was also obtained. This study demonstrates that P. minor may have evolved to contain enzyme that optimally recognise cis-configured nerol as substrate. rPmNeDH structure provides new insights into the substrate specificity and active site plasticity in MDR superfamily. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Essential Oil Characterization of Thymus vulgaris from Various Geographical Locations

PubMed Central

Satyal, Prabodh; Murray, Brittney L.; McFeeters, Robert L.; Setzer, William N.

2016-01-01

Thyme (Thymus vulgaris L.) is a commonly used flavoring agent and medicinal herb. Several chemotypes of thyme, based on essential oil compositions, have been established, including (1) linalool; (2) borneol; (3) geraniol; (4) sabinene hydrate; (5) thymol; (6) carvacrol, as well as a number of multiple-component chemotypes. In this work, two different T. vulgaris essential oils were obtained from France and two were obtained from Serbia. The chemical compositions were determined using gas chromatography–mass spectrometry. In addition, chiral gas chromatography was used to determine the enantiomeric compositions of several monoterpenoid components. The T. vulgaris oil from Nyons, France was of the linalool chemotype (linalool, 76.2%; linalyl acetate, 14.3%); the oil sample from Jablanicki, Serbia was of the geraniol chemotype (geraniol, 59.8%; geranyl acetate, 16.7%); the sample from Pomoravje District, Serbia was of the sabinene hydrate chemotype (cis-sabinene hydrate, 30.8%; trans-sabinene hydrate, 5.0%); and the essential oil from Richerenches, France was of the thymol chemotype (thymol, 47.1%; p-cymene, 20.1%). A cluster analysis based on the compositions of these essential oils as well as 81 additional T. vulgaris essential oils reported in the literature revealed 20 different chemotypes. This work represents the first chiral analysis of T. vulgaris monoterpenoids and a comprehensive description of the different chemotypes of T. vulgaris. PMID:28231164

Structure-Odor Relationship Study on Geraniol, Nerol, and Their Synthesized Oxygenated Derivatives.

PubMed

Elsharif, Shaimaa Awadain; Buettner, Andrea

2018-03-14

Despite being isomers having the same citrus-like, floral odor, geraniol, 1, and nerol, 3, show different odor thresholds. To date, no systematic studies are at hand elucidating the structural features required for their specific odor properties. Therefore, starting from these two basic structures and their corresponding esters, namely, geranyl acetate, 2, and neryl acetate, 4, a total of 12 oxygenated compounds were synthesized and characterized regarding retention indices (RI), mass spectrometric (MS), and nuclear magnetic resonance (NMR) data. All compounds were individually tested for their odor qualities and odor thresholds in air (OT). Geraniol, the Z-isomer, with an OT of 14 ng/L, was found to be more potent than its E-isomer, nerol, which has an OT of 60 ng/L. However, 8-oxoneryl acetate was the most potent derivative within this study, exhibiting an OT of 8.8 ng/L, whereas 8-oxonerol was the least potent with an OT of 493 ng/L. Interestingly, the 8-oxo derivatives smell musty and fatty, whereas the 8-hydroxy derivatives show odor impressions similar to those of 1 and 3. 8-Carboxygeraniol was found to be odorless, whereas its E-isomer, 8-carboxynerol, showed fatty, waxy, and greasy impressions. Overall, we observed that oxygenation on C-8 affects mainly the odor quality, whereas the E/ Z position of the functional group on C-1 affects the odor potency.

Patch tests with fragrance materials and preservatives.

PubMed

de Groot, A C; Liem, D H; Nater, J P; van Ketel, W G

1985-02-01

179 patients suspected of cosmetic allergy were patch tested with a series of 16 fragrance materials and 9 preservatives. In 67 patients (37.4%), 1 or more of these substances gave positive reactions. In the group of fragrance materials, the largest numbers of positive patch test reactions were seen to isoeugenol, oak moss, geraniol, alpha-amylcinnamic alcohol, and a mixture of alpha-amylcinnamic aldehyde and alpha-hexylcinnamic aldehyde. The fragrance mix in the ICDRG standard series detected nearly 80% of cases of contact allergy to fragrance materials other than its constituents. In the group of preservatives, Kathon CG and quaternium-15 scored the highest number of positive reactions. It is argued that the commonly used patch test concentrations of 2% for oak moss and geraniol may be too low to detect all cases of sensitization.

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.

Menthol and geraniol biotransformation and glycosylation capacity of Levisticum officinale hairy roots.

PubMed

Nunes, Inês S; Faria, Jorge M S; Figueiredo, A Cristina; Pedro, Luis G; Trindade, Helena; Barroso, José G

2009-03-01

The biotransformation capacity of Levisticum officinale W.D.J. Koch hairy root cultures was studied by evaluating the effect of the addition of 25 mg/L menthol or geraniol on morphology, growth, and volatiles production. L. officinale hairy root cultures were maintained for 7 weeks in SH medium, in darkness at 24 degrees C and 80 r.p.m., and the substrates were added 15 days after inoculation. Growth was evaluated by measuring fresh and dry weight and by using the dissimilation method. Volatiles composition was analyzed by GC and GC-MS. Hairy roots morphology and growth were not influenced by substrate addition. No new volatiles were detected after menthol addition and, as was also the case with the control cultures, volatiles of these hairy roots were dominated by (Z)-falcarinol (1-45%), N-octanal (3-8%), palmitic acid (3-10%), and (Z)-ligustilide (2-9%). The addition of geraniol induced the production of six new volatiles: nerol/citronellol/neral (traces-15%), alpha-terpineol (0.2-3%), linalool (0.1-1.2%), and geranyl acetate (traces-2%). The relative amounts of the substrates and some of their biotransformation products decreased during the course of the experiment. Following the addition of beta-glycosidase to the remaining distillation water, analysis of the extracted volatiles showed that lovage hairy roots were able to convert both substrates and their biotransformation products into glycosidic forms. GC:gas chromatography GC-MS:gas chromatography-mass spectrometry SH:Schenk and Hildebrandt (1972) culture medium.

Activity-Based Profiling of a Physiologic Aglycone Library Reveals Sugar Acceptor Promiscuity of Family 1 UDP-Glucosyltransferases from Grape1[W

PubMed Central

Bönisch, Friedericke; Frotscher, Johanna; Stanitzek, Sarah; Rühl, Ernst; Wüst, Matthias; Bitz, Oliver; Schwab, Wilfried

2014-01-01

Monoterpenols serve various biological functions and accumulate in grape (Vitis vinifera), where a major fraction occurs as nonvolatile glycosides. We have screened the grape genome for sequences with similarity to terpene URIDINE DIPHOSPHATE GLYCOSYLTRANSFERASES (UGTs) from Arabidopsis (Arabidopsis thaliana). A ripening-related expression pattern was shown for three candidates by spatial and temporal expression analyses in five grape cultivars. Transcript accumulation correlated with the production of monoterpenyl β-d-glucosides in grape exocarp during ripening and was low in vegetative tissue. Targeted functional screening of the recombinant UGTs for their biological substrates was performed by activity-based metabolite profiling (ABMP) employing a physiologic library of aglycones built from glycosides isolated from grape. This approach led to the identification of two UDP-glucose:monoterpenol β-d-glucosyltransferases. Whereas VvGT14a glucosylated geraniol, R,S-citronellol, and nerol with similar efficiency, the three allelic forms VvGT15a, VvGT15b, and VvGT15c preferred geraniol over nerol. Kinetic resolution of R,S-citronellol and R,S-linalool was shown for VvGT15a and VvGT14a, respectively. ABMP revealed geraniol as the major biological substrate but also disclosed that these UGTs may add to the production of further glycoconjugates in planta. ABMP of aglycone libraries provides a versatile tool to uncover novel biologically relevant substrates of small-molecule glycosyltransferases that often show broad sugar acceptor promiscuity. PMID:25073706

Volatility of fragrance chemicals: patch testing implications.

PubMed

Gilpin, Sarah J; Hui, Xiaoying; Maibach, Howard I

2009-01-01

Diagnostic and predictive patch testing to determine contact allergy due to fragrance materials requires applying a fixed dose of material to the skin. This dose can be affected by the volatile nature of fragrances; little data exist on how the loss of fragrance dose due to volatility affects patch testing. (1) To evaluate pH dependence and evaporation rates of two fragrance chemicals, geraniol, citronellol, and a common fragrance solvent, diethyl phthalate (DEP) and (2) Assess implications for predictive patch-testing methods for fragrances. pH analysis of each material at 1% for three values (4.0, 5.0, 7.0) was done over 40 hours. Volatility experiments for each material, nonradiolabeled and radiolabeled, were conducted over a 24-hour period, taking readings at six time points (5 minutes, 15 minutes, 40 minutes, 1 hour, 3 hours, and 24 hours). Evaporation rates were not sensitive to pH shifts from 4.0 to 7.0. Evaporation rates for nonradiolabeled materials were low: after 24 hours, geraniol lost 8.9%, citronellol 27.0% and DEP 14.5%. The volatility data for radiolabeled materials demonstrated that geraniol loses up to 39% of its dose, citronellol loses up to 26%, and DEP up to 14% within 40 minutes. The tendency of fragrance materials to evaporate can impact the dose being applied to the patch and therefore the result of the patch and ultimately the decision-making process regarding that fragrance material's safety. These data, developed with DEP, utilized in a predictive sensitization assay cannot be generalized.

Evaluation of toxicity of essential oils palmarosa, citronella, lemongrass and vetiver in human lymphocytes.

PubMed

Sinha, Sonali; Jothiramajayam, Manivannan; Ghosh, Manosij; Mukherjee, Anita

2014-06-01

The present investigation was undertaken to study the cytotoxic and genotoxic potential of the essential oils (palmarosa, citronella, lemongrass and vetiver) and monoterpenoids (citral and geraniol) in human lymphocytes. Trypan blue dye exclusion and MTT test was used to evaluate cytotoxicity. The genotoxicity studies were carried out by comet and DNA diffusion assays. Apoptosis was confirmed by Annexin/PI double staining. In addition, generation of reactive oxygen species was evaluated by DCFH-DA staining using flow cytometry. The results demonstrated that the four essential oils and citral induced cytotoxicity and genotoxicity at higher concentrations. The essential oils were found to induce oxidative stress evidenced by the generation of reactive oxygen species. With the exception of geraniol, induction of apoptosis was confirmed at higher concentrations of the test substances. Based on the results, the four essential oils are considered safe for human consumption at low concentrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Gd(OTf)3-catalyzed synthesis of geranyl esters for the intramolecular radical cyclization of their epoxides mediated by titanocene(III).

PubMed

García Santos, William H; Puerto Galvis, Carlos E; Kouznetsov, Vladimir V

2015-02-07

A selective and mild method for the esterification of a variety of carboxylic acids with geraniol is developed. We demonstrated that the use of triphenylphosphine, I2, 2-methylimidazole or imidazole and a catalytic amount of Gd(OTf)3 resulted to be more active than the previous protocols, providing a 16-membered library of geranyl esters in higher yields and in shorter reaction times. The use of essential oil of palmarosa (Cymbopogon martinii), enriched with geraniol, as a raw material for the synthesis of the target compounds complemented and proved how sustainable and eco-friendly this protocol is. Finally, the selective 6,7-epoxidation of the obtained geranyl esters led us to study their regio-controlled radical cyclization mediated by titanocene(III) for the synthesis of novel (8-hydroxy-9,9-dimethyl-5-methylene cyclohexyl)methyl esters in moderate yields and with excellent stereoselectivities.

Polyvalent type IV sensitizations to multiple fragrances and a skin protection cream in a metal worker.

PubMed

Tanko, Zita; Shab, Arna; Diepgen, Thomas Ludwig; Weisshaar, Elke

2009-06-01

Fragrances are very common in everyday products. A metalworker with chronic hand eczema and previously diagnosed type IV sensitizations to epoxy resin, balsam of Peru, fragrance mix and fragrance mix II was diagnosed with additional type IV sensitizations to geraniol, hydroxycitronellal, lilial, tree moss, oak moss absolute, citral, citronellol, farnesol, Lyral, fragrance mix II and fragrance mix (with sorbitan sesquioleate). In addition, a type IV sensitization to the skin protection cream containing geraniol and citronellol used at the workplace was detected, and deemed occupationally relevant in this case. The patient could have had contact to fragrances through private use of cosmetics and detergents. On the other hand, the fragrance-containing skin protection cream supports occupational exposure. This case report demonstrates that fragrance contact allergy has to be searched for and clarified individually, which requires a thorough history and a detailed analysis of the work place.

Learning in the Africanized honey bee: Apis mellifera L.

PubMed

Abramson, C I; Aquino, I S; Silva, M C; Price, J M

1997-09-01

Several series of experiments are reported that investigate learning in the Africanized honey bee. In the first series, classical conditioning of proboscis extension was studied by confining bees to small metal tubes where they received pairings of an odor with a 3-s feeding of sucrose. After a number of odor-sucrose pairings, the bees began to extend their proboscis to the odor. Controls include Unpaired, Discrimination, and Pseudoconditioning Groups. This technique was used to look at conditioning to a light CS, and to the odors of beeswax, geraniol, citral, and hexanal. The results indicate that acquisition was best when sucrose was paired with the odor of beeswax. Conditioning to the remaining odors was roughly similar, but acquisition did not occur using a light. In a second series of experiments, odors were no longer followed by sucrose feedings and the conditioned response slowly disappeared. With the exception of geraniol as a CS, this extinction effect did not occur if the animals continued to be fed on an unpaired schedule. In a third series of experiments, conditioned inhibition was demonstrated when geraniol was used as conditioned stimuli, but no effect was found when the odors of hexanal, citral and wax were used. In a fourth series of experiments, unrestrained bees flew back and forth from the laboratory to the hive, where they were taught to distinguish targets based on color and odor. With this technique, color and odor discrimination in the Africanized bees was demonstrated. In addition, it was found that more intruder bees visited the experimental station when the stimuli used were olfactory rather than visual.

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.

Biosynthesis of geraniol and nerol and their β-d-glucosides in Perlargonium graveolens and Rosa dilecta

PubMed Central

Banthorpe, Derek V.; Le Patourel, Geoffrey N. J.; Francis, Martin J. O.

1972-01-01

1. 3R-[2-14C]Mevalonate was incorporated into geranyl and neryl β-d-glucosides in petals of Rosa dilecta in up to 10.6% yield, and the terpenoid part was specifically and equivalently labelled in the moieties derived from isopentenyl pyrophosphate and 3,3-dimethylallyl pyrophosphate. A similar labelling pattern, with incorporations of 0.06–0.1% was found for geraniol or nerol formed in leaves of Pelargonium graveolens The former results provide the best available evidence for the mevalonoid route to regular monoterpenes in higher plants. 2. Incorporation studies with 3RS-[2-14C,(4R)-4-3H1]-mevalonate and its (4S)-isomer showed that the pro-4R hydrogen atom of the precursor was retained and the pro-4S hydrogen atom was eliminated in both alcohols and both glucosides. These results suggest that the correlation of retention of the pro-4S hydrogen atom of mevalonate with formation of a cis-substituted double bond, such as has been found in certain higher terpenoids, does not apply to the biosynthesis of monoterpenes. It is proposed that either nerol is derived from isomerization of geraniol or the two alcohols are directly formed by different prenyltransferases. Possible mechanisms for these processes are discussed. 3. The experiments with [14C,3H]mevalonate also show that in these higher plants, as has been previously found in animal tissue and yeast, the pro-4S hydrogen atom of mevalonate was lost in the conversion of isopentenyl pyrophosphate into 3,3-dimethylallyl pyrophosphate. PMID:4348258

Gas-phase ozonolysis of the monoterpenoids ( S)-(+)-carvone, ( R)-(-)-carvone, (-)-carveol, geraniol and citral

NASA Astrophysics Data System (ADS)

Nunes, Fabíola Maria N.; Veloso, M. C. C.; de P. Pereira, P. A.; de Andrade, J. B.

Biogenic emissions of volatile organic compounds (VOCs) play a fundamental role in atmospheric chemistry. Vegetation is the most abundant natural source of VOCs, while terpenoids, as limonene, α and β pinene and mircene, top the plants emission list. Much interest has been demonstrated in oxidation and photooxidation reactions of VOCs, particularly of monoterpenoids, owing to their diversity and to uncertainties regarding their mechanism of reaction. Quantification of primary carbonylic compounds, as well as of biradical reaction components, is highly relevant to the understanding of the major reactions. In this context, taking into account both structural factors and the fact that these compounds are found in the essential oils of plants typically found in Brazil and that they may be present in the atmosphere from emission by the plants, the monoterpenoids ( S)-(+)-carvone, ( R)-(-)-carvone, (-)-carveol, geraniol and citral (a mixture of the isomers geranial and neral) were selected for this study. The ozonolysis reactions of the monoterpenoids were carried out under dark conditions for all experiments, due to their photochemical reactivity. The analysis of the results lets us propose a mechanism by which these reactions occur. The observed results of the ozonolysis of S and R carvone suggest that the stereochemistry of asymmetric carbon does not affect either in the yields of both formaldehyde and of OH radicals produced in the reaction, or in the reactivity of these compounds, for which the rate constants were in the scale of 10 -6 s -1. We found that, in the (-)-carveol's cis and trans mixture, even though the hydroxyl in the axial position—in the case of trans-(C) and cis-(D') isomers—favors the attack by the ozone molecule on the external double bond, thus increasing the mixture's reactivity (k=2.0×10-4s), it affects the average production of formaldehyde. The presence of geraniol and citral led to the production of formaldehyde, propanone, glyoxal, methyl-glyoxal and cyclohexanone (OH radicals) as reaction products. The influence of an electron attractor group bonded to the carbon of the double bond, on the reactivity of the double bond, could not be observed in the case of citral, due to strong interference occurring in the instrument in all experiments with this monoterpenoid. For this reason, only the kinetics of geraniol was monitored (k=9.0×10-4s).

Field trials of fatty acids and geraniol applied to cattle for suppression of horn flies, Haematobia irritans (Diptera: Muscidae), with observations on fly defensive behaviors.

PubMed

Mullens, Bradley A; Watson, D Wes; Gerry, Alec C; Sandelin, Broc A; Soto, Diane; Rawls, Diana; Denning, Steve; Guisewite, Lena; Cammack, Jonathan

2017-10-15

Adult horn fly populations were tracked on cattle for 2-week periods before, during and after multiple treatments (every 3-4days) with two repellents in a mineral oil carrier. Cattle were sprayed four times in a two-week period either with 2% geraniol (125ml/cow) or a 15% mixture of short chain fatty acids (C8-C9-C10)(250ml/cow), and there were untreated control cattle. Trials were conducted in California and North Carolina for 3 summers. Short-term fly counts (same day) on treated cattle were reduced by 61-99%, depending on material and trial, and the fatty acid mixture provided better control than geraniol. Horn fly counts were suppressed for 1-3 d and rebounded somewhat after both treatments. Consecutive treatments showed evidence of persistent impact in California where herds were more isolated. Rebounds to pre-treatment levels 3-4 d after treatment occurred more often in North Carolina, where other infested cattle were closer to treated herds. By 3-4 d post-treatment, horn flies were reduced by 29-61% in California and 0-83% in North Carolina, relative to pre-treatment. Background behavior frequencies were assessed from hundreds of counts on untreated, infested California cattle, where horn flies were the only abundant biting fly. Behavior averages were 16.5 tail flicks, 7.6 skin twitches, 1.2 head throws, or 0.2 leg stamps per 2min observation period. At horn fly densities from about 200 to more than 1000 flies per animal (moderate to high numbers), fly defensive behaviors on control cattle were poorly related (or unrelated) to fly numbers. Immediately after repellent application, however, flies were almost absent and behavior frequencies dropped distinctly. Cattle fly defensive behaviors therefore seem to be quite sensitive to low (less than 100 flies/animal) horn fly densities, and behaviors would be a poor quantitative tool to track fly stress at moderate densities and above. Both geraniol and the fatty acids show promise for horn fly control, especially in organic agriculture. Treatments at 1-2 d intervals probably would keep infestations below the economic threshold (200 flies/cow). Copyright © 2017 Elsevier B.V. All rights reserved.

Metabolic engineering of geranic acid in maize to achieve fungal resistance is compromised by novel glycosylation patterns.

PubMed

Yang, Ting; Stoopen, Geert; Yalpani, Nasser; Vervoort, Jacques; de Vos, Ric; Voster, Alessandra; Verstappen, Francel W A; Bouwmeester, Harro J; Jongsma, Maarten A

2011-07-01

Many terpenoids are known to have antifungal properties and overexpression of these compounds in crops is a potential tool in disease control. In this study, 15 different mono- and sesquiterpenoids were tested in vitro against two major pathogenic fungi of maize (Zea mays), Colletotrichum graminicola and Fusarium graminearum. Among all tested terpenoids, geranic acid showed very strong inhibitory activity against both fungi (MIC<46 μM). To evaluate the possibility of enhancing fungal resistance in maize by overexpressing geranic acid, we generated transgenic plants with the geraniol synthase gene cloned from Lippia dulcis under the control of a ubiquitin promoter. The volatile and non-volatile metabolite profiles of leaves from transgenic and control lines were compared. The headspaces collected from intact seedlings of transgenic and control plants were not significantly different, although detached leaves of transgenic plants emitted 5-fold more geranyl acetate compared to control plants. Non-targeted LC-MS profiling and LC-MS-MS identification of extracts from maize leaves revealed that the major significantly different non-volatile compounds were 2 geranic acid derivatives, a geraniol dihexose and 4 different types of hydroxyl-geranic acid-hexoses. A geranic acid glycoside was the most abundant, and identified by NMR as geranoyl-6-O-malonyl-β-d-glucopyranoside with an average concentration of 45μM. Fungal bioassays with C. graminicola and F. graminearum did not reveal an effect of these changes in secondary metabolite composition on plant resistance to either fungus. The results demonstrate that metabolic engineering of geraniol into geranic acid can rely on the existing default pathway, but branching glycosylation pathways must be controlled to achieve accumulation of the aglycones. Copyright © 2011 Elsevier Inc. All rights reserved.

Proliferating effect of radiolytically depolymerized carrageenan on physiological attributes, plant water relation parameters, essential oil production and active constituents of Cymbopogon flexuosus Steud. under drought stress.

PubMed

Singh, Minu; Khan, M Masroor A; Uddin, Moin; Naeem, M; Qureshi, M Irfan

2017-01-01

Carrageenan has been proved as potent growth promoting substance in its depolymerized form. However, relatively little is known about its role in counteracting the adverse effects of drought stress on plants. In a pot experiment, lemongrass (Cymbopogon flexuosus Steud.), grown under different water stress regimes [(100% field capacity (FC), 80% FC and 60% FC)], was sprayed with 40, 80 and 120 mg L-1 of gamma irradiated carrageenan (ICA). Foliar application of ICA mitigated the harmful effects of drought stress to various extents and improved the biochemical characteristics, quality attributes and active constituents (citral and geraniol) of lemongrass significantly. Among the applied treatments, ICA-80 mg L-1 proved the best in alleviating detrimental effects of drought. However, drought stress (80 and 60% FC), irrespective of the growth stages, had an adverse impact on most of the studied attributes. Generally, 60% FC proved more deleterious than 80% FC. At 80% FC, application of ICA-80 mg L-1 elevated the essential oil (EO) content by 18.9 and 25%, citral content by 7.33 and 8.19% and geraniol content by 9.2 and 8.9% at 90 and 120 days after planting (DAP), respectively, as compared to the deionized-water (DW) spray treatment (80% FC+ DW). Whereas, at 60% FC, foliar application of 80 mg L-1 ICA significantly augmented the EO content by 15.4 and 17.8% and active constituents viz. citral and geraniol, by 5.01 and 5.62% and by 6.06 and 5.61% at 90 and 120 DAP, respectively, as compared to the control (water-spray treatment).

Proliferating effect of radiolytically depolymerized carrageenan on physiological attributes, plant water relation parameters, essential oil production and active constituents of Cymbopogon flexuosus Steud. under drought stress

PubMed Central

Khan, M. Masroor A.; Uddin, Moin; Naeem, M.; Qureshi, M. Irfan

2017-01-01

Carrageenan has been proved as potent growth promoting substance in its depolymerized form. However, relatively little is known about its role in counteracting the adverse effects of drought stress on plants. In a pot experiment, lemongrass (Cymbopogon flexuosus Steud.), grown under different water stress regimes [(100% field capacity (FC), 80% FC and 60% FC)], was sprayed with 40, 80 and 120 mg L-1 of gamma irradiated carrageenan (ICA). Foliar application of ICA mitigated the harmful effects of drought stress to various extents and improved the biochemical characteristics, quality attributes and active constituents (citral and geraniol) of lemongrass significantly. Among the applied treatments, ICA-80 mg L-1 proved the best in alleviating detrimental effects of drought. However, drought stress (80 and 60% FC), irrespective of the growth stages, had an adverse impact on most of the studied attributes. Generally, 60% FC proved more deleterious than 80% FC. At 80% FC, application of ICA-80 mg L-1 elevated the essential oil (EO) content by 18.9 and 25%, citral content by 7.33 and 8.19% and geraniol content by 9.2 and 8.9% at 90 and 120 days after planting (DAP), respectively, as compared to the deionized-water (DW) spray treatment (80% FC+ DW). Whereas, at 60% FC, foliar application of 80 mg L-1 ICA significantly augmented the EO content by 15.4 and 17.8% and active constituents viz. citral and geraniol, by 5.01 and 5.62% and by 6.06 and 5.61% at 90 and 120 DAP, respectively, as compared to the control (water-spray treatment). PMID:28708833

Essential oils have different effects on human pathogenic and commensal bacteria in mixed faecal fermentations compared with pure cultures.

PubMed

Thapa, Dinesh; Louis, Petra; Losa, Riccardo; Zweifel, Béatrice; Wallace, R John

2015-02-01

A static batch culture system inoculated with human faeces was used to determine the influence of essential oil compounds (EOCs) on mixed faecal microbiota. Bacteria were quantified using quantitative PCR of 16S rRNA genes. Incubation for 24 h of diluted faeces from six individuals caused enrichment of Bifidobacterium spp., but proportions of other major groups were unaffected. Thymol and geraniol at 500 p.p.m. suppressed total bacteria, resulting in minimal fermentation. Thymol at 100 p.p.m. had no effect, nor did eugenol or nerolidol at 100 or 500 p.p.m. except for a slight suppression of Eubacterium hallii. Methyl isoeugenol at 100 or 500 p.p.m. suppressed the growth of total bacteria, accompanied by a large fall in the molar proportion of propionate formed. The relative abundance of Faecalibacterium prausnitzii was unaffected except with thymol at 500 p.p.m. The ability of EOCs to control numbers of the pathogen Clostridium difficile was investigated in a separate experiment, in which the faecal suspensions were amended by the addition of pure culture of C. difficile. Numbers of C. difficile were suppressed by thymol and methyl isoeugenol at 500 p.p.m. and to a lesser extent at 100 p.p.m. Eugenol and geraniol gave rather similar suppression of C. difficile numbers at both 100 and 500 p.p.m. Nerolidol had no significant effect. It was concluded from these and previous pure-culture experiments that thymol and geraniol at around 100 p.p.m. could be effective in suppressing pathogens in the small intestine, with no concern for beneficial commensal colonic bacteria in the distal gut. © 2015 The Authors.

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

'Fortified' wines volatile composition: Effect of different postharvest dehydration conditions of wine grapes cv. Malvasia moscata (Vitis vinifera L.).

PubMed

Urcan, Delia Elena; Giacosa, Simone; Torchio, Fabrizio; Río Segade, Susana; Raimondi, Stefano; Bertolino, Marta; Gerbi, Vincenzo; Pop, Nastasia; Rolle, Luca

2017-03-15

The impact of postharvest dehydration on the volatile composition of Malvasia moscata grapes and fortified wines produced from them was assessed. The ripeness effect of fresh grapes on volatile compounds of dehydrated grapes was evaluated for the first time in this study. Fresh grape berries were densimetrically sorted, and more represented density classes were selected. Dehydration of riper berries (20.5 °Brix) led to volatile profiles richer in terpenes, particularly linalool and geraniol. The effect of dehydration rate on the volatile composition of dehydrated grapes and fortified wines was also evaluated. Fast dehydration grapes were richer in total free terpenes, and the resulting wines contained greater amounts of volatile compounds. The predominant compounds were free esters, but linalool, rose oxide, citronellol and geraniol can also contribute to wine aroma, particularly for fast dehydration. β-Damascenone can be an active odorant, although its contribution was greater in wines made from slow dehydrated grapes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Geraniol attenuates α-synuclein expression and neuromuscular impairment through increase dopamine content in MPTP intoxicated mice by dose dependent manner.

PubMed

Rekha, Karamkolly R; Selvakumar, Govindasamy P; Santha, Karunanithi; Inmozhi Sivakamasundari, Ramu

2013-11-01

Parkinson's disease (PD) is characterized by progressive loss of dopamine (DA) neurons in the nigrostriatal system and by the presence of Lewy bodies (LB), proteinaceous inclusions mainly composed of filamentous α-synuclein (α-Syn) aggregates. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was adopted to generate PD models in C57BL/6 mice. In the present study, we investigated the effect of geraniol (GE) against α-Syn aggregation on MPTP induced mouse model of PD in dose dependant manner. When pretreatment of GE improved neuromuscular impairment, TH expressions and decreases α-Syn expressions in MPTP intoxicated PD mice by dose dependent manner. In addition, we confirmed that sub-chronic administration of MPTP in mice leads to permanent neuromuscular deficits and depletion of dopamine and its metabolites. Our results suggest that GE is beneficial for the treatment of PD associated with neuromuscular disability and LB aggregation. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Effects of structure on the interactions between five natural antimicrobial compounds and phospholipids of bacterial cell membrane on model monolayers

USDA-ARS?s Scientific Manuscript database

Monolayers composed of bacterial phospholipids were used as model membranes to study interactions of naturally occurring phenolic compounds 2,5-dihydroxybenzaldehyde, 2-hydroxy-5-methoxybenzaldehyde and the plant essential oil compounds carvacrol, cinnamaldehyde, and geraniol, previously found to be...

Evaluation of essential oils in beef cattle manure slurries and applications of select compounds to beef feedlot surfaces to control zoonotic pathogens

USDA-ARS?s Scientific Manuscript database

Aims: To evaluate natural terpene compounds for antimicrobial activities and determine if these compounds could be used to control microbial activities and pathogens in production animal facilities. Methods and Results: Thymol, geraniol, glydox, linalool, pine oil, plinol, and terpineol were teste...

[Contact dermatitis caused by perfumes and essences contained in various preparations for topical use].

PubMed

Romaguera, C; Grimalt, F; Vilaplana, J; Mascaro, J M

1987-01-01

Regarding two cases of allergic contact dermatitis caused by geraniol, containing in two different pharmaceutical products, a revision has been made of the preparations of topical application which contain this and other fragrances. At the same time the clinical picture and examination of these cause is reported.

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.

Odor mimetism? : Key substances inOphrys lutea-Andrena pollination relationship (Orchidaceae: Andrenidae).

PubMed

Borg-Karlson, A K; Tengö, J

1986-09-01

The hypothesis of chemical mimesis in the relationship betweenOphrys orchids and their pollinators was tested experimentally using preparations ofOphrys lutea var.lutea odor and the males of the solitary beeAndrena fuscipes, a species constellation that does not coexist under natural conditions. Correspondence in odor production was shown to occur. Identification of the compounds in the cephalic secretion ofA. fuscipes, males and females, and the flower labella extracts, was performed by gas chromatography and mass spectrometry. Geraniol, nerol, citral,E,E-farnesol and 6-methyl-5-hepten-2-one were present in the extracts of both the orchid and one or both sexes of the bee. Extracts, TLC fractions of extracts, blends, and separate compounds were tested in the field in the mating flight areas ofA. fuscipes males. Extracts and blends containingE,E-farnesol, geraniol, and geranial showed the highest attractivity to the male bees. These compounds seem to be responsible for the release of the odor-guided mating behavior at theO. lutea labellum and can be regarded as general attractants for many species ofAndrena.

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.

Preparation and characterization of Ni based on natural zeolite catalyst for citronellol conversion to 3,7-Dimethyl-1-Octanol

NASA Astrophysics Data System (ADS)

Sudiyarmanto, Hidayati, Luthfiana N.; Kristiani, Anis; Ghaisani, Almira; Sukandar, Dede; Adilina, Indri B.; Tursiloadi, Silvester

2017-11-01

Citronella oil is a kind of essential oil that contains three main components, namely citronellal, citronellol, and geraniol. The high demand of citronellal and geraniol derivative prompted scientists to develop methods which are stereo-selective synthesis. A hydrogenation reaction using heterogeneous catalyst is one way of synthesis of citronella oil derivatives. In this research, synthesis of citronellol oil derivatives using Ni based on natural zeolite (Ni/ZAB) catalyst which is expected to produce the compound of 3,7-dimethyl-1-octanol. The catalyst was prepared by supporting Ni on natural zeolite by impregnation method. The physical and chemical properties of Ni/ZAB catalyst have been characterized by TGA, BET, XRD and FTIR instrumentations. Variation of pressure and temperature reactions were conducted to determine the optimum conditions for the hydrogenation of citronellol. The products from this reaction were analyzed using GC-MS instrumentation. The yield and selectivity of 3,7-dimethyl-1-octanol compound were achieved with optimum conditions at 200°C and 20 bar during 3 hours which produced around 51.97% and 47.81% respectively.

Insights into the mode of action of anticandidal herbal monoterpenoid geraniol reveal disruption of multiple MDR mechanisms and virulence attributes in Candida albicans.

PubMed

Singh, Shweta; Fatima, Zeeshan; Hameed, Saif

2016-07-01

The anticandidal potential of Geraniol (Ger) against Candida albicans has already been established. The present study reveals deeper insights into the mechanisms of action of Ger. We observed that the repertoire of antifungal activity was not only limited to C. albicans and its clinical isolates but also against non-albicans species of Candida. The membrane tampering effect was visualized through transmission electron micrographs, depleted ergosterol levels and altered plasma membrane ATPase activity. Ger also affects cell wall as revealed by spot assays with cell wall-perturbing agents and scanning electron micrographs. Functional calcineurin pathway seems to be indispensable for the antifungal effect of Ger as calcineurin signaling mutant was hypersensitive to Ger while calcineurin overexpressing strain remained resistant. Ger also causes mitochondrial dysfunction, impaired iron homeostasis and genotoxicity. Furthermore, Ger inhibits both virulence attributes of hyphal morphogenesis and biofilm formation. Taken together, our results suggest that Ger is potential antifungal agent that warrants further investigation in clinical applications so that it could be competently employed in therapeutic strategies to treat Candida infections.

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.

Geranyl acetate esterase controls and regulates the level of geraniol in lemongrass (Cymbopogon flexuosus Nees ex Steud.) mutant cv. GRL-1 leaves.

PubMed

Ganjewala, Deepak; Luthra, Rajesh

2009-01-01

Essential oil isolated from lemongrass (Cymbopogon flexuosus) mutant cv. GRL-1 leaves is mainly composed of geraniol (G) and geranyl acetate (GA). The proportion of G and GA markedly fluctuates during leaf development. The proportions of GA and G in the essential oil recorded at day 10 after leaf emergence were approximately 59% and approximately 33% respectively. However, the level of GA went down from approximately 59 to approximately 3% whereas the level of G rose from approximately 33 to approximately 91% during the leaf growth period from day 10 to day 50. However, the decline in the level of GA was most pronounced in the early (day 10 to day 30) stage of leaf growth. The trend of changes in the proportion of GA and G has clearly indicated the role of an esterase that must be involved in the conversion of GA to G during leaf development. We isolated an esterase from leaves of different ages that converts GA into G and has been given the name geranyl acetate esterase (GAE). The GAE activity markedly varied during the leaf development cycle; it was closely correlated with the monoterpene (GA and G) composition throughout leaf development. GAE appeared as several isoenzymes but only three (GAE-I, GAE-II, and GAE-III) of them had significant GA cleaving activity. The GAE isoenzymes pattern was greatly influenced by the leaf developmental stages and so their GA cleaving activities. Like the GAE activity, GAE isoenzyme patterns were also found to be consistent with the monoterpene (GA and G) composition. GAE had an optimum pH at 8.5 and temperature at 30 degrees C. Besides GAE, a compound with phosphatase activity capable of hydrolyzing geranyl diphosphate (GPP) to produce geraniol has also been isolated.

Functional expression of a putative geraniol 8-hydroxylase by reconstitution of bacterially expressed plant CYP76F45 and NADPH-cytochrome P450 reductase CPR I from Croton stellatopilosus Ohba.

PubMed

Sintupachee, Siriluk; Promden, Worrawat; Ngamrojanavanich, Nattaya; Sitthithaworn, Worapan; De-Eknamkul, Wanchai

2015-10-01

While attempting to isolate the enzyme geranylgeraniol 18-hydroxylase, which is involved in plaunotol biosynthesis in Croton stellatopilosus (Cs), the cDNAs for a cytochrome P450 monooxygenase(designated as CYP76F45) and an NADPH-cytochrome P450 reductase (designated as CPR I based on its classification) were isolated from the leaf. The CYP76F45 and CsCPR I genes have open reading frames (ORFs) encoding 507- and 711-amino acid proteins with predicted relative molecular weights of 56.7 and 79.0 kDa,respectively. Amino acid sequence comparison showed that both CYP76F45 (63–73%) and CsCPR I (79–83%) share relatively high sequence identities with homologous proteins in other plant species.Phylogenetic tree analysis confirmed that CYP76F45 belongs to the CYP76 family and that CsCPR I belongs to Class I of dicotyledonous CPRs, with both being closely related to Ricinus communis genes. Functional characterization of both enzymes, each expressed separately in Escherichia coli as recombinant proteins,showed that only simultaneous incubation of the membrane bound proteins with the substrate geraniol (GOH) and the coenzyme NADPH could form 8-hydroxygeraniol. The enzyme mixture could also utilize acyclic sesquiterpene farnesol (FOH) with a comparable substrate preference ratio (GOH:FOH) of 54:46. The levelsof the CYP76F45 and CsCPR I transcripts in the shoots, leaves and twigs of C. stellatopilosus were correlated with the levels of a major monoterpenoid indole alkaloid, identified tentatively as 19-Evallesamine,that accumulated in these plant parts. These results suggested that CYP76F45 and CPR I function as the enzyme geraniol-8-hydroxylase (G8H), which is likely to be involved in the biosynthesis of the indole alkaloid in C. stellatopilosus [corrected]. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effect of surfactant on headspace single drop microextraction for the determination of some volatile aroma compounds in citronella grass and lemongrass leaves by gas chromatography

USDA-ARS?s Scientific Manuscript database

A rapid method for the determination of some volatile aromatic compounds (VACs), including citronellal, citronellol, neral, geranial, geraniol, and eugenol in citronella grass and lemongrass leaves, was developed using surfactant as a surface tension modifier while performing headspace single drop m...

Chemoselective Reactions of Citral: Green Syntheses of Natural Perfumes for the Undergraduate Organic Laboratory

ERIC Educational Resources Information Center

Cunningham, Anna D.; Ham, Eun Y.; Vosburg, David A.

2011-01-01

Chemoselectivity is a central concept in organic synthesis and may be readily appreciated in the context of the fragrant, polyfunctional natural product citral. We describe three single-step reactions students may perform on citral to synthesize other natural perfumes: citronellal, geraniol, nerol, or epoxycitral. Each of the reactions uses a…

Molecules with polymerizable ligands as precursors to porous doped materials

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

Hubert-Pfalzgraf, L.G.; Pajot, N.; Papiernik, R.

1996-12-31

Titanium and aluminum alkoxide derivatives with polymerizable ligands such as 2-(methacryloyloxy)ethylacetoacetate (HAAEMA), oleic acid and geraniol (HOGE) have been obtained. The various compounds have been characterized by FT-IR and NMR {sup 1}H. Copolymerization with styrene and divinylbenzene affords porous doped organic materials which have been characterized by scanning electron microscopy (SEM), elemental analysis, density measurements.

Condensation of the isoprenoid and amino precursors in the biosynthesis of domoic acid.

PubMed

Savage, Thomas J; Smith, G Jason; Clark, Amy T; Saucedo, Portia N

2012-01-01

Understanding how environmental signals regulate production of domoic acid in blooms of Pseudo-nitzschia spp. at a molecular level requires description of the biochemical pathway to this kainoid neurotoxin. Precursor feeding studies have suggested domoic acid arises from the condensation of the C(10) isoprenoid geranyl diphosphate with glutamate, but the specific reactions leading to domoic acid from these precursors remain undescribed. Here, we develop a method to derivatize domoic acid with propyl chloroformate that enables gas chromatography-mass spectrometry (GC-MS) analysis to measure incorporation of stable isotopes into domoic acid generated in cultures incubated with isotopically-labeled substrates. We apply this method to demonstrate that both (2)H from [1-(2)H(2)]geraniol are incorporated into domoic acid, suggesting that the condensation of geranyl diphosphate with an amino group occurs by nucleophilic substitution of the diphosphate rather than by oxidation of geraniol to the aldehyde before reaction with an amino group to form an imine. Ultimately, these and similar studies will facilitate the identification of DA biosynthetic enzymes and genes which will enable the study of how environmental factors regulate DA biosynthesis at the molecular level. Copyright © 2011 Elsevier Ltd. All rights reserved.

Evaluation of three headspace sorptive extraction coatings for the determination of volatile terpenes in honey using gas chromatography-mass spectrometry.

PubMed

Cacho, J I; Campillo, N; Viñas, P; Hernández-Córdoba, M

2015-06-19

Headspace sorptive extraction (HSSE) was used to preconcentrate seven monoterpenes (eucalyptol, linalool, menthol, geraniol, carvacrol, thymol and eugenol) for separation by gas chromatography and mass spectrometry (GC-MS). Three commercially available coatings for the stir bars, namely Polydimethylsiloxane (PDMS), polyacrilate (PA) and Ethylene glycol-silicone (EG-Silicone), were tested, and the influential parameters both in the adsorption and the thermal desorption steps were optimized. PDMS provided the best sensitivity for linalool, geraniol, menthol and eucalyptol, whereas EG-Silicone was best for extracting the phenolic monoterpenes studied. Considering the average obtained slopes from all compounds, PDMS pointed as the best option, and the analytical characteristics for the HSSE-TD-GC-MS method using this coating were obtained. Quantification of the samples was carried out by matrix-matched calibration using a synthetic honey. Detection limits ranged between 0.007 and 0.032 ng g(-1), depending on the compound. Twelve honey samples of different floral origins were analyzed using the HSSE-GC-MS method, the analytes being detected at concentrations up to 64 ng g(-1). Copyright © 2015 Elsevier B.V. All rights reserved.

Sensory and Instrumental Flavor Changes in Green Tea Brewed Multiple Times

PubMed Central

Lee, Jeehyun; Chambers, Delores; Chambers, Edgar

2013-01-01

Green teas in leaf form are brewed multiple times, a common selling point. However, the flavor changes, both sensory and volatile compounds, of green teas that have been brewed multiple times are unknown. The objectives of this study were to determine how the aroma and flavor of green teas change as they are brewed multiple times, to determine if a relationship exists between green tea flavors and green tea volatile compounds, and to suggest the number of times that green tea leaves can be brewed. The first and second brews of the green tea samples provided similar flavor intensities. The third and fourth brews provided milder flavors and lower bitterness and astringency when measured using descriptive sensory analysis. In the brewed liquor of green tea mostly linalool, nonanal, geraniol, jasmone, and β-ionone volatile compounds were present at low levels (using gas chromatography-mass spectrometry). The geraniol, linalool, and linalool oxide compounds in green tea may contribute to the floral/perfumy flavor. Green teas in leaf form may be brewed up to four times: the first two brews providing stronger flavor, bitterness, and astringency whereas the third and fourth brews will provide milder flavor, bitterness, and astringency. PMID:28239138

A Three-Dimensional DOSY HMQC Experiment for the High-Resolution Analysis of Complex Mixtures

NASA Astrophysics Data System (ADS)

Barjat, Hervé; Morris, Gareth A.; Swanson, Alistair G.

1998-03-01

A three-dimensional experiment is described in which NMR signals are separated according to their proton chemical shift,13C chemical shift, and diffusion coefficient. The sequence is built up from a stimulated echo sequence with bipolar field gradient pulses and a conventional decoupled HMQC sequence. Results are presented for a model mixture of quinine, camphene, and geraniol in deuteriomethanol.

Contact allergy to fragrances: frequencies of sensitization from 1996 to 2002. Results of the IVDK*.

PubMed

Schnuch, Axel; Lessmann, Holger; Geier, Johannes; Frosch, Peter J; Uter, Wolfgang

2004-02-01

Increasing frequencies of sensitization to the fragrance mix (FM) have been acknowledged as a serious problem for many years. It is well known that the single compounds (SCs) of the FM contribute differently to the FM patch rest reactions. In this study, we were interested in the time trends of the FM, the SCs, Myroxylon pereirae resin (MP; balsam of Peru) and oil of turpentine (OT) as possible further indicators of perfume allergy and analysed the data collected by the Information Network of Departments of Dermatology multicentre project from 1996 to 2002. During the study period (1996-2002), the FM [8% petrolatum (pet.)], MP (25% pet.) and OT (1% pet.) were tested in 59,298, 59,334 and 59,478 patients, respectively. SCs were tested in a selected group of patients, ranging from n = 1083 to n = 1924 per year. A significant increase in the proportions of patients with positive reactions to FM, MP and OT between 1996 and 1998 is noted, and a significant decline from 1999 to 2002 (Cochrane Armitage trend test, P < 0.0001). The highest frequency of sensitization to the FM was 13.1% in 1999, and the lowest 7.8% in 2002. The number of concomitant reactions to OT, a surrogate marker for terpenes, in FM-positive patients was significantly increased between 1997 and 1999. Reactions to SCs in FM-positive patients were observed in 29.9% (oak moss absolute) to 5.9% (geraniol). There was no time trend in reactions to SCs, although the relative share was increased for isoeugenol, cinnamic aldehyde and geraniol in 1999. In summary, we report for the first time, a significant decline in sensitization to the FM, very probably due to a reduced exposure (less potent allergens used in fine fragrances, possibly less use of natural ingredient-based cosmetics and lowered use concentration of important fragrance allergens). The differences in ranking of SCs could stimulate (a) a redefinition of the FM and (b) a differentiated preventive and regulatory approach, with oak moss and isoeugenol being regulated strictly by prohibition, concentration limits further reconsidered and/or health warnings and clearly less noxious substances like geraniol treated less restrictively.

RADIATION DOSIMETER AND DOSIMETRIC METHODS

DOEpatents

Taplin, G.V.

1958-10-28

The determination of ionizing radiation by means of single fluid phase chemical dosimeters of the colorimetric type is presented. A single fluid composition is used consisting of a chlorinated hydrocarbon, an acidimetric dye, a normalizer and water. Suitable chlorinated hydrocarbons are carbon tetrachloride, chloroform, trichloroethylene, trichlorethane, ethylene dichioride and tetracbloroethylene. Suitable acidimetric indicator dyes are phenol red, bromcresol purple, and creosol red. Suitable normallzers are resorcinol, geraniol, meta cresol, alpha -tocopberol, and alpha -naphthol.

Allergenicity evaluation of fragrance mix and its ingredients by using ex vivo local lymph node assay-BrdU endpoints.

PubMed

Ulker, Ozge Cemiloglu; Kaymak, Yesim; Karakaya, Asuman

2014-03-01

The present studies were performed to compare the differences between sensitization potency of fragrance mix and its ingredients (oak moss absolute, isoeugenol, eugenol, cinnamal, hydroxycitronellal, geraniol, cinnamic alcohol, alpha amyl cinnamal), by using ex vivo LLNA-BrdU ELISA. The SI and EC3 values were calculated and potency classification was found for the mixture and for each ingredients. TH1 cytokines (IL-2, IFN-γ) and TH2 cytokines (IL-4, IL-5) releases from lymph node cell culture were also investigated as contact sensitization endpoints. The EC3 values were calculated and the potency of contact sensitization were classified for fragrance mix, oak moss absolute, isoeugenol, eugenol, cinnamal, hydroxycitronellal, geraniol, cinnamic alcohol, alpha amyl cinnamal respectively: 4.4% (moderate), 3.4% (moderate), 0.88% (strong), 16.6% (weak), 1.91% (moderate), 9.77% (moderate), 13.1% (weak), 17.93% (weak), 7.74% (moderate). According to our results it should be concluded that exposure to fragrance mix does not constitute an evidently increased hazard compared to exposure to each of the eight fragrance ingredients separately. Cytokine analyses results indicate that both TH1 and TH2 cytokines are involved in the regulation of murine contact allergy and can be considered as useful endpoints. Copyright © 2014 Elsevier Ltd. All rights reserved.

Volatile Compounds with Characteristic Odor of Essential Oil from Magnolia obovata Leaves by Hydrodistillation and Solvent-assisted Flavor Evaporation.

PubMed

Miyazawa, Mitsuo; Nakashima, Yoshimi; Nakahashi, Hiroshi; Hara, Nobuyuki; Nakagawa, Hiroki; Usami, Atsushi; Chavasiri, Warinthorn

2015-01-01

The present study focuses on the volatile compounds with characteristic odor of essential oil from the leaves of Magnolia obovata by hydrodistillation (HD) and solvent-assisted flavor evaporation (SAFE) method. Eighty-seven compounds, representing 98.0% of the total oil, were identified using HD. The major compounds of HD oil were (E)-β-caryophyllene (23.7%), α-humulene (11.6%), geraniol (9.1%), and borneol (7.0%). In SAFE oil, fifty-eight compounds, representing 99.7% of the total oil, were identified. The main compounds of SAFE oil were (E)-β-caryophyllene (48.9%), α-humulene (15.7%), and bicyclogermacrene (4.2%). In this study, we newly identified eighty-five compounds of the oils from M. obovata leaves. These oils were also subjected to aroma evaluation by gas chromatography-olfactometry (GC-O) and aroma extract dilution analysis (AEDA). As a result, twenty-four (HD) and twenty-five (SAFE) aroma-active compounds were detected. (E)-β-Caryophyllene, α-humulene, linalool, geraniol, 1,8-cineole, and bicyclogermacrene were found to impart the characteristic odor of M. obovata leaves. These results imply that the oils of M. obovata leaves must be investigated further to clarify their potential application in the food and pharmaceutical industries.

Antibacterial activities of plant essential oils and their components against Escherichia coli O157:H7 and Salmonella enterica in apple juice.

PubMed

Friedman, Mendel; Henika, Philip R; Levin, Carol E; Mandrell, Robert E

2004-09-22

We evaluated 17 plant essential oils and nine oil compounds for antibacterial activity against the foodborne pathogens Escherichia coli O157:H7 and Salmonella enterica in apple juices in a bactericidal assay in terms of % of the sample that resulted in a 50% decrease in the number of bacteria (BA(50)). The 10 compounds most active against E. coli (60 min BA(50) range in clear juice, 0.018-0.093%) were carvacrol, oregano oil, geraniol, eugenol, cinnamon leaf oil, citral, clove bud oil, lemongrass oil, cinnamon bark oil, and lemon oil. The corresponding compounds against S. enterica (BA(50) range, 0.0044-0.011%) were Melissa oil, carvacrol, oregano oil, terpeineol, geraniol, lemon oil, citral, lemongrass oil, cinnamon leaf oil, and linalool. The activity (i) was greater for S. enterica than for E. coli, (ii) increased with incubation temperature and storage time, and (iii) was not affected by the acidity of the juices. The antibacterial agents could be divided into two classes: fast-acting and slow-acting. High-performance liquid chromatography analysis showed that the bactericidal results are related to the composition of the oils. These studies provide information about new ways to protect apple juice and other foods against human pathogens.

Identification of Insecticidal Constituents from the Essential Oil from the Aerial Parts Stachys riederi var. japonica.

PubMed

Quan, Meirong; Liu, Qi Zhi; Liu, Zhi Long

2018-05-17

The essential oil of Stachys riederi var. japonica (Family: Lamiaceae) was extracted by hydrodistillation and determined by GC and GC-MS. A total of 40 components were identified, representing 96.01% of the total oil composition. The major compounds in the essential oil were acetanisole (15.43%), anisole (9.43%), 1,8-cineole (8.07%), geraniol (7.89%), eugenol (4.54%), caryophyllene oxide (4.47%), caryophyllene (4.21%) and linalool (4.07%). Five active constituents (acetanisole, anisole, 1,8-cineole, eugenol and geraniol) were identified by bioactivity-directed fractionation. The essential oil possessed fumigant toxicity against maize weevils ( Sitophilus zeamais ) and booklice ( Liposcelis bostrychophila ), with LC 50 values of 15.0 mg/L and 0.7 mg/L, respectively. Eugenol and anisole exhibited stronger fumigant toxicity than the oil against booklice. 1,8-Cineole showed stronger toxicity, and anisole as well as eugenol exhibited the same level of fumigant toxicity as the essential oil against maize weevils. The essential oil also exhibited contact toxicity against S. zeamais adults and L. bostrychophila , with LC 50 values of 21.8 µg/adult and 287.0 µg/cm², respectively. The results indicated that the essential oil of S. riederi var. japonica and its isolates show potential as fumigants, and for their contact toxicity against grain storage insects.

Volatile constituents of essential oil and rose water of damask rose (Rosa damascena Mill.) cultivars from North Indian hills.

PubMed

Verma, Ram Swaroop; Padalia, Rajendra Chandra; Chauhan, Amit; Singh, Anand; Yadav, Ajai Kumar

2011-10-01

Rosa damascena Mill. is an important aromatic plant for commercial production of rose oil, water, concrete and absolute. The rose water and rose oil produced under the mountainous conditions of Uttarakhand were investigated for their chemical composition. The major components of rose water volatiles obtained from the bud, half bloom and full bloom stages of cultivar 'Ranisahiba' were phenyl ethyl alcohol (66.2-79.0%), geraniol (3.3-6.6%) and citronellol (1.8-5.5%). The rose water volatiles of cultivar 'Noorjahan' and 'Kannouj' also possessed phenyl ethyl alcohol (80.7% and 76.7%, respectively) as a major component at full bloom stage. The essential oil of cultivar 'Noorjahan' obtained from two different growing sites was also compared. The major components of these oils were citronellol (15.9-35.3%), geraniol (8.3-30.2%), nerol (4.0-9.6%), nonadecane (4.5-16.0%), heneicosane (2.6-7.9%) and linalool (0.7-2.8%). This study clearly showed that the flower ontogeny and growing site affect the composition of rose volatiles. The rose oil produced in this region was comparable with ISO standards. Thus, it was concluded that the climatic conditions of Uttarakhand are suitable for the production of rose oil of international standards.

Geraniol produces antidepressant-like effects in a chronic unpredictable mild stress mice model.

PubMed

Deng, Xue-Yang; Xue, Jin-Song; Li, Hong-Yan; Ma, Zhan-Qiang; Fu, Qiang; Qu, Rong; Ma, Shi-Ping

2015-12-01

Geraniol (GE), which has neuroprotection and anti-inflammation activities, is mostly abundant in the essential oils of rose, ginger, lemon, orange, lavender etc. However, its antidepressant-like effect has not been reported before. The present study was designed to investigate whether GE confers an antidepressant effect in mice exposed to a chronic unpredictable mild stress (CUMS) model of depression and to explore its possible mechanisms. The results showed that GE treatments for 3 weeks significantly alleviated the depression-related behaviors of CUMS-exposed mice, as indicated by restored decreased sucrose preference and shortened immobile time in both the forced swimming tests (FST) and tail suspension tests (TST). And these ameliorative effects of GE treatment were involved with regulating CUMS-induced pro-inflammatory cytokine interleukin-1 beta (IL-1β) related neuro-inflammation. We further found that GE treatment reversed CUMS-induced IL-1β elevation, possibly by inhibiting nuclear factor kappa B (NF-κB) pathway activation and regulating nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome expression. Taken together, our findings suggested that GE exerted a potential antidepressant-like effect in CUMS mice model of depression, which may provide an insight into the potential of GE in therapeutic implications for depression. Copyright © 2015 Elsevier Inc. All rights reserved.

Temperature and Drug Treatments in Mevalonate Kinase Deficiency: An Ex Vivo Study

PubMed Central

Tricarico, Paola Maura; Piscianz, Elisa; Crovella, Sergio

2013-01-01

Mevalonate Kinase Deficiency (MKD) is a rare autosomal recessive inborn disorder of cholesterol biosynthesis caused by mutations in the mevalonate kinase (MK) gene, leading to MK enzyme decreased activity. The consequent shortage of mevalonate-derived isoprenoid compounds results in an inflammatory phenotype, caused by the activation of the NALP3 inflammasome that determines an increased caspase-1 activation and IL-1β release. In MKD, febrile temperature can further decrease the residual MK activity, leading to mevalonate pathway modulation and to possible disease worsening. We previously demonstrated that the administration of exogenous isoprenoids such as geraniol or the modulation of the enzymatic pathway with drugs, such as Tipifarnib, partially rescues the inflammatory phenotype associated with the defective mevalonic pathway. However, it has not been investigated yet how temperature can affect the success of these treatments. Thus, we investigated the effect of temperature on primary human monocytes from MKD patients. Furthermore the ability of geraniol and Tipifarnib to reduce the abnormal inflammatory response, already described at physiological temperature in MKD, was studied in a febrile condition. We evidenced the role of temperature in the modulation of the inflammatory events and suggested strongly considering this variable in future researches aimed at finding a treatment for MKD. PMID:24073415

Circadian Rhythms in Neurospora crassa: Clock Mutant Effects in the Absence of a frq-Based Oscillator

PubMed Central

Lombardi, Laura; Schneider, Kevin; Tsukamoto, Michelle; Brody, Stuart

2007-01-01

In Neurospora, the circadian rhythm is expressed as rhythmic conidiation driven by a feedback loop involving the protein products of frq (frequency), wc-1 (white collar-1), and wc-2, known as the frq/wc (FWC) oscillator. Although strains carrying null mutations such as frq10 or wc-2Δ lack a functional FWC oscillator and do not show a rhythm under most conditions, a rhythm can be observed in them by the addition of geraniol or farnesol to the media. Employing this altered media as an assay, the effect of other clock mutations in a frq10- or wc-2Δ-null background can be measured. It was found that the existing clock mutations fall into three classes: (1) those, such as prd-3 or prd-4 or frq1, that showed no effect in a clock null background; (2) those, such as prd-1 or prd-2 or prd-6, that did have a measurable effect in the frq10 background; and (3) those, such as the new mutation ult, that suppressed the frq10 or wc-2Δ effect, i.e., geraniol/farnesol was not required for a visible rhythm. This classification suggests that some of the known clock mutations are part of a broader multioscillator system. PMID:17237512

Gene expression regulation of Bcl2, Bax and cytochrome-C by geraniol on chronic MPTP/probenecid induced C57BL/6 mice model of Parkinson's disease.

PubMed

Rekha, Karamkolly R; Selvakumar, Govindasamy P

2014-06-25

Parkinson's disease (PD) is a common disabling movement disorder owing to progressive depletion of dopamine in nigrostriatal region, and can be experimentally accelerated by the neurotoxin 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP). MPTP-treated mice are a representative animal model for searching for the therapeutic agents for PD without adverse effect. In this study we investigated the effect of geraniol (GE) on chronic MPTP/probenecid (MPTP/p) induced apoptotic changes in nigrostriatal region. We observed that chronic exposure to MPTP/p led to increased expression of apoptotic markers, results in neurodegeneration and motor behavioral impairments in mice. Pretreatment with GE to MPTP/p significantly improved motor functions and ameliorated striatal antioxidant balance. In addition, GE attenuated the expression of apoptotic markers evident by the normalized Bcl-2/Bax ratio and decreased expression of cytochrome-C and caspase-9 in the substantia nigra and striatum of MPTP/p induced mice model of PD. The findings of the present study suggested that GE, a new therapeutic potential avenue may have beneficial effects in slowing or preventing the progression of PD and other neurodegenerative disorders. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Bactericidal activities of plant essential oils and some of their isolated constituents against Campylobacter jejuni, Escherichia coli, Listeria monocytogenes, and Salmonella enterica.

PubMed

Friedman, Mendel; Henika, Philip R; Mandrell, Robert E

2002-10-01

An improved method of sample preparation was used in a microplate assay to evaluate the bactericidal activity levels of 96 essential oils and 23 oil compounds against Campylobacter jejuni, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica obtained from food and clinical sources. Bactericidal activity (BA50) was defined as the percentage of the sample in the assay mixture that resulted in a 50% decrease in CFU relative to a buffer control. Twenty-seven oils and 12 compounds were active against all four species of bacteria. The oils that were most active against C. jejuni (with BA50 values ranging from 0.003 to 0.009) were marigold, ginger root, jasmine, patchouli, gardenia, cedarwood, carrot seed, celery seed, mugwort, spikenard, and orange bitter oils; those that were most active against E. coli (with BA50 values ranging from 0.046 to 0.14) were oregano, thyme, cinnamon, palmarosa, bay leaf, clove bud, lemon grass, and allspice oils; those that were most active against L monocytogenes (with BA50 values ranging from 0.057 to 0.092) were gardenia, cedarwood, bay leaf, clove bud, oregano, cinnamon, allspice, thyme, and patchouli oils; and those that were most active against S. enterica (with BA50 values ranging from 0.045 to 0.14) were thyme, oregano, cinnamon, clove bud, allspice, bay leaf, palmarosa, and marjoram oils. The oil compounds that were most active against C. jejuni (with BA50 values ranging from 0.003 to 0.034) were cinnamaldehyde, estragole, carvacrol, benzaldehyde, citral, thymol, eugenol, perillaldehyde, carvone R, and geranyl acetate; those that were most active against E. coli (with BA50 values ranging from 0.057 to 0.28) were carvacrol, cinnamaldehyde, thymol, eugenol, salicylaldehyde, geraniol, isoeugenol, citral, perillaldehyde, and estragole; those that were most active against L monocytogenes (with BA50 values ranging from 0.019 to 0.43) were cinnamaldehyde, eugenol, thymol, carvacrol, citral, geraniol, perillaldehyde, carvone S, estragole, and salicylaldehyde; and those that were most active against S. enterica (with BA50 values ranging from 0.034 to 0.21) were thymol, cinnamaldehyde, carvacrol, eugenol, salicylaldehyde, geraniol, isoeugenol, terpineol, perillaldehyde, and estragole. The possible significance of these results with regard to food microbiology is discussed.

Insecticidal Properties of Essential Oils and Some of Their Constituents on the Turkestan Cockroach (Blattodea: Blattidae).

PubMed

Gaire, Sudip; O'Connell, Mary; Holguin, Francisco O; Amatya, Anup; Bundy, Scott; Romero, Alvaro

2017-04-01

The Turkestan cockroach, Blatta lateralis (Walker), has become the most important peridomestic species in urban areas of the Southwestern United States. The aim of this study was to evaluate the use of botanical compounds to control this urban pest. We tested the acute toxicity and repellency of six botanical constituents and three essential oils on Turkestan cockroach nymphs. Chemical composition of the essential oils was also determined. Topical and fumigant assays with nymphs showed that thymol was the most toxic essential oil constituent, with a LD50 of 0.34 mg/nymph and a LC50 of 27.6 mg/liter air, respectively. Contact toxicity was also observed in assays with trans-Cinnamaldehyde, eugenol, geraniol, methyl eugenol, and p-Cymene. Methyl eugenol and geraniol had limited fumigant toxicity. The essential oils from red thyme, clove bud, and Java citronella exhibited toxicity against nymphs. Cockroaches avoided fresh dry residues of thymol and essential oils. Chemical analysis of the essential oils confirmed high contents of effective essential oil constituents. Our results demonstrated that essential oils and some of their constituents have potential as eco-friendly insecticides for the management of Turkestan cockroaches. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Synergistic and antagonistic interactions of terpenes against Meloidogyne incognita and the nematicidal activity of essential oils from seven plants indigenous to Greece.

PubMed

Ntalli, Nikoletta G; Ferrari, Federico; Giannakou, Ioannis; Menkissoglu-Spiroudi, Urania

2011-03-01

Biorational means for phytonematode control were studied within the context of an increasingly ecofriendly pest management global approach. The nematicidal activity and the chemical composition of essential oils (EOs) isolated from seven plants grown in Greece and ten selected compounds extracted from them against second-stage juveniles (J2) of Meloidogyne incognita (Kof. & White) Chitwood were evaluated using juvenile paralysis experiments. Additionally, synergistic and antagonistic interactions between nematicidal terpenes were studied using an effect addition model, with the comparison made at one concentration level. The 96 h EC(50) values of Foeniculum vulgare Mill., Pimpinella anisum L., Eucalyptus meliodora A Cunn ex Schauer and Pistacia terebinthus L. were 231, 269, 807 and 1116 µg mL(-1) , respectively, in an immersion bioassay. Benzaldehyde (9 µg mL(-1) ) was the most toxic compound, followed by γ-eudesmol (50 µg mL(-1) ) and estragole (180 µg mL(-1) ), based on 96 h EC(50) values. The most potent terpene pairs between which synergistic actions were found, in decreasing order, were: trans-anethole/geraniol, trans-anethole/eugenol, carvacrol/eugenol and geraniol/carvacrol. This is the first report on the activity of F. vulgare, P. anisum, E. meliodora and P. terebinthus, and additionally on synergistic/antagonistic nematicidal terpene interactions, against M. incognita, providing alternative methods for nematode control. Copyright © 2010 Society of Chemical Industry.

Synergism Effect of the Essential Oil from Ocimum basilicum var. Maria Bonita and Its Major Components with Fluconazole and Its Influence on Ergosterol Biosynthesis

PubMed Central

Cardoso, Nathalia N. R.; Alviano, Celuta S.; Blank, Arie F.; Romanos, Maria Teresa V.; Fonseca, Beatriz B.; Rozental, Sonia; Rodrigues, Igor A.; Alviano, Daniela S.

2016-01-01

The aim of this study was to evaluate the activity of the EO and its major components of Ocimum basilicum var. Maria Bonita, a genetically improved cultivar, against the fluconazole sensitive and resistant strains of Candida albicans and Cryptococcus neoformans. Geraniol presented better results than the EO, with a low MIC (76 μg/mL against C. neoformans and 152 μg/mL against both Candida strains). The combination of EO, linalool, or geraniol with fluconazole enhanced their antifungal activity, especially against the resistant strain (MIC reduced to 156, 197, and 38 μg/mL, resp.). The ergosterol assay showed that subinhibitory concentrations of the substances were able to reduce the amount of sterol extracted. The substances tested were able to reduce the capsule size which suggests they have an important mechanism of action. Transmission electron microscopy demonstrated cell wall destruction of C. neoformans after treatment with subinhibitory concentrations. In C. albicans ultrastructure alterations such as irregularities in the membrane, presence of vesicles, and cell wall thickening were observed. The biofilm formation was inhibited in both C. albicans strains at MIC and twice MIC. These results provide further support for the use of O. basilicum EO and its major components as a potential source of antifungal agents. PMID:27274752

Co-overexpression of geraniol-10-hydroxylase and strictosidine synthase improves anti-cancer drug camptothecin accumulation in Ophiorrhiza pumila

PubMed Central

Cui, Lijie; Ni, Xiaoling; Ji, Qian; Teng, Xiaojuan; Yang, Yanru; Wu, Chao; Zekria, David; Zhang, Dasheng; Kai, Guoyin

2015-01-01

Camptothecin (CPT) belongs to a group of monoterpenoidindole alkaloids (TIAs) and its derivatives such as irinothecan and topothecan have been widely used worldwide for the treatment of cancer, giving rise to rapidly increasing market demands. Genes from Catharanthus roseus encoding strictosidine synthase (STR) and geraniol 10-hydroxylase (G10H), were separately and simultaneously introduced into Ophiorrhiza pumila hairy roots. Overexpression of individual G10H (G lines) significantly improved CPT production with respect to non-transgenic hairy root cultures (NC line) and single STR overexpressing lines (S lines), indicating that G10H plays a more important role in stimulating CPT accumulation than STR in O. pumila. Furthermore, co-overexpression of G10H and STR genes (SG Lines) caused a 56% increase on the yields of CPT compared to NC line and single gene transgenic lines, showed that simultaneous introduction of G10H and STR can produce a synergistic effect on CPT biosynthesis in O. pumila. The MTT assay results indicated that CPT extracted from different lines showed similar anti-tumor activity, suggesting that transgenic O. pumila hairy root lines could be an alternative approach to obtain CPT. To our knowledge, this is the first report on the enhancement of CPT production in O. pumila employing a metabolic engineering strategy. PMID:25648209

Investigation of the dermal sensitization potential of various essential oils in the local lymph node assay.

PubMed

Lalko, J; Api, A M

2006-05-01

Essential oils are commonly used fragrance ingredients. The oils themselves are complex mixtures, which may contain naturally occurring contact sensitizers. The local lymph node assay was used to evaluate the dermal sensitization potential of basil, citronella, clove leaf, geranium, litsea cubeba, lemongrass, and palmarosa oils. Three of the major components--citral, eugenol, and geraniol--were included to investigate any difference in sensitization potential arising from their exposure in a mixture. Each fragrance material was tested at five concentration ranging from 2.5% to 50% w/v in 1:3 ethanol:diethyl phthalate. The stimulation index (SI) values were calculated for each dose level, an SI > or = 3 was considered a positive response. The estimated concentration (EC3) required to elicit a positive was calculated and taken as a measure of relative potency. The EC3 values and potency classification for basil, clove leaf, litsea cubeba, lemongrass and palmarosa oils were calculated to be <2.5% (> or = moderate), 7.1% (weak), 8.4% (weak), 6.5% (weak) and 9.6% (weak), respectively. Citronella and geranium oils were negative. The individual components citral, eugenol and geraniol resulted in EC3 values of 6.3%, 5.4% and 11.4%, respectively. In general, the potency of each essential oil did not differ significantly from that observed for its main individual component.

Geraniol attenuates 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced oxidative stress and inflammation in mouse skin: possible role of p38 MAP Kinase and NF-κB.

PubMed

Khan, Abdul Quaiyoom; Khan, Rehan; Qamar, Wajhul; Lateef, Abdul; Rehman, Muneeb U; Tahir, Mir; Ali, Farrah; Hamiza, Oday O; Hasan, Syed Kazim; Sultana, Sarwat

2013-06-01

Abnormal production of reactive oxygen species (ROS) and proinflammatory cytokines often act as trigger for development of most of the chronic human diseases including cancer via up-regulation of transcription factors and activation of MAP kinases. We investigated the protective effects of geraniol (GOH) against 12-O-tetradecanoyl phorbol-13-acetate (TPA) induced oxidative and inflammatory responses, expression of p38MAPK, NF-κB and COX-2 in mouse skin. Animals were divided into four groups I-IV (n=6). Group II and III received topical application of TPA at the dose of 10 nmol/0.2 ml of acetone/animal/day, for two days. Group III was pre-treated with GOH (250 μg) topically 30 min prior to each TPA administration. While group I and IV were given acetone (0.2 ml) and GOH respectively. Our results show that GOH significantly inhibited TPA induced lipid peroxidation (LPO), inflammatory responses, proinflammatory cytokine release, up regulates reduced glutathione (GSH) content and the activity of different antioxidant enzymes. Interestingly, GOH also inhibited TPA induced altered activity of p38MAPK. Further, TPA induced altered expression of NF-κB (p65) and COX-2 was also attenuated by GOH. Thus, our results suggest that GOH attenuates early tumor promotional changes, and it may serve as one of the various ways to prevent carcinogenesis. Copyright © 2013 Elsevier Inc. All rights reserved.

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.

Cytotoxic and Antimicrobial Constituents from the Essential Oil of Lippia alba (Verbenaceae)

PubMed Central

dos Santos, Nara O.; Pascon, Renata C.; Vallim, Marcelo A.; Figueiredo, Carlos R.; Soares, Marisi G.; Lago, João Henrique G.; Sartorelli, Patricia

2016-01-01

Backgroud: Lippia alba (Verbenaceae) is a plant widely used in folk medicine to treat various diseases. The present work deals with the chemical composition of the crude essential oil extracted from leaves of L. alba and evaluation of its antimicrobial and cytotoxic activities. Methods: Leaves of L. alba were extracted by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) as well as by nuclear magnetic resonance (NMR) spectroscopy. Cytotoxic and antimicrobial activities of crude essential oil were evaluated in vitro using MTT and broth microdilution assays, respectively. Results: Chemical analysis afforded the identification of 39 substances corresponding to 99.45% of the total oil composition. Concerning the main compounds, monoterpenes nerol/geraniol and citral correspond to approximately 50% of crude oil. The cytotoxic activity of obtained essential oil against several tumor cell lines showed IC50 values ranging from 45 to 64 µg/mL for B16F10Nex2 (murine melanoma) and A549 (human lung adenocarcinoma). In the antimicrobial assay, was observed that all tested yeast strains, except C. albicans, were sensitive to crude essential oil. MIC values were two to four-folds lower than those determined to bacterial strains. Conclusion: Analysis of chemical composition of essential oils from leaves of L. alba suggested a new chemotype nerol/geraniol and citral. Based in biological evidences, a possible application for studied oil as an antifungal in medicine, as well as in agriculture, is described. PMID:28930132

Essential oil from Cymbopogon flexuosus as the potential inhibitor for HSP90.

PubMed

Gaonkar, Roopa; Shiralgi, Yallappa; Lakkappa, Dhananjaya B; Hegde, Gurumurthy

2018-01-01

The essential oil of Cymbopogon flexuosus or lemongrass oil (LO) is reported to have antibacterial, antifungal and anticancerous effects. HSP90 is one of the major chaperones responsible for the proper folding of cancer proteins. In this paper we show that the essential oil of C. flexuosus significantly suppresses the HSP90 gene expression. The cytotoxicity of the compounds was tested by MTT assay and the gene expression studies were carried out using HEK-293 and MCF-7 cells. Also we tested the efficacy of the major component of this essential oil viz. citral and geraniol in inhibiting the HSP90 expression. The oil was found to be more cytotoxic to MCF-7 cells with different IC 50 values for the oil (69.33 μg/mL), citral (140.7 μg/mL) and geraniol (117 μg/mL). The fold change of expression was calculated by RT-qPCR using ΔΔCt (2 ^-ΔΔCt ) method and it was 0.1 and 0.03 in MCF-7 cells at 80 μg/mL and 160 μg/mL of LO. Western blot results showed suppression of HSP90 protein expression and HSP90 - ATPase activity inhibition was also observed using LO. This study shows the anticancer mechanism exhibited by the essential oil of C. flexuosus is by the inhibition of the important chaperone protein HSP90.

Cytotoxic and Antimicrobial Constituents from the Essential Oil of Lippia alba (Verbenaceae).

PubMed

Santos, Nara O Dos; Pascon, Renata C; Vallim, Marcelo A; Figueiredo, Carlos R; Soares, Marisi G; Lago, João Henrique G; Sartorelli, Patricia

2016-08-12

Backgroud: Lippia alba (Verbenaceae) is a plant widely used in folk medicine to treat various diseases. The present work deals with the chemical composition of the crude essential oil extracted from leaves of L. alba and evaluation of its antimicrobial and cytotoxic activities. Methods: Leaves of L. alba were extracted by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) as well as by nuclear magnetic resonance (NMR) spectroscopy. Cytotoxic and antimicrobial activities of crude essential oil were evaluated in vitro using MTT and broth microdilution assays, respectively. Results: Chemical analysis afforded the identification of 39 substances corresponding to 99.45% of the total oil composition. Concerning the main compounds, monoterpenes nerol/geraniol and citral correspond to approximately 50% of crude oil. The cytotoxic activity of obtained essential oil against several tumor cell lines showed IC 50 values ranging from 45 to 64 µg/mL for B16F10Nex2 (murine melanoma) and A549 (human lung adenocarcinoma). In the antimicrobial assay, was observed that all tested yeast strains, except C. albicans , were sensitive to crude essential oil. MIC values were two to four-folds lower than those determined to bacterial strains. Conclusion: Analysis of chemical composition of essential oils from leaves of L. alba suggested a new chemotype nerol/geraniol and citral. Based in biological evidences, a possible application for studied oil as an antifungal in medicine, as well as in agriculture, is described.

Volatile Ester Formation in Roses. Identification of an Acetyl-Coenzyme A. Geraniol/Citronellol Acetyltransferase in Developing Rose Petals1

PubMed Central

Shalit, Moshe; Guterman, Inna; Volpin, Hanne; Bar, Einat; Tamari, Tal; Menda, Naama; Adam, Zach; Zamir, Dani; Vainstein, Alexander; Weiss, David; Pichersky, Eran; Lewinsohn, Efraim

2003-01-01

The aroma of roses (Rosa hybrida) is due to more than 400 volatile compounds including terpenes, esters, and phenolic derivatives. 2-Phenylethyl acetate, cis-3-hexenyl acetate, geranyl acetate, and citronellyl acetate were identified as the main volatile esters emitted by the flowers of the scented rose var. “Fragrant Cloud.” Cell-free extracts of petals acetylated several alcohols, utilizing acetyl-coenzyme A, to produce the corresponding acetate esters. Screening for genes similar to known plant alcohol acetyltransferases in a rose expressed sequence tag database yielded a cDNA (RhAAT1) encoding a protein with high similarity to several members of the BAHD family of acyltransferases. This cDNA was functionally expressed in Escherichia coli, and its gene product displayed acetyl-coenzyme A:geraniol acetyltransferase enzymatic activity in vitro. The RhAAT1 protein accepted other alcohols such as citronellol and 1-octanol as substrates, but 2-phenylethyl alcohol and cis-3-hexen-1-ol were poor substrates, suggesting that additional acetyltransferases are present in rose petals. The RhAAT1 protein is a polypeptide of 458 amino acids, with a calculated molecular mass of 51.8 kD, pI of 5.45, and is active as a monomer. The RhAAT1 gene was expressed exclusively in floral tissue with maximum transcript levels occurring at stage 4 of flower development, where scent emission is at its peak. PMID:12692346

Geraniol attenuates 2-acetylaminofluorene induced oxidative stress, inflammation and apoptosis in the liver of wistar rats.

PubMed

Hasan, Syed Kazim; Sultana, Sarwat

2015-01-01

2-Acetylaminofluorene (2-AAF), is a well-known liver toxicant, generally used to induce tumors in laboratory animals. Geraniol (GE), a monoterpene found in essential oils of herbs and fruits, has been known to possess preventive efficacy against chemically induced toxicities. The present study was designed to analyze the protective effect of GE against 2-AAF induced oxidative stress, inflammation, hyperproliferation and apoptotic tissue damage in the liver of female Wistar rats. 2-AAF (0.02% w/w in diet) was administered and subjected to partial hepatectomy, as a mitogenic stimulus for the induction of hyperproliferation of liver tissue. GE was pre-treated orally at two different doses (100 and 200 mg/kg b.wt.) dissolved in corn oil. GE pre-treatment significantly ameliorated 2-AAF induced oxidative damage by diminishing tissue lipid peroxidation accompanied by the increase in enzymatic activities of catalase, glutathione peroxidase, glutathione reductase, superoxide dismutase and reduced glutathione content. The level of serum toxicity markers (AST, ALT, LDH) was found to be decreased. Pre-treatment with GE downregulated the expression of caspase-3,9, COX-2, NFkB, PCNA, iNOS, VEGF and significantly decreased disintegration of DNA. Histological findings further revealed that GE significantly restores the architecture of liver tissue. In the light of the above observations it may be concluded that GE may be used as preventive agent against 2-AAF induced oxidative stress, inflammation, hyperproliferation and apoptotic damage.

Geraniol attenuates fibrosis and exerts anti-inflammatory effects on diet induced atherogenesis by NF-κB signaling pathway.

PubMed

Jayachandran, Muthukumaran; Chandrasekaran, Balaji; Namasivayam, Nalini

2015-09-05

Atherosclerosis is now generally accepted as a chronic inflammatory condition. The transcription factor nuclear factor kappa B (NF-κB) is a key regulator of inflammation, immune responses, cell survival and cell proliferation. Tissue remodeling plays a significant role during the phase of inflammation and oxidative stress. In our study we have evaluated the effect of geraniol (GOH), a natural terpenoid on oxidative stress, inflammation and tissue remodeling in experimental animals. Experimental animals (hamsters) were divided into four groups; group 1 were control animals; group 2 were animals fed GOH alone (100mg/kg b.w. p.o); group 3 were animals fed atherogenic diet (standard pellet diet+10% coconut oil+0.25% cholesterol); group 4 animals were fed atherogenic diet as in group 3+GOH (100mg/kg b.w). At the end of the experimental period animals were killed and liver, heart and aorta tissues were analyzed for lipid peroxidation markers, non enzymic antioxidants and collagen distribution using histological studies like Milligan's trichrome and Picrosirius red staining. As inflammation plays a key role in tissue remodeling we also targeted the key inflammatory cytokine, NF-κB. GOH supplementation greatly prevented the remodeling of tissues by enhancing the free radical scavenging and anti-inflammatory effects. Thus in conclusion it can be suggested that GOH (100mg/kg b.w) prevents the atherogenic diet induced fibrosis in experimental hamsters. Copyright © 2015 Elsevier B.V. All rights reserved.

Temperature Dependence of Positron Annihilation in beta-Cyclodextrin and beta-Cyclodextrin Complexes

NASA Astrophysics Data System (ADS)

Hu, Y.; Hsu Hadley, F. H., Jr.; Trinh, T.

1996-11-01

The effects of temperature on positron annihilation in beta-cyclodextrin and beta-cyclodextrin complexed with benzyl salicylate, benzyl acetate, ethyl salicylate, geraniol, linalool and nerol were studied. Samples were prepared by slurry, air-dried and freeze-dried methods. Lifetime spectra were measured as a function of temperature for each sample. Comparison of the annihilation rate and intensity of the longer-lived component showed that positronium formation was affected by guest molecules, preparation methods and temperature variations. Results can be used to explain beta-cyclodextrin complex formation with different guest molecules.

Assessing the chemotaxis behavior of Physarum polycephalum to a range of simple volatile organic chemicals.

PubMed

de Lacy Costello, Ben P J; Adamatzky, Andrew I

2013-09-01

The chemotaxis behavior of the plasmodial stage of the true slime mold Physarum Polycephalum was assessed when given a binary choice between two volatile organic chemicals (VOCs) placed in its environment. All possible binary combinations were tested between 19 separate VOCs selected due to their prevalence and biological activity in common plant and insect species. The slime mold exhibited positive chemotaxis toward a number of VOCs with the following order of preference:   Farnesene > β-myrcene > tridecane > limonene > p-cymene > 3-octanone > β-pinene > m-cresol > benzylacetate > cis-3-hexenylacetate. For the remaining compounds, no positive chemotaxis was observed in any of the experiments, and for most compounds there was an inhibitory effect on the growth of the slime mold. By assessing this lack of growth or failure to propagate, it was possible to produce a list of compounds ranked in terms of their inhibitory effect: nonanal > benzaldehyde > methylbenzoate > linalool > methyl-p-benzoquinone > eugenol > benzyl alcohol > geraniol > 2-phenylethanol. This analysis shows a distinct preference of the slime mold for non-oxygenated terpene and terpene-like compounds (farnesene, β-myrcene, limonene, p-cymene and β-pinene). In contrast, terpene-based alcohols such as geraniol and linalool were found to have a strong inhibitory effect on the slime mold. Both the aldehydes utilized in this study had the strongest inhibitory effect on the slime mold of all the 19 VOCs tested. Interestingly, 3-octanone, which has a strong association with a "fungal odor," was the only compound with an oxygenated functionality where Physarum Polycephalum exhibits distinct positive chemotaxis.

Assessing the chemotaxis behavior of Physarum polycephalum to a range of simple volatile organic chemicals

PubMed Central

de Lacy Costello, Ben P.J.; Adamatzky, Andrew I.

2013-01-01

The chemotaxis behavior of the plasmodial stage of the true slime mold Physarum Polycephalum was assessed when given a binary choice between two volatile organic chemicals (VOCs) placed in its environment. All possible binary combinations were tested between 19 separate VOCs selected due to their prevalence and biological activity in common plant and insect species. The slime mold exhibited positive chemotaxis toward a number of VOCs with the following order of preference:   Farnesene > β-myrcene > tridecane > limonene > p-cymene > 3-octanone > β-pinene > m-cresol > benzylacetate > cis-3-hexenylacetate. For the remaining compounds, no positive chemotaxis was observed in any of the experiments, and for most compounds there was an inhibitory effect on the growth of the slime mold. By assessing this lack of growth or failure to propagate, it was possible to produce a list of compounds ranked in terms of their inhibitory effect: nonanal > benzaldehyde > methylbenzoate > linalool > methyl-p-benzoquinone > eugenol > benzyl alcohol > geraniol > 2-phenylethanol. This analysis shows a distinct preference of the slime mold for non-oxygenated terpene and terpene-like compounds (farnesene, β-myrcene, limonene, p-cymene and β-pinene). In contrast, terpene-based alcohols such as geraniol and linalool were found to have a strong inhibitory effect on the slime mold. Both the aldehydes utilized in this study had the strongest inhibitory effect on the slime mold of all the 19 VOCs tested. Interestingly, 3-octanone, which has a strong association with a “fungal odor,” was the only compound with an oxygenated functionality where Physarum Polycephalum exhibits distinct positive chemotaxis. PMID:24265848

Inhibitory effects of terpene alcohols and aldehydes on growth of green alga Chlorella pyrenoidosa

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

Ikawa, Miyoshi; Mosley, S.P.; Barbero, L.J.

1992-10-01

The growth of the green alga Chlorella pyrenoidosa was inhibited by terpene alcohols and the terpene aldehyde citral. The strongest activity was shown by citral. Nerol, geraniol, and citronellol also showed pronounced activity. Strong inhibition was linked to acyclic terpenes containing a primary alcohol or aldehyde function. Inhibition appeared to be taking place through the vapor phase rather than by diffusion through the agar medium from the terpene-treated paper disks used in the system. Inhibition through agar diffusion was shown by certain aged samples of terpene hydrocarbons but not by recently purchased samples.

Concept, design, and use of the photoacoustic heat pipe cell

NASA Astrophysics Data System (ADS)

Jalink, Henk; Bicanic, Dane

1989-10-01

A resonant photoacoustic cell suitable for studies of liquid samples having low vapor pressures has been developed and tested. The cell, the working of which is based on that of the heat pipe, is of a simple, compact design; its operational temperature range is limited only by the choice of working fluid and the material used to construct the cell. The feasibility of this novel-type cell has been demonstrated by obtaining the absorption spectrum of geraniol C10H18O at 403 K in the spectral region covered by the CO2 laser emission.

Epoxidation of Geraniol: An Advanced Organic Experiment that Illustrates Asymmetric Synthesis

NASA Astrophysics Data System (ADS)

Bradley, Lynn M.; Springer, Joseph W.; Delate, Gregory M.; Goodman, Andrew

1997-11-01

The Sharpless epoxidation reaction is considered one of the most powerful advances in asymmetric organic synthesis (1). It is a classic example of the use of an asymmetric catalyst to provide an enantiomerically enriched mixture of epoxy alcohols. The procedure typically uses titanium(IV) tetraisopropoxide (Ti(OiPr)4) as a catalyst, a peroxide, and dialkyl tartrates to induce asymmetry in the epoxidation reaction of allylic alcohols. The experiment described in this paper illustrates the principle of asymmetric epoxidation and enables students to determine enantiomeric product ratios using chiral shift reagents and NMR spectroscopy.

Terminal steps of bacteriochlorophyll a phytol formation in purple photosynthetic bacteria

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

Shioi, Y.; Sasa, T.

1984-04-01

Four chemically different bacteriochlorophylls (Bchls) a esterified with geranylgeraniol, dihydrogeranyl-geraniol, tetrahydrogeraniol, and phytol have been detected by high-pressure liquid chromatography in cell extracts from Rhodopseudomonas sphaeroides and Chromatium vinosum. Bchl a containing phytol is the principal component, and the other three Bchls a comprise about 4% of the total Bchls a in stationary-phase cells of R. sphaeroides and C. vinosum. The high levels of the minor pigments occur in the beginning of Bchl a phytol formation, indicating that they are not degradation products, but intermediates of Bchl a phytol formation.

Effects of Fatty Acid and Geraniol Repellent-Oil Mixtures Applied to Cattle on Blood Feeding and Reproductive Parameters in Field Populations of Haematobia irritans (Diptera: Muscidae).

PubMed

Mullens, Bradley A; Soto, Diane; Gerry, Alec C; Fowler, Fallon E; Diniz, Alesha N

2018-02-28

California pastured cattle were treated with 250 ml of a 15% mixture of fatty acids (C8-C9-C10) or 125 ml of 2% geraniol in a mineral oil carrier to assess impacts on horn flies, Haematobia irritans (L.) (Diptera: Muscidae) over two summers. Horn flies were netted from cattle every 3-4 d for 2 wk before treatment, 2 wk during treatment (four treatments, with flies collected before each treatment), and 2 wk after treatments ceased. Blood meal weights were estimated by hemoglobin assay of excised abdomens. Other females were dissected to determine the number of active ovarioles and the stage of primary follicle development. Depending on year and herd, pretreatment males contained an average of 0.6-1.0 mg of blood, while females contained 1.7-2.7 mg. Pretreatment egg development (least developed oocytes were stage 1 and fully developed eggs were stage 5) averaged 3.7-4.3, and number of active ovarioles averaged 18.1 to 19.6/female. During treatment periods, significant reductions in blood weight were noted for females, but usually not for males, and females also often exhibited reduced mean oocyte stage and number of active ovarioles. Peaks in proportions of young nulliparous females (oocyte stages 1 or 2) were seen during some repellent application periods. This suggested older females had been killed or driven off from the local population by the treatments, and flies on cattle included more young flies that likely were recent arrivals. The repellent-oil mixture thus impacted blood feeding, reproductive fitness, and probably age structure in the field.

Comparison of Essential Oil Content, Constituents, and Antioxidant Activity of Nepeta Glomerulosa during Three Developmental Stages

NASA Astrophysics Data System (ADS)

Moradi, H.; Azizi, M.; Rowshan, V.

2014-12-01

The genus Nepeta with the common Persian name "Pune-Sa" is one of the most important genera of Lamiaceae family. More than 250 species in the world and 67 annual or perennial species in Iran have been reported. Some of these species are valuable in medicine and are used for medicinal purposes. The aim of this study was to identify essential oil content, its chemical composition, and antioxidant activity in the N. glomerulosa during vegetative, flowering and seed set stages. The samples of N. glomerulosa in the three above-mentioned stages were collected from Abade region of Fars Province. The essential oil was obtained though hydrodistillation and was analyzed by GC and GC/MS. Essential oil of the plant in vegetative, flowering and seed set stages were measured to be 55, 53 and 53 components, respectively, with geranyl acetate (16.644%, 18.182% and 24.441%), geraniol (10.797%, 11.372% and 12.389%), caryophyllene oxide (8.302%, 10.515% and 6.661%), humulene epoxide ΙΙ (7.974%, 7.112% and 2.587%), α-pinene (4.743%, 4.126% and 6.724%), limonene (4.086%, 3.848% and 4.711%) and 1,8-cineol (3.397%, 4.609% and 3.759%) being the major components of the essential oil. The results confirmed that phonological stages have a significant effect on essential oils constituents. Geranyl acetate and geraniol increased by development of plant from vegetative to seed set stage and geranyl acetate was the main essential oils constituent of the plants throughout the three phonological stages. Antioxidant activity in flowering and seed set stages was significantly higher than vegetative stage, but compared with Gallic acid, which is a very strong antioxidant substance, had insignificant antioxidant activity.

Olive phenolic compounds: metabolic and transcriptional profiling during fruit development

PubMed Central

2012-01-01

Background Olive (Olea europaea L.) fruits contain numerous secondary metabolites, primarily phenolics, terpenes and sterols, some of which are particularly interesting for their nutraceutical properties. This study will attempt to provide further insight into the profile of olive phenolic compounds during fruit development and to identify the major genetic determinants of phenolic metabolism. Results The concentration of the major phenolic compounds, such as oleuropein, demethyloleuropein, 3–4 DHPEA-EDA, ligstroside, tyrosol, hydroxytyrosol, verbascoside and lignans, were measured in the developing fruits of 12 olive cultivars. The content of these compounds varied significantly among the cultivars and decreased during fruit development and maturation, with some compounds showing specificity for certain cultivars. Thirty-five olive transcripts homologous to genes involved in the pathways of the main secondary metabolites were identified from the massive sequencing data of the olive fruit transcriptome or from cDNA-AFLP analysis. Their mRNA levels were determined using RT-qPCR analysis on fruits of high- and low-phenolic varieties (Coratina and Dolce d’Andria, respectively) during three different fruit developmental stages. A strong correlation was observed between phenolic compound concentrations and transcripts putatively involved in their biosynthesis, suggesting a transcriptional regulation of the corresponding pathways. OeDXS, OeGES, OeGE10H and OeADH, encoding putative 1-deoxy-D-xylulose-5-P synthase, geraniol synthase, geraniol 10-hydroxylase and arogenate dehydrogenase, respectively, were almost exclusively present at 45 days after flowering (DAF), suggesting that these compounds might play a key role in regulating secoiridoid accumulation during fruit development. Conclusions Metabolic and transcriptional profiling led to the identification of some major players putatively involved in biosynthesis of secondary compounds in the olive tree. Our data represent the first step towards the functional characterisation of important genes for the determination of olive fruit quality. PMID:22963618

Geraniol Induces Antinociceptive Effect in Mice Evaluated in Behavioural and Electrophysiological Models.

PubMed

La Rocca, Viviana; da Fonsêca, Diogo Vilar; Silva-Alves, Kerly Shamyra; Ferreira-da-Silva, Francisco Walber; de Sousa, Damião Pergentino; Santos, Priscila Laise; Quintans-Júnior, Lucindo José; Leal-Cardoso, José Henrique; de Almeida, Reinaldo Nóbrega

2017-01-01

Geraniol (GER) is a monoterpene alcohol with various biochemical and pharmacological properties present in the essential oil of more than 160 species of herbs (especially the Cymbopogon genus). In this study, we evaluated the antinociceptive activity of GER in behavioural and electrophysiological in vitro experimental models of nociception using male Swiss mice. GER (12.5, 25 or 50 mg/kg i.p. and 50 or 200 mg/kg p.o.) reduced the number of writhes induced by acetic acid. The opioid antagonist naloxone (5 mg/kg s.c.) administered in mice subsequently treated with GER (25 mg/kg i.p.) did not reverse such antinociceptive activity, suggesting a non-opioid pathway for the mechanism of action. GER (12.5, 25 and 50 mg/kg i.p.) reduced paw licking time in the second phase of the formalin test. Also, in the glutamate test, GER when administered 50 mg/kg i.p. reduced paw licking time, probably modulating glutamatergic neurotransmission. GER blocked reversibly components of the compound action potential (CAP) recorded in isolated sciatic nerve in a concentration- and drug exposure time-dependent manner: 1 mM to 120 min. for the first component and 0.6 mM to 90 min. for the second component. The IC 50 was calculated for the peak-to-peak amplitude (PPA) at 0.48 ± 0.04 mM. The conduction velocity was also reduced by exposure to GER starting from the concentration of 0.3 mM for both components of the CAP. In conclusion, it is suggested that GER has antinociceptive activity, especially in pain related to inflammation, and in part related to reduced peripheral nerve excitability. © 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

Mitigation of acrylamide-induced behavioral deficits, oxidative impairments and neurotoxicity by oral supplements of geraniol (a monoterpene) in a rat model.

PubMed

Prasad, Sathya N; Muralidhara

2014-11-05

In the recent past, several phytoconstituents are being explored for their potential neuromodulatory effects in neurological diseases. Repeated exposure of acrylamide (ACR) leads to varying degree of neuronal damage in experimental animals and humans. In view of this, the present study investigated the efficacy of geraniol (GE, a natural monoterpene) to mitigate acrylamide (ACR)-induced oxidative stress, mitochondrial dysfunction and neurotoxicity in a rat model and compared its efficacy to that of curcumin (CU, a spice active principle with multiple biological activities). ACR administration (50mg/kg bw, i.p. 3times/week) for 4weeks to growing rats caused typical symptoms of neuropathy. ACR rats provided with daily oral supplements of phytoconstituents (GE: 100mg/kg bw/d; CU: 50mg/kg bw/d, 4weeks) exhibited marked improvement in behavioral tests. Both phytoconstituents markedly attenuated ACR-induced oxidative stress as evidenced by the diminished levels of reactive oxygen species, malondialdehyde and nitric oxide and restored the reduced glutathione levels in sciatic nerve (SN) and brain regions (cortex - Ct, cerebellum - Cb). Further, both phytoconstituents effectively diminished ACR-induced elevation in cytosolic calcium levels in SN and Cb. Furthermore, diminution in the levels of oxidative markers in the mitochondria was associated with elevation in the activities of antioxidant enzymes. While ACR mediated elevation in the acetylcholinesterase activity was reduced by both actives, the depletion in dopamine levels was restored only by CU in brain regions. Taken together our findings for the first time demonstrate that the neuromodulatory propensity of GE is indeed comparable to that of CU and may be exploited as a therapeutic adjuvant in the management of varied human neuropathy conditions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Inhibitory efficacy of geraniol on biofilm formation and development of adaptive resistance in Staphylococcus epidermidis RP62A.

PubMed

Kannappan, Arunachalam; Sivaranjani, Murugesan; Srinivasan, Ramanathan; Rathna, Janarthanam; Pandian, Shunmugiah Karutha; Ravi, Arumugam Veera

2017-10-01

The current study has been designed to delineate the efficacy of geraniol (GE) on biofilm formation in Staphylococcus epidermidis as well as the effect of subinhibitory concentrations of GE on the development of adaptive resistance. Biofilm biomass quantification assay was performed to evaluate the antibiofilm activity of GE against S. epidermidis. Microscopic observation of biofilms and extracellular polymeric substance (EPS), slime and cell surface hydrophobicity (CSH) production were also studied to support the antibiofilm potential of GE. In addition, S. epidermidis was examined for its adaptive resistance development upon continuous exposure of GE at its subinhibitory concentrations.Results/Key findings. The MIC of GE against S. epidermidis was 512 µg ml -1 . Without hampering the growth of the pathogen, GE at its sub-MICs (50, 100, 150 and 200 µg ml -1 ) exhibited a dose-dependent increase in antibiofilm activity. The minimal biofilm inhibitory concentration (MBIC) of GE was found to be 200 µg ml -1 with a maximum biofilm inhibition of 85 %. Disintegrated biofilm architecture, reduced EPS, slime and CSH production validated the antibiofilm efficacy of GE. Although the action of GE on preformed biofilm is limited, a 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay and live/dead cell staining method revealed reduction in the viability (47 %) of biofilm inhabitants at 2×MIC concentration. Sequential exposure of S. epidermidis to the sub-MICs of GE resulted in poor development of adaptive resistance with diminished biofilm formation. The present study highlights the potential of GE as a suitable candidate for the control of biofilm-mediated S. epidermidis infections.

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.

The extraction and chromatographic determination of the essentials oils from Ocimum basilicum L. by different techniques

NASA Astrophysics Data System (ADS)

Loredana Soran, Maria; Codruta Cobzac, Simona; Varodi, Codruta; Lung, Ildiko; Surducan, Emanoil; Surducan, Vasile

2009-08-01

Three different techniques (maceration, sonication and extraction in microwave field) were used for extraction of essential oils from Ocimum basilicum L. The extracts were analyzed by TLC/HPTLC technique and the fingerprint informations were obtained. The GC-FID was used to characterized the extraction efficiency and for identify the terpenic bioactive compounds. The most efficient extraction technique was maceration followed by microwave and ultrasound. The best extraction solvent system was ethyl ether + ethanol (1:1, v/v). The main compounds identified in Ocimum basilicum L. extracts were: α and β-pinene (mixture), limonene, citronellol, and geraniol.

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.

Restrained eaters show altered brain response to food odor.

PubMed

Kemmotsu, Nobuko; Murphy, Claire

2006-02-28

Do restrained and unrestrained eaters differ in their brain response to food odor? We addressed this question by examining restrained eaters' brain response to food (chocolate) and non-food (geraniol, floral) odors, both when odor was attended to and when ignored. Using olfactory event-related potentials (OERPs), we found that restrained eaters and controls responded similarly to the non-food odor; however, unlike controls, restrained eaters showed no increase in brain response to the food odor when they focused attention on it. Rather, restrained eaters showed attenuated OERP amplitudes to the food odor in both attended and ignored conditions, suggesting that the brain's response to attended food odor was abnormally suppressed.

Study on essential oils from the leaves of two Vietnamese plants: Jasminum subtriplinerve C.L. Blume and Vitex quinata (Lour) F.N. Williams.

PubMed

Dai, Do N; Thang, Tran D; Ogunwande, Isiaka A; Lawal, Oladipupo A

2016-01-01

The essential oil constituents of the leaves of Jasminum subtriplinerve (Oleaceae) and Vitex quinata (Verbanaceae) cultivated in Vietnam were analysed by gas chromatography--flame ionisation detector (GC-FID) and gas chromatography--mass spectrometry (GC-MS) techniques. The main constituents identified in J. subtriplinerve were mainly oxygenated monoterpenes represented by linalool (44.2%), α-terpineol (15.5%), geraniol (19.4%) and cis-linalool oxide (8.8%). The quantitative significant components of V. quinata were terpene hydrocarbons comprising of β-pinene (30.1%), β-caryophyllene (26.9%) and β-elemene (7.4%). The chemical compositions of the essential oils are being reported for the first time.

Identification of Key Odorants in Withering-Flavored Green Tea by Aroma Extract Dilution Analysis

NASA Astrophysics Data System (ADS)

Mizukami, Yuzo; Yamaguchi, Yuichi

This research aims to identify key odorants in withering-flavored green tea. Application of the aroma extract dilution analysis using the volatile fraction of green tea and withering-flavored green tea revealed 25 and 35 odor-active peaks with the flavor dilution factors of≥4, respectively. 4-mercapto-4-methylpentan-2-one, (E)-2-nonenal, linalool, (E,Z)-2,6-nonadienal and 3-methylnonane-2,4-dione were key odorants in green tea with the flavor dilution factor of≥16. As well as these 5 odorants, 1-octen-3-one, β-damascenone, geraniol, β-ionone, (Z)-methyljasmonate, indole and coumarine contributed to the withering flavor of green tea.

Next generation sequencing and de novo transcriptome analysis of Costus pictus D. Don, a non-model plant with potent anti-diabetic properties

PubMed Central

2012-01-01

Background Phyto-remedies for diabetic control are popular among patients with Type II Diabetes mellitus (DM), in addition to other diabetic control measures. A number of plant species are known to possess diabetic control properties. Costus pictus D. Don is popularly known as “Insulin Plant” in Southern India whose leaves have been reported to increase insulin pools in blood plasma. Next Generation Sequencing is employed as a powerful tool for identifying molecular signatures in the transcriptome related to physiological functions of plant tissues. We sequenced the leaf transcriptome of C. pictus using Illumina reversible dye terminator sequencing technology and used combination of bioinformatics tools for identifying transcripts related to anti-diabetic properties of C. pictus. Results A total of 55,006 transcripts were identified, of which 69.15% transcripts could be annotated. We identified transcripts related to pathways of bixin biosynthesis and geraniol and geranial biosynthesis as major transcripts from the class of isoprenoid secondary metabolites and validated the presence of putative norbixin methyltransferase, a precursor of Bixin. The transcripts encoding these terpenoids are known to be Peroxisome Proliferator-Activated Receptor (PPAR) agonists and anti-glycation agents. Sequential extraction and High Performance Liquid Chromatography (HPLC) confirmed the presence of bixin in C. pictus methanolic extracts. Another significant transcript identified in relation to anti-diabetic, anti-obesity and immuno-modulation is of Abscisic Acid biosynthetic pathway. We also report many other transcripts for the biosynthesis of antitumor, anti-oxidant and antimicrobial metabolites of C. pictus leaves. Conclusion Solid molecular signatures (transcripts related to bixin, abscisic acid, and geranial and geraniol biosynthesis) for the anti-diabetic properties of C. pictus leaves and vital clues related to the other phytochemical functions like antitumor, anti-oxidant, immuno-modulatory, anti-microbial and anti-malarial properties through the secondary metabolite pathway annotations are reported. The data provided will be of immense help to researchers working in the treatment of DM using herbal therapies. PMID:23176672

Comparison of transcripts in Phalaenopsis bellina and Phalaenopsis equestris (Orchidaceae) flowers to deduce monoterpene biosynthesis pathway.

PubMed

Hsiao, Yu-Yun; Tsai, Wen-Chieh; Kuoh, Chang-Sheng; Huang, Tian-Hsiang; Wang, Hei-Chia; Wu, Tian-Shung; Leu, Yann-Lii; Chen, Wen-Huei; Chen, Hong-Hwa

2006-07-13

Floral scent is one of the important strategies for ensuring fertilization and for determining seed or fruit set. Research on plant scents has hampered mainly by the invisibility of this character, its dynamic nature, and complex mixtures of components that are present in very small quantities. Most progress in scent research, as in other areas of plant biology, has come from the use of molecular and biochemical techniques. Although volatile components have been identified in several orchid species, the biosynthetic pathways of orchid flower fragrance are far from understood. We investigated how flower fragrance was generated in certain Phalaenopsis orchids by determining the chemical components of the floral scent, identifying floral expressed-sequence-tags (ESTs), and deducing the pathways of floral scent biosynthesis in Phalaneopsis bellina by bioinformatics analysis. The main chemical components in the P. bellina flower were shown by gas chromatography-mass spectrometry to be monoterpenoids, benzenoids and phenylpropanoids. The set of floral scent producing enzymes in the biosynthetic pathway from glyceraldehyde-3-phosphate (G3P) to geraniol and linalool were recognized through data mining of the P. bellina floral EST database (dbEST). Transcripts preferentially expressed in P. bellina were distinguished by comparing the scent floral dbEST to that of a scentless species, P. equestris, and included those encoding lipoxygenase, epimerase, diacylglycerol kinase and geranyl diphosphate synthase. In addition, EST filtering results showed that transcripts encoding signal transduction and Myb transcription factors and methyltransferase, in addition to those for scent biosynthesis, were detected by in silico hybridization of the P. bellina unigene database against those of the scentless species, rice and Arabidopsis. Altogether, we pinpointed 66% of the biosynthetic steps from G3P to geraniol, linalool and their derivatives. This systems biology program combined chemical analysis, genomics and bioinformatics to elucidate the scent biosynthesis pathway and identify the relevant genes. It integrates the forward and reverse genetic approaches to knowledge discovery by which researchers can study non-model plants.

A Phase of Liposomes with Entangled Tubular Vesicles

NASA Astrophysics Data System (ADS)

Chiruvolu, Shivkumar; Warriner, Heidi E.; Naranjo, Edward; Idziak, Stefan H. J.; Radler, Joachim O.; Plano, Robert J.; Zasadzinski, Joseph A.; Safinya, Cyrus R.

1994-11-01

An equilibrium phase belonging to the family of bilayer liposomes in ternary mixtures of dimyristoylphosphatidylcholine (DMPC), water, and geraniol (a biological alcohol derived from oil-soluble vitamins that acts as a cosurfactant) has been identified. Electron and optical microscopy reveal the phase, labeled Ltv, to be composed of highly entangled tubular vesicles. In situ x-ray diffraction confirms that the tubule walls are multilamellar with the lipids in the chain-melted state. Macroscopic observations show that the Ltv phase coexists with the well-known L_4 phase of spherical vesicles and a bulk L_α phase. However, the defining characteristic of the Ltv phase is the Weissenberg rod climbing effect under shear, which results from its polymer-like entangled microstructure.

Pest-managing efficacy of trans-asarone isolated from Daucus carota L. seeds.

PubMed

Momin, Rafikali A; Nair, Muraleeddharan G

2002-07-31

The bioactive hexane extract of Daucus carota seed yielded 2,4,5-trimethoxybenzaldehyde (1), oleic acid (2), trans-asarone (3), and geraniol (4). Compounds 1-4 were evaluated for their mosquitocidal, nematicidal, antifeedant, and antimicrobial activities. Only trans-asarone was active in the assays performed, causing 100% mortality to fourth-instar mosquito larvae, Aedes aegyptii, at 200 microg mL(-1) and the nematodes Caenorhabditis elegans and Panagrellus redivivus at 100 microg mL(-1). In feeding trials, trans-asarone also caused significant weight reductions of the caterpillars Helicovarpa zea, Heliothis virescens, and Manduca sexta when incorporated into artificial diet at a concentration of 100 microg mL(-1). Also, it exhibited slight activity at 100 microg mL(-1) against the yeasts Candida albicans, Candida parapsilasis, and Candida kruseii.

Composition of essential oil of lemon thyme (Thymus × citriodorus) at different hydrodistillation times.

PubMed

Jurevičiūtė, Rūta; Ložienė, Kristina; Bruno, Maurizio; Maggio, Antonella; Rosselli, Sergio

2018-02-02

Distillation time can both to optimise the production and to engineer the composition of essential oil in essential oil bearing plants. Purpose of this study was to evaluate the effect of duration of hydrodistillation on composition of essential oil of Thymus × citriodorus, the natural source of commercially important geraniol and citral, a component with valuable biological properties. Essential oils were isolated by hydrodistillation at different distillation times and analysed by GC/MS analytical methods. Increase in percentage of essential oil during all hydrodistillation time gradient was uneven. Elongation of hydrodistillation time decreased percentages of monoterpenes but increased percentages of sesquiterpenes in essential oil. Results showed that the hydrodistillation of essential oil from lemon thyme longer than 60 min is useless.

Study of the solubility and stability of polystyrene wastes in a dissolution recycling process

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

Garcia, Maria Teresa; Gracia, Ignacio; Duque, Gema

2009-06-15

Dissolution with suitable solvents is one of the cheapest and more efficient processes for polystyrene waste management. In this work the solubility of polystyrene foams in several solvents benzene, toluene, xylene, tetrahydrofuran, chloroform, 1,3-butanediol, 2-butanol, linalool, geraniol, d-limonene, p-cymene, terpinene, phellandrene, terpineol, menthol, eucalyptol, cinnamaldheyde, nitrobenzene, N,N-dimethylformamide and water has been determined. Experimental results have shown that to develop a 'green process' the constituents of essential oils, d-limonene, p-cymene, terpinene, phellandrene, are the most appropriate solvents. The action of these solvent does not produce any degradation of polymer chains. The solubility of the polymer in the mentioned solvents at differentmore » temperatures has been investigated. The solvent can be easily recycled by distillation.« less

Identification and field evaluation of attractants for the cranberry weevil, Anthonomus musculus Say.

PubMed

Szendrei, Zsofia; Averill, Anne; Alborn, Hans; Rodriguez-Saona, Cesar

2011-04-01

Studies were conducted to develop an attractant for the cranberry weevil, Anthonomus musculus, a pest of blueberry and cranberry flower buds and flowers in the northeastern United States. In previous studies, we showed that cinnamyl alcohol, the most abundant blueberry floral volatile, and the green leaf volatiles (Z)-3-hexenyl acetate and hexyl acetate, emitted from both flowers and flower buds, elicit strong antennal responses from A. musculus. Here, we found that cinnamyl alcohol did not increase capture of A. musculus adults on yellow sticky traps compared with unbaited controls; however, weevils were highly attracted to traps baited with the Anthonomus eugenii Cano aggregation pheromone, indicating that these congeners share common pheromone components. To identify the A. musculus aggregation pheromone, headspace volatiles were collected from adults feeding on blueberry or cranberry flower buds and analyzed by gas chromatography-mass spectrometry. Three male-specific compounds were identified: (Z)-2-(3,3-dimethyl-cyclohexylidene) ethanol (Z grandlure II); (Z)-(3,3-dimethylcyclohexylidene) acetaldehyde (grandlure III); and (E)-(3,3- dimethylcyclohexylidene) acetaldehyde (grandlure IV). A fourth component, (E)-3,7-dimethyl-2,6-octadien-1-ol (geraniol), was emitted in similar quantities by males and females. The emission rates of these volatiles were about 2.8, 1.8, 1.3, and 0.9 ng/adult/d, respectively. Field experiments in highbush blueberry (New Jersey) and cranberry (Massachusetts) examined the attraction of A. musculus to traps baited with the male-produced compounds and geraniol presented alone and combined with (Z)-3-hexenyl acetate and hexyl acetate, and to traps baited with the pheromones of A. eugenii and A. grandis. In both states and crops, traps baited with the A. musculus male-produced compounds attracted the highest number of adults. Addition of the green leaf volatiles did not affect A. musculus attraction to its pheromone but skewed the sex ratio of the captured adults towards females. Although the role of plant volatiles in host-plant location by A. musculus is still unclear, our studies provide the first identification of the primary A. musculus aggregation pheromone components that can be used to monitor this pest in blueberry and cranberry pest management programs.

Analysis of the main active ingredients and bioactivities of essential oil from Osmanthus fragrans Var. thunbergii using a complex network approach.

PubMed

Wang, Le; Tan, Nana; Hu, Jiayao; Wang, Huan; Duan, Dongzhu; Ma, Lin; Xiao, Jian; Wang, Xiaoling

2017-12-28

Osmanthus fragrans has been used as folk medicine for thousands of years. The extracts of Osmanthus fragrans flowers were reported to have various bioactivities including free radical scavenging, anti-inflammation, neuroprotection and antitumor effects. However, there is still lack of knowledge about its essential oil. In this work, we analyzed the chemical composition of the essential oil from Osmanthus fragrans var. thunbergii by GC-MS. A complex network approach was applied to investigate the interrelationships between the ingredients, target proteins, and related pathways for the essential oil. Statistical characteristics of the networks were further studied to explore the main active ingredients and potential bioactivities of O. fragrans var. thunbergii essential oil. A total of 44 ingredients were selected from the chemical composition of O. fragrans var. thunbergii essential oil, and that 191 potential target proteins together with 70 pathways were collected for these compounds. An ingredient-target-pathway network was constructed based on these data and showed scale-free property as well as power-law degree distribution. Eugenol and geraniol were screened as main active ingredients with much higher degree values. Potential neuroprotective and anti-tumor effect of the essential oil were also found. A core subnetwork was extracted from the ingredient-target-pathway network, and indicated that eugenol and geraniol contributed most to the neuroprotection of this essential oil. Furthermore, a pathway-based protein association network was built and exhibited small-world property. MAPK1 and MAPK3 were considered as key proteins with highest scores of centrality indices, which might play an important role in the anti-tumor effect of the essential oil. This work predicted the main active ingredients and bioactivities of O. fragrans var. thunbergii essential oil, which would benefit the development and utilization of Osmanthus fragrans flowers. The application of complex network theory was proved to be effective in bioactivities studies of essential oil. Moreover, it provides a novel strategy for exploring the molecular mechanisms of traditional medicines.

Geraniol, Alone and in Combination with Pioglitazone, Ameliorates Fructose-Induced Metabolic Syndrome in Rats via the Modulation of Both Inflammatory and Oxidative Stress Status

PubMed Central

Ibrahim, Sherehan M.; El- Denshary, Ezzedin S.; Abdallah, Dalaal M.

2015-01-01

Geraniol (GO) potent antitumor and chemopreventive effects are attributed to its antioxidant and anti-inflammatory properties. In the current study, the potential efficacy of GO (250 mg/kg) in ameliorating metabolic syndrome (MetS) induced by fructose in drinking water was elucidated. Moreover, the effect of pioglitazone (5 and 10 mg/kg; PIO) and the possible interaction of the co-treatment of GO with PIO5 were studied in the MetS model. After 4 weeks of treatment, GO and/or PIO reduced the fasting blood glucose and the glycemic excursion in the intraperitoneal glucose tolerance test. GO and PIO5/10 restrained visceral adiposity and partly the body weight gain. The decreased level of peroxisome proliferator activated receptor (PPAR)-γ transcriptional activity in the visceral adipose tissue of MetS rats was increased by single treatment regimens. Though GO did not affect MetS-induced hyperinsulinemia, PIO5/10 lowered it. Additionally, GO and PIO5/10 suppressed glycated hemoglobin and the receptor for advanced glycated end products (RAGE). These single regimens also ameliorated hyperuricemia, the disrupted lipid profile, and the elevated systolic blood pressure evoked by MetS. The rise in serum transaminases, interleukin-1β, and tumor necrosis factor-α, as well as hepatic lipid peroxides and nitric oxide (NO) was lowered by the single treatments to different extents. Moreover, hepatic non-protein thiols, as well as serum NO and adiponectin were enhanced by single regimens. Similar effects were reached by the combination of GO with PIO5; however, a potentiative interaction was noted on fasting serum insulin level, while synergistic effects were reflected as improved insulin sensitivity, as well as reduced RAGE and triglycerides. Therefore, GO via the transcriptional activation of PPAR-γ reduces inflammation and free radical injury produced by MetS. Thereby, these effects provide novel mechanistic insights on GO management of MetS associated critical risk factors. Moreover, the co-administration of GO to PIO5 exalted the antidiabetic drug anti-MetS efficacy. PMID:25679220

Comparison of transcripts in Phalaenopsis bellina and Phalaenopsis equestris (Orchidaceae) flowers to deduce monoterpene biosynthesis pathway

PubMed Central

Hsiao, Yu-Yun; Tsai, Wen-Chieh; Kuoh, Chang-Sheng; Huang, Tian-Hsiang; Wang, Hei-Chia; Wu, Tian-Shung; Leu, Yann-Lii; Chen, Wen-Huei; Chen, Hong-Hwa

2006-01-01

Background Floral scent is one of the important strategies for ensuring fertilization and for determining seed or fruit set. Research on plant scents has hampered mainly by the invisibility of this character, its dynamic nature, and complex mixtures of components that are present in very small quantities. Most progress in scent research, as in other areas of plant biology, has come from the use of molecular and biochemical techniques. Although volatile components have been identified in several orchid species, the biosynthetic pathways of orchid flower fragrance are far from understood. We investigated how flower fragrance was generated in certain Phalaenopsis orchids by determining the chemical components of the floral scent, identifying floral expressed-sequence-tags (ESTs), and deducing the pathways of floral scent biosynthesis in Phalaneopsis bellina by bioinformatics analysis. Results The main chemical components in the P. bellina flower were shown by gas chromatography-mass spectrometry to be monoterpenoids, benzenoids and phenylpropanoids. The set of floral scent producing enzymes in the biosynthetic pathway from glyceraldehyde-3-phosphate (G3P) to geraniol and linalool were recognized through data mining of the P. bellina floral EST database (dbEST). Transcripts preferentially expressed in P. bellina were distinguished by comparing the scent floral dbEST to that of a scentless species, P. equestris, and included those encoding lipoxygenase, epimerase, diacylglycerol kinase and geranyl diphosphate synthase. In addition, EST filtering results showed that transcripts encoding signal transduction and Myb transcription factors and methyltransferase, in addition to those for scent biosynthesis, were detected by in silico hybridization of the P. bellina unigene database against those of the scentless species, rice and Arabidopsis. Altogether, we pinpointed 66% of the biosynthetic steps from G3P to geraniol, linalool and their derivatives. Conclusion This systems biology program combined chemical analysis, genomics and bioinformatics to elucidate the scent biosynthesis pathway and identify the relevant genes. It integrates the forward and reverse genetic approaches to knowledge discovery by which researchers can study non-model plants. PMID:16836766

Monoterpenol Oxidative Metabolism: Role in Plant Adaptation and Potential Applications

PubMed Central

Ilc, Tina; Parage, Claire; Boachon, Benoît; Navrot, Nicolas; Werck-Reichhart, Danièle

2016-01-01

Plants use monoterpenols as precursors for the production of functionally and structurally diverse molecules, which are key players in interactions with other organisms such as pollinators, flower visitors, herbivores, fungal, or microbial pathogens. For humans, many of these monoterpenol derivatives are economically important because of their pharmaceutical, nutraceutical, flavor, or fragrance applications. The biosynthesis of these derivatives is to a large extent catalyzed by enzymes from the cytochrome P450 superfamily. Here we review the knowledge on monoterpenol oxidative metabolism in plants with special focus on recent elucidations of oxidation steps leading to diverse linalool and geraniol derivatives. We evaluate the common features between oxidation pathways of these two monoterpenols, such as involvement of the CYP76 family, and highlight the differences. Finally, we discuss the missing steps and other open questions in the biosynthesis of oxygenated monoterpenol derivatives. PMID:27200002

Negative inotropism of terpenes on guinea pig left atrium: structure-activity relationships.

PubMed

Vasconcelos, Carla M L; Oliveira, Ingrid S N; Santos, José N A; Souza, Américo A; Menezes-Filho, José E R; Silva Neto, Júlio A; Lima, Tamires C; de Sousa, Damião P

2018-06-01

The aim of this work was to evaluate the pharmacological effect of seven structurally related terpenes on the contractility of cardiac muscle. The effect of terpenes was studied on isolated electrically driven guinea pig left atrium. From concentration-response curves for inotropic effect were determined the EC 50 and relative potency of such terpenes. Our results revealed that all terpenes, except phytol, showed ability to reduce the contractile response of guinea pig left atrium. Further, relative potency was directly related to the number of isoprene units and to the lipophilicity of the compounds. For example, sesquiterpenes farnesol and nerolidol showed higher relative potency when compared with the monoterpenes citronellol, geraniol and nerol. We can conclude that most of the evaluated terpenes showed a promising negative inotropism on the atrial muscle. Future studies are necessary to investigate their action mechanism.

A phase of liposomes with entangled tubular vesicles

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

Chiruvolu, S.; Naranjo, E.; Warriner, H.E.

1994-11-18

An equilibrium phase belonging to the family of bilayer liposomes in ternary mixtures of dimyristoylphosphatidylcholine (DMPC), water, and geraniol (a biological alcohol derived from oil-soluble vitamins that acts as a cosurfactant) has been identified. Electron and optical microscopy reveal the phase, labeled L{sub tv}, to be composed of highly entangled tubular vesicles. In situ x-ray diffraction confirms that the tubule walls are multilamellar with the lipids in the chain-melted state. Macroscopic observations show that the L{sub tv} phase coexists with the well-known L{sub 4} phase of spherical vesicles and a bulk L{sub {alpha}} phase. However, the defining characteristic of themore » L{sub tv} phase is the Weissenberg rod climbing effect under shear, which results from its polymer-like entangled microstructure. 26 refs., 5 figs.« less

A selected ion flow tube study of the reactions of H3O+, NO+ and O2+ with some oxygenated biogenic volatile organic compounds

NASA Astrophysics Data System (ADS)

Amelynck, C.; Schoon, N.; Kuppens, T.; Bultinck, P.; Arijs, E.

2005-12-01

The rate constants and product ion distributions of the reactions of H3O+, NO+ and O2+ with 2-methyl-3-buten-2-ol, cis-3-hexen-1-ol, cis-3-hexenyl acetate, 1,8-cineole, 6-methyl-5-hepten-2-one, camphor and linalool have been determined at 150 Pa and 297 K using a selected ion flow tube (SIFT). All reactions were found to proceed at a rate close to the collision rate, calculated with the Su and Chesnavich model, using the polarizability and electric dipole moment of the compounds derived from B3LYP/aug-cc-pVDZ quantum chemical calculations. Additionally the product ion distributions of the reactions of these three ions with the terpenoid alcohols nerol and geraniol have been obtained.

Development of small-size tubular-flow continuous reactors for the analysis of operational stability of enzymes in low-water systems.

PubMed

Pirozzi, D; Halling, P J

2001-01-20

A very small-scale continuous flow reactor has been designed for use with enzymes in organic media, particularly for operational stability studies. It is constructed from fairly inexpensive components, and typically uses 5 mg of catalyst and flow rates of 1 to 5 mL/h, so only small quantities of feedstock need to be handled. The design allows control of the thermodynamic water activity of the feed, and works with temperatures up to at least 80 degrees C. The reactor has been operated with both nonpolar (octane) and polar (4-methyl-pentan-2-one) solvents, and with the more viscous solvent-free reactant mixture. It has been applied to studies of the operational stability of lipases from Chromobacterium viscosum (lyophilized powder or polypropylene-adsorbed) and Rhizomucor miehei (Lipozyme) in different experimental conditions. Transesterification of geraniol and ethylcaproate has been adopted as a model transformation.

The Essential Oil Compositions of Ocimum basilicum from Three Different Regions: Nepal, Tajikistan, and Yemen.

PubMed

Sharopov, Farukh S; Satyal, Prabodh; Ali, Nasser A Awadh; Pokharel, Suraj; Zhang, Hanjing; Wink, Michael; Kukaniev, Muhammadsho A; Setzer, William N

2016-02-01

The aerial parts of Ocimum basilicum L. were collected from four different geographical locations, Sindhuli and Biratnagar (Nepal), Chormaghzak village (Tajikistan), and Sana'a (Yemen). The essential oils were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry. A cluster analysis of 179 essential oil compositions revealed six major chemotypes: Linalool, eugenol, estragole, methyl eugenol, 1,8-cineole, and geraniol. All four of the basil oils in this study were of the linalool-rich variety. Some of the basil oils were screened for bioactivity including antimicrobial, cytotoxicity in human cancer cells, brine shrimp lethality, nematicidal, larvicidal, insecticidal, and antioxidant. The basil oils in this study were not notably antibacterial, cytotoxic, antioxidant, nor nematicidal, but were active in the brine shrimp lethality test, and did show larvicidal and insecticidal activities. Copyright © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

Influence of water stress and storage time on preservation of the fresh volatile profile of three basil genotypes.

PubMed

Jordán, María J; Quílez, María; Luna, María C; Bekhradi, Farzaneh; Sotomayor, José A; Sánchez-Gómez, Pedro; Gil, María I

2017-04-15

The main goal of the present study was to describe the volatile profile of three different basil genotypes (Genovese and Green and Purple Iranian), and the impact that water stress (75% and 50% field capacity) and storage time (up to 7days) have under mild refrigerated conditions. The chromatographic profile pointed to three different chemotypes: linalool/eugenol, neral/geranial, and estragol, for Genovese, Green, and Purple genotypes, respectively. Water stress depleted the volatile profile of these three landraces, due to a reduction in the absolute concentrations of some of the components related to fresh aroma (linalool, nerol, geraniol and eugenol). The stability of the basil volatile profile during storage varied depending on the water stress that had been applied. Concentration reductions of close to 50% were quantified for most of the components identified in the Purple genotype. Copyright © 2016 Elsevier Ltd. All rights reserved.

Scientific basis for the therapeutic use of Cymbopogon citratus, stapf (Lemon grass)

PubMed Central

Shah, Gagan; Shri, Richa; Panchal, Vivek; Sharma, Narender; Singh, Bharpur; Mann, A. S.

2011-01-01

Cymbopogon citratus, Stapf (Lemon grass) is a widely used herb in tropical countries, especially in Southeast Asia. The essential oil of the plant is used in aromatherapy. The compounds identified in Cymbopogon citratus are mainly terpenes, alcohols, ketones, aldehyde and esters. Some of the reported phytoconstituents are essential oils that contain Citral α, Citral β, Nerol Geraniol, Citronellal, Terpinolene, Geranyl acetate, Myrecene and Terpinol Methylheptenone. The plant also contains reported phytoconstituents such as flavonoids and phenolic compounds, which consist of luteolin, isoorientin 2’-O-rhamnoside, quercetin, kaempferol and apiginin. Studies indicate that Cymbopogon citratus possesses various pharmacological activities such as anti-amoebic, antibacterial, antidiarrheal, antifilarial, antifungal and anti-inflammatory properties. Various other effects like antimalarial, antimutagenicity, antimycobacterial, antioxidants, hypoglycemic and neurobehaviorial have also been studied. These results are very encouraging and indicate that this herb should be studied more extensively to confirm these results and reveal other potential therapeutic effects. PMID:22171285

[Profile-effect on quality control of Houttuynia cordata injection].

PubMed

Lu, Hong-mei; Liang, Yi-zeng; Qian, Pin

2005-12-01

To find corresponding relationship between the fingerprint of Houttuynia cordata injections from different factories and their effects. Houttuynia cordata injections from six different factories were determined by gas chromatography (GC) and gas chromatography-mass spectra (GC-MS), and GC fingerprints were classified by hierarchical clustering. The anti-inflammatory activity of Houttuynia cordata injections was characterized through the rat pleurisy model induced by carrageenin and the mice ear edema model by dimethylbenzene. The anti-inflammatory effect of the injections from the first class factories on the two model was significant, while those from the second class not. GC-MS analysis result indicated that main effect compounds in Houttuynia cordata injections are methyl n-nonyl ketone, decanoylacetaldehyde, lauryl aldehyde, capryl aldehyde, beta-pinene, beta-linalool, 1-nonanol, 4-terpineol, alpha-terpineol, bornyl acetate, n-decanoic acid and acetic acid, geraniol ester etc. There is corresponding relationship between the fingerprint of Houttuynia cordata injections and effect to a certain extent.

Bioactivity against Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) of Cymbopogon citratus and Eucalyptus citriodora essential oils grown in Colombia.

PubMed

Olivero-Verbel, Jesús; Nerio, Luz S; Stashenko, Elena E

2010-06-01

Essential oils isolated from Cymbopogon citratus (DC) Stapf. and Eucalyptus citriodora Hook grown in Colombia were analysed by gas chromatography-mass spectrometry (GC-MS) and tested for repellent activity and contact toxicity against Tribolium castaneum (Herbst.) (Coleoptera: Tenebrionidae). The main components of C. citratus oil were geranial (34.4%), neral (28.4%) and geraniol (11.5%), whereas those of E. citriodora were citronellal (40%), isopulegol (14.6%) and citronellol (13%). The mean repellent doses after 4 h exposure were 0.021 and 0.084 mL L(-1) for C. citratus and E. citriodora oils respectively-values lower than that observed for the commercial product IR3535 (0.686 mL L(-1)). These studies showed the composition and repellent activity of essential oils of C. citratus and E. citriodora, suggesting that these are potential candidates as insect repellents.

Bitter-sensitive gustatory receptor neuron responds to chemically diverse insect repellents in the common malaria mosquito Anopheles quadrimaculatus

NASA Astrophysics Data System (ADS)

Sparks, Jackson T.; Dickens, Joseph C.

2016-06-01

Female mosquitoes feed on blood from animal hosts to obtain nutritional resources used for egg production. These contacts facilitate the spread of harmful human diseases. Chemical repellents are used to disrupt mosquito host-seeking and blood-feeding behaviors; however, little is known about the gustatory sensitivity of mosquitoes to known repellents. Here, we recorded electrical responses from gustatory receptor neurons (GRNs) housed within the labellar sensilla of female Anopheles quadrimaculatus to N,N-diethyl-3-methylbenzamide (DEET), picaridin, IR3535, 2-undecanone, p-menthane-3,8-diol, geraniol, trans-2-hexen-1-ol, quinine, and quinidine. A bitter-sensitive GRN responded to all tested repellents and quinine, a known feeding deterrent. Responses of the bitter-sensitive neuron to quinine and an isomer, quinidine, did not differ. Delayed bursts of electrical activity were observed in response to continuous stimulation with synthetic repellents at high concentrations. Electrophysiological recordings from bitter-sensitive GRNs associated with mosquito gustatory sensilla represent a convenient model to evaluate candidate repellents.

Skin diseases in workers at a perfume factory.

PubMed

Schubert, Hans-Jürgen

2006-08-01

The aim of this study is to find out the causes of skin diseases in one-third of the staff of a perfume factory, in which 10 different perfume sprays were being manufactured. Site inspection, dermatological examination and patch testing of all 26 persons at risk with 4 perfume oils and 30 ingredients of them. The results showed 6 bottlers were found suffering from allergic contact dermatitis, 2 from irritant contact dermatitis, 12 workers showed different strong reactions to various fragrances. The main causes of allergic contact dermatitis were 2 perfume oils (12 cases) and their ingredients geraniol (12 cases), benzaldehyde(9), cinnamic aldehyde (6), linalool, neroli oil, terpenes of lemon oil and orange oil (4 each). Nobody was tested positive to balsam of Peru. Job changes for office workers, packers or printers to other rooms, where they had no longer contact with fragrances, led to a settling. To conclude, automation and replacement of glass bottles by cartridges from non-fragile materials and using gloves may minimize the risk.

Control of stored grain pest, Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) using the essential oil isolated from Plectranthus zeylanicus.

PubMed

Balachandra, B A H E; Pathirathna, P U; Paranagama, P A

2012-01-01

The bruchid, Callosobruchus maculatus (F.) causes major losses during the storage of cowpea seeds [Vigna unguiculata (L.)Walp.] in Sri Lanka. Essential oil isolated from Plectranthus zeylanicus plant was tested for potential insecticidal activity against C. maculatus. The gas chromatography studies of the essential oil of P. zeylanicus showed that ρ-cymene (3.5%), β-caryophyllene (0.2%), geranyl acetate (9.3%) and geraniol (7.2%) were the major constituents. The adults of C. maculatus were susceptible to both fumigant and contact toxicity of P. zeylanicus plant oil. LC(50) values of 0.927 and 0.010 g L(-1) were obtained for fumigant toxicity and contact toxicity assays, respectively. Oviposition and F(1) adult emergence were significantly inhibited by P. zeylanicus plant oil at a concentration higher than 0.001 g L(-1) in both fumigant and contact toxicities. The analysis of olfactometer and choice camber bioassays revealed the repellent effects of the oil of P. zeylanicus plant.

Characterisation of odorants in roasted stem tea using gas chromatography-mass spectrometry and gas chromatography-olfactometry analysis.

PubMed

Sasaki, Tetsuya; Koshi, Erina; Take, Harumi; Michihata, Toshihide; Maruya, Masachika; Enomoto, Toshiki

2017-04-01

Roasted stem tea has a characteristic flavour, which is obtained by roasting tea stems, by-product of green tea production. This research aims to understand the characteristic odorants in roasted stem tea by comparing it to roasted leaf tea. We revealed potent odorants in commercial roasted stem tea using gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry with aroma extract dilution analysis (AEDA). The difference between roasted stem and leaf tea derived from the same tea plants were investigated using GC-MS. Pyrazine compounds exhibited a roasted odour and high flavour dilution (FD) factors, as determined via AEDA. Roasted stem tea was richer in these pyrazines than roasted leaf tea. Geraniol and linalool exhibited high FD factors and a floral odour, and roasted stem tea was richer in these compounds than roasted leaf tea. These results may have a positive impact on the development of tea products. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bitter-sensitive gustatory receptor neuron responds to chemically diverse insect repellents in the common malaria mosquito Anopheles quadrimaculatus.

PubMed

Sparks, Jackson T; Dickens, Joseph C

2016-06-01

Female mosquitoes feed on blood from animal hosts to obtain nutritional resources used for egg production. These contacts facilitate the spread of harmful human diseases. Chemical repellents are used to disrupt mosquito host-seeking and blood-feeding behaviors; however, little is known about the gustatory sensitivity of mosquitoes to known repellents. Here, we recorded electrical responses from gustatory receptor neurons (GRNs) housed within the labellar sensilla of female Anopheles quadrimaculatus to N,N-diethyl-3-methylbenzamide (DEET), picaridin, IR3535, 2-undecanone, p-menthane-3,8-diol, geraniol, trans-2-hexen-1-ol, quinine, and quinidine. A bitter-sensitive GRN responded to all tested repellents and quinine, a known feeding deterrent. Responses of the bitter-sensitive neuron to quinine and an isomer, quinidine, did not differ. Delayed bursts of electrical activity were observed in response to continuous stimulation with synthetic repellents at high concentrations. Electrophysiological recordings from bitter-sensitive GRNs associated with mosquito gustatory sensilla represent a convenient model to evaluate candidate repellents.

Analysis of hop-derived terpenoids in beer and evaluation of their behavior using the stir bar-sorptive extraction method with GC-MS.

PubMed

Kishimoto, Toru; Wanikawa, Akira; Kagami, Noboru; Kawatsura, Katsuyuki

2005-06-15

Hop aroma components, which mainly comprise terpenoids, contribute to the character of beers. However, pretreatments are necessary before analyzing these components because of their trace levels and complicated matrixes. Here, the stir bar-sorptive extraction (SBSE) method was used to detect and quantify many terpenoids simultaneously from small samples. This simple technique showed low coefficients of variation, high accuracy, and low detection limits. An investigation of the behavior of terpenoids identified two distinct patterns of decreasing concentration during wort boiling. The first, which was seen in myrcene and linalool, involved a rapid decrease that was best fitted by a quadratic curve. The second, which was observed in beta-eudesmol, humulene, humulene epoxide I, beta-farnesene, caryophyllene, and geraniol, involved a gentle linear decrease. Conversely, the concentration of beta-damascenone increased after boiling. As the aroma composition depended on the hop variety, we also examined the relationship between terpenoid content and sensory analysis in beer.

Antimicrobial, antioxidant, and anti-inflammatory activities of essential oils from five selected herbs.

PubMed

Tsai, Mei-Lin; Lin, Chih-Chien; Lin, Wei-Chao; Yang, Chao-Hsun

2011-01-01

Eucalyptus bridgesiana, Cymbopogon martinii, Thymus vulgaris, Lindernia anagallis, and Pelargonium fragrans are five species of herbs used in Asia. Their essential oils were analyzed by GC-MS, and a total of 36 components were detected. The results of our study indicated that, except for the essential oil of P. fragrans, all of the essential oils demonstrated obvious antimicrobial activity against a broad range of microorganisms. The C. martinii essential oil, which is rich in geraniol, was the most effective antimicrobial additive. All of the essential oils demonstrated antioxidant activities on 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, β-carotene/linoleic acid assay, and nitric oxide radical scavenging assay. Furthermore, the T. vulgaris essential oil, which possesses plentiful thymol, exhibited the highest antioxidant activity. For P. acnes-induced secretion of pro-inflammatory cytokines, the essential oils of P. aeruginosa, C. martinii, and T. vulgaris reduced the TNF-α, IL-1β, and IL-8 secretion levels of THP-1 cells.

In Vitro Antifungal Activity of New and Known Geranylated Phenols against Phytophthora cinnamomi Rands.

PubMed

Chavez, María I; Soto, Mauricio; Cimino, Franco A; Olea, Andrés F; Espinoza, Luis; Díaz, Katy; Taborga, Lautaro

2018-05-29

A series of new and known geranylated phenol/methoxyphenol derivatives has been tested in vitro as inhibitor agents of mycelial growth of Phytophthora cinnamomi . The activity of tested compounds is correlated with the nature, number, and position of the substituent group on the aromatic ring. Results indicate that the most active geranylated derivatives are those having two hydroxyl groups (or one ⁻OH and one ⁻OCH₃) attached to the aromatic ring. Interestingly, these derivatives are as active as Metalaxil ® , a commonly used commercial fungicide. Thus, our results suggest that some of these compounds might be of agricultural interest due to their potential use as fungicides against P. cinnamomi . The effect of structure on fungicide activity is discussed in terms of electronic distribution on both the aromatic ring and side geranyl chain. All tested compounds have been synthesized by direct coupling of geraniol and the respective phenol. Interestingly, new digeranylated derivatives were obtained by increasing the reaction time.

Phytochemical composition and antimicrobial activities of the essential oils and organic extracts from pelargonium graveolens growing in Tunisia

PubMed Central

2012-01-01

Background Pelargonium graveolens (P. graveolens) L. is an aromatic and medicinal plant belonging to the geraniacea family. Results The chemical compositions of the essential oil as well as the in vitro antimicrobial activities were investigated. The GC-MS analysis of the essential oil revealed 42 compounds. Linallol L, Citronellol, Geraniol, 6-Octen-1-ol, 3,7-dimethyl, formate and Selinene were identified as the major components. The tested oil and organic extracts exhibited a promising antimicrobial effect against a panel of microorganisms with diameter inhibition zones ranging from 12 to 34 mm and MICs values from 0.039 to10 mg/ml. The investigation of the phenolic content showed that EtOAc, MeOH and water extracts had the highest phenolic contents. Conclusion Overall, results presented here suggest that the essential oil and organic extracts of P. graveolens possesses antimicrobial and properties, and is therefore a potential source of active ingredients for food and pharmaceutical industry. PMID:23216669

Chemical composition and antigenotoxic properties of Lippia alba essential oils

PubMed Central

López, Molkary Andrea; Stashenko, Elena E.; Fuentes, Jorge Luis

2011-01-01

The present work evaluated the chemical composition and the DNA protective effect of the essential oils (EOs) from Lippia alba against bleomycin-induced genotoxicity. EO constituents were determined by Gas Chromatography/Mass Spectrometric (GC-MS) analysis. The major compounds encountered being citral (33% geranial and 25% neral), geraniol (7%) and trans-β-caryophyllene (7%) for L. alba specimen COL512077, and carvone (38%), limonene (33%) and bicyclosesquiphellandrene (8%) for the other, COL512078. The genotoxicity and antigenotoxicity of EO and the compounds citral, carvone and limonene, were assayed using the SOS Chromotest in Escherichia coli. The EOs were not genotoxic in the SOS chromotest, but one of the major compound (limonene) showed genotoxicity at doses between 97 and 1549 mM. Both EOs protected bacterial cells against bleomycin-induced genotoxicity. Antigenotoxicity in the two L. alba chemotypes was related to the major compounds, citral and carvone, respectively. The results were discussed in relation to the chemopreventive potential of L. alba EOs and its major compounds. PMID:21931523

Chemical composition and antigenotoxic properties of Lippia alba essential oils.

PubMed

López, Molkary Andrea; Stashenko, Elena E; Fuentes, Jorge Luis

2011-07-01

The present work evaluated the chemical composition and the DNA protective effect of the essential oils (EOs) from Lippia alba against bleomycin-induced genotoxicity. EO constituents were determined by Gas Chromatography/Mass Spectrometric (GC-MS) analysis. The major compounds encountered being citral (33% geranial and 25% neral), geraniol (7%) and trans-β-caryophyllene (7%) for L. alba specimen COL512077, and carvone (38%), limonene (33%) and bicyclosesquiphellandrene (8%) for the other, COL512078. The genotoxicity and antigenotoxicity of EO and the compounds citral, carvone and limonene, were assayed using the SOS Chromotest in Escherichia coli. The EOs were not genotoxic in the SOS chromotest, but one of the major compound (limonene) showed genotoxicity at doses between 97 and 1549 mM. Both EOs protected bacterial cells against bleomycin-induced genotoxicity. Antigenotoxicity in the two L. alba chemotypes was related to the major compounds, citral and carvone, respectively. The results were discussed in relation to the chemopreventive potential of L. alba EOs and its major compounds.

Synthesis and in Vitro Antifungal Activity against Botrytis cinerea of Geranylated Phenols and Their Phenyl Acetate Derivatives

PubMed Central

Chávez, María I.; Soto, Mauricio; Taborga, Lautaro; Díaz, Katy; Olea, Andrés F.; Bay, Camila; Peña-Cortés, Hugo; Espinoza, Luis

2015-01-01

The inhibitory effects on the mycelial growth of plant pathogen Botritys cinerea have been evaluated for a series of geranylphenols substituted with one, two and three methoxy groups in the aromatic ring. The results show that the antifungal activity depends on the structure of the geranylphenols, increasing from 40% to 90% by increasing the number of methoxy groups. On the other hand, the acetylation of the –OH group induces a change of activity that depends on the number of methoxy groups. The biological activity of digeranyl derivatives is lower than that exhibited by the respective monogeranyl compound. All tested geranylphenols have been synthesized by direct coupling of geraniol and the respective phenol. The effect of solvent on yields and product distribution is discussed. For monomethoxyphenols the reaction gives better yields when acetonitrile is used as a solvent and AgNO3 is used as a secondary catalyst. However, for di- and trimethoxyphenols the reaction proceeds only in dioxane. PMID:26287171

Frequency of false-negative reactions to the fragrance mix.

PubMed

de Groot, A C; van der Kley, A M; Bruynzeel, D P; Meinardi, M M; Smeenk, G; van Joost, T; Pavel, S

1993-03-01

To estimate the frequency of false-negative reactions to the fragrance mix, the 8 constituents of the mix in concentrations of 5% (2% for cinnamic aldehyde) were added to the European standard series for routine testing. Patients with positive reactions to individual ingredients in the absence of a reaction to the mix were retested with serial dilutions. In a 4-month period, 677 patients were tested. 61 (9%) reacted to the mix and to 1 or more of the ingredients. 4 patients (0.6% of all patients tested and 6.2% of the patients allergic to fragrances) had false-negative reactions to the mix. They were allergic to cinnamic alcohol, geraniol, isoeugenol and oak moss (1 reaction each), in the absence of a reaction to the fragrance mix. It is concluded that the currently used concentration of the mix (8 x 1%) not infrequently results in false-negative reactions, and that further research should be done to overcome this problem.

Modulation by geraniol of gene expression involved in lipid metabolism leading to a reduction of serum-cholesterol and triglyceride levels.

PubMed

Galle, Marianela; Kladniew, Boris Rodenak; Castro, María Agustina; Villegas, Sandra Montero; Lacunza, Ezequiel; Polo, Mónica; de Bravo, Margarita García; Crespo, Rosana

2015-07-15

Geraniol (G) is a natural isoprenoid present in the essential oils of several aromatic plants, with various biochemical and pharmacologic properties. Nevertheless, the mechanisms of action of G on cellular metabolism are largely unknown. We propose that G could be a potential agent for the treatment of hyperlipidemia that could contribute to the prevention of cardiovascular disease. The aim of the present study was to advance our understanding of its mechanism of action on cholesterol and TG metabolism. NIH mice received supplemented diets containing 25, 50, and 75 mmol G/kg chow. After a 3-week treatment, serum total-cholesterol and triglyceride levels were measured by commercial kits and lipid biosynthesis determined by the [(14)C] acetate incorporated into fatty acids plus nonsaponifiable and total hepatic lipids of the mice. The activity of the mRNA encoding HMGCR-the rate-limiting step in cholesterol biosynthesis-along with the enzyme levels and catalysis were assessed by real-time RT-PCR, Western blotting, and HMG-CoA-conversion assays, respectively. In-silico analysis of several genes involved in lipid metabolism and regulated by G in cultured cells was also performed. Finally, the mRNA levels encoded by the genes for the low-density-lipoprotein receptor (LDLR), the sterol-regulatory-element-binding transcription factor (SREBF2), the very-low-density-lipoprotein receptor (VLDLR), and the acetyl-CoA carboxylase (ACACA) were determined by real-time RT-PCR. Plasma total-cholesterol and triglyceride levels plus hepatic fatty-acid, total-lipid, and nonsaponifiable-lipid biosynthesis were significantly reduced by feeding with G. Even though an up-regulation of the mRNA encoding HMGCR occurred in the G treated mouse livers, the protein levels and specific activity of the enzyme were both inhibited. G also enhanced the mRNAs encoding the LDL and VLDL receptors and reduced ACACA mRNA, without altering the transcription of the mRNA encoding the SREBF2. The following mechanisms may have mediated the decrease in plasma lipids levels in mice: a down-regulation of hepatocyte-cholesterol synthesis occurred as a result of decreased HMGCR protein levels and catalytic activity; the levels of LDLR mRNA became elevated, thus suggesting an increase in the uptake of serum LDL, especially by the liver; and TG synthesis became reduced very likely because of a decrease in fatty-acid synthesis. Copyright © 2015 Elsevier GmbH. All rights reserved.

Use of response surface methodology for the assessment of changes in the volatile composition of Moscato bianco (Vitis vinifera L.) grape berries during ripening.

PubMed

Torchio, Fabrizio; Giacosa, Simone; Vilanova, Mar; Río Segade, Susana; Gerbi, Vincenzo; Giordano, Manuela; Rolle, Luca

2016-12-01

The changes in the volatile composition of Moscato bianco grapes were evaluated during ripening. Grape berries were sampled for five weeks (16-20 °Brix) and sorted for each date in ten density classes (1.05-1.12g/cm(3)). The highest total concentration of free terpenes was found at 19.3 °Brix; however, total concentration of the bound fraction increased significantly throughout ripening. Response surface methodology was used to assess the simultaneous effect of sampling time and berry density on the volatile composition, which was satisfactorily fitted to regression models for some key terpene compounds. Total free and bound terpenes were more affected by grape density than by sampling date. The same behaviour was observed for free and bound linalool and bound nerol, whereas the stronger effect of sampling date was exhibited for bound t-rose oxide, c-rose oxide and geraniol. The results showed that the sampling strategy impacted strongly on the aroma quality of berries. Copyright © 2016 Elsevier Ltd. All rights reserved.

Structured plant metabolomics for the simultaneous exploration of multiple factors.

PubMed

Vasilev, Nikolay; Boccard, Julien; Lang, Gerhard; Grömping, Ulrike; Fischer, Rainer; Goepfert, Simon; Rudaz, Serge; Schillberg, Stefan

2016-11-17

Multiple factors act simultaneously on plants to establish complex interaction networks involving nutrients, elicitors and metabolites. Metabolomics offers a better understanding of complex biological systems, but evaluating the simultaneous impact of different parameters on metabolic pathways that have many components is a challenging task. We therefore developed a novel approach that combines experimental design, untargeted metabolic profiling based on multiple chromatography systems and ionization modes, and multiblock data analysis, facilitating the systematic analysis of metabolic changes in plants caused by different factors acting at the same time. Using this method, target geraniol compounds produced in transgenic tobacco cell cultures were grouped into clusters based on their response to different factors. We hypothesized that our novel approach may provide more robust data for process optimization in plant cell cultures producing any target secondary metabolite, based on the simultaneous exploration of multiple factors rather than varying one factor each time. The suitability of our approach was verified by confirming several previously reported examples of elicitor-metabolite crosstalk. However, unravelling all factor-metabolite networks remains challenging because it requires the identification of all biochemically significant metabolites in the metabolomics dataset.

Rosa damascena as holy ancient herb with novel applications

PubMed Central

Mahboubi, Mohaddese

2015-01-01

Rosa damascena as an ornamental plant is commonly known as “Gole Mohammadi” in Iran. Iranian people have been called this plant, the flower of Prophet “Mohammad”. R. damascena is traditionally used for treatment of abdominal and chest pains, strengthening the heart, menstrual bleeding, digestive problems and constipation. This paper reviews the ethnopharmacology, phytochemistry and pharmaceutical investigations on R. damascena. All relevant databases and local books on ethnopharmacology of R. damascena were probed without limitation up to 31st March 2015 and the results of these studies were collected and reviewed. R. damascena has an important position in Iranian traditional medicine. It is economically a valuable plant with therapeutic applications in modern medicine. The antimicrobial, antioxidant, analgesic, anti-inflammatory, anti-diabetic and anti-depressant properties of R. damascena have been confirmed. Citronellol and geraniol as the main components of R. damascena essential oil are responsible for pharmacological activities. Overall, R. damascena as holy ancient plant with modern pharmacological investigations should be more investigated as traditional uses in large preclinical and clinical studies. PMID:26870673

Effects of irrigation over three years on the amino acid composition of Treixadura (Vitis vinifera L.) musts and wines, and on the aromatic composition and sensory profiles of its wines.

PubMed

Bouzas-Cid, Yolanda; Falqué, Elena; Orriols, Ignacio; Mirás-Avalos, José M

2018-02-01

Amino acids and volatile compounds play an important role in wine aroma and sensory characteristics. The concentrations of these compounds might be altered by climate interanual variability and by management practices such as irrigation. The aim of the current study was to assess the amino acid profile of musts and wines, volatile composition and sensory profile of wines from Vitis vinifera (L.) cultivar 'Treixadura' obtained from vines under rain-fed and irrigation conditions over three consecutive vintages (2012-2014). Musts and wines from the irrigation treatment tended to be higher in acidity than those from rain-fed. However, amino acid and aromatic profiles were mostly affected by climate conditions of each year; although irrigation exerted a significant effect on several compounds (proline, cysteine, tryptophan, phenylalanine, α-terpineol and geraniol). Wines from both treatments received similar marks in the sensory tests, suggesting that irrigation did not greatly modify wine quality under the conditions of this study. Copyright © 2017 Elsevier Ltd. All rights reserved.

Free and glycosidically bound volatile compounds in sun-dried raisins made from different fragrance intensities grape varieties using a validated HS-SPME with GC-MS method.

PubMed

Wang, Dong; Duan, Chang-Qing; Shi, Ying; Zhu, Bao-Qing; Javed, Hafiz Umer; Wang, Jun

2017-08-01

The conditions of sample pretreatments and HS-SPME for extracting volatile compounds from raisins were optimized, and the method was validated in the study. Free and glycosidically bound volatile compounds in three different fragrance intensities raisins were analysed using this method. There were 91 compounds identified, and 72, 26 and 8 of these compounds came from fresh grapes, the auto-oxidation of unsaturated fatty acids (UFAO) and the Maillard reaction, respectively. The aroma profiles of Thompson Seedless raisins (TSRs) and Centennial Seedless raisins (CSRs) were similar, while the floral, fruity, green and roasted aromas of CSRs were higher than those of TSRs due to the contributions of benzeneacetaldehyde, 2-pentylfuran, (E)-2-nonenal and 3-ethyl-2,5-dimethyl pyrazine. Decanal, rose oxide, geraniol, linalool and β-damascenone made the floral and fruity aromas of Zixiang Seedless raisins (ZSRs) greater than those in TSRs and CSRs, but the green and roasted aroma intensities of ZSRs were lower. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of grape bunch sunlight exposure and UV radiation on phenolics and volatile composition of Vitis vinifera L. cv. Pinot noir wine.

PubMed

Song, Jianqiang; Smart, Richard; Wang, Hua; Dambergs, Bob; Sparrow, Angela; Qian, Michael C

2015-04-15

The effect of canopy leaf removal and ultraviolet (UV) on Pinot noir grape and wine composition was investigated in this study. Limited basal leaf removal in the fruit zone was conducted, compared to shaded bunches. The UV exposure was controlled using polycarbonate screens to block UV radiation, and acrylic screens to pass the UV. The results showed that bunch sunlight and UV exposure significantly increased the Brix and pH in the grape juice, and increased substantially wine colour density, anthocyanins, total pigment, total phenolics and tannin content. Bunch sunlight and UV exposure affected terpene alcohols, C13-norisprenoids and other volatile composition of the wine differently. Sunlight exposure and UV resulted in increase of nerol, geraniol and citronellol but not linalool. Sunlight exposure slightly increased the concentration of β-ionone, but the increase was not statistically significant for UV treatment. Neither sunlight nor UV treatment showed any impact on the concentration of β-damascenone. Copyright © 2014 Elsevier Ltd. All rights reserved.

Applications of the Non-Conventional Yeast Yarrowia lipolytica

NASA Astrophysics Data System (ADS)

Thevenieau, France; Nicaud, Jean-Marc; Gaillardin, Claude

The yeast Yarrowia lipolytica is often found associated to proteinaceous or hydrophobic substrates such as alkanes or lipids. To assimilate these hydropho-bic substrates, Y. lipolytica has developed an adaptative strategy resulting in elaborated morphological and physiological changes leading to terminal and β-oxidation of substrates as well as to lipid storage. The completion of the Y. lipolytica genome greatly improved our understanding of these mechanisms. Three main applications of this metabolism will be discussed. The first class corresponds to bioconver-sion processes for the production of secondary metabolites (citric acid), of aroma ( γ - lactone, green note, epoxy geraniol) and of chemicals (dicarboxylic acids). The second class leads to fine chemical production by enantio separation of pharmaceutical compounds using Y. lipolytica enzymes such as epoxyde hydrolase or lipase. The third one refers to production of Single Cell Oils (SCO) from agriculture feedstock. In addition to its ability to handle hydrophobic substrates, Y. lipolytica has also been recognised as a strong secretor of various proteins such as proteases, lipases, RNases and others. A comprehensive review of recent developments of the Y. lipolytica expression/secretion system will finally be presented.

Comparing terpenes from plant essential oils as pesticides for the poultry red mite (Dermanyssus gallinae).

PubMed

Sparagano, O; Khallaayoune, K; Duvallet, G; Nayak, S; George, D

2013-11-01

Resistance to conventional synthetic pesticides has been widely reported in ticks, parasitic mites and other pests of veterinary and medical significance. New and novel approaches to manage these pests are therefore needed to ensure efficient control programmes that can be implemented now and in the future. Recent research in this area has focused on the pesticidal potential of plant essential oils. These products are attractive as pesticide candidates on the grounds of low mammalian toxicity, short environmental persistence and complex chemistries (limiting the development of pest resistance against them). Although issues may exist concerning reliability in efficacy of essential oils, these may be overcome by identifying and developing bioactive oil components for use in pest management. In the current work, three such components (terpenes) found in essential oils (eugenol, geraniol and citral) were tested against the poultry red mite Dermanyssus gallinae. All provided 100% mortality in toxicity tests when undiluted. Even at 1% of this dose, eugenol was 20% effective against experimental pest populations, although the remaining terpenes were largely ineffective at this concentration. © 2013 Blackwell Verlag GmbH.

Transformation of chemical constituents of lychee wine by simultaneous alcoholic and malolactic fermentations.

PubMed

Chen, Dai; Liu, Shao-Quan

2016-04-01

This work examined for the first time the impact of malolactic fermentation (MLF) on the chemical constituents of lychee wine. Oenococcus oeni Viniflora Oenos (MLF inducer) and Saccharomyces cerevisiae MERIT.ferm were co-inoculated into lychee juice to induce simultaneous alcoholic fermentation (AF) and MLF. MLF did not affect sugar utilisation and ethanol production statistically (8.54% v/v for MLF and 9.27% v/v for AF). However, MLF resulted in dramatic degradation of malic and citric acids with concomitant increases of lactic acid, ethyl lactate and pH. The final concentrations of acetic and succinic acids between AF and MLF wines had no significant difference. The MLF wine contained significantly higher amounts of amino acids than the AF wine. More importantly, MLF significantly elevated the levels of potent aroma-active compounds including isoamyl acetate, linalool, geraniol and cis-rose oxide (to levels above or near respective detection thresholds), suggesting that MLF is an effective way of retaining the original lychee flavour. Copyright © 2015 Elsevier Ltd. All rights reserved.

Flavor characterization of sugar-added pennywort (Centella asiatica L.) juices treated with ultra-high pressure and thermal processes.

PubMed

Apichartsrangkoon, Arunee; Wongfhun, Pronprapa; Gordon, Michael H

2009-01-01

The flavor characteristics of pennywort juices with added sugar treated by ultra-high pressure, pasteurization, and sterilization were investigated using solid phase microextraction combined with gas chromatography-mass spectrometry. It was found that sesquiterpene hydrocarbons comprised the major class of volatile components present and the juices had a characteristic aroma due to the presence of volatiles including beta-caryophyllene and humulene and alpha-copaene. In comparison with heated juices, HPP-treated samples could retain more volatile compounds such as linalool and geraniol similar to those present in fresh juice, whereas some volatiles such as alpha-terpinene and ketone class were apparently formed by thermal treatment. All processing operations produced juice that was not significantly different in the concentration of total volatiles. Practical Application: Pennywort juice is considered a nutraceutical drink for health benefits. Therefore, to preserve all aroma and active components in this juice, a nonthermal process such as ultra-high pressure should be a more appropriate technique for retention of its nutritive values than pasteurization and sterilization.

Flavor and chiral stability of lemon-flavored hard tea during storage.

PubMed

He, Fei; Qian, YanPing L; Qian, Michael C

2018-01-15

Flavor stability of hard tea beverage was investigated over eight weeks of storage. The volatile compounds were analyzed using solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) and two-dimensional GC-MS. Quantitative analysis showed that the concentrations of linalool, citronellol, geranial, neral, geraniol, and nerol decreased dramatically during storage, whereas α-terpineol showed an increasing trend during storage. Heart-cut two-dimensional GC-MS (2D-GC-MS) chirality analysis showed that (R)-(+)-limonene, (R)-(-)-linalool, (S)-(-)-α-terpineol and (S)-(-)-4-terpineol dominated in the fresh hard tea samples, however, the configuration changed during storage for the terpene alcohols. The storage conditions did not change the configuration of limonene. A conversion of (R)-(-)-linalool to (S)-(+) form was observed during storage. Both (S)-α-terpineol and (S)-4-terpineol dominated at beginning of the storage, but (R)-(+)-α-terpineol became dominated after storage, suggested in addition to isomerization from (S)-α-terpineol, other precursors could also generate α-terpineol with (R)-isomer preference. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis of New Hydrated Geranylphenols and in Vitro Antifungal Activity against Botrytis cinerea

PubMed Central

Soto, Mauricio; Espinoza, Luis; Chávez, María I.; Díaz, Katy; Olea, Andrés F.; Taborga, Lautaro

2016-01-01

Geranylated hydroquinones and other geranylated compounds isolated from Aplydium species have shown interesting biological activities. This fact has prompted a number of studies where geranylated phenol derivatives have been synthesized in order to assay their bioactivities. In this work, we report the synthesis of a series of new hydrated geranylphenols using two different synthetic approaches and their inhibitory effects on the mycelial growth of Botrytis cinerea. Five new hydrated geranylphenols were obtained by direct coupling reaction between geraniol and phenol in dioxane/water and using BF3·Et2O as the catalyst or by the reaction of a geranylated phenol with BF3·Et2O. Two new geranylated quinones were also obtained. The synthesis and structural elucidation of all new compounds is presented. All hydrated geranylphenols efficiently inhibit the mycelial growth of B. cinerea. Their activity is higher than that observed for non-hydrated compounds. These results indicate that structural modification on the geranyl chain brings about an enhancement of the inhibition effect of geranylated phenol derivatives. PMID:27271604

Antifungal activity of Cymbopogon winterianus jowitt ex bor against Candida albicans

PubMed Central

de Oliveira, Wylly Araújo; de Oliveira Pereira, Fillipe; de Luna, Giliara Carol Diniz Gomes; Lima, Igara Oliveira; Wanderley, Paulo Alves; de Lima, Rita Baltazar; de Oliveira Lima, Edeltrudes

2011-01-01

Candida albicans is an opportunistic yeast and a member of the normal human flora that commonly causes infections in patients with any type of deficiency of the immune system. The essential oils have been tested for antimycotic activity and pose much potential as antifungal agents. This work investigated the activity of the essential oil of Cymbopogon winterianus against C. albicans by MIC, MFC and time-kill methods. The essential oil (EO) was obtained by hydrodistillation using a Clevenger-type apparatus. It was tested fifteen strains of C. albicans. The MIC was determined by the microdilution method and the MFC was determined when an aliquot of the broth microdilution was cultivated in SDA medium. The phytochemical analysis of EO showed presence of citronellal (23,59%), geraniol (18,81%) and citronellol (11,74%). The EO showed antifungal activity, and the concentrations 625 µg/mL and 1250 µg/mL inhibited the growth of all strains tested and it was fungicidal, respectively. The antimicrobial activity of various concentrations of EO was analyzed over time, it was found concentration-dependent antifungal activity, whose behavior was similar to amphotericin B and nystatin. PMID:24031651

Zein Nanoparticles as Eco-Friendly Carrier Systems for Botanical Repellents Aiming Sustainable Agriculture.

PubMed

Oliveira, Jhones L de; Campos, Estefânia V R; Pereira, Anderson E S; Pasquoto, Tatiane; Lima, Renata; Grillo, Renato; Andrade, Daniel Junior de; Santos, Fabiano Aparecido Dos; Fraceto, Leonardo Fernandes

2018-02-14

Botanical repellents represent one of the main ways of reducing the use of synthetic pesticides and the contamination of soil and hydric resources. However, the poor stability and rapid degradation of these compounds in the environment hinder their effective application in the field. Zein nanoparticles can be used as eco-friendly carrier systems to protect these substances against premature degradation, provide desirable release characteristics, and reduce toxicity in the environment and to humans. In this study, we describe the preparation and characterization of zein nanoparticles loaded with the main constituents of the essential oil of citronella (geraniol and R-citronellal). The phytotoxicity, cytotoxicity, and insect activity of the nanoparticles toward target and nontarget organisms were also evaluated. The botanical formulations showed high encapsulation efficiency (>90%) in the nanoparticles, good physicochemical stability, and effective protection of the repellents against UV degradation. Cytotoxicity and phytotoxicity assays showed that encapsulation of the botanical repellents decreased their toxicity. Repellent activity tests showed that nanoparticles containing the botanical repellents were highly repellent against the Tetranychus urticae Koch mite. This nanotechnological formulation offers a new option for the effective use of botanical repellents in agriculture, reducing toxicity, protecting against premature degradation, and providing effective pest control.

Phytochemistry and nematicidal activity of the essential oils from 8 Greek Lamiaceae aromatic plants and 13 terpene components.

PubMed

Ntalli, Nikoletta G; Ferrari, Federico; Giannakou, Ioannis; Menkissoglu-Spiroudi, Urania

2010-07-14

Eight essential oils (EOs) as well as 13 single terpenes were studied for their nematicidal activity against Meloidogyne incognita , for three immersion periods (24, 48, and 96 h). The EOs were isolated from eight Greek Lamiaceae species: Melissa officinalis , Sideritis clandestina , Origanum dictamnus , Ocimum basilicum , Mentha pulegium , Origanum vulgare , Vitex agnus castus , and Salvia officinalis . The EOs nematicidal activity was correlated to their chemical composition as well as to the pure terpenes' activity tested individually. Clear dose and time response relationships were established. The EOs of O. vulgare, O. dictamnus, M. pulegium, and M. officinalis exhibited high nematicidal activity against M. incognita, and the EC(50) values (96 h) were calculated at 1.55, 1.72, 3.15, and 6.15 muL/mL, respectively. The activity of the nematicidal terpenes was found to decrease in the order l-carvone, pulegone, trans-anethole, geraniol, eugenol, carvacrol, thymol, terpinen-4-ol, and the respective EC(50) values (24 h) were calculated in the range of 115-392 mug/mL. Terpenes tested individually were more active than as components in EO, implementing antagonistic action.

Effectiveness of Liquid-Liquid Extraction, Solid Phase Extraction, and Headspace Technique for Determination of Some Volatile Water-Soluble Compounds of Rose Aromatic Water

PubMed Central

2017-01-01

Steam distillation is used to isolate scent of rose flowers. Rose aromatic water is commonly used in European cuisine and aromatherapy besides its use in cosmetic industry for its lovely scent. In this study, three different sampling techniques, liquid-liquid extraction (LLE), headspace technique (HS), and solid phase extraction (SPE), were compared for the analysis of volatile water-soluble compounds in commercial rose aromatic water. Some volatile water-soluble compounds of rose aromatic water were also analyzed by gas chromatography mass spectrometry (GCMS). In any case, it was concluded that one of the solid phase extraction methods led to higher recoveries for 2-phenylethyl alcohol (PEA) in the rose aromatic water than the liquid-liquid extraction and headspace technique. Liquid-liquid extraction method provided higher recovery ratios for citronellol, nerol, and geraniol than others. Ideal linear correlation coefficient values were observed by GCMS for quantitative analysis of volatile compounds (r2 ≥ 0.999). Optimized methods showed acceptable repeatability (RSDs < 5%) and excellent recovery (>95%). For compounds such as α-pinene, linalool, β-caryophyllene, α-humulene, methyl eugenol, and eugenol, the best recovery values were obtained with LLE and SPE. PMID:28791049

Recruits of the stingless bee Scaptotrigona pectoralis learn food odors from the nest atmosphere.

PubMed

Reichle, Christian; Jarau, Stefan; Aguilar, Ingrid; Ayasse, Manfred

2010-05-01

The ability to learn food odors inside the nest and to associate them with food sources in the field is of essential importance for the recruitment of nestmates in social bees. We investigated odor learning by workers within the hive and the influence of these odors on their food choice in the field in the stingless bee Scaptotrigona pectoralis. During the experiments, recruited bees had to choose between two feeders, one with an odor that was present inside the nest during the recruitment process, and one with an unknown odor. In all experiments with different odor combinations (linalool/phenylacetaldehyde, geraniol/eugenol) a significant majority of bees visited the feeder with the odor they had experienced in their nest (chi (2)-tests; p < 0.05). By contrast, the bees showed no preference for one of two feeders when they were either baited with the same odor (linalool) or contained no odor. Our results clearly show that naïve workers of S. pectoralis can learn the odor of a food source during the recruitment process from the nest atmosphere and that their subsequent food search in the field is influenced by the learned odor.

Hierarchical cluster analysis and chemical characterisation of Myrtus communis L. essential oil from Yemen region and its antimicrobial, antioxidant and anti-colorectal adenocarcinoma properties.

PubMed

Anwar, Sirajudheen; Crouch, Rebecca A; Awadh Ali, Nasser A; Al-Fatimi, Mohamed A; Setzer, William N; Wessjohann, Ludger

2017-09-01

The hydrodistilled essential oil obtained from the dried leaves of Myrtus communis, collected in Yemen, was analysed by GC-MS. Forty-one compounds were identified, representing 96.3% of the total oil. The major constituents of essential oil were oxygenated monoterpenoids (87.1%), linalool (29.1%), 1,8-cineole (18.4%), α-terpineol (10.8%), geraniol (7.3%) and linalyl acetate (7.4%). The essential oil was assessed for its antimicrobial activity using a disc diffusion assay and resulted in moderate to potent antibacterial and antifungal activities targeting mainly Bacillus subtilis, Staphylococcus aureus and Candida albicans. The oil moderately reduced the diphenylpicrylhydrazyl radical (IC 50  = 4.2 μL/mL or 4.1 mg/mL). In vitro cytotoxicity evaluation against HT29 (human colonic adenocarcinoma cells) showed that the essential oil exhibited a moderate antitumor effect with IC 50 of 110 ± 4 μg/mL. Hierarchical cluster analysis of M. communis has been carried out based on the chemical compositions of 99 samples reported in the literature, including Yemeni sample.

Intranasal Localizability of Odorants: Influence of Stimulus Volume

PubMed Central

Frasnelli, J.; Berg, J.; Huang, G.; Doty, R.L.

2011-01-01

When an odorant is presented to one side of the nose and air to the other, the ability to localize which side received the odorant depends upon trigeminal nerve stimulation. It has been shown that performance on this lateralization task increases as stimulus concentration increases. In this study, we determined the influences of stimulus volume and sex on the ability to localize each of 8 odorants presented at neat concentrations: anethole, geraniol, limonene, linalool, menthol, methyl salicyclate, phenyl ethanol, and vanillin. At a low stimulus volume (11 mL), only menthol was localized at an above-chance level. At a high stimulus volume (21 mL), above-chance localization occurred for all odorants except vanillin. Women were significantly better than men in localizing menthol. Stimuli rated as most intense were those that were most readily localized. The detection performance measures, as well as rated intensity values, significantly correlated with earlier findings of the trigeminal detectability of odorants presented to anosmic and normosmic subjects. This study suggests that differences in stimulus volume may explain some discrepant findings within the trigeminal chemosensory literature and supports the concept that vanillin may be a “relatively pure” olfactory stimulus. PMID:21310764

Intranasal localizability of odorants: influence of stimulus volume.

PubMed

Frasnelli, J; Hummel, T; Berg, J; Huang, G; Doty, R L

2011-05-01

When an odorant is presented to one side of the nose and air to the other, the ability to localize which side received the odorant depends upon trigeminal nerve stimulation. It has been shown that performance on this lateralization task increases as stimulus concentration increases. In this study, we determined the influences of stimulus volume and sex on the ability to localize each of 8 odorants presented at neat concentrations: anethole, geraniol, limonene, linalool, menthol, methyl salicylate, phenyl ethanol, and vanillin. At a low stimulus volume (11 mL), only menthol was localized at an above-chance level. At a high stimulus volume (21 mL), above-chance localization occurred for all odorants except vanillin. Women were significantly better than men in localizing menthol. Stimuli rated as most intense were those that were most readily localized. The detection performance measures, as well as rated intensity values, significantly correlated with earlier findings of the trigeminal detectability of odorants presented to anosmic and normosmic subjects. This study suggests that differences in stimulus volume may explain some discrepant findings within the trigeminal chemosensory literature and supports the concept that vanillin may be a "relatively pure" olfactory stimulus.

Identification of Genes and Proteins Necessary for Catabolism of Acyclic Terpenes and Leucine/Isovalerate in Pseudomonas aeruginosa

PubMed Central

Förster-Fromme, Karin; Höschle, Birgit; Mack, Christina; Bott, Michael; Armbruster, Wolfgang; Jendrossek, Dieter

2006-01-01

Geranyl-coenzyme A (CoA)-carboxylase (GCase; AtuC/AtuF) and methylcrotonyl-CoA-carboxylase (MCase; LiuB/LiuD) are characteristic enzymes of the catabolic pathway of acyclic terpenes (citronellol and geraniol) and of saturated methyl-branched compounds, such as leucine or isovalerate, respectively. Proteins encoded by two gene clusters (atuABCDEFGH and liuRABCDE) of Pseudomonas aeruginosa PAO1 were essential for acyclic terpene utilization (Atu) and for leucine and isovalerate utilization (Liu), respectively, as revealed by phenotype analysis of 10 insertion mutants, two-dimensional gel electrophoresis, determination of GCase and MCase activities, and Western blot analysis of wild-type and mutant strains. Analysis of the genome sequences of other pseudomonads (P. putida KT2440 and P. fluorescens Pf-5) revealed candidate genes for Liu proteins for both species and candidate genes for Atu proteins in P. fluorescens. This result concurred with the finding that P. fluorescens, but not P. putida, could grow on acyclic terpenes (citronellol and citronellate), while both species were able to utilize leucine and isovalerate. A regulatory gene, atuR, was identified upstream of atuABCDEFGH and negatively regulated expression of the atu gene cluster. PMID:16820476

Recruits of the stingless bee Scaptotrigona pectoralis learn food odors from the nest atmosphere

NASA Astrophysics Data System (ADS)

Reichle, Christian; Jarau, Stefan; Aguilar, Ingrid; Ayasse, Manfred

2010-05-01

The ability to learn food odors inside the nest and to associate them with food sources in the field is of essential importance for the recruitment of nestmates in social bees. We investigated odor learning by workers within the hive and the influence of these odors on their food choice in the field in the stingless bee Scaptotrigona pectoralis. During the experiments, recruited bees had to choose between two feeders, one with an odor that was present inside the nest during the recruitment process, and one with an unknown odor. In all experiments with different odor combinations (linalool/phenylacetaldehyde, geraniol/eugenol) a significant majority of bees visited the feeder with the odor they had experienced in their nest ( χ 2-tests; p < 0.05). By contrast, the bees showed no preference for one of two feeders when they were either baited with the same odor (linalool) or contained no odor. Our results clearly show that naïve workers of S. pectoralis can learn the odor of a food source during the recruitment process from the nest atmosphere and that their subsequent food search in the field is influenced by the learned odor.

Sensitization to fragrance materials in Indonesian cosmetics.

PubMed

Roesyanto-Mahadi, I D; Geursen-Reitsma, A M; van Joost, T; van den Akker, T W

1990-04-01

2 different groups of patients were patch tested with 2 test series (A and B) containing extracts of fragrance raw materials, traditionally used in Indonesian cosmetics. Series A consisted of diluted extracts of commercially available Indonesian fragrances. Series B consisted of extracts prepared in our department from corresponding indigenous flowers and fruits. Group 1 consisted of 32 patients positive to fragrance-mix, of whom 8 (25%) had positive tests to 1 or more of the different extracts of fragrance raw materials. Reactions were observed to extracts of: Rosa hybrida Hort (7); Canangium odoratum Baill (5); Citrus aurantifolia Swingle (4); Jasminum sambac Ait (2). 6 of the 8 patients had reactions to 1 or more of the components of fragrance-mix: oakmoss (3); cinnamic alcohol (2), isoeugenol (1); cinnamic aldehyde (1) and geraniol (1). Group 2 consisted of 159 patients patch tested on suspicion of contact dermatitis, who were fragrance-mix negative. Only 2 (1.2%) had a positive patch test to the extracts of fragrance raw materials. Specimens taken (as is) from the flowers and citrus fruits (being the basis sources of the fragrance raw materials) were less antigenic. The use of additional test series in Indonesia to detect allergy to traditional cosmetics and perfumes merits further investigation.

Performance of the plant-based repellent TT-4302 against mosquitoes in the laboratory and field and comparative efficacy to 16 mosquito repellents against Aedes aegypti (Diptera: Culicidae).

PubMed

Bissinger, B W; Schmidt, J P; Owens, J J; Mitchell, S M; Kennedy, M K

2014-03-01

Repellent efficacy of the plant-based repellent, TT-4302 (5% geraniol), was compared with 16 other products in laboratory arm-in-cage trials against Aedes aegypti (L). Eight repellents (Badger, BioUD, Burt's bees, California Baby, Cutter Natural, EcoSMART, Herbal Armor, and SkinSmart) exhibited a mean repellency below 90% to Ae. aegypti at 0.5 h after application. Three repellents (Buzz Away Extreme, Cutter Advanced, and OFF! Botanicals lotion) fell below 90% repellency 1.5 h after application. TT-4302 exhibited 94.7% repellency 5 h posttreatment, which was a longer duration than any of the other repellents tested. The positive control, 15% DEET (OFF! Active), was repellent for 3 h before activity dropped below 90%. Additional arm-in-cage trials comparing TT-4302 with 15% DEET were carried out against Anopheles quadrimaculatus Say. At 6 h after treatment, TT-4302 provided 95.2% repellency while DEET exhibited 72.2%. In North Carolina field trials, TT-4302 provided 100% repellency 5 h after application against Aedes albopictus Skuse while DEET provided 77.6% repellency. These results demonstrate that TT-4302 is an efficacious plant-based repellent that provides an extended duration of protection compared with many other commercially available products.

New record of Scedosporium dehoogii from Chile: Phylogeny and susceptibility profiles to classic and novel putative antifungal agents.

PubMed

Alvarez, Eduardo; Sanhueza, Camila

Scedosporium species are considered emerging agents causing illness in immunocompromised patients. In Chile, only Scedosporium apiospermum, Scedosporium boydii and Lomentospora prolificans haven been reported previously. The study aimed to characterize genetically Scedosporium dehoogii strains from Chilean soil samples, and assessed the antifungal susceptibility profile to classic and novel putative antifungal molecules. In 2014, several samples were obtained during a survey of soil fungi in urban areas from Chile. Morphological and phylogenetic analyses of the internal transcribed spacer region (ITS), tubulin (TUB), and calmodulin (CAL) sequences were performed. In addition, the susceptibility profiles to classic antifungal and new putative antifungal molecules were determined. Four strains of Scedosporium dehoogii were isolated from soil samples. The methodology confirmed the species (reported here as a new record for Chile). Antifungal susceptibility testing demonstrates the low activity of terpenes (α-pinene and geraniol) against this species. Voriconazole (VRC), posaconazole (PSC), and the hydroxyquinolines (clioquinol, and 5,7-dibromo-8-hydroxyquinoline) showed the best antifungal activity. Our results demonstrate that Scedosporium dehoogii is present in soil samples from Chile. This study shows also that hydroxyquinolines have potential as putative antifungal molecules. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

Microbe-based technology ameliorates glandular trichomes, secondary metabolites and antioxidants in Pelargonium graveolens L'Hér.

PubMed

Gupta, Rupali; Singh, Akanksha; Pandey, Rakesh

2016-09-01

Despite the vast exploration of microbes for plant health, there is a lack of knowledge about the synergistic effects of specific microorganisms in sustainable agriculture, especially in medicinal plants such as Pelargonium graveolens L'Hér. The aim of this study was to evaluate how synergistic microbes Trichoderma harzianum ThU, Glomus intraradices and Bacillus subtilis CIM affected crop productivity, secondary metabolites and glandular trichome number in P. graveolens. The results demonstrated a significant (P < 0.05) increase in plant growth, secondary metabolites, total chlorophyll, carotenoids, carbohydrates, total phenolics, total flavonoids, free radical-scavenging activity and total antioxidant capacity of P. graveolens treated with synergistic bioinoculants as compared with the control. Most interestingly, an increase in essential oil by 32% in the treatment with all three microbes was observed. Furthermore, the principal aroma compounds citronellol and geraniol also increased in the same treatment. A positive and direct correlation was observed between essential oil content and number of glandular trichomes in all treatments. The present study highlights an explicit amalgamation of prospective microbes showing potential for synergism that act as biostimulants in enhancing plant production and improving the antioxidant and aroma profile of P. graveolens. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Performance of rose scented geranium (Pelargonium graveolens) in heavy metal polluted soil vis-à-vis phytoaccumulation of metals.

PubMed

Chand, Sukhmal; Singh, Geetu; Patra, D D

2016-08-02

An investigation was carried out to evaluate the effect of heavy metal toxicity on growth, herb, oil yield and quality and metal accumulation in rose scented geranium (Pelargonium graveolens) grown in heavy metal enriched soils. Four heavy metals (Cd, Ni, Cr, and Pb) each at two levels (10 and 20 mg kg-1 soil) were tested on geranium. Results indicated that Cr concentration in soil at 20 mg kg-1 reduced leaves, stem and root yield by 70, 83, and 45%, respectively, over control. Root growth was significantly affected in Cr stressed soil. Nickel, Cr, and Cd concentration and accumulation in plant increased with higher application of these metals. Chromium, nickel and cadmium uptake was observed to be higher in leaves than in stem and roots. Essential oil constituents were generally not significantly affected by heavy metals except Pb at 10 and 20 ppm, which significantly increased the content of citronellol and Ni at 20 ppm increased the content of geraniol. Looking in to the higher accumulation of toxic metals by geranium and the minimal impact of heavy metals on quality of essential oil, geranium can be commercially cultivated in heavy metal polluted soil for production of high value essential oil.

Comparative efficacy of new commercial pediculicides against adults and eggs of Pediculus humanus capitis (head lice).

PubMed

Gallardo, Anabella; Mougabure-Cueto, Gastón; Vassena, Claudia; Picollo, María Inés; Toloza, Ariel Ceferino

2012-05-01

The use of pyrethroids to control head louse infestations have suffered considerable loss of efficacy due to the development of resistance. In the last past years, several new alternative products to synthetic pyrethroids have been developed and are sold in the Argentinean market against head lice. The present study investigated the efficacy of two new Argentinean products Nopucid Qubit® and Nopucid Bio Citrus® and its comparison with two reference products Nyda® and Hedrin®. Nopucid Qubit® is a two-phase lotion containing geraniol and citronellol (phase 1) and ciclopentaxiloxane (phase 2); while Nopucid Bio Citrus® contains dimethicone, ciclopentaxiloxane, and bergamot essential oil. These products are physically acting compounds. The sensitivity of two laboratory assays for testing insecticide activity of new formulations was also compared. Mortality (100%) of motile forms occurred after they were exposed to any product for 1 and 2 min, either by in vitro or ex vivo test. Concerning ovicidal activity, the most effective pediculicides were Nopucid Bio Citrus® and Nyda®, followed by Hedrin® and Nopucid Qubit®. The present study revealed, for the first time, the efficacy of over-the-counter commercial pediculicides available in Argentine (Nopucid Bio Citrus® and Nopucid Qubit®) on either motile stages or eggs against head lice.

Naturally occurring bioactive compounds from four repellent essential oils against Bemisia tabaci whiteflies.

PubMed

Deletre, Emilie; Chandre, Fabrice; Barkman, Barbara; Menut, Chantal; Martin, Thibaud

2016-01-01

In tropical countries, netting is an effective sustainable tool for protecting horticultural crops against Lepidoptera, although not against small pests such as Bemisia tabaci, while smaller mesh netting can be used in temperate regions. A solution is to combine a net with a repellent. Previously we identified repellent essential oils: lemongrass (Cymbopogon citratus), cinnamon (Cinnamomum zeylanicum), cumin (Cuminum cyminum) and citronella (Cymbopogon winternarius). The present study was designed to identify the active compounds of these essential oils, characterise their biological activity and examine their potential for coating nets. We investigated the efficiency and toxicity of nets dipped in different solutions. We then studied the repellent effect with an olfactometer and the irritant effect by videotracking. Geraniol and citronellol were the most promising net coatings owing to their repellent effect. The repellency, irritancy or toxicity varied with the product and concentration, and these features were independent, indicating that the repellent and the irritant/toxic mechanisms were not the same. The combined effects of these different compounds account for the bioactivity of the mixture, suggesting interactions between the compounds. This new sustainable strategy for protecting vegetable crops against whiteflies is discussed, in addition to the use of companion plants that could produce such bioactive compounds. © 2015 Society of Chemical Industry.

Selective hydrogenation of citral over supported Pt catalysts: insight into support effects

NASA Astrophysics Data System (ADS)

Wang, Xiaofeng; Hu, Weiming; Deng, Baolin; Liang, Xinhua

2017-04-01

Highly dispersed platinum (Pt) nanoparticles (NPs) were deposited on various substrates by atomic layer deposition (ALD) in a fluidized bed reactor at 300 °C. The substrates included multi-walled carbon nanotubes (MWCNTs), silica gel (SiO2), commercial γ-Al2O3, and ALD-prepared porous Al2O3 particles (ALD-Al2O3). The results of TEM analysis showed that 1.3 nm Pt NPs were highly dispersed on all different supports. All catalysts were used for the reaction of selective hydrogenation of citral to unsaturated alcohols (UA), geraniol, and nerol. Both the structure and acidity of supports affected the activity and selectivity of Pt catalysts. Pt/SiO2 showed the highest activity due to the strong acidity of SiO2 and the conversion of citral reached 82% after 12 h with a selectivity of 58% of UA. Pt/MWCNTs showed the highest selectivity of UA, which reached 65% with a conversion of 38% due to its unique structure and electronic effect. The cycling experiments indicated that Pt/MWCNTs and Pt/ALD-Al2O3 catalysts were more stable than Pt/SiO2, as a result of the different interactions between the Pt NPs and the supports.

A novel poly(3,4-ethylenedioxythiophene)-ionic liquid composite coating for the headspace solid-phase microextraction and gas chromatography determination of several alcohols in soft drinks.

PubMed

Wu, Mian; Zhang, Haibo; Zhao, Faqiong; Zeng, Baizhao

2014-11-19

A novel poly(3,4-ethylenedioxythiophene)-ionic liquid (i.e., 1-hydroxyethyl-3-methyl imidazolium-bis[(trifluoromethyl)sulfonyl]imide) composite film was electrodeposited on a Pt wire for headspace solid-phase microextraction. The film showed nodular structure and had large specific surface. In addition, it displayed high thermal stability (up to 300°C) and durable property (could be used for more than 200 times). Coupled with gas chromatography-flame ionization detection, the resulting fiber was applied to the headspace solid-phase microextraction and determination of several alcohols (i.e., linalool, nonanol, terpineol, geraniol, decanol and dodecanol). It presented higher extraction capability in comparison with the poly(3,4-ethylenedioxythiophene) and commercial polydimethylsiloxane/divinylbenzene fiber. Under the optimized conditions, the linear ranges exceeded three magnitudes with correlation coefficients above 0.9952 and the low limits of detection were 34.2-81.3ng L(-1). For different alcohols the repeatabilities (defined as RSD) were <5.8% and <7.8% for single fiber (n=5) and fiber-to-fiber (n=4), respectively. The proposed method was applied to the determination of these alcohols in real samples with acceptable recoveries from 81.1% to 106.6%. Copyright © 2014 Elsevier B.V. All rights reserved.

Content of fragrance mix ingredients and customer complaints of cosmetic products.

PubMed

Bárány, E; Lodén, M

2000-06-01

In relation to the wide use of cosmetics, serious adverse effects are rare. Occasionally, unwanted effects such as contact dermatitis are reported. Allergic reactions to cosmetics are often caused by fragrances. The aim was to investigate the content of fragrance mix (FM) ingredients in cosmetic products of the brand ACO HUD (Stockholm, Sweden) and the frequency of customer skin complaints about fragranced and unfragranced products over 4.5 years. Content of FM ingredients in the fragrances used was both analyzed and requested from the suppliers. Customer complaints were those reported to the company. Between 1 and 7 of FM ingredients were present in levels of less than 0.1 to 770 ppm. The ingredients, in order of frequency, were geraniol, eugenol, hydroxycitronellal, alpha-amyl cinnamic aldehyde, isoeugenol, cinnamic alcohol, and oak moss. Cinnamic aldehyde was not found. No significant difference was found either between the frequency of complaints about products with and without fragrance (P = .21) or in a paired comparison of 17 formulas marketed with and without fragrance (P = .24). The study suggests that the investigated fragranced products had a low content of FM ingredients, which might explain the absence of a higher frequency of adversities. Furthermore, it appears that under such circumstances fragrances may be used without introducing an increased rate of spontaneous complaints of skin reactions.

Rose geranium essential oil as a source of new and safe anti-inflammatory drugs

PubMed Central

Boukhatem, Mohamed Nadjib; Kameli, Abdelkrim; Ferhat, Mohamed Amine; Saidi, Fairouz; Mekarnia, Maamar

2013-01-01

Background Since the available anti-inflammatory drugs exert an extensive variety of side effects, the search for new anti-inflammatory agents has been a priority of pharmaceutical industries. Aims The aim of the present study was to assess the anti-inflammatory activities of the essential oil of rose geranium (RGEO). Methods The chemical composition of the RGEO was investigated by gas chromatography. The major components were citronellol (29.13%), geraniol (12.62%), and citronellyl formate (8.06%). In the carrageenan-induced paw edema, five different groups were established and RGEO was administered orally in three different doses. Results RGEO (100 mg/kg) was able to significantly reduce the paw edema with a comparable effect to that observed with diclofenac, the positive control. In addition, RGEO showed a potent anti-inflammatory activity by topical treatment in the method of croton oil-induced ear edema. When the dose was 5 or 10 µl of RGEO per ear, the inflammation was reduced by 73 and 88%, respectively. This is the first report to demonstrate a significant anti-inflammatory activity of Algerian RGEO. In addition, histological analysis confirmed that RGEO inhibited the inflammatory responses in the skin. Conclusion Our results indicate that RGEO may have significant potential for the development of novel anti-inflammatory drugs with improved safety profile. PMID:24103319

Fragrance allergens in 'specific' cosmetic products.

PubMed

Nardelli, Andrea; Drieghe, Jacques; Claes, Lieve; Boey, Lies; Goossens, An

2011-04-01

Together with preservative agents, fragrance components are the most important sensitizing culprits in cosmetic products. To identify the nature of the fragrance ingredients responsible for allergic contact dermatitis (ACD) from specific cosmetic products. Between 2000 and 2009, positive patch test reactions or positive usage tests with the patients' own cosmetic products, were recorded using a standardised form. Of the 806 cosmetic records, corresponding to 485 patient files, 344 concerned reactions to fragrance ingredients that according to the label were present ('Presence Confirmed' [PC n = 301]) or suspected to be present ('Presence Not Confirmed' [PNC n = 376]) in the causal cosmetic products used, which belonged to 15 different categories, toilet waters/fine perfumes being the most frequent. Geraniol in fragrance mix I (FM I) and hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC) in FM II were the most frequent PC, and together with hydroxycitronellal and Evernia prunastri (oak moss) the most frequent PNC ingredients in the causal cosmetic products. Limonene was the most frequent PC confirmed fragrance allergen. This study not only underlines the usefulness of fragrance-ingredient labelling in order to identify the causal allergen(s) present in specific cosmetic products, but may also provide information on trends in the actual use of sensitizing fragrance ingredients in them. © 2011 John Wiley & Sons A/S.

Chemical stability and in chemico reactivity of 24 fragrance ingredients of concern for skin sensitization risk assessment.

PubMed

Avonto, Cristina; Wang, Mei; Chittiboyina, Amar G; Vukmanovic, Stanislav; Khan, Ikhlas A

2018-02-01

Twenty-four pure fragrance ingredients have been identified as potential concern for skin sensitization. Several of these compounds are chemically unstable and convert into reactive species upon exposure to air or light. In the present work, a systematic investigation of the correlation between chemical stability and reactivity has been undertaken. The compounds were subjected to forced photodegradation for three months and the chemical changes were studied with GC-MS. At the end of the stability study, two-thirds of the samples were found to be unstable. The generation of chemically reactive species was investigated using the in chemico HTS-DCYA assay. Eleven and fourteen compounds were chemically reactive before and after three months, respectively. A significant increase in reactivity upon degradation was found for isoeugenol, linalool, limonene, lyral, citronellol and geraniol; in the same conditions, the reactivity of hydroxycitronellal decreased. The non-reactive compounds α-isomethyl ionone, benzyl alcohol, amyl cinnamal and farnesol became reactive after photo-oxidative degradation. Overall, forced degradation resulted in four non-reactive fragrance compounds to display in chemico thiol reactivity, while ten out of 24 compounds remained inactive. Chemical degradation does not necessarily occur with generation of reactive species. Non-chemical activation may be involved for the 10 stable unreactive compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fragrance ingredient labelling in products on sale in the U.K.

PubMed

Buckley, D A

2007-08-01

The seventh amendment of the European Union (EU) Cosmetics Directive (March 2005) and the Detergents Regulations of the EU (October 2005) are now legal requirements in Europe. Cosmetic products and detergents must be labelled for 26 individual named fragrances, when present at concentrations of > 10 parts per million (p.p.m.) in leave-on products and > 100 p.p.m. in rinse-off products. To make an assessment of the exposure pattern to fragrance of the U.K. consumer and to determine the frequency with which the constituent fragrances of fragrance mix I (FM I) and fragrance mix II (FM II) are included in products currently sold in the U.K. A study of perfumed cosmetic and household products available on the shelves of U.K. retailers was carried out in January 2006. Products were included if 'parfum' or 'aroma' was listed among the ingredients. Three hundred products were surveyed and any of the 26 listed fragrances named on the label were recorded. The top six most frequently labelled fragrances were linalool (190; 63%), limonene (189; 63%), citronellol (145; 48%), geraniol (126; 42%), butyl phenyl methyl propional (Lilial(trade mark)) (126; 42%) and hexyl cinnamal (125; (42%). One of these, geraniol, is present in FM I and two others, citronellol and hexyl cinnamal, in FM II, thus tested as part of the British Standard patch test series. The frequencies of other constituents of FM I were as follows: eugenol, 80 (27%); hydroxycitronellal, 52 (17%); isoeugenol, 27 (9%); cinnamic alcohol, 25 (8%); amyl cinnamal, 22 (7%); cinnamal, 17 (6%); Evernia prunastri (oak moss absolute), 13 (4%). The other constituents of FM II occurred as follows: coumarin, 90 (30%); hydroxyisohexyl-3-cyclohexene carboxaldehyde (Lyral(trade mark)), 88 (29%); citral, 74 (25%); farnesol, 23 (8%). Linalool (n = 46; 66%) was the most frequently found fragrance in 70 personal care products (soap, shampoo, shower gel). Linalool (n = 47; 80%) and limonene (n = 45; 76%) were the most frequent in 59 products for men (e.g. aftershave). Limonene (n = 29; 51%) predominated in 57 household products (washing-up liquid, detergent). Limonene (n = 43; 98%) and linalool (n = 42; 95%) were the most frequent fragrances in 44 perfumes for women. Alpha-isomethyl ionone (n = 28; 72%) was the most frequent in 39 cosmetics (foundation, lipstick, etc). Citronellol predominated (n = 15; 88%) in 17 deodorants and limonene (n = 9; 64%) was the commonest in 14 dental products (toothpaste and mouthwash). Thirty-four products (11%) contained none of the listed fragrances but were labelled as containing 'parfum' or 'aroma'. There is ongoing consumer exposure to the most frequent sensitizers in FM I: E. prunastri, isoeugenol and the cinnamon fragrances cinnamal and cinnamic alcohol. Hydroxyisohexyl-3-cyclohexene carboxaldehyde (Lyral(trade mark)) is present at significant concentrations in almost one-third of products. Linalool and limonene, fragrance terpenes which are significant allergens in their oxidized state, are the most frequent fragrances encountered by individuals living in the U.K. The current exposure pattern of the U.K. consumer suggests that we should add oxidized limonene and oxidized linalool to the test series for patients suspected to have fragrance allergy.

Parameters for Novel Production of Fruity Floral Fragrance Ester (Geranyl Butyrate) by Locally Isolated Lipase Geobacillus thermodenitrificans nr68 (LGT)

NASA Astrophysics Data System (ADS)

Nik Raikhan, N. H.

2018-05-01

Geranyl butyrate has been synthesized successfully using our locally isolated lipase Geobacillus thermodenitrificans nr68 (LGT) as the fragrance ester with aim to be used in a nanotechnology fragrance application. We have used and modified few parameters from the previous research and then, continued with optimization of the synthesis by looking into degree of esterification and water content in the system. Butyric acid (C4), stearic acid (C18: 0), caprylic acid (C8), linolenic acid (C18: 3), myristic acid (C14), linoleic acid (C18: 2) and oleic acid (C18: 1) were used in the substrate selection. The yield of geranyl butyrate before the optimization was 31.68±0.01%. The optimum parameters for the synthesis of geranyl butyrate were recorded as temperature of 65°C, shaking rate at 200 rpm, 5.0 ml of geraniol and 0.40 ml of butyric acid and 4.0 ml of n-butanol and 0.40 ml of oleic acid. After the optimization, geranyl butyrate synthesis was increased by 297% as to compare with the value before the parameters were optimized. We also have significantly reduced water content as a byproduct of the esterification and managed to run the system a success. The ability thermotolerant lipase from Geobacillus thermodenitrificans (LGT) in this synthesis is novel to Malaysian fragrance industry.

Efficacy of an Essential Oil-Based Pesticide for Controlling Bed Bug (Cimex lectularius) Infestations in Apartment Buildings.

PubMed

Wang, Changlu; Singh, Narinderpal; Cooper, Richard

2014-11-05

Bed bugs (Cimex lectularius L. and Cimex hemipterus F.) are among the most difficult urban pests to manage. Many essential oil-based bed bug control products that are considered reduced risk to mammals compared to synthetic insect neurotoxins have become commercially available, but their effectiveness as a stand-alone control method is unknown. This study assessed the field efficacy of an essential oil-based bed bug control product (EcoRaider; a.i. 1% geraniol + 1% cedar oil + 2% sodium lauryl sulfate) compared to a pyrethroid and neonicotinoid mixture spray (0.075% Temprid SC; a.i. beta-cyfluthrin + imidacloprid). After 12 weeks, the three treatments-EcoRaider, Temprid SC, and EcoRaider + Temprid SC caused 92.5 ± 2.7, 92.9 ± 3.0, and 91.7% ± 2.7% bed bug count reduction, respectively. No significant differences existed in the bed bug reduction among the treatments. Bed bugs were eliminated from only 22% of the treated apartments. Among those still with bed bugs, 76% of the residents did not know bed bugs were present. We documented the residents' self-control practices and discussed the potential of using essential oil-based insecticides in bed bug management programs to minimize the health risks to building occupants and pets and to slow down the development of insecticide resistance.

Characterization of the Migration of Hop Volatiles into Different Crown Cork Liner Polymers and Can Coatings.

PubMed

Wietstock, Philip C; Glattfelder, Richard; Garbe, Leif-Alexander; Methner, Frank-Jürgen

2016-04-06

Absorption of hop volatiles by crown cork liner polymers and can coatings was investigated in beer during storage. All hop volatiles measured were prone to migrate into the closures, and the absorption kinetics was demonstrated to fit Fick's second law of diffusion well for a plane sheet. The extent and rate of diffusion were significantly dissimilar and were greatly dependent upon the nature of the volatile. Diffusion coefficients ranged from 1.32 × 10(-5) cm(2)/day (limonene) to 0.26 × 10(-5) cm(2)/day (α-humulene). The maximum amounts absorbed into the material at equilibrium were in the following order: limonene > α-humulene > trans-caryophyllene > myrcene ≫ linalool > α-terpineol > geraniol. With the application of low-density polyethylene (LDPE) liners with oxygen-scavenging functionality, oxygen-barrier liners made up from high-density polyethylene (HDPE) or liner polymers from a different manufacturer had no significant effect on the composition of hop volatiles in beers after prolonged storage of 55 days; however, significantly higher amounts of myrcene and limonene were found in the oxygen-barrier-type crown cork, while all other closures behaved similarly. Can coatings were demonstrated to absorb hop volatiles in a similar pattern as crown corks but to a lesser extent. Consequently, significantly higher percentages of myrcene were found in the beers.

Comparative study of anthocyanin and volatile compounds content of four varieties of Mexican roselle (Hibiscus sabdariffa L.) by multivariable analysis.

PubMed

Camelo-Méndez, G A; Ragazzo-Sánchez, J A; Jiménez-Aparicio, A R; Vanegas-Espinoza, P E; Paredes-López, O; Del Villar-Martínez, A A

2013-09-01

Anthocyanins are a group of water-soluble pigments that provide red, purple or blue color to the leaves, flowers, and fruits. In addition, benefits have been attributed to hypertension and cardiovascular diseases. This study compared the content of total anthocyanins and volatile compounds in aqueous and ethanolic extracts of four varieties of Mexican roselle, with different levels of pigmentation. The multivariable analysis of categorical data demonstrated that ethanol was the best solvent for the extraction of both anthocyanins and volatile compounds. The concentration of anthocyanin in pigmented varieties ranged from 17.3 to 32.2 mg of cyanidin 3-glucoside/g dry weight, while volatile compounds analysis showed that geraniol was the main compound in extracts from the four varieties. The principal component analysis (PCA) allowed description of results with 77.38% of variance establishing a clear grouping for each variety in addition to similarities among some of these varieties. These results were validated by the confusion matrix obtained in the classification by the factorial discriminate analysis (FDA); it can be useful for roselle varieties classification. Small differences in anthocyanin and volatile compounds content could be detected, and it may be of interest for the food industry in order to classify a new individual into one of several groups using different variables at once.

Efficacy of an Essential Oil-Based Pesticide for Controlling Bed Bug (Cimex lectularius) Infestations in Apartment Buildings

PubMed Central

Wang, Changlu; Singh, Narinderpal; Cooper, Richard

2014-01-01

Bed bugs (Cimex lectularius L. and Cimex hemipterus F.) are among the most difficult urban pests to manage. Many essential oil-based bed bug control products that are considered reduced risk to mammals compared to synthetic insect neurotoxins have become commercially available, but their effectiveness as a stand-alone control method is unknown. This study assessed the field efficacy of an essential oil-based bed bug control product (EcoRaider; a.i. 1% geraniol + 1% cedar oil + 2% sodium lauryl sulfate) compared to a pyrethroid and neonicotinoid mixture spray (0.075% Temprid SC; a.i. beta-cyfluthrin + imidacloprid). After 12 weeks, the three treatments—EcoRaider, Temprid SC, and EcoRaider + Temprid SC caused 92.5 ± 2.7, 92.9 ± 3.0, and 91.7% ± 2.7% bed bug count reduction, respectively. No significant differences existed in the bed bug reduction among the treatments. Bed bugs were eliminated from only 22% of the treated apartments. Among those still with bed bugs, 76% of the residents did not know bed bugs were present. We documented the residents’ self-control practices and discussed the potential of using essential oil-based insecticides in bed bug management programs to minimize the health risks to building occupants and pets and to slow down the development of insecticide resistance. PMID:26462944

Comparative study of submerged and surface culture acetification process for orange vinegar.

PubMed

Cejudo-Bastante, Cristina; Durán-Guerrero, Enrique; García-Barroso, Carmelo; Castro-Mejías, Remedios

2018-02-01

The two main acetification methodologies generally employed in the production of vinegar (surface and submerged cultures) were studied and compared for the production of orange vinegar. Polyphenols (UPLC/DAD) and volatiles compounds (SBSE-GC/MS) were considered as the main variables in the comparative study. Sensory characteristics of the obtained vinegars were also evaluated. Seventeen polyphenols and 24 volatile compounds were determined in the samples during both acetification processes. For phenolic compounds, analysis of variance showed significant higher concentrations when surface culture acetification was employed. However, for the majority of volatile compounds higher contents were observed for submerged culture acetification process, and it was also reflected in the sensory analysis, presenting higher scores for the different descriptors. Multivariate statistical analysis such as principal component analysis demonstrated the possibility of discriminating the samples regarding the type of acetification process. Polyphenols such as apigenin derivative or ferulic acid and volatile compounds such as 4-vinylguaiacol, decanoic acid, nootkatone, trans-geraniol, β-citronellol or α-terpineol, among others, were those compounds that contributed more to the discrimination of the samples. The acetification process employed in the production of orange vinegar has been demonstrated to be very significant for the final characteristics of the vinegar obtained. So it must be carefully controlled to obtain high quality products. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Simultaneous determination of 76 micropollutants in water samples by headspace solid phase microextraction and gas chromatography-mass spectrometry.

PubMed

Martínez, C; Ramírez, N; Gómez, V; Pocurull, E; Borrull, F

2013-11-15

This study focuses on the development of an analytical method based on headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) for the simultaneous determination of 76 micropollutants in water samples. The selected micropollutants include volatile organic compounds (VOCs) (e.g. chlorobenzenes, chloroalkanes), endocrine disrupting compounds (EDCs) (e.g. bisphenol A and tributyl phosphate), odour compounds (e.g. limonene, phenol), fragrance allergens (e.g. geraniol, eugenol) and some pesticides (e.g. heptachlor, terbutryn). The experimental conditions affecting their extraction, such as the type of fibre, temperature and time of extraction, sample volume and ionic strength of the samples were optimized using HS-SPME. The method showed good linear range, reproducibility between days, repeatability and low detection limits (at ng L(-1) levels). The validated method has been applied to determine the target organic micropollutants in aqueous samples from different experimental research units of surface water, sea water, waste water and those effluents of advance membrane treatments. The optimized method showed good performance in the different types of samples studied. The analysis revealed the presence of several micropollutants at concentrations between 20 and 5000 μg L(-1), such as ethylbenzene, o-xylene, p-isopropilbenzene, D-limonene, citral and isoeugenol, due to the fact that these species are commonly used in domestic and industrial applications. © 2013 Elsevier B.V. All rights reserved.

Essential oil biosynthesis and regulation in the genus Cymbopogon.

PubMed

Ganjewala, Deepak; Luthra, Rajesh

2010-01-01

Essential oils distilled from Cymbopogon species are of immense commercial value as flavors and fragrances in the perfumery, cosmetics, soaps, and detergents and in pharmaceutical industries. Two major constituents of the essential oil, geraniol and citral, due to their specific rose and lemon like aromas are widely used as flavors, fragrances and cosmetics. Citral is also used for the synthesis of vitamin A and ionones (for example, beta-ionone, methyl ionone). Moreover, Cymbopogon essential oils and constituents possess many useful biological activities including cytotoxic, anti-inflammatory and antioxidant. Despite the immense commercial and biological significance of the Cymbopogon essential oils, little is known about their biosynthesis and regulatory mechanisms. So far it is known that essential oils are biosynthesized via the classical acetate-MVA route and existence of a newly discovered MEP pathway in Cymbopogon remains as a topic for investigation. The aim of the present review is to discuss the biosynthesis and regulation of essential oils in the genus Cymbopogon with given emphasis to two elite members, lemongrass (C. flexuosus Nees ex Steud) and palmarosa (C. martinii Roxb.). This article highlights the work done so far towards understanding of essential oil biosynthesis and regulation in the genus Cymbopogon. Also, based on our experiences with Cymbopogon species, we would like to propose C. flexuosus as a model system for the study of essential oil metabolism beyond the much studied plant family Lamiaceae.

Doping of three-dimensional porous carbon nanotube-graphene-ionic liquid composite into polyaniline for the headspace solid-phase microextraction and gas chromatography determination of alcohols.

PubMed

Li, Lulu; Wu, Mian; Feng, Yingying; Zhao, Faqiong; Zeng, Baizhao

2016-12-15

In this work, ionic liquid (IL, i.e. 1-hydroxyethyl-3-methylimidazolium tetrafluoroborate), carboxyl multiwall carbon nanotubes (MWCNTs) and reduced graphene oxide (rGO) were used to prepare three-dimensional porous material (MWCNTs-rGO-IL) by one-step self-assembly, then it was co-electrodeposited with polyaniline (PANI) on stainless steel wires by cyclic voltammetry. The resulting coating (PANI-MWCNTs-rGO-IL) was characterized by using FT-IR and scanning electron microscopy etc, and it showed porous structure and had high thermal stability. Furthermore, it was found to be very suitable for the headspace solid-phase microextraction of alcohols (i.e. octanol, nonanol, geraniol, decanol, undecanol and dodecanol). By coupling with gas chromatography, wide linear ranges and low limits of detection (i.e. 2.2-28.3 ng L -1 ) were obtained for the alcohols. The coating also presented good repeatability and reproducibility; the relative standard deviations for intra-fiber and fiber-to-fiber were less than 5.6% (n = 5) and 7.0% (n = 5) respectively. In addition, the proposed method was successfully applied to the determination of alcohols in tea drinks, and the recoveries for standards added were 85.6-114%. Copyright © 2016 Elsevier B.V. All rights reserved.

Estimation of Theaflavins (TF) and Thearubigins (TR) Ratio in Black Tea Liquor Using Electronic Vision System

NASA Astrophysics Data System (ADS)

Akuli, Amitava; Pal, Abhra; Ghosh, Arunangshu; Bhattacharyya, Nabarun; Bandhopadhyya, Rajib; Tamuly, Pradip; Gogoi, Nagen

2011-09-01

Quality of black tea is generally assessed using organoleptic tests by professional tea tasters. They determine the quality of black tea based on its appearance (in dry condition and during liquor formation), aroma and taste. Variation in the above parameters is actually contributed by a number of chemical compounds like, Theaflavins (TF), Thearubigins (TR), Caffeine, Linalool, Geraniol etc. Among the above, TF and TR are the most important chemical compounds, which actually contribute to the formation of taste, colour and brightness in tea liquor. Estimation of TF and TR in black tea is generally done using a spectrophotometer instrument. But, the analysis technique undergoes a rigorous and time consuming effort for sample preparation; also the operation of costly spectrophotometer requires expert manpower. To overcome above problems an Electronic Vision System based on digital image processing technique has been developed. The system is faster, low cost, repeatable and can estimate the amount of TF and TR ratio for black tea liquor with accuracy. The data analysis is done using Principal Component Analysis (PCA), Multiple Linear Regression (MLR) and Multiple Discriminate Analysis (MDA). A correlation has been established between colour of tea liquor images and TF, TR ratio. This paper describes the newly developed E-Vision system, experimental methods, data analysis algorithms and finally, the performance of the E-Vision System as compared to the results of traditional spectrophotometer.

Social signals and aversive learning in honey bee drones and workers

PubMed Central

Pérez, Eddie; Vallejo, Lianna; Pérez, María E.; Abramson, Charles I.; Giray, Tugrul

2017-01-01

ABSTRACT The dissemination of information is a basic element of group cohesion. In honey bees (Apis mellifera Linnaeus 1758), like in other social insects, the principal method for colony-wide information exchange is communication via pheromones. This medium of communication allows multiple individuals to conduct tasks critical to colony survival. Social signaling also establishes conflict at the level of the individual who must trade-off between attending to the immediate environment or the social demand. In this study we examined this conflict by challenging highly social worker honey bees, and less social male drone honey bees undergoing aversive training by presenting them with a social stress signal (isopentyl acetate, IPA). We utilized IPA exposure methods that caused lower learning performance in appetitive learning in workers. Exposure to isopentyl acetate (IPA) did not affect performance of drones and had a dose-specific effect on worker response, with positive effects diminishing at higher IPA doses. The IPA effects are specific because non-social cues, such as the odor cineole, improve learning performance in drones, and social homing signals (geraniol) did not have a discernible effect on drone or worker performance. We conclude that social signals do generate conflict and that response to them is dependent on signal relevance to the individual as well as the context. We discuss the effect of social signal on learning both related to its social role and potential evolutionary history. PMID:27895050

Lipase-catalyzed production of short-chain acids terpenyl esters of interest to the food industry.

PubMed

Laboret, F; Perraud, R

1999-12-01

The production of low molecular weight esters as flavor compounds by biotechnological processes has a potential interest for the food industry. The use of natural available substrates and enzymes is an essential part of the process design, because the products may obtain natural label. In this study, direct esterification of citronellol and geraniol with short-chain fatty acids catalyzed by free lipase from Mucor miehei was performed with high yields in n-hexane. The effects of the acid:alcohol ratio on the bioconversion rate of increasing chain length esters was investigated. To reach the optimum yield, substrates and enzyme concentration were determined. The inhibiting effects of acid are strongly attenuated by reducing the quantity of acid and increasing the amount of enzyme in media following the optimum values. Improvements have been made to increase the ester purity. The consumption of excess substrate by adding calculated amounts of acid gives a 10% yield enhancement, and leads to 100% pure terpenyl esters. The first steps to a scale-up application were attempted using a reactor that allowed us to produce ester quantities up to 100 cm3. Separation and purification of the products were treated with success, underlining the lipase stability and efficiency under the conditions of this study. The ability to recover the enzyme, and reusing it in bioconversions, plays a major role in reducing the cost of the overall process.

Fungal endophytes of Catharanthus roseus enhance vindoline content by modulating structural and regulatory genes related to terpenoid indole alkaloid biosynthesis

PubMed Central

Pandey, Shiv S.; Singh, Sucheta; Babu, C. S. Vivek; Shanker, Karuna; Srivastava, N. K.; Shukla, Ashutosh K.; Kalra, Alok

2016-01-01

Not much is known about the mechanism of endophyte-mediated induction of secondary metabolite production in Catharanthus roseus. In the present study two fungal endophytes, Curvularia sp. CATDLF5 and Choanephora infundibulifera CATDLF6 were isolated from the leaves of the plant that were found to enhance vindoline content by 229–403%. The isolated endophytes did not affect the primary metabolism of the plant as the maximum quantum efficiency of PSII, net CO2 assimilation, plant biomass and starch content of endophyte-inoculated plants was similar to endophyte-free control plants. Expression of terpenoid indole alkaloid (TIA) pathway genes, geraniol 10-hydroxylase (G10H), tryptophan decarboxylase (TDC), strictosidine synthase (STR), 16-hydoxytabersonine-O-methyltransferase (16OMT), desacetoxyvindoline-4-hydroxylase (D4H), deacetylvindoline-4-O-acetyltransferase (DAT) were upregulated in endophyte-inoculated plants. Endophyte inoculation upregulated the expression of the gene for transcriptional activator octadecanoid-responsive Catharanthus AP2-domain protein (ORCA3) and downregulated the expression of Cys2/His2-type zinc finger protein family transcriptional repressors (ZCTs). The gene for the vacuolar class III peroxidase (PRX1), responsible for coupling vindoline and catharanthine, was upregulated in endophyte-inoculated plants. These endophytes may enhance vindoline production by modulating the expression of key structural and regulatory genes of vindoline biosynthesis without affecting the primary metabolism of the host plant. PMID:27220774

Effect of Methanolic Leaf Extract of Ocimum basilicum L. on Benzene-Induced Hematotoxicity in Mice

PubMed Central

Saha, S.; Mukhopadhyay, M. K.; Ghosh, P. D.; Nath, D.

2012-01-01

The aim of the present study was to investigate the protective role of methanolic leaf extract of Ocimum basilicum L. against benzene-induced hematotoxicity in Swiss albino mice. GC analysis and subacute toxicity level of the extract were tested. Mice were randomly divided into three groups among which II and III were exposed to benzene vapour at a dose 300 ppm × 6 hr/day × 5 days/week for 2 weeks and group I was control. Group III of this experiment was treated with the leaf methanolic extract at a dose of 100 mg/kg body weight, a dose in nontoxic range. Hematological parameters (Hb%, RBC and WBC counts), cell cycle regulatory proteins expression and DNA fragmentation analysis of bone marrow cells was performed. There was an upregulation of p53 and p21 and downregulation of levels of CDK2, CDK4, CDK6, and cyclins D1 and E in leaf extract-treated group. DNA was less fragmented in group III compared to group II (P < 0.05). The present study indicates that the secondary metabolites of O. basilicum L. methanolic leaf extract, comprising essential oil monoterpene geraniol and its oxidized form citral as major constituents, have modulatory effect in cell cycle deregulation and hematological abnormalities induced by benzene in mice. PMID:22988471

Antigenotoxic Effect Against Ultraviolet Radiation-induced DNA Damage of the Essential Oils from Lippia Species.

PubMed

Quintero Ruiz, Nathalia; Córdoba Campo, Yuri; Stashenko, Elena E; Fuentes, Jorge Luis

2017-07-01

The antigenotoxicity against ultraviolet radiation (UV)-induced DNA damage of essential oils (EO) from Lippia species was studied using SOS Chromotest. Based on the minimum concentration that significantly inhibits genotoxicity, the genoprotective potential of EO from highest to lowest was Lippia graveolens, thymol-RC ≈ Lippia origanoides, carvacrol-RC ≈ L. origanoides, thymol-RC > Lippia alba, citral-RC ≈ Lippia citriodora, citral-RC ≈ Lippia micromera, thymol-RC > L. alba, myrcenone-RC. EO from L. alba, carvone/limonene-RC, L. origanoides, α-phellandrene-RC and L. dulcis, trans-β-caryophyllene-RC did not reduce the UV genotoxicity at any of the doses tested. A gas chromatography with flame ionization detection analysis (GC-FID) was conducted to evaluate the solubility of the major EO constituents under our experimental conditions. GC-FID analysis showed that, at least partially, major EO constituents were water-soluble and therefore, they were related with the antigenotoxicity detected for EO. Constituents such as p-cymene, geraniol, carvacrol, thymol, citral and 1,8-cineole showed antigenotoxicity. The antioxidant activity of EO constituents was also determined using the oxygen radical antioxidant capacity (ORAC) assay. The results showed that the antigenotoxicity of the EO constituents was unconnected with their antioxidant activity. The antigenotoxicity to different constituent binary mixtures suggests that synergistic effects can occur in some of the studied EO. © 2017 The American Society of Photobiology.

Essential oil from Ocimum basilicum (Omani Basil): a desert crop.

PubMed

Al-Maskri, Ahmed Yahya; Hanif, Muhammad Asif; Al-Maskari, Masoud Yahya; Abraham, Alfie Susan; Al-sabahi, Jamal Nasser; Al-Mantheri, Omar

2011-10-01

The focus of the present study was on the influence of season on yield, chemical composition, antioxidant and antifungal activities of Omani basil (Ocimum basilicum) oil. The present study involved only one of the eight Omani basil varieties. The hydro-distilled essential oil yields were computed to be 0.1%, 0.3% and 0.1% in the winter, spring and summer seasons, respectively. The major components identified were L- linalool (26.5-56.3%), geraniol (12.1-16.5%), 1,8-cineole (2.5-15.1%), p-allylanisole (0.2-13.8%) and DL-limonene (0.2-10.4%). A noteworthy extra component was beta- farnesene, which was exclusively detected in the oil extracted during winter and spring at 6.3% and 5.8%, respectively. The essential oil composition over the different seasons was quite idiosyncratic, in which the principal components of one season were either trivial or totally absent in another. The essential oil extracted in spring exhibited the highest antioxidant activity (except DPPH scavenging ability) in comparison with the oils from other seasons. The basil oil was tested against pathogenic fungi viz. Aspergillus niger, A. fumigatus, Penicillium italicum and Rhizopus stolonifer using a disc diffusion method, and by determination of minimum inhibitory concentration. Surprisingly high antifungal values were found highlighting the potential of Omani basil as a preservative in the food and medical industries.

Multicentre study of fragrance allergy in Hungary. Immediate and late type reactions.

PubMed

Temesvári, Erzsébet; Németh, Ilona; Baló-Banga, Mátyás J; Husz, Sándor; Kohánka, Valéria; Somos, Zsuzsa; Judák, Rita; Remenyik, E V A; Szegedi, Andrea; Nebenführer, László; Mészáros, Csilla; Horváth, Attila

2002-06-01

The authors followed the frequency of fragrance contact sensitization in Hungary in a multicentre study in the years 1998 and 1999. A total of 3,604 patients were tested with fragrance mix (FM), and positive reactions were observed in 294 (8.2%). In 160 FM hypersensitive patients, the study was continued with patch testing of the mix constituents (cinnamic alcohol, cinnamic aldehyde, eugenol, amyl cinnamic aldehyde, hydroxycitronellal, geraniol, isoeugenol, oak moss absolute). Of the patients tested, 70.6% produced positive reactions to the constituents. FM contact sensitization was mainly observed in female patients (74.4%). The incidence of contact urticaria in FM hypersensitive patients was 6.1%. Simultaneous patch test trials of other environmental contact allergens, in both early and late evaluations, mainly confirmed hypersensitivity reactions to balsams. Female dominance of hypersensitivity reactions observed during testing the individual components of the mix was striking (82.4%). In positive skin reactions, cinnamic alcohol, isoeugenol and oak moss provoked skin symptoms most frequently. We also tested the 104 patients who produced negative reactions to FM with the constituent individual allergens, with 11.9% positive incidence. The clinical symptoms of the patients were above all manifest in the form of contact eczema, located on the hands, face, eyelids and axillae. With this study, the authors, members of the Hungarian Contact Dermatitis Research Group, call attention to one of the most frequent allergens in the environment.

Preparation, Characterization, and Pharmacological Activity of Cymbopogon winterianus Jowitt ex Bor (Poaceae) Leaf Essential Oil of β-Cyclodextrin Inclusion Complexes

PubMed Central

Santos, Priscila L.; Araújo, Adriano A. S.; Quintans, Jullyana S. S.; Oliveira, Makson G. B.; Brito, Renan G.; Serafini, Mairim R.; Menezes, Paula P.; Santos, Marcio R. V.; Alves, Pericles B.; de Lucca Júnior, Waldecy; Blank, Arie F.; La Rocca, Viviana; Almeida, Reinaldo N.; Quintans-Júnior, Lucindo J.

2015-01-01

This study aimed to evaluate the orofacial antinociceptive effect of the Cymbopogon winterianus essential oil (LEO) complexed in β-cyclodextrin (LEO-CD) and to assess the possible involvement of the central nervous system (CNS). The LEO was extracted, chromatographed, and complexed in β-cyclodextrin. The complex was characterized by differential scanning calorimetry (DSC) and thermogravimetry derivative (TG/DTG). Male Swiss mice (2-3 months) were treated with LEO-CD (50–200 mg/kg, p.o.), vehicle (distilled water, p.o.), or standard drug (i.p.) and subjected to the orofacial nociception formalin-, capsaicin-, and glutamate-induced. After the formalin test, the animals were perfused and the brains subjected to immunofluorescence for Fos. The rota-rod test (7 rpm/min) was carried out. Geraniol (37.57%) was the main compound of LEO. DSC and TG/DTG proved the complexation. The orofacial nociceptive behavior was significantly (p < 0.05) reduced. The number of Fos-positive cells was significantly changed in the dorsal raphe nucleus (p < 0.01), locus coeruleus (p < 0.001), trigeminal nucleus (p < 0.05), and trigeminal thalamic tract (p < 0.05). LEO-CD did not cause changes in motor coordination in the rota-rod test. Thus, our results suggested that LEO-CD has an orofacial antinociceptive profile, probably mediated by the activation of the CNS without changing the motor coordination. PMID:26246838

Hydrodistillation extraction time effect on essential oil yield, composition, and bioactivity of coriander oil.

PubMed

Zheljazkov, Valtcho D; Astatkie, Tess; Schlegel, Vicki

2014-01-01

Coriander (Coriandrum sativum L.) is a major essential oil crop grown throughout the world. Coriander essential oil is extracted from coriander fruits via hydrodistillation, with the industry using 180-240 min of distillation time (DT), but the optimum DT for maximizing essential oil yield, composition of constituents, and antioxidant activities are not known. This research was conducted to determine the effect of DT on coriander oil yield, composition, and bioactivity. The results show that essential oil yield at the shorter DT was low and generally increased with increasing DT with the maximum yields achieved at DT between 40 and 160 min. The concentrations of the low-boiling point essential oil constituents: α-pinene, camphene, β-pinene, myrcene, para-cymene, limonene, and γ-terpinene were higher at shorter DT (< 2.5 min) and decreased with increasing DT; but the trend reversed for the high-boiling point constituents: geraniol and geranyl-acetate. The concentration of the major essential oil constituent, linalool, was 51% at DT 1.15 min, and increased steadily to 68% with increasing DT. In conclusion, 40 min DT is sufficient to maximize yield of essential oil; and different DT can be used to obtain essential oil with differential composition. Its antioxidant capacity was affected by the DT, with 20 and 240 min DT showing higher antioxidant activity. Comparisons of coriander essential oil composition must consider the length of the DT.

Weed control in rose-scented geranium (Pelargonium spp).

PubMed

Kothari, Sushil K; Singh, Chandra P; Singh, Kamla

2002-12-01

Abstract: Field investigations were carried out during 1999 and 2000 to identify effective chemical/ cultural methods of weed control in rose-scented geranium (Pelargonium spp). The treatments comprised pre-emergence applications of oxyfluorfen (0.15, 0.20 and 0.25 kg AI ha(-1)) and pendimethalin (0.50, 0.75 and 1.00kg AI ha(-1)), successive hand weeding, hoeing and mulching using spent of lemon grass (at 5 tonnes ha(-1)) 45 days after planting (DAP), three hand-weedings 30, 60 and 90 DAP, weed-free (frequent manual weeding) and weedy control. Broad-leaf weeds were more predominant than grass and sedge weeds, accounting for 85.8% weed density and 93.0% weed dry weight in 1999 and 77.2% weed density and 93.9% weed dry weight in 2000. Unrestricted weed growth significantly reduced geranium oil yield, by 61.6% and 70.6% in 1999 and 2000, respectively. Pre-emergence application of pendimethalin (0.75-1.00 kgAI ha(-1)) or oxyfluorfen (0.25 kg AI ha(-1)), successive hand-weeding, hoeing and mulching and three hand-weedings were highly effective in reducing weed density and dry weight and gave oil yield comparable to the weed-free check. Application of oxyfluorfen (0.15 or 0.20 kg AI ha(-1)) and pendimethalin (0.50 kg AI ha(-1)) were less effective in controlling the weed species in geranium. None of the herbicides impaired the quality of rose-scented geranium oil measured in terms of citronellol and geraniol content.

Potential of Essential Oil-Based Pesticides and Detergents for Bed Bug Control.

PubMed

Singh, Narinderpal; Wang, Changlu; Cooper, Richard

2014-12-01

The bed bug, (Cimex lectularius L.), is a difficult pest to control. Prevalence of insecticide resistance among bed bug populations and concerns over human-insecticide exposure has stimulated the development of alternative bed bug control materials. Many essential oil-based pesticides and detergent insecticides targeting bed bugs have been developed in recent years. We evaluated the efficacy of nine essential oil-based products and two detergents using direct spray and residual contact bioassays in the laboratory. Two conventional insecticides, Temprid SC (imidacloprid and β-cyfluthrin) and Demand CS (λ-cyhalothrin), were used for comparison. Among the 11 nonsynthetic insecticides tested, only EcoRaider (1% geraniol, 1% cedar extract, and 2% sodium lauryl sulfate) and Bed Bug Patrol (0.003% clove oil, 1% peppermint oil, and 1.3% sodium lauryl sulfate) caused >90% mortality of nymphs in direct spray and forced exposure residual assays. However, the efficacy of EcoRaider and Bed Bug Patrol was significantly lower than that of Temprid SC and Demand CS in choice exposure residual bioassay. Direct spray of EcoRaider caused 87% egg mortality, whereas the other nonsynthetic insecticides had little effect on bed bug eggs. EcoRaider and Bed Bug Patrol did not exhibit detectable repellency against bed bugs in the presence of a carbon dioxide source. These findings suggest that EcoRaider and Bed Bug Patrol are potentially useful pesticides for controlling bed bug infestations, but further testing in naturally infested environments is needed. © 2014 Entomological Society of America.

Phytochemical, antioxidant and antibacterial properties of Melissa officinalis and Dracocephalum moldavica essential oils.

PubMed

Ehsani, Ali; Alizadeh, Omar; Hashemi, Mohammad; Afshari, Asma; Aminzare, Majid

2017-01-01

Aromatic plants are rich in essential oils with considerable antimicrobial properties. The aim of this study was to investigate chemical composition, antimicrobial activity and antioxidant properties of Melissa officinalis and Deracocephalum moldavica essential oils (EOs). The identification of chemical constituents of the EOs was carried out using gas chromato-graphy-mass spectrometry analysis and antimicrobial activity of the EOs was evaluated by disc diffusion assay as well as determination of minimal inhibitory concentration (MIC) and minimal bactericidal concentration against four important food-borne bacteria: Salmonella typhimorium, Escherichia coli, Listeria monocytogenes and Staphylococcus aureus . Antioxidant activity of the EOs was also determined by 2,2-diphenyl-1-picrylhydrazyl, 2,2-azinobis 3-ethylbenzo thiazoline-6-sulfonic acid and β-carotene bleaching tests. The major compounds of D. moldavica were geranial (28.52%), neral (21.21%), geraniol (19.60%), geranyl acetate (16.72%) and the major compounds of M. officinalis EO were citronellal (37.33%), thymol (11.96%), citral (10.10%) and β-caryophyllene (7.27%). The underlying results indicated strong antimicrobial effects of the oils against tested bacteria. Staphylococcus aureus with the lowest MIC value (0.12 mg mL -1 ) for both EOs was the most sensitive bacterium, although, antibacterial effect of M. officinalis EO was stronger than D. moldavica . In addition, the results of the antioxidant activity showed that both EOs had notable antioxidant properties. In conclusion, both EOs are appropriate alternatives as potential sources of natural preservative agents with the aim of being applied in food industries.

Chemical characterization (GC/MS and NMR Fingerprinting) and bioactivities of South-African Pelargonium capitatum (L.) L' Her. (Geraniaceae) essential oil.

PubMed

Guerrini, Alessandra; Rossi, Damiano; Paganetto, Guglielmo; Tognolini, Massimiliano; Muzzoli, Mariavittoria; Romagnoli, Carlo; Antognoni, Fabiana; Vertuani, Silvia; Medici, Alessandro; Bruni, Alessandro; Useli, Chiara; Tamburini, Elena; Bruni, Renato; Sacchetti, Gianni

2011-04-01

Chemical fingerprinting of commercial Pelargonium capitatum (Geraniaceae) essential oil samples of south African origin was performed by GC, GC/MS, and (13) C- and (1) H-NMR. Thirty-seven compounds were identified, among which citronellol (32.71%) and geraniol (19.58%) were the most abundant. NMR Spectra of characteristic chemicals were provided. Broad-spectrum bioactivity properties of the oil were evaluated and compared with those of commercial Thymus vulgaris essential oil with the aim to obtain a functional profile in terms of efficacy and safety. P. capitatum essential oil provides a good performance as antimicrobial, with particular efficacy against Candida albicans strains. Antifungal activity performed against dermatophyte and phytopathogen strains revealed the latter as more sensitive, while antibacterial activity was not remarkable against both Gram-positive and Gram-negative bacteria. P. capitatum oil provided a lower antioxidant activity (IC(50) ) than that expressed by thyme essential oil, both in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and β-carotene bleaching tests. Results in photochemiluminescence (PCL) assay were negligible. To test the safety aspects of P. capitatum essential oil, mutagenic and toxicity properties were assayed by Ames test, with and without metabolic activation. Possible efficacy of P. capitatum essential oil as mutagenic protective agent against NaN(3) , 2-nitrofluorene, and 2-aminoanthracene was also assayed, providing interesting and significant antigenotoxic properties. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich.

Essential-oil composition of Daucus carota ssp. major (Pastinocello Carrot) and nine different commercial varieties of Daucus carota ssp. sativus fruits.

PubMed

Flamini, Guido; Cosimi, Elena; Cioni, Pier Luigi; Molfetta, Ilaria; Braca, Alessandra

2014-07-01

The chemical composition of the essential oils obtained by hydrodistillation from the pastinocello carrot, Daucus carota ssp. major (Vis.) Arcang. (flowers and achenes), and from nine different commercial varieties of D. carota L. ssp. sativus (achenes) was investigated by GC/MS analyses. Selective breeding over centuries of a naturally occurring subspecies of the wild carrot, D. carota L. ssp. sativus, has produced the common garden vegetable with reduced bitterness, increased sweetness, and minimized woody core. On the other hand, the cultivation of the pastinocello carrot has been abandoned, even if, recently, there has been renewed interest in the development of this species, which risks genetic erosion. The cultivated carrot (D. carota ssp. sativus) and the pastinocello carrot (D. carota ssp. major) were classified as different subspecies of the same species. This close relationship between the two subspecies urged us to compare the chemical composition of their essential oils, to evaluate the differences. The main essential-oil constituents isolated from the pastinocello fruits were geranyl acetate (34.2%), α-pinene (12.9%), geraniol (6.9%), myrcene (4.7%), epi-α-bisabolol (4.5%), sabinene (3.3%), and limonene (3.0%). The fruit essential oils of the nine commercial varieties of D. carota ssp. sativus were very different from that of pastinocello, as also confirmed by multivariate statistical analyses. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

Social signals and aversive learning in honey bee drones and workers.

PubMed

Avalos, Arian; Pérez, Eddie; Vallejo, Lianna; Pérez, María E; Abramson, Charles I; Giray, Tugrul

2017-01-15

The dissemination of information is a basic element of group cohesion. In honey bees (Apis mellifera Linnaeus 1758), like in other social insects, the principal method for colony-wide information exchange is communication via pheromones. This medium of communication allows multiple individuals to conduct tasks critical to colony survival. Social signaling also establishes conflict at the level of the individual who must trade-off between attending to the immediate environment or the social demand. In this study we examined this conflict by challenging highly social worker honey bees, and less social male drone honey bees undergoing aversive training by presenting them with a social stress signal (isopentyl acetate, IPA). We utilized IPA exposure methods that caused lower learning performance in appetitive learning in workers. Exposure to isopentyl acetate (IPA) did not affect performance of drones and had a dose-specific effect on worker response, with positive effects diminishing at higher IPA doses. The IPA effects are specific because non-social cues, such as the odor cineole, improve learning performance in drones, and social homing signals (geraniol) did not have a discernible effect on drone or worker performance. We conclude that social signals do generate conflict and that response to them is dependent on signal relevance to the individual as well as the context. We discuss the effect of social signal on learning both related to its social role and potential evolutionary history. © 2017. Published by The Company of Biologists Ltd.

Repellents and acaricides as personal protection measures in the prevention of tick-borne diseases.

PubMed

Cisak, Ewa; Wójcik-Fatla, Angelina; Zając, Violetta; Dutkiewicz, Jacek

2012-01-01

A number of preventive measures for the protection of humans against tick-borne diseases were evaluated. Measures involving the avoidance of tick bites with the use of protective clothing and insect repellents are the simplest and most effective. Repellents are applied directly to the skin or clothing and other fabrics, such as bednets, tents and anti-mosquito screens. Currently, DEET (N,N-diethyl-m-toluamide) is considered the most efficient arthropod repellent reference substance. The registered and recommended active repellent ingredients for skin and/or cloths application, among others, are: DEET, 1-methyl-propyl-2- (hydroxyethyl)-1-piperidinecarboxylate (picaridin), p-menthane-3,8-diol (PMD), ethyl butylactyloaminopropionate ( IR3535), 1S,2S-2-methylpiperidinyl-3-cyclohexene-1-carboxamide (SS220), racemic 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (AI3-37220) and synthethic pyrethroid - 3-phenoxybenzyl-cis-trans-3(2,2 dichlorovinyl)-2,2-dimethylcyclopropancarboxylate (permethrin) - an acaricide with repellent properties. To achieve the protection from tick bites by avoiding attachment and/or engorgement by the arthropod, acaricides with repellent properties, such as synthetic pyrethroid-permethrin are used. This pyrethroid is an acaricide of choice used for clothing impregnation, which is effective for personal protection against all three parasitic stages of western black-legged ticks. Products based on natural compounds, e.g. eugenol from Ocimum basilicum, 2-undecanone originally derived from wild tomato, geraniol - a natural product extracted from plants, and many others, represent an interesting alternative to common synthetic repellents and/or acaricides.

Influence of extraction methodologies on the analysis of five major volatile aromatic compounds of citronella grass (Cymbopogon nardus) and lemongrass (Cymbopogon citratus) grown in Thailand.

PubMed

Chanthai, Saksit; Prachakoll, Sujitra; Ruangviriyachai, Chalerm; Luthria, Devanand L

2012-01-01

This paper deals with the systematic comparison of extraction of major volatile aromatic compounds (VACs) of citronella grass and lemongrass by classical microhydrodistillation (MHD), as well as modern accelerated solvent extraction (ASE). Sixteen VACs were identified by GC/MS. GC-flame ionization detection was used for the quantification of five VACs (citronellal, citronellol, geraniol, citral, and eugenol) to compare the extraction efficiency of the two different methods. Linear range, LOD, and LOQ were calculated for the five VACs. Intraday and interday precisions for the analysis of VACs were determined for each sample. The extraction recovery, as calculated by a spiking experiment with known standards of VACs, by ASE and MHD ranged from 64.9 to 91.2% and 74.3 to 95.2%, respectively. The extraction efficiency of the VACs was compared for three solvents of varying polarities (hexane, dichloromethane, and methanol), seven different temperatures (ranging from 40 to 160 degrees C, with a gradual increment of 20 degrees C), five time periods (from 1 to 10 min), and three cycles (1, 2, and 3 repeated extractions). Optimum extraction yields of VACs were obtained when extractions were carried out for 7 min with dichloromethane and two extraction cycles at 120 degrees C. The results showed that the ASE technique is more efficient than MHD, as it results in improved yields and significant reduction in extraction time with automated extraction capabilities.

Deodorants on the European market: quantitative chemical analysis of 21 fragrances.

PubMed

Rastogi, S C; Johansen, J D; Frosch, P; Menné, T; Bruze, M; Lepoittevin, J P; Dreier, B; Andersen, K E; White, I R

1998-01-01

Deodorants are one of the most frequently used types of cosmetics and side-effects from them are common. Recent studies relate perfume allergy to this type of product. 73 deodorants were analyzed by gas chromatography--mass spectrometry for the determination of the contents of 7 wellknown fragrance allergens from the fragrance mix and 14 other commonly used fragrance materials. The deodorants were purchased at retail outlets in 5 European countries. It was found that in general, fragrance mix ingredients were more frequently present in vapo- and aerosol sprays than in roll-on products. The levels of the fragrance mix substances ranged from 0.0001-0.2355%. The products investigated contained cinnamic aldehyde and isoeugenol less frequently (17% and 29% respectively), and eugenol and geraniol most frequently (57% and 76% respectively). The 14 other fragrance materials were found in 40-97% of the deodorants, with hedione and benzyl acetate the most frequently found substances. The concentration of these 14 substances ranged from 0.0001-2.7%. It is concluded that the levels of cinnamic aldehyde and isoeugenol found in the deodorants could prove to be relevant for elicitation of contact dermatitis. No conclusions could be drawn about the other fragrance mix constituents, as threshold levels in sensitized individuals have not been investigated. Furthermore, all of the fragrance materials investigated were frequently found in deodorants and, apart from the fragrance mix ingredients, the extent of problems with sensitization to these fragrance materials is largely unknown.

Development of a headspace-solid phase micro extraction method to monitor changes in volatile profile of rose (Rosa hybrida, cv David Austin) petals during processing.

PubMed

Bianchi, Giulia; Nuzzi, Monica; Avitabile Leva, Alexa; Rizzolo, Anna

2007-05-25

In the present study, headspace solid phase microextraction combined to capillary gas chromatography (HS-SPME-GC) has been applied for the determination of changes in the volatile profile of rose petals (Rosa hybrida, cvs David Austin) following processing (heat treatment and addition as an ingredient to a food product--for example yoghurt). Four SPME fibres at two sampling temperatures (40 and 60 degrees C) with a sampling time of 30 min were examined. Volatile profiles were detected either by FID or/and by olfactometry (ODP-II, Gerstel). Fibre testing was performed using raw rose petals for sampling temperature selection and an 18 characteristic rose volatile standard mixture in water was used to compare fibre performances at the sampling temperature of 60 degrees C. Polydimethylsiloxane-divinylbenzene (PDMS-DVB) fibre at the sampling temperature of 60 degrees C was the most suitable to sample the rose alcohols phenyl ethanol, citronellol, nerol, geraniol and eugenol, as assessed by GC-olfactometry, not only from raw petals, but also from processed rose petals and the food product. PDMS-DVB fibre also showed a desired low affinity to volatiles from yoghurt, which reduces the influence of food matrix on the volatile profile. The method was linear over two orders of magnitude and had satisfactory repeatability, with limits of detection for the rose alcohols ranging from <1 to 10 ng/ml concentration levels.

Overproduction of isoprenoids by Saccharomyces cerevisiae in a synthetic grape juice medium in the absence of plant genes.

PubMed

Camesasca, L; Minteguiaga, M; Fariña, L; Salzman, V; Aguilar, P S; Gaggero, C; Carrau, F

2018-06-06

The objective of this work is to demonstrate if the hexaprenyl pyrophosphate synthetase Coq1p might be involved in monoterpenes synthesis in Saccharomyces cerevisiae, although its currently known function in yeast is to catalyze the first step in ubiquinone biosynthesis. However, in a BY4743 laboratory strain, the presence of an empty plasmid in a chemically defined grape juice medium results in a statistically significant increase of linalool, (E)-nerolidol and (E,E)-farnesol. When COQ1 is overexpressed from a plasmid, the levels of the volatile isoprenoids are further increased. Furthermore, overexpression of COQ1 in the same genetic context but with a mutated farnesyl pyrophosphate synthetase (erg20 mutation K197E), results in statistically significant higher levels of linalool (above 750 μg/L), geraniol, α-terpineol, and the sesquiterpenes, farnesol and nerolidol (total concentration of volatile isoprenoids surpasses 1300 μg/L). We show that the levels of monoterpenes and sesquiterpenes that S. cerevisiae can produce, in the absence of plant genes, depend on the composition of the medium and the genetic context. To the best of our knowledge, this is the highest level of linalool produced by S. cerevisiae up to now. Further research will be needed for understanding how COQ1 and the medium composition might interact to increase flavor complexity of fermented beverages. Copyright © 2018. Published by Elsevier B.V.

Introgression of Swertia mussotii gene into Bupleurum scorzonerifolium via somatic hybridization

PubMed Central

2011-01-01

Background The wild herb Swertia mussotii is a source of the anti-hepatitis compounds swertiamarin, mangiferin and gentiopicroside. Its over-exploitation has raised the priority of producing these compounds heterologously. Somatic hybridization represents a novel approach for introgressing Swertia mussotii genes into a less endangered species. Results Protoplasts derived from calli of Bupleurum scorzonerifolium and S. mussotii were fused to produce 194 putative hybrid cell lines, of which three (all derived from fusions where the S. mussotii protoplasts were pre-treated for 30 s with UV light) later differentiated into green plants. The hybridity of the calli was confirmed by a combination of isozyme, RAPD and chromosomal analysis. The hybrid calli genomes were predominantly B. scorzonerifolium. GISH analysis of mitotic chromosomes confirmed that the irradiation of donor protoplasts increased the frequency of chromosome elimination and fragmentation. RFLP analysis of organellar DNA revealed that mitochondrial and chloroplast DNA of both parents coexisted and recombined in some hybrid cell lines. Some of the hybrid calli contained SmG10H from donor, and produced swertiamarin, mangiferin and certain volatile compounds characteristic of S. mussotii. The expression of SmG10H (geraniol 10-hydroxylase) was associated with the heterologous accumulation of swertiamarin. Conclusions Somatic hybrids between B. scorzonerifolium and S. mussotii were obtained, hybrids selected all contained introgressed nuclear and cytoplasmic DNA from S. mussotii; and some produced more mangiferin than the donor itself. The introgression of SmG10H was necessary for the accumulation of swertiamarin. PMID:21513581

Citral and carvone chemotypes from the essential oils of Colombian Lippia alba (Mill.) N.E. Brown: composition, cytotoxicity and antifungal activity.

PubMed

Mesa-Arango, Ana Cecilia; Montiel-Ramos, Jehidys; Zapata, Bibiana; Durán, Camilo; Betancur-Galvis, Liliana; Stashenko, Elena

2009-09-01

Two essential oils of Lippia alba (Mill.) N.E. Brown (Verbenacea), the carvone and citral chemotypes and 15 of their compounds were evaluated to determine cytotoxicity and antifungal activity. Cytotoxicity assays for both the citral and carvone chemotypes were carried out with tetrazolium-dye, which showed a dose-dependent cytotoxic effect against HeLa cells. Interestingly, this effect on the evaluated cells (HeLa and the non-tumoural cell line, Vero) was lower than that of commercial citral alone. Commercial citral showed the highest cytotoxic activity on HeLa cells. The antifungal activity was evaluated against Candida parapsilosis, Candida krusei, Aspergillus flavus and Aspergillus fumigatus strains following the standard protocols, Antifungal Susceptibility Testing Subcommittee of the European Committee on Antibiotic Susceptibility Testing and CLSI M38-A. Results demonstrated that the most active essential oil was the citral chemotype, with geometric means-minimal inhibitory concentration (GM-MIC) values of 78.7 and 270.8 microg/mL for A. fumigatus and C. krusei, respectively. Commercial citral showed an antifungal activity similar to that of the citral chemotype (GM-MIC values of 62.5 microg/mL for A. fumigatus and 39.7 microg/mL for C. krusei). Although the citronellal and geraniol were found in lower concentrations in the citral chemotype, they had significant antifungal activity, with GM-MIC values of 49.6 microg/mL for C. krusei and 176.8 microg/mL for A. fumigatus.

High-performance liquid chromatographic method for the simultaneous determination of 24 fragrance allergens to study scented products.

PubMed

Villa, C; Gambaro, R; Mariani, E; Dorato, S

2007-07-27

The European legislation on cosmetic products has recently required the declaration of 26 compounds (24 volatile chemicals and 2 natural extracts) on the label of final products when exceeding a stipulated cut-off level. In this work a rapid reliable and specific RP-HPLC method coupled with diode array detector (DAD) has been developed for the simultaneous determination and quantification of the 24 volatile chemicals: amyl cinnamal, benzyl alcohol, cinnamyl alcohol, citral, eugenol, hydroxy-citronellal, isoeugenol, amylcinnamyl alcohol, benzyl salicylate, cinnamal, coumarin, geraniol, Lyral (hydroxy-methylpentylcyclohexene carboxaldehyde), anisyl alcohol, benzyl cinnamate, farnesol, Lilial (2-(4-tert-butylbenzyl)propionaldehyde) linalool, benzyl benzoate, citronellol, hexyl cinnamal, limonene, methylheptin carbonate, alpha-isomethyl ionone (3-methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one). The 24 analytes were appropriately separated over a running time of 40 min, on a C18 column using a simple gradient elution (acetonitrile/water) with flow rate from 0.7 to 1.0 ml/min and UV acquisition at 210, 254 and 280 nm. All calibration curves showed good linearity (r2>0.99) within test ranges. The method was successfully applied to the qualitative and quantitative determination of the potential allergens in four commercial scented products, with satisfactory accuracy and precision. The results indicated that this simple and efficient method can be used for quality assessment of complex matrices such us cosmetic scented products.

Characterization of Two Distinct Glycosyl Hydrolase Family 78 α-l-Rhamnosidases from Pediococcus acidilactici▿†

PubMed Central

Michlmayr, Herbert; Brandes, Walter; Eder, Reinhard; Schümann, Christina; del Hierro, Andrés M.; Kulbe, Klaus D.

2011-01-01

α-l-Rhamnosidases play an important role in the hydrolysis of glycosylated aroma compounds (especially terpenes) from wine. Although several authors have demonstrated the enological importance of fungal rhamnosidases, the information on bacterial enzymes in this context is still limited. In order to fill this important gap, two putative rhamnosidase genes (ram and ram2) from Pediococcus acidilactici DSM 20284 were heterologously expressed, and the respective gene products were characterized. In combination with a bacterial β-glucosidase, both enzymes released the monoterpenes linalool and cis-linalool oxide from a muscat wine extract under ideal conditions. Additionally, Ram could release significant amounts of geraniol and citronellol/nerol. Nevertheless, the potential enological value of these enzymes is limited by the strong negative effects of acidity and ethanol on the activities of Ram and Ram2. Therefore, a direct application in winemaking seems unlikely. Although both enzymes are members of the same glycosyl hydrolase family (GH 78), our results clearly suggest the distinct functionalities of Ram and Ram2, probably representing two subclasses within GH 78: Ram could efficiently hydrolyze only the synthetic substrate p-nitrophenyl-α-l-rhamnopyranoside (Vmax = 243 U mg−1). In contrast, Ram2 displayed considerable specificity toward hesperidin (Vmax = 34 U mg−1) and, especially, rutinose (Vmax = 1,200 U mg−1), a disaccharide composed of glucose and rhamnose. Both enzymes were unable to hydrolyze the flavanone glycoside naringin. Interestingly, both enzymes displayed indications of positive substrate cooperativity. This study presents detailed kinetic data on two novel rhamnosidases, which could be relevant for the further study of bacterial glycosidases. PMID:21784921

Isolation of cDNAs and functional characterisation of two multi-product terpene synthase enzymes from sandalwood, Santalum album L.

PubMed

Jones, Christopher G; Keeling, Christopher I; Ghisalberti, Emilio L; Barbour, Elizabeth L; Plummer, Julie A; Bohlmann, Jörg

2008-09-01

Sandalwood, Santalum album (Santalaceae) is a small hemi-parasitic tropical tree of great economic value. Sandalwood timber contains resins and essential oils, particularly the santalols, santalenes and dozens of other minor sesquiterpenoids. These sesquiterpenoids provide the unique sandalwood fragrance. The research described in this paper set out to identify genes involved in essential oil biosynthesis, particularly terpene synthases (TPS) in S. album, with the long-term aim of better understanding heartwood oil production. Degenerate TPS primers amplified two genomic TPS fragments from S. album, one of which enabled the isolation of two TPS cDNAs, SamonoTPS1 (1731bp) and SasesquiTPS1 (1680bp). Both translated protein sequences shared highest similarity with known TPS from grapevine (Vitis vinifera). Heterologous expression in Escherichia coli produced catalytically active proteins. SamonoTPS1 was identified as a monoterpene synthase which produced a mixture of (+)-alpha-terpineol and (-)-limonene, along with small quantities of linalool, myrcene, (-)-alpha-pinene, (+)-sabinene and geraniol when assayed with geranyl diphosphate. Sesquiterpene synthase SasesquiTPS1 produced the monocyclic sesquiterpene alcohol germacrene D-4-ol and helminthogermacrene, when incubated with farnesyl diphosphate. Also present were alpha-bulnesene, gamma-muurolene, alpha- and beta-selinenes, as well as several other minor bicyclic compounds. Although these sesquiterpenes are present in only minute quantities in the distilled sandalwood oil, the genes and their encoded enzymes described here represent the first TPS isolated and characterised from a member of the Santalaceae plant family and they may enable the future discovery of additional TPS genes in sandalwood.

Activity of essential oils and individual components against acetyl- and butyrylcholinesterase.

PubMed

Orhan, Ilkay; Kartal, Murat; Kan, Yüksel; Sener, Bilge

2008-01-01

We have tested acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of nineteen essential oils obtained from cultivated plants, namely one from Anethum graveolens L. (organic fertilizer), two from Foeniculum vulgare Mill. collected at fully-mature and flowering stages (organic fertilizer), two from Melissa officinalis L. (cultivated using organic and chemical fertilizers), two from Mentha piperita L. and M. spicata L. (organic fertilizer), two from Lavandula officinalis Chaix ex Villars (cultivated using organic and chemical fertilizers), two from Ocimum basilicum L. (green and purple-leaf varieties cultivated using only organic fertilizer), four from Origanum onites L., O. vulgare L., O. munitiflorum Hausskn., and O. majorana L. (cultivated using organic fertilizer), two from Salvia sclarea L. (organic and chemical fertilizers), one from S. officinalis L. (organic fertilizer), and one from Satureja cuneifolia Ten. (organic fertilizer) by a spectrophotometric method of Ellman using ELISA microplate-reader at 1 mg/ml concentration. In addition, a number of single components widely encountered in most of the essential oils [gamma-terpinene, 4-allyl anisole, (-)-carvone, dihydrocarvone, (-)-phencone, cuminyl alcohol, cumol, 4-isopropyl benzaldehyde, trans-anethole, camphene, iso-borneol, (-)-borneol, L-bornyl acetate, 2-decanol, 2-heptanol, methyl-heptanol, farnesol, nerol, iso-pulegol, 1,8-cineole, citral, citronellal, citronellol, geraniol, linalool, alpha-pinene, beta-pinene, piperitone, iso-menthone, menthofurane, linalyl oxide, linalyl ester, geranyl ester, carvacrol, thymol, menthol, vanilline, and eugenol] was also screened for the same activity in the same manner. Almost all of the essential oils showed a very high inhibitory activity (over 80%) against both enzymes, whereas the single components were not as active as the essential oils.

Extracting the Behaviorally Relevant Stimulus: Unique Neural Representation of Farnesol, a Component of the Recruitment Pheromone of Bombus terrestris

PubMed Central

Strube-Bloss, Martin F.; Brown, Austin; Spaethe, Johannes; Schmitt, Thomas; Rössler, Wolfgang

2015-01-01

To trigger innate behavior, sensory neural networks are pre-tuned to extract biologically relevant stimuli. Many male-female or insect-plant interactions depend on this phenomenon. Especially communication among individuals within social groups depends on innate behaviors. One example is the efficient recruitment of nest mates by successful bumblebee foragers. Returning foragers release a recruitment pheromone in the nest while they perform a ‘dance’ behavior to activate unemployed nest mates. A major component of this pheromone is the sesquiterpenoid farnesol. How farnesol is processed and perceived by the olfactory system, has not yet been identified. It is much likely that processing farnesol involves an innate mechanism for the extraction of relevant information to trigger a fast and reliable behavioral response. To test this hypothesis, we used population response analyses of 100 antennal lobe (AL) neurons recorded in alive bumblebee workers under repeated stimulation with four behaviorally different, but chemically related odorants (geraniol, citronellol, citronellal and farnesol). The analysis identified a unique neural representation of the recruitment pheromone component compared to the other odorants that are predominantly emitted by flowers. The farnesol induced population activity in the AL allowed a reliable separation of farnesol from all other chemically related odor stimuli we tested. We conclude that the farnesol induced population activity may reflect a predetermined representation within the AL-neural network allowing efficient and fast extraction of a behaviorally relevant stimulus. Furthermore, the results show that population response analyses of multiple single AL-units may provide a powerful tool to identify distinct representations of behaviorally relevant odors. PMID:26340263

The SOS Chromotest applied for screening plant antigenotoxic agents against ultraviolet radiation.

PubMed

Fuentes, J L; García Forero, A; Quintero Ruiz, N; Prada Medina, C A; Rey Castellanos, N; Franco Niño, D A; Contreras García, D A; Córdoba Campo, Y; Stashenko, E E

2017-09-13

In this work, we investigated the usefulness of the SOS Chromotest for screening plant antigenotoxic agents against ultraviolet radiation (UV). Fifty Colombian plant extracts obtained by supercritical fluid (CO 2 ) extraction, twelve plant extract constituents (apigenin, carvacrol, β-caryophyllene, 1,8-cineole, citral, p-cymene, geraniol, naringenin, pinocembrin, quercetin, squalene, and thymol) and five standard antioxidant and/or photoprotective agents (curcumin, epigallocatechin gallate, resveratrol, α-tocopherol, and Trolox®) were evaluated for their genotoxicity and antigenotoxicity against UV using the SOS Chromotest. None of the plant extracts, constituents or agents were genotoxic in the SOS Chromotest at tested concentrations. Based on the minimal extract concentration that significantly inhibited UV-genotoxicity (CIG), five plant extracts were antigenotoxic against UV as follows: Baccharis nítida (16 μg mL -1 ) = Solanum crotonifolium (16 μg mL -1 ) > Hyptis suaveolens (31 μg mL -1 ) = Persea caerulea (31 μg mL -1 ) > Lippia origanoides (62 μg mL -1 ). Based on CIG values, the flavonoid compounds showed the highest antigenotoxic potential as follows: apigenin (7 μM) > pinocembrin (15 μM) > quercetin (26 μM) > naringenin (38 μM) > epigallocatechin gallate (108 μM) > resveratrol (642 μM). UV-genotoxicity inhibition with epigallocatechin gallate, naringenin and resveratrol was related to its capability for inhibiting protein synthesis. A correlation analysis between compound antigenotoxicity estimates and antioxidant activity evaluated by the oxygen radical absorbance capacity (ORAC) assay showed that these activities were not related. The usefulness of the SOS Chromotest for bioprospecting of plant antigenotoxic agents against UV was discussed.

Ceropegia sandersonii Mimics Attacked Honeybees to Attract Kleptoparasitic Flies for Pollination.

PubMed

Heiduk, Annemarie; Brake, Irina; von Tschirnhaus, Michael; Göhl, Matthias; Jürgens, Andreas; Johnson, Steven D; Meve, Ulrich; Dötterl, Stefan

2016-10-24

Four to six percent of plants, distributed over different angiosperm families, entice pollinators by deception [1]. In these systems, chemical mimicry is often used as an efficient way to exploit the olfactory preferences of animals for the purpose of attracting them as pollinators [2,3]. Here, we report a very specific type of chemical mimicry of a food source. Ceropegia sandersonii (Apocynaceae), a deceptive South African plant with pitfall flowers, mimics attacked honeybees. We identified kleptoparasitic Desmometopa flies (Milichiidae) as the main pollinators of C. sandersonii. These flies are well known to feed on honeybees that are eaten by spiders, which we thus predicted as the model chemically mimicked by the plant. Indeed, we found that the floral scent of C. sandersonii is comparable to volatiles released from honeybees when under simulated attack. Moreover, many of these shared compounds elicited physiological responses in antennae of pollinating Desmometopa flies. A mixture of four compounds-geraniol, 2-heptanone, 2-nonanol, and (E)-2-octen-1-yl acetate-was highly attractive to the flies. We conclude that C. sandersonii is specialized on kleptoparasitic fly pollinators by deploying volatiles linked to the flies' food source, i.e., attacked and/or freshly killed honeybees. The blend of compounds emitted by C. sandersonii is unusual among flowering plants and lures kleptoparasitic flies into the trap flowers. This study describes a new example of how a plant can achieve pollination through chemical mimicry of the food sources of adult carnivorous animals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Phytochemical, antioxidant and antibacterial properties of Melissa officinalis and Dracocephalum moldavica essential oils

PubMed Central

Ehsani, Ali; Alizadeh, Omar; Hashemi, Mohammad; Afshari, Asma; Aminzare, Majid

2017-01-01

Aromatic plants are rich in essential oils with considerable antimicrobial properties. The aim of this study was to investigate chemical composition, antimicrobial activity and antioxidant properties of Melissa officinalis and Deracocephalum moldavica essential oils (EOs). The identification of chemical constituents of the EOs was carried out using gas chromato-graphy-mass spectrometry analysis and antimicrobial activity of the EOs was evaluated by disc diffusion assay as well as determination of minimal inhibitory concentration (MIC) and minimal bactericidal concentration against four important food-borne bacteria: Salmonella typhimorium, Escherichia coli, Listeria monocytogenes and Staphylococcus aureus. Antioxidant activity of the EOs was also determined by 2,2-diphenyl-1-picrylhydrazyl, 2,2-azinobis 3-ethylbenzo thiazoline-6-sulfonic acid and β-carotene bleaching tests. The major compounds of D. moldavica were geranial (28.52%), neral (21.21%), geraniol (19.60%), geranyl acetate (16.72%) and the major compounds of M. officinalis EO were citronellal (37.33%), thymol (11.96%), citral (10.10%) and β-caryophyllene (7.27%). The underlying results indicated strong antimicrobial effects of the oils against tested bacteria. Staphylococcus aureus with the lowest MIC value (0.12 mg mL-1) for both EOs was the most sensitive bacterium, although, antibacterial effect of M. officinalis EO was stronger than D. moldavica. In addition, the results of the antioxidant activity showed that both EOs had notable antioxidant properties. In conclusion, both EOs are appropriate alternatives as potential sources of natural preservative agents with the aim of being applied in food industries. PMID:29085610

Chemical composition, anthelmintic, antibacterial and antioxidant effects of Thymus bovei essential oil.

PubMed

Jaradat, Nidal; Adwan, Lina; K'aibni, Shadi; Shraim, Naser; Zaid, Abdel Naser

2016-10-26

It has been recently recognized that oxidative stress, helminth and microbial infections are the cause of much illness found in the underdeveloped, developing and developed countries. The present study was undertaken to identify the chemical composition, and to assess anthelmintic, antimicrobial and antioxidant effects of Thymus bovei essential oil. The chemical composition of the essential oil was analyzed using gas chromatography mass spectrometry (GC-MS). Antimicrobial activity was tested against the selected strains from American Type Culture Collection (ATCC) and clinical isolates such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Methicillin Resistant Staphylococcus aureus, Candida albicans using MIC assay. The anthelmintic assay was carried out on adult earthworm (Pheretima posthuma), while antioxidant activity was analyzed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. Trans-geraniol (35.38 %), α-citral (20.37 %) and β-citral (14.76 %) were the major compounds comprising 70.51 % of the essential oil. Our results showed that T. bovei essential oil exhibited strong anthelmintic activity, even higher than piperazine citrate, the used reference standard, with potential antioxidant activity almost equal to the Trolox standard. Furthermore, T. bovei essential oil had powerful antibacterial and antifungal activities against the studied pathogens. Essential oil of T. bovei exerted excellent antioxidant, antimicrobial, and anthelmintic activities. Moreover, this study found that T. bovei volatile oil contains active substances that could potentially be used as natural preservatives in food and pharmaceutical industries, these substances could also be employed for developing new anthelmintic, antimicrobial and antioxidant agents.

Fragrance contact allergy: a 4-year retrospective study.

PubMed

Cuesta, Laura; Silvestre, Juan Francisco; Toledo, Fernando; Lucas, Ana; Pérez-Crespo, María; Ballester, Irene

2010-08-01

Fragrance chemicals are the second most frequent cause of contact allergy. The mandatory labelling of 26 fragrance chemicals when present in cosmetics has facilitated management of patients allergic to fragrances. The study was aimed to define the characteristics of the population allergic to perfumes detected in our hospital district, to determine the usefulness of markers of fragrance allergy in the baseline GEIDAC series, and to describe the contribution made by the fragrance series to the data obtained with the baseline series. We performed a 4-year retrospective study of patients tested with the Spanish baseline series and/or fragrance series. There are four fragrance markers in the baseline series: fragrance mix I (FM I), Myroxylon pereirae, fragrance mix II (FM II), and hydroxyisohexyl 3-cyclohexene carboxaldehyde. A total of 1253 patients were patch tested, 117 (9.3%) of whom were positive to a fragrance marker. FM I and M. pereirae detected 92.5% of the cases of fragrance contact allergy. FM II and hydroxyisohexyl 3-cyclohexene carboxaldehyde detected 6 additional cases and provided further information in 8, enabling improved management. A fragrance series was tested in a selected group of 86 patients and positive results were obtained in 45.3%. Geraniol was the allergen most frequently found in the group of patients tested with the fragrance series. Classic markers detect the majority of cases of fragrance contact allergy. We recommend incorporating FM II in the Spanish baseline series, as in the European baseline series, and using a specific fragrance series to study patients allergic to a fragrance marker.

Sensitization to 26 fragrances to be labelled according to current European regulation. Results of the IVDK and review of the literature.

PubMed

Schnuch, Axel; Uter, Wolfgang; Geier, Johannes; Lessmann, Holger; Frosch, Peter J

2007-07-01

To study the frequency of sensitization to 26 fragrances to be labelled according to current European regulation. During 4 periods of 6 months, from 1 January 2003 to 31 December 2004, 26 fragrances were patch tested additionally to the standard series in a total of 21 325 patients; the number of patients tested with each of the fragrances ranged from 1658 to 4238. Hydroxymethylpentylcyclohexene carboxaldehyde (HMPCC) was tested throughout all periods. The following frequencies of sensitization (rates in %, standardized for sex and age) were observed: tree moss (2.4%), HMPCC (2.3), oak moss (2.0), hydroxycitronellal (1.3), isoeugenol (1.1), cinnamic aldehyde (1.0), farnesol (0.9), cinnamic alcohol (0.6), citral (0.6), citronellol (0.5), geraniol (0.4), eugenol (0.4), coumarin (0.4), lilial (0.3), amyl-cinnamic alcohol (0.3), benzyl cinnamate (0.3), benzyl alcohol (0.3), linalool (0.2), methylheptin carbonate (0.2), amyl-cinnamic aldehyde (0.1), hexyl-cinnamic aldehyde (0.1), limonene (0.1), benzyl salicylate (0.1), gamma-methylionon (0.1), benzyl benzoate (0.0), anisyl alcohol (0.0). 1) Substances with higher sensitization frequencies were characterized by a considerable number of '++/+++' reactions. 2) Substances with low sensitization frequencies were characterized by a high number of doubtful/irritant and a low number of stronger (++/+++) reactions. 3) There are obviously fragrances among the 26 which are, with regard to contact allergy, of great, others of minor, and some of no importance at all.

The Efficacy of Some Commercially Available Insect Repellents for Aedes aegypti (Diptera: Culicidae) and Aedes albopictus (Diptera: Culicidae)

PubMed Central

Rodriguez, Stacy D.; Drake, Lisa L.; Price, David P.; Hammond, John I.; Hansen, Immo A.

2015-01-01

Reducing the number of host-vector interactions is an effective way to reduce the spread of vector-borne diseases. Repellents are widely used to protect humans from a variety of protozoans, viruses, and nematodes. DEET (N,N-Diethyl-meta-toluamide), a safe and effective repellent, was developed during World War II. Fear of possible side effects of DEET has created a large market for “natural” DEET-free repellents with a variety of active ingredients. We present a comparative study on the efficacy of eight commercially available products, two fragrances, and a vitamin B patch. The products were tested using a human hand as attractant in a Y-tube olfactometer setup with Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse), both major human disease vectors. We found that Ae. albopictus were generally less attracted to the test subject’s hand compared with Ae, aegypti. Repellents with DEET as active ingredient had a prominent repellency effect over longer times and on both species. Repellents containing p-menthane-3,8-diol produced comparable results but for shorter time periods. Some of the DEET-free products containing citronella or geraniol did not have any significant repellency effect. Interestingly, the perfume we tested had a modest repellency effect early after application, and the vitamin B patch had no effect on either species. This study shows that the different active ingredients in commercially available mosquito repellent products are not equivalent in terms of duration and strength of repellency. Our results suggest that products containing DEET or p-menthane-3,8-diol have long-lasting repellent effects and therefore provide good protection from mosquito-borne diseases. PMID:26443777

The floral transcriptome of ylang ylang (Cananga odorata var. fruticosa) uncovers biosynthetic pathways for volatile organic compounds and a multifunctional and novel sesquiterpene synthase

PubMed Central

Jin, Jingjing; Kim, Mi Jung; Dhandapani, Savitha; Tjhang, Jessica Gambino; Yin, Jun-Lin; Wong, Limsoon; Sarojam, Rajani; Chua, Nam-Hai; Jang, In-Cheol

2015-01-01

The pleasant fragrance of ylang ylang varieties (Cananga odorata) is mainly due to volatile organic compounds (VOCs) produced by the flowers. Floral scents are a key factor in plant–insect interactions and are vital for successful pollination. C. odorata var. fruticosa, or dwarf ylang ylang, is a variety of ylang ylang that is popularly grown in Southeast Asia as a small shrub with aromatic flowers. Here, we describe the combined use of bioinformatics and chemical analysis to discover genes for the VOC biosynthesis pathways and related genes. The scented flowers of C. odorata var. fruticosa were analysed by gas chromatography/mass spectrometry and a total of 49 VOCs were identified at four different stages of flower development. The bulk of these VOCs were terpenes, mainly sesquiterpenes. To identify the various terpene synthases (TPSs) involved in the production of these essential oils, we performed RNA sequencing on mature flowers. From the RNA sequencing data, four full-length TPSs were functionally characterized. In vitro assays showed that two of these TPSs were mono-TPSs. CoTPS1 synthesized four products corresponding to β-thujene, sabinene, β-pinene, and α-terpinene from geranyl pyrophosphate and CoTPS4 produced geraniol from geranyl pyrophosphate. The other two TPSs were identified as sesqui-TPSs. CoTPS3 catalysed the conversion of farnesyl pyrophosphate to α-bergamotene, whereas CoTPS2 was found to be a multifunctional and novel TPS that could catalyse the synthesis of three sesquiterpenes, β-ylangene, β-copaene, and β-cubebene. Additionally, the activities of the two sesqui-TPSs were confirmed in planta by transient expression of these TPS genes in Nicotiana benthamiana leaves by Agrobacterium-mediated infiltration. PMID:25956881

Traditional herbal remedies and dietary spices from Cameroon as novel sources of larvicides against filariasis mosquitoes?

PubMed

Pavela, Roman; Maggi, Filippo; Mbuntcha, Hélène; Woguem, Verlaine; Fogang, Hervet Paulin Dongmo; Womeni, Hilaire Macaire; Tapondjou, Léon Azefack; Barboni, Luciano; Nicoletti, Marcello; Canale, Angelo; Benelli, Giovanni

2016-12-01

In Cameroon, many dietary spices are used by traditional healers to cure several diseases such as cancer and microbial infections. Aframomum daniellii, Dichrostachys cinerea and Echinops giganteus are Cameroonian spices widely used as flavourings and as food additives. Moreover, they are traditionally herbal remedies employed to treat several diseases, as well as to control populations of insect pests. In this research, we analysed the chemical composition of A. daniellii, D. cinerea and E. giganteus essential oils and we evaluated their larvicidal potential against larvae of the filariasis and West Nile virus vector Culex quinquefasciatus. The essential oils were obtained from different plant parts by hydrodistillation and their composition was analysed by GC-MS. The three spices exhibited different volatile chemical profiles, being characterized by 1,8-cineole, sabinene and β-pinene (A. daniellii), geraniol and terpinen-4-ol (D. cinerea), and silphiperfol-6-ene and presilphiperfolan-8-ol (E. giganteus). Results showed that the highest larvicidal toxicity on Cx. quinquefasciatus was exerted by D. cinerea essential oil (LC 50  = 39.1 μL L -1 ), followed by A. daniellii (pericarp essential oil: LC 50  = 65.5 μL L -1 ; leaves: LC 50  = 65.5μL L -1 ; seeds: LC 50  = 106.5μL L -1 ) and E. giganteus (LC 50  = 227.4 μL L -1 ). Overall, the chance to use the D. cinerea essential oil against Cx. quinquefasciatus young instars seems promising, since it is effective at moderate doses and could be an advantageous alternative to build newer mosquito control tools.

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.

Comparison of fortified, sfursat, and passito wines produced from fresh and dehydrated grapes of aromatic black cv. Moscato nero (Vitis vinifera L.).

PubMed

Ossola, Carolina; Giacosa, Simone; Torchio, Fabrizio; Río Segade, Susana; Caudana, Alberto; Cagnasso, Enzo; Gerbi, Vincenzo; Rolle, Luca

2017-08-01

Moscato nero d'Acqui is an Italian aromatic black winegrape variety characterized by a low content of anthocyanins (mostly tri-substituted), a satisfactory content of high molecular mass tannins, and a fair amount of terpenes. The grapes were subjected to a postharvest dehydration process under controlled thermohygrometric conditions (16-18°C, 55-70 RH%, 0.6m/s air speed) with the aim to produce three different special wine types (fortified, sfursat, and passito) from fresh, partially dehydrated (27°Brix), and withered (36°Brix) grapes, respectively. Chemical traits of produced grapes and wines were then evaluated through spectrophotometric, HPLC, and GC-MS methods. Increased contents of skin phenolic compounds and reduced extractable contents of seed phenolic compounds were observed as dehydration progressed. Few significant differences were found in the anthocyanin profile of grapes, although the relative abundance of coumaroylated anthocyanins was higher in dehydrated grapes. The predominant free volatile compound found in grapes was geraniol, which decreased with increasing water loss, whereas the contents of major glycosylated volatile compounds increased even above the concentration effect. The changes in the phenolic composition among wines agreed with those among grape skins. Fortified wines were chromatically unsatisfactory probably due to the low content of total anthocyanins, whereas sfursat and passito wines meet good chromatic characteristics as a result of the concentration effect during grape dehydration. Fortified and sfursat wines had free aroma profiles richer in 2-phenylethanol and citronellol, whereas passito wines were mainly composed of 2-phenylethanol and 2-phenylethyl acetate, citronellol being the predominant terpenol in all the wine types studied. Copyright © 2016 Elsevier Ltd. All rights reserved.

Functional effect of grapevine 1-deoxy-D-xylulose 5-phosphate synthase substitution K284N on Muscat flavour formation

PubMed Central

Battilana, Juri; Emanuelli, Francesco; Gambino, Giorgio; Gribaudo, Ivana; Gasperi, Flavia; Boss, Paul K.; Grando, Maria Stella

2011-01-01

Grape berries of Muscat cultivars (Vitis vinifera L.) contain high levels of monoterpenols and exhibit a distinct aroma related to this composition of volatiles. A structural gene of the plastidial methyl-erythritol-phosphate (MEP) pathway, 1-deoxy-D-xylulose 5-phosphate synthase (VvDXS), was recently suggested as a candidate gene for this trait, having been co-localized with a major quantitative trait locus for linalool, nerol, and geraniol concentrations in berries. In addition, a structured association study discovered a putative causal single nucleotide polymorphism (SNP) responsible for the substitution of a lysine with an asparagine at position 284 of the VvDXS protein, and this SNP was significantly associated with Muscat-flavoured varieties. The significance of this nucleotide difference was investigated by comparing the monoterpene profiles with the expression of VvDXS alleles throughout berry development in Moscato Bianco, a cultivar heterozygous for the SNP mutation. Although correlation was detected between the VvDXS transcript profile and the accumulation of free monoterpenol odorants, the modulation of VvDXS expression during berry development appears to be independent of nucleotide variation in the coding sequence. In order to assess how the non-synonymous mutation may enhance Muscat flavour, an in vitro characterization of enzyme isoforms was performed followed by in vivo overexpression of each VvDXS allele in tobacco. The results showed that the amino acid non-neutral substitution influences the enzyme kinetics by increasing the catalytic efficiency and also dramatically affects monoterpene levels in transgenic lines. These findings confirm a functional effect of the VvDXS gene polymorphism and may pave the way for metabolic engineering of terpenoid contents in grapevine. PMID:21868399

Protective antifungal activity of essential oils extracted from Buddleja perfoliata and Pelargonium graveolens against fungi isolated from stored grains.

PubMed

Juárez, Z N; Bach, H; Sánchez-Arreola, E; Bach, H; Hernández, L R

2016-05-01

The chemical composition and antifungal activity of essential oils extracted from Buddleja perfoliata and Pelargonium graveolens were analysed to assess their efficacy as a potential alternative to synthetic chemical fungicides to protect stored grain. Essential oils were obtained by hydrodistillation, while GC-MS were used to characterize the components of theses oils. The main components identified from the essential oil of B. perfoliata were cubenol, eudesmol, germacrene D-4-ol and cis-verbenol; whereas (-)-aristolene, β-citronellol and geraniol, were identified in P. graveolens. These essential oils were tested against a panel of fungal strains isolated from stored grains. Toxicity of the essential oils was assessed using two models represented by human-derived macrophages and the brine shrimp assay. Moreover, inflammatory response of the oils was assessed by measuring secretion of the pro-inflammatory cytokines IL-6 and TNF-α using a human-derived macrophage cell line. Results show potent antifungal activity against a collection of fungi, with minimal inhibitory concentrations ranging from 0·3 to 50 μg ml(-1) for both plants. A moderated cytotoxicity was observed, but no inflammatory responses. These oils can be used as an alternative for synthetic chemical fungicides used to protect stored grains. Synthetic chemical fungicides are used to protect stored grains, but their broad use raises concerns about effects on the environment and human health. The impact of the present report is that the use of essential oils is an eco-friendly alternative for fungal control in postharvest grains with a low impact to the environment. © 2016 The Society for Applied Microbiology.

Citral Sensing by TRANSient Receptor Potential Channels in Dorsal Root Ganglion Neurons

PubMed Central

Stotz, Stephanie C.; Vriens, Joris; Martyn, Derek; Clardy, Jon; Clapham, David E.

2008-01-01

Transient receptor potential (TRP) ion channels mediate key aspects of taste, smell, pain, temperature sensation, and pheromone detection. To deepen our understanding of TRP channel physiology, we require more diverse pharmacological tools. Citral, a bioactive component of lemongrass, is commonly used as a taste enhancer, as an odorant in perfumes, and as an insect repellent. Here we report that citral activates TRP channels found in sensory neurons (TRPV1 and TRPV3, TRPM8, and TRPA1), and produces long-lasting inhibition of TRPV1–3 and TRPM8, while transiently blocking TRPV4 and TRPA1. Sustained citral inhibition is independent of internal calcium concentration, but is state-dependent, developing only after TRP channel opening. Citral's actions as a partial agonist are not due to cysteine modification of the channels nor are they a consequence of citral's stereoisoforms. The isolated aldehyde and alcohol cis and trans enantiomers (neral, nerol, geranial, and geraniol) each reproduce citral's actions. In juvenile rat dorsal root ganglion neurons, prolonged citral inhibition of native TRPV1 channels enabled the separation of TRPV2 and TRPV3 currents. We find that TRPV2 and TRPV3 channels are present in a high proportion of these neurons (94% respond to 2-aminoethyldiphenyl borate), consistent with our immunolabeling experiments and previous in situ hybridization studies. The TRPV1 activation requires residues in transmembrane segments two through four of the voltage-sensor domain, a region previously implicated in capsaicin activation of TRPV1 and analogous menthol activation of TRPM8. Citral's broad spectrum and prolonged sensory inhibition may prove more useful than capsaicin for allodynia, itch, or other types of pain involving superficial sensory nerves and skin. PMID:18461159

Citral sensing by Transient [corrected] receptor potential channels in dorsal root ganglion neurons.

PubMed

Stotz, Stephanie C; Vriens, Joris; Martyn, Derek; Clardy, Jon; Clapham, David E

2008-05-07

Transient receptor potential (TRP) ion channels mediate key aspects of taste, smell, pain, temperature sensation, and pheromone detection. To deepen our understanding of TRP channel physiology, we require more diverse pharmacological tools. Citral, a bioactive component of lemongrass, is commonly used as a taste enhancer, as an odorant in perfumes, and as an insect repellent. Here we report that citral activates TRP channels found in sensory neurons (TRPV1 and TRPV3, TRPM8, and TRPA1), and produces long-lasting inhibition of TRPV1-3 and TRPM8, while transiently blocking TRPV4 and TRPA1. Sustained citral inhibition is independent of internal calcium concentration, but is state-dependent, developing only after TRP channel opening. Citral's actions as a partial agonist are not due to cysteine modification of the channels nor are they a consequence of citral's stereoisoforms. The isolated aldehyde and alcohol cis and trans enantiomers (neral, nerol, geranial, and geraniol) each reproduce citral's actions. In juvenile rat dorsal root ganglion neurons, prolonged citral inhibition of native TRPV1 channels enabled the separation of TRPV2 and TRPV3 currents. We find that TRPV2 and TRPV3 channels are present in a high proportion of these neurons (94% respond to 2-aminoethyldiphenyl borate), consistent with our immunolabeling experiments and previous in situ hybridization studies. The TRPV1 activation requires residues in transmembrane segments two through four of the voltage-sensor domain, a region previously implicated in capsaicin activation of TRPV1 and analogous menthol activation of TRPM8. Citral's broad spectrum and prolonged sensory inhibition may prove more useful than capsaicin for allodynia, itch, or other types of pain involving superficial sensory nerves and skin.

Comparison of antispasmodic effects of Dracocephalum kotschyi essential oil, limonene and α-terpineol.

PubMed

Sadraei, H; Asghari, G; Kasiri, F

2015-01-01

Dracocephalum kotschyi is an essential oil containing plant found in Iran. In Iranian traditional medicine, D. kotschyi has been used as antispasmodic and analgesic but so far there is no pharmacological report about its antispasmodic activity. Therefore, the objective of this research was to study antispasmodic activity of the essential oil of D. kotschyi and two of its constituents namely limonene and α-terpineol. The essential oil was obtained from aerial parts of D. kotschyi using hydrodistillation method. The main components found in the essential oil were α-pinene (10%), neral (11%), geraniol (10%), α-citral (12%), limonene (9%) and α-terpineol (1.1%). For antispasmodic studies, a portion of rat ileum was suspended under 1 g tension in Tyrode's solution at 37 °C and gassed with O2. Effect of the D. kotschyi essential oil, limonene and α-terpineol were studied on ileum contractions induced by KCl (80 mM), acetylcholine (ACh, 500 nM) and electrical field stimulation (EFS). The essential oil, in a concentration dependent manner inhibited the response to KCl (IC50=51 ± 8.7 nl/ml), ACh (IC50=19 ± 2.7 nl/ml) and EFS (IC50=15 ± 0.5 nl/ml). Limonene and α-terpineol showed same pattern of inhibitory effect on ileum contraction. Their inhibitory effects were also concentration dependent. However, limonene was more potent than the essential oil while the α-terpineol was less potent than either limonene or the essential oil. From this experiment it was concluded that D. kotschyi essential oil has inhibitory effect on ileum contractions. Limonene contribute a major role in inhibitory effect of the essential oil while α-terpineol has weak antispasmodic activity.

Inactivation of Staphylococcus aureus in Oat and Soya Drinks by Enterocin AS-48 in Combination with Other Antimicrobials.

PubMed

Burgos, María José Grande; Aguayo, M Carmen López; Pulido, Rubén Pérez; Gálvez, Antonio; López, Rosario Lucas

2015-09-01

The presence of toxicogenic Staphylococcus aureus in foods and the dissemination of methicillin-resistant S. aureus (MRSA) in the food chain are matters of concern. In the present study, the circular bacteriocin enterocin AS-48, applied singly or in combination with phenolic compounds (carvacrol, eugenol, geraniol, and citral) or with 2-nitro-1-propanol (2NPOH), was investigated in the control of a cocktail made from 1 methicillin-sensitive and 1 MRSA strains inoculated on commercial oat and soya drinks. Enterocin AS-48 exhibited low bactericidal activity against staphylococci in the drinks investigated when applied singly. The combinations of sub-inhibitory concentrations of enterocin AS-48 (25 μg/mL) and phenolic compounds or 2NPOH caused complete inactivation of staphylococci in the drinks within 24 h of incubation at 22 °C. When tested in oat and soya drinks stored for 7 d at 10 °C, enterocin AS-48 (25 μg/mL) in combination with 2NPOH (5.5 mM) reduced viable counts rapidly in the case of oat drink (4.2 log cycles after 12 h) or slowly in soya drink (3.8 log cycles after 3 d). The same combined treatment applied on drinks stored at 22 °C achieved a fast inactivation of staphylococci within 12 to 24 h in both drinks, and no viable staphylococci were detected for up to 7 d of storage. Results from the study highlight the potential of enterocin AS-48 in combination with 2NPOH for inactivation of staphylococci. © 2015 Institute of Food Technologists®

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.

Genome-wide Escherichia coli stress response and improved tolerance towards industrially relevant chemicals.

PubMed

Rau, Martin Holm; Calero, Patricia; Lennen, Rebecca M; Long, Katherine S; Nielsen, Alex T

2016-10-13

Economically viable biobased production of bulk chemicals and biofuels typically requires high product titers. During microbial bioconversion this often leads to product toxicity, and tolerance is therefore a critical element in the engineering of production strains. Here, a systems biology approach was employed to understand the chemical stress response of Escherichia coli, including a genome-wide screen for mutants with increased fitness during chemical stress. Twelve chemicals with significant production potential were selected, consisting of organic solvent-like chemicals (butanol, hydroxy-γ-butyrolactone, 1,4-butanediol, furfural), organic acids (acetate, itaconic acid, levulinic acid, succinic acid), amino acids (serine, threonine) and membrane-intercalating chemicals (decanoic acid, geraniol). The transcriptional response towards these chemicals revealed large overlaps of transcription changes within and between chemical groups, with functions such as energy metabolism, stress response, membrane modification, transporters and iron metabolism being affected. Regulon enrichment analysis identified key regulators likely mediating the transcriptional response, including CRP, RpoS, OmpR, ArcA, Fur and GadX. These regulators, the genes within their regulons and the above mentioned cellular functions therefore constitute potential targets for increasing E. coli chemical tolerance. Fitness determination of genome-wide transposon mutants (Tn-seq) subjected to the same chemical stress identified 294 enriched and 336 depleted mutants and experimental validation revealed up to 60 % increase in mutant growth rates. Mutants enriched in several conditions contained, among others, insertions in genes of the Mar-Sox-Rob regulon as well as transcription and translation related gene functions. The combination of the transcriptional response and mutant screening provides general targets that can increase tolerance towards not only single, but multiple chemicals.

Antiviral activities of extracts and selected pure constituents of Ocimum basilicum.

PubMed

Chiang, Lien-Chai; Ng, Lean-Teik; Cheng, Pei-Win; Chiang, Win; Lin, Chun-Ching

2005-10-01

1. Ocimum basilicum (OB), also known as sweet basil, is a well known medicinal herb in traditional Chinese medicine preparations. In the present study, extracts and purified components of OB were used to identify possible antiviral activities against DNA viruses (herpes viruses (HSV), adenoviruses (ADV) and hepatitis B virus) and RNA viruses (coxsackievirus B1 (CVB1) and enterovirus 71 (EV71)). 2. The results show that crude aqueous and ethanolic extracts of OB and selected purified components, namely apigenin, linalool and ursolic acid, exhibit a broad spectrum of antiviral activity. Of these compounds, ursolic acid showed the strongest activity against HSV-1 (EC50 = 6.6 mg/L; selectivity index (SI) = 15.2), ADV-8 (EC50 = 4.2 mg/L; SI = 23.8), CVB1 (EC50 = 0.4 mg/L; SI = 251.3) and EV71 (EC50 = 0.5 mg/L; SI = 201), whereas apigenin showed the highest activity against HSV-2 (EC50 = 9.7 mg/L; SI = 6.2), ADV-3 (EC50 = 11.1 mg/L; SI = 5.4), hepatitis B surface antigen (EC50 = 7.1 mg/L; SI = 2.3) and hepatitis B e antigen (EC50 = 12.8 mg/L; SI = 1.3) and linalool showed strongest activity against AVD-II (EC50 = 16.9 mg/L; SI = 10.5). 3. No activity was noted for carvone, cineole, beta-caryophyllene, farnesol, fenchone, geraniol, beta-myrcene and alpha-thujone. 4. The action of ursolic acid against CVB1 and EV71 was found to occur during the infection process and the replication phase. 5. With SI values greater than 200, the potential use of ursolic acid for treating infection with CVB1 and EV71 merits further investigation.

Study of two-stage ohmic hydro-extraction of essential oil from Artemisia aucheri Boiss.: Antioxidant and antimicrobial characteristics.

PubMed

Mojtahed Zadeh Asl, Rozita; Niakousari, Mehrdad; Hashemi Gahruie, Hadi; Saharkhiz, Mohammad Jamal; Mousavi Khaneghah, Amin

2018-05-01

The effect of two-stage ohmic-assisted hydrodistillation (TSOH) on the extraction and characteristics of essential oils (EOs) from the Artemisia aucheri Boiss. was studied, and the results were compared to conventional hydrodistillation (HD). According to the results, the yield of EOs obtained through TSOH was almost 30% higher than those extracted by HD in nearly one-quarter of a time used by the HD. Scanning electron micrographs of A. aucheri leaves showed almost complete eruption of EO glands and their surrounding area in TSOH extraction method, hence achieving higher yield. The components of the EOs obtained through TSOH were only slightly different from those of HD. GC/MS analysis indicated some differences in the quantity of the main components, too. The main components of EOs were identified as Thymol, Linalool, Geraniol, Camphor, and 1, 8-Cineole, Davana ether and Cis-Davanone. Thymol (~17%) and Cis-Davanone (~23%) were the highest quantity in the EOs extracted from TSOH and HD, respectively. The variation of antioxidant and antimicrobial activities of the EOs may be attributed to these differences in the percentage of the main components. The radical scavenging activity of the EOs obtained by TSOH was almost twice that of HD. Based on antimicrobial activity assays, the EOs were efficient against S. aureus (a Gram-positive), E. coli (a Gram-negative), and S. cerevisiae (yeast). However, the efficacy was higher in gram-positive than gram-negative bacteria and yeast. The results indicate TSOH has a potential to produce EOs from herbal plants at a faster rate, higher yield, being probably more efficient in terms of energy although having similar antimicrobial and antioxidant efficacy. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ozone-initiated terpene reaction products in five European offices: replacement of a floor cleaning agent.

PubMed

Nørgaard, A W; Kofoed-Sørensen, V; Mandin, C; Ventura, G; Mabilia, R; Perreca, E; Cattaneo, A; Spinazzè, A; Mihucz, V G; Szigeti, T; de Kluizenaar, Y; Cornelissen, H J M; Trantallidi, M; Carrer, P; Sakellaris, I; Bartzis, J; Wolkoff, P

2014-11-18

Cleaning agents often emit terpenes that react rapidly with ozone. These ozone-initiated reactions, which occur in the gas-phase and on surfaces, produce a host of gaseous and particulate oxygenated compounds with possible adverse health effects in the eyes and airways. Within the European Union (EU) project OFFICAIR, common ozone-initiated reaction products were measured before and after the replacement of the regular floor cleaning agent with a preselected low emitting floor cleaning agent in four offices located in four EU countries. One reference office in a fifth country did not use any floor cleaning agent. Limonene, α-pinene, 3-carene, dihydromyrcenol, geraniol, linalool, and α-terpineol were targeted for measurement together with the common terpene oxidation products formaldehyde, 4-acetyl-1-methylcyclohexene (4-AMCH), 3-isopropenyl-6-oxo-heptanal (IPOH), 6-methyl-5-heptene-2-one, (6-MHO), 4-oxopentanal (4-OPA), and dihydrocarvone (DHC). Two-hour air samples on Tenax TA and DNPH cartridges were taken in the morning, noon, and in the afternoon and analyzed by thermal desorption combined with gas chromatography/mass spectrometry and HPLC/UV analysis, respectively. Ozone was measured in all sites. All the regular cleaning agents emitted terpenes, mainly limonene and linalool. After the replacement of the cleaning agent, substantially lower concentrations of limonene and formaldehyde were observed. Some of the oxidation product concentrations, in particular that of 4-OPA, were also reduced in line with limonene. Maximum 2 h averaged concentrations of formaldehyde, 4-AMCH, 6-MHO, and IPOH would not give rise to acute eye irritation-related symptoms in office workers; similarly, 6-AMCH, DHC and 4-OPA would not result in airflow limitation to the airways.

Dynamic and organizational studies by SH NMR of polyisoprenols (PIs) in model membranes

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

Troy, F.A.; Knudsen, M.J.

1987-05-01

The objective of the authors studies seeks to understand the molecular details of how undecaprenol (C55) and dolichol (C95) function as chemical carriers of glycosyl residues in the membrane-directed synthesis of glycoconjugates. SH NMR studies provide information on the organization and dynamics of PIs in model membranes. Incorporation of polar or omega-terminus SH-labeled PIs into multilamellar membranes of phosphatidylcholine (PC) give rise to SH-NMR spectra interpretable in terms of quadrupole splittings ( vq), a measure of the degree of orderness of the SH-labeled site, and spin lattice relaxation times (T1's), revealing rates of motion. The authors results show: 1) vqmore » of the PIs increased with increase concentration of label and with lowering of temperature; 2) little difference in T1 or vq values between tail-group or headgroup SH-labeled geraniol (C10), farnesol (C15) or solanesol (C45) was observed; and 3) T1 measurements revealed correlation times close to the fatty acyl CH3 termini in PC. These data indicate that both ends of the esterified PI molecules see similar environments in the bilayer (BL) interior, and suggest that the esterified PIs studied here do not adopt a conventional head-group-at-interface orientation of lipids within the BL. These data support the authors earlier conclusions based on spin label EPR studies. Headgroup labeled dolichol (C95-CD2-OH) and dolichol phosphate (C94-CD2-O-PO3H2) have been synthesized. Surprisingly, no anisotropic quadrupole splitting in PC vesicles were observed. This may indicate an unusual conformation of the long poly-cis prenyl chains.« less

Inhibition of P-glycoprotein-mediated transport by extracts of and monoterpenoids contained in Zanthoxyli Fructus

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

Yoshida, Naoko; Takagi, Akiyoshi; Kitazawa, Hidenori

2005-12-01

Citrus (rutaceous) herbs are often used in traditional medicine and Japanese cuisine and can be taken concomitantly with conventional medicine. In this study, the effect of various citrus-herb extracts on P-glycoprotein (P-gp)-mediated transport was examined in vitro to investigate a possible interaction with P-gp substrates. Component monoterpenoids of the essential oil in Zanthoxyli Fructus was screened to find novel P-gp inhibitors. LLC-GA5-COL150 cells transfected with human MDR1 cDNA encoding P-gp were used. Cellular accumulation of [{sup 3}H]digoxin was measured in the presence or absence of P-gp inhibitors or test samples. Aurantii Fructus, Evodiae Fructus, Aurantii Fructus Immaturus, Aurantii Nobilis Pericarpium,more » Phellodendri Cortex, and Zanthoxyli Fructus were extracted with hot water (decocted) and then fractionated with ethyl acetate. The cell to medium ratio of [{sup 3}H]digoxin accumulation increased significantly in the presence of the decoction of Evodiae Fructus, Aurantii Nobilis Pericarpium, and Zanthoxyli Fructus, and the ethyl acetate fraction of all citrus herbs used. The ethyl acetate fraction of Zanthoxyli Fructus exhibited the strongest inhibition of P-gp among tested samples with an IC{sub 5} value of 166 {mu}g/mL. Then its component monoterpenoids, geraniol, geranyl acetate (R)-(+)-limonene, (R)-(+)-linalool, citronellal (R)-(+)-citronellal, DL-citronellol (S)-(-)-{beta}-citronellol, and cineole, were screened. (R)-(+)-citronellal and (S)-(-)-{beta}-citronellol inhibited P-gp with IC{sub 5} values of 167 {mu}M and 504 {mu}M, respectively. These findings suggest that Zanthoxyli Fructus may interact with P-gp substrates and that some monoterpenoids with the relatively lower molecular weight of about 150 such as (R)-(+)-citronellal can be potent inhibitors of P-gp.« less

Role of the vomeronasal system in intersexual attraction in female mice.

PubMed

Martínez-Ricós, J; Agustín-Pavón, C; Lanuza, E; Martínez-García, F

2008-05-02

Although it is generally accepted that rodents' sociosexual behavior relies mainly on chemosignals, the specific roles played by the vomeronasal and olfactory systems in detecting these signals are presently unclear. This work reports the results of three experiments aimed at clarifying the role of the vomeronasal system on gender recognition and intersexual attraction, by analyzing the effects of lesions of the accessory olfactory bulbs (AOB) in chemically naïve female mice. The first experiment demonstrates that lesions of the AOB abolish the preference that females show for male-soiled bedding in tests in which the females can contact the bedding, thus having access to both volatile and involatile male chemosignals. The second experiment shows that airborne male-derived chemosignals are not attractive to intact, chemically naïve females but tend to be preferentially explored by females whose AOB has been lesioned. However, repeated exposure to male-soiled bedding has opposite effects in sham-operated and AOB-lesioned female mice. Whereas after this experience sham-operated females show an (acquired) attraction toward male airborne chemosignals, in AOB-lesioned females the same experience makes male-derived volatiles aversive. Finally, in the third experiment we have confirmed that our AOB-lesioned females are able to detect urine-borne male odorants, as well as to discriminate them from the synthetic terpene geraniol. These findings strongly suggest that in mice, the involatile male sexual pheromone that is intrinsically attractive is detected by the vomeronasal system of the females. In addition, the repeated experience of females with male-soiled bedding would probably allow the association of this pheromone, acting as unconditioned stimulus, with olfactory stimuli (odorants) that therefore would become conditioned attractors to the females.

Comparison of antispasmodic effects of Dracocephalum kotschyi essential oil, limonene and α-terpineol

PubMed Central

Sadraei, H.; Asghari, G.; Kasiri, F.

2015-01-01

Dracocephalum kotschyi is an essential oil containing plant found in Iran. In Iranian traditional medicine, D. kotschyi has been used as antispasmodic and analgesic but so far there is no pharmacological report about its antispasmodic activity. Therefore, the objective of this research was to study antispasmodic activity of the essential oil of D. kotschyi and two of its constituents namely limonene and α-terpineol. The essential oil was obtained from aerial parts of D. kotschyi using hydrodistillation method. The main components found in the essential oil were α-pinene (10%), neral (11%), geraniol (10%), α-citral (12%), limonene (9%) and α-terpineol (1.1%). For antispasmodic studies, a portion of rat ileum was suspended under 1 g tension in Tyrode's solution at 37 °C and gassed with O2. Effect of the D. kotschyi essential oil, limonene and α-terpineol were studied on ileum contractions induced by KCl (80 mM), acetylcholine (ACh, 500 nM) and electrical field stimulation (EFS). The essential oil, in a concentration dependent manner inhibited the response to KCl (IC50=51 ± 8.7 nl/ml), ACh (IC50=19 ± 2.7 nl/ml) and EFS (IC50=15 ± 0.5 nl/ml). Limonene and α-terpineol showed same pattern of inhibitory effect on ileum contraction. Their inhibitory effects were also concentration dependent. However, limonene was more potent than the essential oil while the α-terpineol was less potent than either limonene or the essential oil. From this experiment it was concluded that D. kotschyi essential oil has inhibitory effect on ileum contractions. Limonene contribute a major role in inhibitory effect of the essential oil while α-terpineol has weak antispasmodic activity. PMID:26487887

Content and reactivity to product perfumes in fragrance mix positive and negative eczema patients. A study of perfumes used in toiletries and skin-care products.

PubMed

Johansen, J D; Rastogi, S C; Andersen, K E; Menné, T

1997-06-01

The aim of the study was to investigate the elicitation potential of perfumes from 17 commonly sold lower-price cosmetic products. 8 of the perfumes were from stay-on cosmetics and 9 were from wash-off cosmetics. Each perfume was tested in 500 consecutive eczema patients, who also were tested with the European standard patch test series. 4.2% reacted to 1 or more of the wash-off product perfumes and 3.2% to 1 or more of the stay-on product perfumes. Concordant positive reactions between the fragrance mix and the product perfumes were found in 81.3% of positive reactions to the stay-on product perfumes and in 52.4% of the reactions to the wash-off product perfumes. Compared to the fragrance mix alone, only 1 additional case of contact allergy to the product perfumes was detected by balsam of Peru. Chemical analysis revealed that between 1 and 5 of the chemically-defined constituents of the fragrance mix were present in all of the product perfumes. Geraniol was found in 12 of the 17 perfumes and was most often detected. The concentration of the target fragrance materials ranged from 0.005%-1.35 w/v%. It is concluded that the allergenic constituents of the fragrance mix are impossible to avoid if perfumed cosmetics are used. Furthermore, patients suspected of perfume allergy need to be tested with their own perfumed products, as far from all cases of perfume allergy are detected by the fragrance mix and/or balsam of Peru in the European standard patch test series.

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

Transient Receptor Potential Channels Encode Volatile Chemicals Sensed by Rat Trigeminal Ganglion Neurons

PubMed Central

Schöbel, Nicole; Beltrán, Leopoldo; Wetzel, Christian Horst; Hatt, Hanns

2013-01-01

Primary sensory afferents of the dorsal root and trigeminal ganglia constantly transmit sensory information depicting the individual’s physical and chemical environment to higher brain regions. Beyond the typical trigeminal stimuli (e.g. irritants), environmental stimuli comprise a plethora of volatile chemicals with olfactory components (odorants). In spite of a complete loss of their sense of smell, anosmic patients may retain the ability to roughly discriminate between different volatile compounds. While the detailed mechanisms remain elusive, sensory structures belonging to the trigeminal system seem to be responsible for this phenomenon. In order to gain a better understanding of the mechanisms underlying the activation of the trigeminal system by volatile chemicals, we investigated odorant-induced membrane potential changes in cultured rat trigeminal neurons induced by the odorants vanillin, heliotropyl acetone, helional, and geraniol. We observed the dose-dependent depolarization of trigeminal neurons upon application of these substances occurring in a stimulus-specific manner and could show that distinct neuronal populations respond to different odorants. Using specific antagonists, we found evidence that TRPA1, TRPM8, and/or TRPV1 contribute to the activation. In order to further test this hypothesis, we used recombinantly expressed rat and human variants of these channels to investigate whether they are indeed activated by the odorants tested. We additionally found that the odorants dose-dependently inhibit two-pore potassium channels TASK1 and TASK3 heterologously expressed In Xenopus laevis oocytes. We suggest that the capability of various odorants to activate different TRP channels and to inhibit potassium channels causes neuronal depolarization and activation of distinct subpopulations of trigeminal sensory neurons, forming the basis for a specific representation of volatile chemicals in the trigeminal ganglia. PMID:24205061

Using Citrus aurantifolia essential oil for the potential biocontrol of Colocasia esculenta (taro) leaf blight caused by Phytophthora colocasiae.

PubMed

Tchameni, Séverin Nguemezi; Mbiakeu, Staelle Njamou; Sameza, Modeste Lambert; Jazet, Pierre Michel Dongmo; Tchoumbougnang, François

2017-11-17

The aim of this work was to evaluate the antimicrobial activities of leaves and epicarp of Citrus aurantifolia essential oil against Phytophthora colocasiae, the causative agent of taro leaf blight. Oils were extracted by hydrodistillation, and their chemical composition was determined by gas chromatography and gas chromatography coupled with mass spectrometry. Antimicrobial activities of oils were tested in vitro against mycelium growth and sporangium production. In situ tests were done on healthy taro leaves, and the necrosis symptoms were evaluated. Results showed that the essential oil extraction yields from leaves and epicarp were 0.61 and 0.36%, respectively. Limonene (48.96%), bornyl acetate (14.18%), geraniol (10.53%), geranial (3.93%), and myrcene (3.14%) were the main components in leaf oil, while limonene (59.09%), cis-hydrate sabinene (7.53%), geranial (5.61%), myrtenol (5.02%), and terpinen-4-ol (3.48%) were the main components in epicarp oil. Both oils exhibited antimicrobial activities with total inhibition of the mycelium growth at 500 and 900 ppm for leaf and epicarp, respectively. The highest inhibitory concentration of sporangium production was 400 (72.84%) and 800 ppm (80.65%) for leaf and epicarp oil, respectively. For the standard fungicide (metalaxyl), the total inhibition value of mycelial growth and sporangium production was 750 ppm. In situ tests showed that, at 5000 ppm, total inhibition (100%) was obtained for a preventive test, while 50% of the inhibition was observed for a curative test when leaf oil was applied. When epicarp essential oil was applied at 5000 ppm, 47.5 and 16.66% of the reduction of leaf necrosis were observed for the preventive and curative test, respectively. There were positive correlations between both the oil concentration and the reduction of necrosis caused by P. colocasiae. These findings suggest that the C. aurantifolia essential oil could serve as an eco-friendly biocontrol for the management of taro leaf blight.

In vitro study of anti-coccidial activity of essential oils from indigenous plants against Eimeria tenella.

PubMed

Jitviriyanon, Surapan; Phanthong, Phanida; Lomarat, Pattamapan; Bunyapraphatsara, Nuntavan; Porntrakulpipat, Sarthorn; Paraksa, Nuanchan

2016-09-15

This study was designed to evaluate the in vitro anticoccidial properties against Eimeria tenella of different essential oils and their major active components. Efficacy of ten essential oils from different Thai indigenous plants were preliminarily screened and only those with potential were further tested for effective concentrations and identifying their active compounds. Oocysticidal property was evaluated in term of sporulation inhibition of oocysts and the percentage of unsporulated, sporulated and degenerated oocysts, after treatment with 125μg/ml of the selected essential oil, the sample was enumerated by haemocytometer, while coccidiocidal activity was assessed by the inhibition of sporozoite invasion in MDBK cell lines. Results showed that only Boesenbergia pandurata and Ocimum basilicum essential oils had strong sporulation inhibition activity by providing a higher ratio of degenerated oocysts and their IC 50 were 0.134 and 0.101mg/ml, respectively. GC-MS analysis of B. pandurata essential oil found trans-b-ocimene, camphor, 1,8-cineole, geraniol, camphene, methyl cinnamate, l-limonene and linalool as the major components, while methyl chavicol, α-bergamotene, 1,8-cineole and trans-β-ocimene were the main compounds of O. basilicum essential oil. Methyl cinnamate and camphor were the active components of B. pandurata oil, whereas methyl chavicol was the active component of O. basilicum oil by exhibiting the oocysticidal effect against E. tenella with IC 50 values of 0.008, 0.023 and 0.054mg/ml, respectively. Furthermore, B. pandurata and O. basilicum oils also showed a strong cytotoxic property against coccidia with more than 70% inhibition of sporozoite invasion in MDBK cell lines, and their IC 50 were 0.004 and 0.004mg/ml, respectively. Methyl cinnamate as well as camphor from B. pandurata and methyl chavicol from O. basilicum were also effective with IC 50 values of 0.029, 0.023, and 0.022mg/ml, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Water soluble fractions of rose-scented geranium (Pelargonium species) essential oil.

PubMed

Rao, B R Rajeswara; Kaul, P N; Syamasundar, K V; Ramesh, S

2002-09-01

The essential oil of rose-scented geranium (Pelargonium species, family: Geraniaceae) obtained through steam or water plus steam distillation of shoot biomass is extensively used in the fragrance industry and in aromatherapy. During distillation, a part of the essential oil becomes dissolved in the distillation water (hydrosol) and is lost as this hydrosol is discarded. In this investigation, hydrosol was shaken for 30 min with hexane (10:1 proportion) and the hexane was distilled to yield 'secondary' or 'recovered' essential oil. The chemical composition of secondary oil was compared with that of 'primary' oil (obtained directly by distilling shoot biomass of the crop). Primary oil accounted for 93.0% and secondary oil 7.0% of the total oil yield (100.2 ml from 100 kg green shoot biomass). Fifty-two compounds making up 95.0-98.5% of the primary and the secondary oils were characterized through gas chromatography (GC) and gas chromatography-mass spectroscopy (GC--MS). Primary oil was richer in hydrocarbons (8.5-9.4%), citronellyl formate (6.2-7.5%), geranyl formate (4.1-4.7%), citronellyl propionate (1.0-1.2%), alpha-selinene (1.8-2.2%), citronellyl butyrate (1.4-1.7%), 10-epi-gamma-eudesmol (4.9-5.5%) and geranyl tiglate (1.8-2.1%). Recovered oil was richer in organoleptically important oxygenated compounds (88.9-93.9%), commercial rhodinol fraction (74.3-81.2%), sabinene (0.4-6.2%), cis-linool oxide (furanoid) (0.7-1.2%), linalool (14.7-19.6%), alpha-terpineol (3.3-4.8%) and geraniol (21.3-38.4%). Blending of recovered oil with primary oil is recommended to enhance the olfactory value of the primary oil of rose-scented geranium. Distillation water stripped of essential oil through hexane extraction can be recycled for distilling the next batch of rose-scented geranium.

The in vitro antimicrobial activity of Cymbopogon essential oil (lemon grass) and its interaction with silver ions.

PubMed

Ahmad, Aijaz; Viljoen, Alvaro

2015-06-01

It is well known that Cymbopogon (lemon grass) essential oil exhibits antimicrobial activity while the efficacy of silver ions as a disinfectant is equally well reported. The antimicrobial activity of CEO and Ag(+) and their synergistic combinations will be useful in improving the current treatment strategies for various infections. In the present study, we determined the chemical composition and in vitro antimicrobial activity of six different Cymbopogon essential oils (CEO's) alone and in combination with silver ions (Ag(+)) against two Gram-positive (Staphylococcus aureus and Enterococcus faecalis), two Gram-negative (Escherichia coli and Moraxella catarrhalis) and two yeast species (Candida albicans and Candida tropicalis). The nature of potential interactions was determined by fractional inhibitory concentration indices (FICIs) for CEO's and Ag(+) calculated from microdilution assays and time-kill curves. Gas chromatography-mass spectrometry results confirmed the presence of nerol, geranial and geraniol as major volatile compounds. Minimum inhibitory concentration (MIC) values confirmed that all the tested pathogens are variably susceptible to both CEO's as well as Ag(+). The MIC of CEO's and Ag(+) against all the tested pathogens ranged from 0.032 mg/ml to 1 mg/ml and 0.004 and 0.064 mg/ml respectively, whereas when assayed in combination the FICI values were drastically reduced to range between 0.258 and 2.186, indicating synergy, additive and indifferent interactions. The most prominent interaction was observed between Cymbopogon flexuosus essential oil and Ag(+) against C. albicans with ∑FIC = 0.254. The synergistic interactions were further confirmed through the construction of isobolograms and time-kill plots. Transmission electron microscopy showed disturbance in the cell envelope upon the concomitant treatment of CEO's and Ag(+), which ultimately leads to cell death. Results suggest that CEO's and Ag(+) when used in combination offers an opportunity to the formulation scientist to produce novel combinations acting synergistically in the continued quest to control important infectious pathogens. Copyright © 2015 Elsevier GmbH. All rights reserved.

Liquid-phase hydrogenation of citral over Pt/SiO{sub 2} catalysts. 1. Temperature effects on activity and selectivity

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

Singh, U.K.; Vannice, M.A.

2000-04-01

Liquid-phase hydrogenation of citral (3,7-dimethyl-2,6-octadienal) over Pt/SiO{sub 2} catalysts was studied in the temperature and pressure ranges 298--423 K and 7--21 atm, respectively. The reaction kinetics were shown to be free of artifacts arising from transport limitations and poisoning effects. The reaction rate in hexane at the solvent exhibited an activity minimum at 373 K. The initial turnover frequency for citral disappearance over 1.44% Pt/SiO{sub 2} catalyst at 20 atm H{sub 2} pressure decreased from 0.19 s{sup {minus}1} at 298 K to 0.02 s{sup {minus}1} at 373 K, but exhibited normal Arrhenius behavior between 373 and 423 K with anmore » activation energy of 7 kcal/mol. Reaction at 298 K produced substantial deactivation, with the rate decreasing by more than an order of magnitude during the first 4 h of reaction; however, reaction at temperatures greater than 373 K exhibited negligible deactivation and a constant rate up to citral conversions greater than 70%. These unusual temperature effects were modeled using Langmuir-Hinshelwood kinetics invoking dissociative adsorption of hydrogen, competitive adsorption between hydrogen and the organic compounds, and addition of the second hydrogen atom to each reactant as the rate-determining step. Decomposition of the unsaturated alcohol (either geraniol or nerol) was proposed to occur concurrently with the hydrogenation steps to yield adsorbed CO and carbonaceous species which cause the deactivation, but at higher temperatures these species could be removed from the Pt surface by desorption or rapid hydrogenation, respectively. The activity minimum observed in the present study is attributed to the relative rates of the alcohol decomposition reaction and CO desorption, with the decomposition reaction having an activation barrier lower than that for CO desorption.« less

Exploring a volatomic-based strategy for a fingerprinting approach of Vaccinium padifolium L. berries at different ripening stages.

PubMed

Porto-Figueira, Priscilla; Figueira, José A; Berenguer, Pedro; Câmara, José S

2018-04-15

The effect of ripening on the evolution of the volatomic pattern from endemic Vaccinium padifolium L. (Uveira) berries was investigated using headspace-solid phase microextraction (HS-SPME) followed by gas chromatography/quadrupole-mass spectrometry (GC-qMS) and multivariate statistical analysis (MVA). The most significant HS-SPME parameters, namely fibre polymer, ionic strength and extraction time, were optimized in order to improve extraction efficiency. Under optimal experimental conditions (DVB/CAR/PDMS fibre coating, 40°C, 30min extraction time and 5g of sample amount), a total of 72 volatiles of different functionalities were isolated and identified. Terpenes followed by higher alcohols and esters were the predominant classes in the ripening stages - green, break and ripe. Although significant differences in the volatomic profiles at the three stages were obtained, cis-β-ocimene (2.0-40.0%), trans-2-hexenol (2.4-19.4%), cis-3-hexenol (2.5.16.4%), β-myrcene (1.9-13.8%), 1-hexanol (1.7-13.6%), 2-hexenal (0.7-8.0%), 2-heptanone (0.7-7.7%), and linalool (1.9-6.1%) were the main volatile compounds identified. Higher alcohols, carboxylic acids and ketones gradually increased during ripening, whereas monoterpenes significantly decreased. These trends were dominated by the higher alcohols (1-hexanol, cis-3-hexenol, trans-2-hexenol) and monoterpenes (β-myrcene, cis-β-ocimene and trans-β-ocimene). Partial least squares regression (PLSR) revealed that ethyl caprylate (1.000), trans-geraniol (0.995), ethyl isovalerate (-0.994) and benzyl carbinol (0.993) are the key variables that most contributed to the successful differentiation of Uveira berries according to ripening stage. To the best of our knowledge, no study has carried out on the volatomic composition of berries from endemic Uveira. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Lippia alba and Cymbopogon citratus essential oils on biofilms of Streptococcus mutans and cytotoxicity in CHO cells.

PubMed

Tofiño-Rivera, A; Ortega-Cuadros, M; Galvis-Pareja, D; Jiménez-Rios, H; Merini, L J; Martínez-Pabón, M C

2016-12-24

Caries is a public health problem, given that it prevails in 60 to 90% of the school-age global population. Multiple factors interact in its etiology, among them dental plaque is necessary to have lactic acid producing microorganisms like Streptococcus from he Mutans group. Existing prevention and treatment measures are not totally effective and generate adverse effects, which is why it is necessary to search for complementary strategies for their management. The study sought to evaluate the eradication capacity of Streptococcus mutans biofilms and the toxicity on eukaryotic cells of Lippia alba and Cymbopogon citratus essential oils. Essential oils were extracted from plant material through steam distillation and then its chemical composition was determined. The MBEC-high-throughput (MBEC-HTP) (Innovotech, Edmonton, Alberta, Canada) assay used to determine the eradication concentration of S. mutans ATCC 35668 strain biofilms. Cytotoxicity was evaluated on CHO cells through the MTT cell proliferation assay. The major components in both oils were Geraniol and Citral; in L. alba 18.9% and 15.9%, respectively, and in C. citratus 31.3% and 26.7%. The L. alba essential oils presented eradication activity against S. mutans biofilms of 95.8% in 0.01mg/dL concentration and C. citratus essential oils showed said eradication activity of 95.4% at 0.1, 0.01mg/dL concentrations and of 93.1% in the 0.001mg/dL concentration; none of the concentrations of both essential oils showed toxicity on CHO cells during 24h. The L. alba and C. citratus essential oils showed eradication activity against S. mutans biofilms and null cytotoxicity, evidencing the need to conduct further studies that can identify their active components and in order to guide a safe use in treating and preventing dental caries. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Determination of suspected allergens in cosmetic products by headspace-programmed temperature vaporization-fast gas chromatography-quadrupole mass spectrometry.

PubMed

del Nogal Sánchez, Miguel; Pérez-Pavón, José Luis; Moreno Cordero, Bernardo

2010-07-01

In the present work, a strategy for the qualitative and quantitative analysis of 24 volatile compounds listed as suspected allergens in cosmetics by the European Union is reported. The list includes benzyl alcohol, limonene, linalool, methyl 2-octynoate, beta-citronellol, geraniol, citral (two isomers), 7-hydroxycitronellal, anisyl alcohol, cinnamal, cinnamyl alcohol, eugenol, isoeugenol (two isomers), coumarin, alpha-isomethyl ionone, lilial, alpha-amylcinnamal, lyral, alpha-amylcinnamyl alcohol, farnesol (three isomers), alpha-hexyl cinnamal, benzyl cinnamate, benzyl benzoate, and benzyl salicylate. The applicability of a headspace (HS) autosampler in combination with a gas chromatograph (GC) equipped with a programmable temperature vaporizer (PTV) and a quadrupole mass spectrometry (qMS) detector is explored. By using a headspace sampler, sample preparation is reduced to introducing the sample into the vial. This reduces the analysis time and the experimental errors associated with this step of the analytical process. Two different injection techniques were used: solvent-vent injection and hot-split injection. The first offers a way to improve sensitivity at the same time maintaining the simple headspace instrumentation and it is recommended for compounds at trace levels. The use of a liner packed with Tenax-TA allowed the compounds of interest to be retained during the venting process. The signals obtained when hot-split injection was used allowed quantification of all the compounds according to the thresholds of the European Cosmetics Directive. Monodimensional gas chromatography coupled to a conventional quadrupole mass spectrometry detector was used and the 24 analytes were separated appropriately along a run time of about 12 min. Use of the standard addition procedure as a quantification technique overcame the matrix effect. It should be emphasized that the method showed good precision and accuracy. Furthermore, it is rapid, simple, and--in view of the results--highly suitable for the determination of suspected allergens in different cosmetic products.

Aroma Release in Wine Using Co-Immobilized Enzyme Aggregates.

PubMed

Ahumada, Katherine; Martínez-Gil, Ana; Moreno-Simunovic, Yerko; Illanes, Andrés; Wilson, Lorena

2016-11-08

Aroma is a remarkable factor of quality and consumer preference in wine, representing a distinctive feature of the product. Most aromatic compounds in varietals are in the form of glycosidic precursors, which are constituted by a volatile aglycone moiety linked to a glucose residue by an O -glycosidic bond; glucose is often linked to another sugar (arabinose, rhamnose or apiose). The use of soluble β-glycosidases for aroma liberation implies the addition of a precipitating agent to remove it from the product and precludes its reuse after one batch. An attractive option from a technological perspective that will aid in removing such constraints is the use of immobilized glycosidases. Immobilization by aggregation and crosslinking is a simple strategy producing enzyme catalysts of very high specific activity, being an attractive option to conventional immobilization to solid inert supports. The purpose of this work was the evaluation of co-immobilized β-glycosidases crosslinked aggregates produced from the commercial preparation AR2000, which contains the enzymes involved in the release of aromatic terpenes in Muscat wine (α-l-arabinofuranosidase and β-d-glucopyranosidase). To do so, experiments were conducted with co-immobilized crosslinked enzyme aggregates (combi-CLEAs), and with the soluble enzymes, using an experiment without enzyme addition as control. Stability of the enzymes at the conditions of winemaking was assessed and the volatiles composition of wine was determined by SPE-GC-MS. Stability of enzymes in combi-CLEAs was much higher than in soluble form, 80% of the initial activity remaining after 60 days in contact with the wine; at the same conditions, the soluble enzymes had lost 80% of their initial activities after 20 days. Such higher stabilities will allow prolonged use of the enzyme catalyst reducing its impact in the cost of winemaking. Wine treated with combi-CLEAs was the one exhibiting the highest concentration of total terpenes (18% higher than the control) and the highest concentrations of linalool (20% higher), nerol (20% higher) and geraniol (100% higher), which are the most important terpenes in determining Muscat typicity. Co-immobilized enzymes were highly stable at winemaking conditions, so their reutilization is possible and technologically attractive by reducing the impact of enzyme cost on winemaking cost.

Evaluation of essential oils in beef cattle manure slurries and applications of select compounds to beef feedlot surfaces to control zoonotic pathogens.

PubMed

Wells, J E; Berry, E D; Guerini, M N; Varel, V H

2015-02-01

To evaluate natural terpene compounds for antimicrobial activities and determine whether these compounds could be used to control microbial activities and pathogens in production animal facilities. Thymol, geraniol, glydox, linalool, pine oil, plinol and terpineol were tested in laboratory studies for ability to control the production of odorous volatile fatty acid compounds and reduce pathogen levels in manure slurry preparations. Thymol is a terpene phenolic compound and was most effective for reducing fermentation products and pathogen levels (P < 0.05), followed by the extracts linalool, pine oil and terpineol, which are terpene alcohols. Select compounds thymol, linalool and pine oil were further evaluated in two separate studies by applying the agents to feedlot surfaces in cattle pens. Feedlot surface material (FSM; manure and soil) was collected and analysed for fermentation products, levels of coliforms and total Escherichia coli, and the presence of E. coli O157:H7, Campylobacter, Salmonella, Listeria and L. monocytogenes. The reduction in fermentation products but not pathogens was dependent on the moisture present in the FSM. Treatment with 2000 ppm thymol reduced the prevalence of E. coli O157:H7 but not Listeria. In a separate study, treatment with 4000 ppm pine oil reduced E. coli O157:H7, Listeria and Campylobacter (P < 0.05). Linalool was tested at two levels (2000 and 4000 ppm) and did not affect pathogen levels at either concentration. Natural compounds bearing terpenes can control pathogenic bacteria in treated manures and when applied to the feedlot surface in production cattle systems. Pine oil is a cheaper alternative to thymol and may be a useful treatment for controlling pathogens. The control of bacterial pathogens in animal productions systems is an important step in preharvest food safety. Waste products, such as pine oil extract, from the pulp wood industry may have application for treating feedlot pens and manures to reduce the pathogen load. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Chemical composition, cytotoxicity and in vitro antitrypanosomal and antiplasmodial activity of the essential oils of four Cymbopogon species from Benin.

PubMed

Kpoviessi, Salomé; Bero, Joanne; Agbani, Pierre; Gbaguidi, Fernand; Kpadonou-Kpoviessi, Bénédicta; Sinsin, Brice; Accrombessi, Georges; Frédérich, Michel; Moudachirou, Mansourou; Quetin-Leclercq, Joëlle

2014-01-01

Cymbopogon species are largely used in folk medicine for the treatment of many diseases some of which related to parasitical diseases as fevers and headaches. As part of our research on antiparasitic essential oils from Beninese plants, we decided to evaluate the in vitro antiplasmodial and antitrypanosomal activities of essential oils of four Cymbopogon species used in traditional medicine as well as their cytotoxicity. The essential oils of four Cymbopogon species Cymbopogon citratus (I), Cymbopogon giganteus (II), Cymbopogon nardus (III) and Cymbopogon schoenantus (IV) from Benin obtained by hydrodistillation were analysed by GC/MS and GC/FID and were tested in vitro against Trypanosoma brucei brucei and Plasmodium falciparum respectively for antitrypanosomal and antiplasmodial activities. Cytotoxicity was evaluated in vitro against Chinese Hamster Ovary (CHO) cells and the human non cancer fibroblast cell line (WI38) through MTT assay to evaluate the selectivity. All tested oils showed a strong antitrypanosomal activity with a good selectivity. Sample II was the most active against Trypanosoma brucei brucei and could be considered as a good candidate. It was less active against Plasmodium falciparum. Samples II, III and IV had low or no cytotoxicity, but the essential oil of Cymbopogon citratus (I), was toxic against CHO cells and moderately toxic against WI38 cells and needs further toxicological studies. Sample I (29 compounds) was characterised by the presence as main constituents of geranial, neral, β-pinene and cis-geraniol; sample II (53 compounds) by trans-p-mentha-1(7),8-dien-2-ol, trans-carveol, trans-p-mentha-2,8-dienol, cis-p-mentha-2,8-dienol, cis-p-mentha-1(7),8-dien-2-ol, limonene, cis-carveol and cis-carvone; sample III (28 compounds) by β-citronellal, nerol, β-citronellol, elemol and limonene and sample IV (41 compounds) by piperitone, (+)-2-carene, limonene, elemol and β-eudesmol. Our study shows that essential oils of Cymbopogon genus can be a good source of antitrypanosomal agents. This is the first report on the activity of these essential oils against Trypanosoma brucei brucei, Plasmodium falciparum and analysis of their cytotoxicity. © 2013 Published by Elsevier Ireland Ltd.

Functional characterization of SlscADH1, a fruit-ripening-associated short-chain alcohol dehydrogenase of tomato.

PubMed

Moummou, Hanane; Tonfack, Libert Brice; Chervin, Christian; Benichou, Mohamed; Youmbi, Emmanuel; Ginies, Christian; Latché, Alain; Pech, Jean-Claude; van der Rest, Benoît

2012-10-15

A tomato short-chain dehydrogenase-reductase (SlscADH1) is preferentially expressed in fruit with a maximum expression at the breaker stage while expression in roots, stems, leaves and flowers is very weak. It represents a potential candidate for the formation of aroma volatiles by interconverting alcohols and aldehydes. The SlscADH1 recombinant protein produced in Escherichia coli exhibited dehydrogenase-reductase activity towards several volatile compounds present in tomato flavour with a strong preference for the NAD/NADH co-factors. The strongest activity was observed for the reduction of hexanal (K(m)=0.175mM) and phenylacetaldehyde (K(m)=0.375mM) in the presence of NADH. The oxidation process of hexanol and 1-phenylethanol was much less efficient (K(m)s of 2.9 and 23.0mM, respectively), indicating that the enzyme preferentially acts as a reductase. However activity was observed only for hexanal, phenylacetaldehyde, (E)-2-hexenal and acetaldehyde and the corresponding alcohols. No activity could be detected for other aroma volatiles important for tomato flavour, such as methyl-butanol/methyl-butanal, 5-methyl-6-hepten-2-one/5-methyl-6-hepten-2-ol, citronellal/citronellol, neral/nerol, geraniol. In order to assess the function of the SlscADH1 gene, transgenic plants have been generated using the technique of RNA interference (RNAi). Constitutive down-regulation using the 35S promoter resulted in the generation of dwarf plants, indicating that the SlscADH1 gene, although weakly expressed in vegetative tissues, had a function in regulating plant development. Fruit-specific down-regulation using the 2A11 promoter had no morphogenetic effect and did not alter the aldehyde/alcohol balance of the volatiles compounds produced by the fruit. Nevertheless, SlscADH1-inhibited fruit unexpectedly accumulated higher concentrations of C5 and C6 volatile compounds of the lipoxygenase pathway, possibly as an indirect effect of the suppression of SlscADH1 on the catabolism of phospholipids and/or integrity of membranes. Copyright © 2012 Elsevier GmbH. All rights reserved.

Hydrosols of orange blossom (Citrus aurantium), and rose flower (Rosa damascena and Rosa centifolia) support the growth of a heterogeneous spoilage microbiota.

PubMed

Labadie, Cécile; Ginies, Christian; Guinebretiere, Marie-Hélène; Renard, Catherine M G C; Cerutti, Céline; Carlin, Frédéric

2015-10-01

Hydrosols are hydrodistillation products of aromatic plants. They contain less than 1g/L of dispersed essential oils giving organoleptic properties. Hydrosols are subjected to microbial proliferation. Reasons for spoilage have to be found in the nature of substrates supporting growth and of microbiological contaminants. The composition in essential oils and the microbiota of 22 hydrosol samples of Citrus aurantium L. ssp. amara L. (orange blossom), Rosa damascena Miller (rose D.), and Rosa centifolia L. (rose C.) flowers were analyzed to determine the factors responsible for decay. The median concentrations in essential oils were 677mg/L for orange blossom hydrosols, 205mg/L for rose D. hydrosols, and 116mg/L for rose C. hydrosols. The dry matter content of these hydrosols varied between 4.0mg/L and 702mg/L, and the carbohydrate content varied between 0.21mg/L and 0.38mg/L. These non-volatile compounds were likely carried over during distillation by a priming and foaming effect, and could be used as nutrients by microorganisms. A microbial proliferation at ambient temperature and also at 5°C has been observed in all studied hydrosols when stored in a non-sterile container. In contaminated hydrosols, maximal counts were about 7log 10 CFU/mL, while the French pharmacopeia recommends a maximal total bacterial count of 2log 10 CFU/mL. Neither yeast nor mold was detected. The isolated microbial population was composed of environmental Gram-negative bacteria, arranged in four major genera: Pseudomonas sp., Burkholderia cepacia complex, and presumably two new genera belonging to Acetobacteraceae and Rhodospirillaceae. Among those bacteria, Burkholderia vietnamiensis and Novosphingobium capsulatum were able to metabolize volatile compounds, such as geraniol to produce 6-methyl-5-hepten-2-one or geranic acid, or phenylethyl acetate to produce 2-phenylethanol. EO concentrations in hydrosols or cold storage are not sufficient to insure microbiological stability. Additional hurdles such as chemical preservatives or aseptic packaging will be necessary to insure microbial stability. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identification, Expression Profiling and Fluorescence-Based Binding Assays of a Chemosensory Protein Gene from the Western Flower Thrips, Frankliniella occidentalis

PubMed Central

Zhang, Zhi-Ke; Lei, Zhong-Ren

2015-01-01

Using RT-PCR and RACE-PCR strategies, we cloned and identified a new chemosensory protein (FoccCSP) from the Western flower thrips, Frankliniella occidentalis, a species for which no chemosensory protein (CSP) has yet been identified. The FoccCSP gene contains a 387 bp open-reading frame encoding a putative protein of 128 amino acids with a molecular weight of 14.51 kDa and an isoelectric point of 5.41. The deduced amino acid sequence contains a putative signal peptide of 19 amino acid residues at the N-terminus, as well as the typical four—cysteine signature found in other insect CSPs. As FoccCSP is from a different order of insect than other known CSPs, the GenBank FoccCSP homolog showed only 31-50% sequence identity with them. A neighbor-joining tree was constructed and revealed that FoccCSP is in a group with CSPs from Homopteran insects (e.g., AgosCSP4, AgosCSP10, ApisCSP, and NlugCSP9), suggesting that these genes likely developed from a common ancestral gene. The FoccCSP gene expression profile of different tissues and development stages was measured by quantitative real-time PCR. The results of this analysis revealed this gene is predominantly expressed in the antennae and also highly expressed in the first instar nymph, suggesting a function for FoccCSP in olfactory reception and in particular life activities during the first instar nymph stage. We expressed recombinant FoccCSP protein in a prokaryotic expression system and purified FoccCSP protein by affinity chromatography using a Ni-NTA-Sepharose column. Using N-phenyl-1-naphthylamine (1-NPN) as a fluorescent probe in fluorescence-based competitive binding assay, we determined the binding affinities of 19 volatile substances for FoccCSP protein. This analysis revealed that anisic aldehyde, geraniol and methyl salicylate have high binding affinities for FoccCSP, with KD values of 10.50, 15.35 and 35.24 μM, respectively. Thus, our study indicates that FoccCSP may play an important role in regulating the development of the first instar nymph and mediate F. occidentalis host recognition. PMID:25635391

Identification, expression profiling and fluorescence-based binding assays of a chemosensory protein gene from the Western flower thrips, Frankliniella occidentalis.

PubMed

Zhang, Zhi-Ke; Lei, Zhong-Ren

2015-01-01

Using RT-PCR and RACE-PCR strategies, we cloned and identified a new chemosensory protein (FoccCSP) from the Western flower thrips, Frankliniella occidentalis, a species for which no chemosensory protein (CSP) has yet been identified. The FoccCSP gene contains a 387 bp open-reading frame encoding a putative protein of 128 amino acids with a molecular weight of 14.51 kDa and an isoelectric point of 5.41. The deduced amino acid sequence contains a putative signal peptide of 19 amino acid residues at the N-terminus, as well as the typical four-cysteine signature found in other insect CSPs. As FoccCSP is from a different order of insect than other known CSPs, the GenBank FoccCSP homolog showed only 31-50% sequence identity with them. A neighbor-joining tree was constructed and revealed that FoccCSP is in a group with CSPs from Homopteran insects (e.g., AgosCSP4, AgosCSP10, ApisCSP, and NlugCSP9), suggesting that these genes likely developed from a common ancestral gene. The FoccCSP gene expression profile of different tissues and development stages was measured by quantitative real-time PCR. The results of this analysis revealed this gene is predominantly expressed in the antennae and also highly expressed in the first instar nymph, suggesting a function for FoccCSP in olfactory reception and in particular life activities during the first instar nymph stage. We expressed recombinant FoccCSP protein in a prokaryotic expression system and purified FoccCSP protein by affinity chromatography using a Ni-NTA-Sepharose column. Using N-phenyl-1-naphthylamine (1-NPN) as a fluorescent probe in fluorescence-based competitive binding assay, we determined the binding affinities of 19 volatile substances for FoccCSP protein. This analysis revealed that anisic aldehyde, geraniol and methyl salicylate have high binding affinities for FoccCSP, with KD values of 10.50, 15.35 and 35.24 μM, respectively. Thus, our study indicates that FoccCSP may play an important role in regulating the development of the first instar nymph and mediate F. occidentalis host recognition.

"Imposed" and "inherent" mucosal activity patterns. Their composite representation of olfactory stimuli

PubMed Central

1987-01-01

Both regional differences in mucosal sensitivity and a gas chromatography-like process along the mucosal sheet have been separately proposed in two sets of earlier studies to produce different odorant-dependent activity patterns across the olfactory mucosa. This investigation evaluated, in one study, whether and to what degree these two mechanisms contribute to the generation of these activity patterns. Summated multiunit discharges were simultaneously recorded from lateral (LN) and medial (MN) sites on the bullfrog's olfactory nerve to sample the mucosal activity occurring near the internal and external nares, respectively. Precisely controlled sniffs of four odorants (benzaldehyde, butanol, geraniol, and octane) were drawn through the frog's olfactory sac in both the forward (H1) and reverse (H2) hale directions. By combining the four resulting measurements, LNH1, LNH2, MNH1, and MNH2, in different mathematical expressions, indexes reflecting the relative effects of the chromatographic process, regional sensitivity, and hale direction could be calculated. Most importantly, the chromatographic process and the regional sensitivity differences both contributed significantly to the mucosal activity patterns. However, their relative roles varied markedly among the four odorants, ranging from complete dominance by either one to substantial contributions from each. In general, the more strongly an odorant was sorbed by the mucosa, the greater was the relative effect of the chromatographic process; the weaker the sorption, the greater the relative effect of regional sensitivity. Similarly, the greater an odorant's sorption, the greater was the effect of hale direction. Other stimulus variables (sniff volume, sniff duration, and the number of molecules within the sniff) had marked effects upon the overall size of the response. For strongly sorbed odorants, the effect of increasing volume was positive; for a weakly sorbed odorant, it was negative. The reverse may be true for duration. In contrast, the effect of increasing the number of molecules was uniformly positive for all four odorants. However, there was little evidence that these other stimulus variables had a major influence upon the effects of the chromatographic process and regional sensitivity differences in their generation of mucosal activity patterns. PMID:3500998

Use of Synthetic Isoprenoids to Target Protein Prenylation and Rho GTPases in Breast Cancer Invasion

PubMed Central

Chen, Min; Knifley, Teresa; Subramanian, Thangaiah; Spielmann, H. Peter; O’Connor, Kathleen L.

2014-01-01

Dysregulation of Ras and Rho family small GTPases drives the invasion and metastasis of multiple cancers. For their biological functions, these GTPases require proper subcellular localization to cellular membranes, which is regulated by a series of post-translational modifications that result in either farnesylation or geranylgeranylation of the C-terminal CAAX motif. This concept provided the rationale for targeting farnesyltransferase (FTase) and geranylgeranyltransferases (GGTase) for cancer treatment. However, the resulting prenyl transferase inhibitors have not performed well in the clinic due to issues with alternative prenylation and toxicity. As an alternative, we have developed a unique class of potential anti-cancer therapeutics called Prenyl Function Inhibitors (PFIs), which are farnesol or geranyl-geraniol analogs that act as alternate substrates for FTase or GGTase. Here, we test the ability of our lead PFIs, anilinogeraniol (AGOH) and anilinofarnesol (AFOH), to block the invasion of breast cancer cells. We found that AGOH treatment effectively decreased invasion of MDA-MB-231 cells in a two-dimensional (2D) invasion assay at 100 µM while it blocked invasive growth in three-dimensional (3D) culture model at as little as 20 µM. Notably, the effect of AGOH on 3D invasive growth was phenocopied by electroporation of cells with C3 exotransferase. To determine if RhoA and RhoC were direct targets of AGOH, we performed Rho activity assays in MDA-MB-231 and MDA-MB-468 cells and found that AGOH blocked RhoA and RhoC activation in response to LPA and EGF stimulation. Notably, the geranylgeraniol analog AFOH was more potent than AGOH in inhibiting RhoA and RhoC activation and invasive growth. Interestingly, neither AGOH nor AFOH impacted 3D growth of MCF10A cells. Collectively, this study demonstrates that AGOH and AFOH dramatically inhibit breast cancer invasion, at least in part by blocking Rho function, thus, suggesting that targeting prenylation by using PFIs may offer a promising mechanism for treatment of invasive breast cancer. PMID:24587105

The frequency of fragrance allergy in a patch-test population over a 17-year period.

PubMed

Buckley, D A; Wakelin, S H; Seed, P T; Holloway, D; Rycroft, R J; White, I R; McFadden, J P

2000-02-01

Fragrances are widely encountered in our daily environment and are known to be a common cause of allergic contact dermatitis. We have reviewed our patch test data from 1980 to 1996 to establish whether the pattern of fragrance allergy has changed with time. During this period, 25,545 patients (10,450 male, 15,005 female) were patch tested with the European standard series. The mean annual frequency of positive reactions to the fragrance mix was 8.5% in females (range 6.1-10.9) and 6.7% in males (range 5.1-12.9). Females were 1.3 times more likely to be allergic to fragrance (P < 0.001, 95% confidence interval, CI 1.17-1.41). Males with fragrance allergy were older than females by 5.6 years (mean age 48.2 vs. 42.6 years; P < 0.001, 95% CI 3.9-7.3). The incidence of a concomitant positive patch test to balsam of Peru in fragrance-sensitive patients showed wide variation, suggesting that it is not a reliable marker of fragrance allergy. There was a positive correlation between the isomers isoeugenol and eugenol. Oak moss remained the most common overall allergen throughout the study, positive in 38.3% of females and 35.6% of males who were tested to the constituents of the fragrance mix. During the period of the study the incidence of positive tests to oak moss increased by 5% yearly (P = 0.001, 95% CI 2.2-8.7). The frequency of allergic reactions to eugenol and geraniol remained relatively constant. Isoeugenol and alpha-amyl cinnamic aldehyde sensitivity increased and hydroxycitronellal showed a slow decline. There was a striking reduction in the frequency of sensitivity to cinnamic aldehyde (by 18% yearly; P < 0.001, 95% CI 14.3-21.0) and cinnamic alcohol (by 9% yearly; P < 0.001, 95% CI 5.2-12.9); these are now uncommon fragrance allergens. These data show temporal trends which may reflect the frequency of population exposure to individual fragrances.

Patent literature on mosquito repellent inventions which contain plant essential oils--a review.

PubMed

Pohlit, Adrian Martin; Lopes, Norberto Peporine; Gama, Renata Antonaci; Tadei, Wanderli Pedro; Neto, Valter Ferreira de Andrade

2011-04-01

Bites Bites of mosquitoes belonging to the genera Anopheles Meigen, Aedes Meigen, Culex L. and Haemagogus L. are a general nuisance and are responsible for the transmission of important tropical diseases such as malaria, hemorrhagic dengue and yellow fevers and filariasis (elephantiasis). Plants are traditional sources of mosquito repelling essential oils (EOs), glyceridic oils and repellent and synergistic chemicals. A Chemical Abstracts search on mosquito repellent inventions containing plant-derived EOs revealed 144 active patents mostly from Asia. Chinese, Japanese and Korean language patents and those of India (in English) accounted for roughly 3/4 of all patents. Since 1998 patents on EO-containing mosquito repellent inventions have almost doubled about every 4 years. In general, these patents describe repellent compositions for use in topical agents, cosmetic products, incense, fumigants, indoor and outdoor sprays, fibers, textiles among other applications. 67 EOs and 9 glyceridic oils were individually cited in at least 2 patents. Over 1/2 of all patents named just one EO. Citronella [Cymbopogon nardus (L.) Rendle, C.winterianus Jowitt ex Bor] and eucalyptus (Eucalyptus LʼHér. spp.) EOs were each cited in approximately 1/3 of all patents. Camphor [Cinnamomum camphora (L.) J. Presl], cinnamon (Cinnamomum zeylanicum Blume), clove [Syzygium aromaticum (L.) Merr. & L.M. Perry], geranium (Pelargonium graveolens LʼHér.), lavender (Lavandula angustifolia Mill.), lemon [Citrus × limon (L.) Osbeck], lemongrass [Cymbopogon citratus (DC.) Stapf] and peppermint (Mentha × piperita L.) EOs were each cited in > 10% of patents. Repellent chemicals present in EO compositions or added as pure “natural” ingredients such as geraniol, limonene, p-menthane-3,8-diol, nepetalactone and vanillin were described in approximately 40% of all patents. About 25% of EO-containing inventions included or were made to be used with synthetic insect control agents having mosquito repellent properties such as pyrethroids, N,N-diethyl-m-toluamide (DEET), (±)-p-menthane-3,8-diol (PMD) and dialkyl phthalates. Synergistic effects involving one or more EOs and synthetic and/or natural components were claimed in about 10% of all patents. Scientific literature sources provide evidence for the mosquito repellency of many of the EOs and individual chemical components found in EOs used in patented repellent inventions. © Georg Thieme Verlag KG Stuttgart · New York.

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

A Combined Approach of Infrared Spectroscopy and Multivariate Analysis for the Simultaneous Determination of Sugars and Fructans in Strawberry Juices During Storage.

PubMed

Cassani, Lucía; Santos, Mauricio; Gerbino, Esteban; Del Rosario Moreira, María; Gómez-Zavaglia, Andrea

2018-03-01

In this work, a Fourier transform mid-infrared spectroscopy (FTIR)-based method was developed for simultaneously quantifying simple sugars and exogenously added fructooligosaccharides (FOS) in strawberry juices preserved for up to 14 d using nonthermal techniques (geraniol and vanillin+ultrasound). The main spectral differences were observed in the 1200 to 900 cm -1 region. The presence of FOS was identified by the typical bands at 1134, 1034, and 935 cm -1 . During storage, a significant decrease of sucrose was concomitant to an increase of glucose and fructose in juices stored without any previous preservation treatment, as determined by high-performance liquid chromatography (HPLC). A principal component analysis was performed on the FTIR spectra corresponding to the different treatments. The groups observed explained more than 94% of the variance and were related to changes in the carbohydrate composition during storage. Then, different partial least square models (PLS) were defined to determine the concentrations of glucose, sucrose, fructose, and those of exogenously added FOS with degrees of polymerization within 3 and 5. The carbohydrates' concentrations determined by HPLC were used as reference method. The models were validated with independent sets of data. The mean of predicted values fitted nicely those obtained by HPLC (correlation and R 2  > 0.97), thus supporting the use of the PLS models to monitor the quality of strawberry juices in unknown samples. In conclusion, FTIR spectroscopy appears as an adequate analytical tool to quick assess whether juice formulations meet specifications in terms of authenticity, contamination and/or deterioration. FTIR spectroscopy provided a method potentially transferable to the food industry when associated with the multivariate analysis. The robust 21 PLS models defined in this work provided reliable tools for the rapid monitoring of juices' authenticity and/or deterioration. In this regard, FTIR associated to multivariate analysis enabled the determination of different sugars in a single measurement without the need of pure sugars as standards. This experimental simplicity supports the use of FTIR at the production line, and also contributes to save time in determining carbohydrates' composition and stability, in an environmentally friendly way. © 2017 Institute of Food Technologists®.

Essential Oil of Cymbopogon nardus (L.) Rendle: A Strategy to Combat Fungal Infections Caused by Candida Species

PubMed Central

De Toledo, Luciani Gaspar; Ramos, Matheus Aparecido Dos Santos; Spósito, Larissa; Castilho, Elza Maria; Pavan, Fernando Rogério; Lopes, Érica De Oliveira; Zocolo, Guilherme Julião; Silva, Francisca Aliny Nunes; Soares, Tigressa Helena; dos Santos, André Gonzaga; Bauab, Taís Maria; De Almeida, Margarete Teresa Gottardo

2016-01-01

Background: The incidence of fungal infections, especially those caused by Candida yeasts, has increased over the last two decades. However, the indicated therapy for fungal control has limitations. Hence, medicinal plants have emerged as an alternative in the search for new antifungal agents as they present compounds, such as essential oils, with important biological effects. Published data demonstrate important pharmacological properties of the essential oil of Cymbopogon nardus (L.) Rendle; these include anti-tumor, anti-nociceptive, and antibacterial activities, and so an investigation of this compound against pathogenic fungi is interesting. Objective: The aim of this study was to evaluate the chemical composition and biological potential of essential oil (EO) obtained from the leaves of C. nardus focusing on its antifungal profile against Candida species. Methods: The EO was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). Testing of the antifungal potential against standard and clinical strains was performed by determining the minimal inhibitory concentration (MIC), time-kill, inhibition of Candida albicans hyphae growth, and inhibition of mature biofilms. Additionally, the cytotoxicity was investigated by the IC50 against HepG-2 (hepatic) and MRC-5 (fibroblast) cell lines. Results: According to the chemical analysis, the main compounds of the EO were the oxygen-containing monoterpenes: citronellal, geranial, geraniol, citronellol, and neral. The results showed important antifungal potential for all strains tested with MIC values ranging from 250 to 1000 μg/mL, except for two clinical isolates of C. tropicalis (MIC > 1000 μg/mL). The time-kill assay showed that the EO inhibited the growth of the yeast and inhibited hyphal formation of C. albicans strains at concentrations ranging from 15.8 to 1000 μg/mL. Inhibition of mature biofilms of strains of C. albicans, C. krusei and C. parapsilosis occurred at a concentration of 10× MIC. The values of the IC50 for the EO were 96.6 μg/mL (HepG-2) and 33.1 μg/mL (MRC-5). Conclusion: As a major virulence mechanism is attributed to these types of infections, the EO is a promising compound to inhibit Candida species, especially considering its action against biofilm. PMID:27517903

Essential Oil of Cymbopogon nardus (L.) Rendle: A Strategy to Combat Fungal Infections Caused by Candida Species.

PubMed

De Toledo, Luciani Gaspar; Ramos, Matheus Aparecido Dos Santos; Spósito, Larissa; Castilho, Elza Maria; Pavan, Fernando Rogério; Lopes, Érica De Oliveira; Zocolo, Guilherme Julião; Silva, Francisca Aliny Nunes; Soares, Tigressa Helena; Dos Santos, André Gonzaga; Bauab, Taís Maria; De Almeida, Margarete Teresa Gottardo

2016-08-09

The incidence of fungal infections, especially those caused by Candida yeasts, has increased over the last two decades. However, the indicated therapy for fungal control has limitations. Hence, medicinal plants have emerged as an alternative in the search for new antifungal agents as they present compounds, such as essential oils, with important biological effects. Published data demonstrate important pharmacological properties of the essential oil of Cymbopogon nardus (L.) Rendle; these include anti-tumor, anti-nociceptive, and antibacterial activities, and so an investigation of this compound against pathogenic fungi is interesting. The aim of this study was to evaluate the chemical composition and biological potential of essential oil (EO) obtained from the leaves of C. nardus focusing on its antifungal profile against Candida species. The EO was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). Testing of the antifungal potential against standard and clinical strains was performed by determining the minimal inhibitory concentration (MIC), time-kill, inhibition of Candida albicans hyphae growth, and inhibition of mature biofilms. Additionally, the cytotoxicity was investigated by the IC50 against HepG-2 (hepatic) and MRC-5 (fibroblast) cell lines. According to the chemical analysis, the main compounds of the EO were the oxygen-containing monoterpenes: citronellal, geranial, geraniol, citronellol, and neral. The results showed important antifungal potential for all strains tested with MIC values ranging from 250 to 1000 μg/mL, except for two clinical isolates of C. tropicalis (MIC > 1000 μg/mL). The time-kill assay showed that the EO inhibited the growth of the yeast and inhibited hyphal formation of C. albicans strains at concentrations ranging from 15.8 to 1000 μg/mL. Inhibition of mature biofilms of strains of C. albicans, C. krusei and C. parapsilosis occurred at a concentration of 10× MIC. The values of the IC50 for the EO were 96.6 μg/mL (HepG-2) and 33.1 μg/mL (MRC-5). As a major virulence mechanism is attributed to these types of infections, the EO is a promising compound to inhibit Candida species, especially considering its action against biofilm.

An in-line micro-pyrolysis system to remove contaminating organic species for precise and accurate water isotope analysis by spectroscopic techniques

NASA Astrophysics Data System (ADS)

Panetta, R. J.; Hsiao, G.

2011-12-01

Trace levels of organic contaminants such as short alcohols and terpenoids have been shown to cause spectral interference in water isotope analysis by spectroscopic techniques. The result is degraded precision and accuracy in both δD and δ18O for samples such as beverages, plant extracts or slightly contaminated waters. An initial approach offered by manufacturers is post-processing software that analyzes spectral features to identify and flag contaminated samples. However, it is impossible for this software to accurately reconstruct the water isotope signature, thus it is primarily a metric for data quality. Here, we describe a novel in-line pyrolysis system (Micro-Pyrolysis Technology, MPT) placed just prior to the inlet of a cavity ring-down spectroscopy (CRDS) analyzer that effectively removes interfering organic molecules without altering the isotope values of the water. Following injection of the water sample, N2 carrier gas passes the sample through a micro-pyrolysis tube heated with multiple high temperature elements in an oxygen-free environment. The temperature is maintained above the thermal decomposition threshold of most organic compounds (≤ 900 oC), but well below that of water (~2000 oC). The main products of the pyrolysis reaction are non-interfering species such as elemental carbon and H2 gas. To test the efficacy and applicability of the system, waters of known isotopic composition were spiked with varying amounts of common interfering alcohols (methanol, ethanol, propanol, hexanol, trans-2-hexenol, cis-3-hexanol up to 5 % v/v) and common soluble plant terpenoids (carveol, linalool, geraniol, prenol). Spiked samples with no treatment to remove the organics show strong interfering absorption peaks that adversely affect the δD and δ18O values. However, with the MPT in place, all interfering absorption peaks are removed and the water absorption spectrum is fully restored. As a consequence, the δD and δ18O values also return to their original values, demonstrating effective removal of interfering species with no isotopic fractionation during the pyrolysis. Tests of water spiked quantitatively show the MPT is most effective at removing interferences up to 1 % v/v. This level is typical for plant extracts and interstitial waters, i.e. the majority of natural samples that suffer from spectral interference.

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.

Patch testing with fragrances: results of a multicenter study of the European Environmental and Contact Dermatitis Research Group with 48 frequently used constituents of perfumes.

PubMed

Frosch, P J; Pilz, B; Andersen, K E; Burrows, D; Camarasa, J G; Dooms-Goossens, A; Ducombs, G; Fuchs, T; Hannuksela, M; Lachapelle, J M

1995-11-01

The objective of this study was to determine the frequency of reactivity to a series of commonly used fragrances in dermatological patients. A total of 48 fragrances (FF) were chosen, based on the publication of Fenn in 1989 in which the top 25 constituents of 3 types (1. perfumes, 2. household products, 3. soaps) of 400 commercial products on the US market had been determined. In a pilot study on a total of 1069 patients in 11 centres, the appropriate test concentration and vehicle were examined. For most fragrances, 1% and 5% were chosen, and petrolatum proved to be the best vehicle in comparison to isopropyl myristate and diethyl phthalate. In the main study, a set of 5 to 10 fragrances at 2 concentrations was patch tested in each centre on a minimum of 100 consecutive patients seen in the patch test clinic. These patients were also patch tested to a standard series with the 8% fragrance mix (FM) and its 8 constituents. In patients with a positive reaction to any of the 48 FF, a careful history with regard to past or present reactions to perfumed products was taken. A total of 1323 patients were tested in 11 centres. The 8% FM was positive in 89 patients (8.3% of 1072 patients). Allergic reactions to the constituents were most frequent to oak moss (24), isoeugenol (20), eugenol (13), cinnamic aldehyde (10) and geraniol (8). Reactions read as allergic on day 3/4 were observed only 10X to 7 materials of the new series (Iso E Super (2), Lyral (3), Cyclacet (1), DMBCA (1), Vertofix (1), citronellol (1) and amyl salicylate (1)). The remaining 41 fragrances were negative. 28 irritant or doubtful reactions on day 3/4 were observed to a total of 19 FF materials (more than 1 reaction: 5% citronellol (2), 1% amyl salicylate (2), 1% isononyl acetate (3), 0.1% musk xylol (2), 1% citral (2), and 1% ionone beta (2)). Clinical relevance of positive reactions to any of the FF series was not proved in a single case. This included the 4 reactions in patients who were negative to the 8% FM. In conclusion, the top 25 fragrances commonly found in various products caused few reactions in dermatological patients and these few appeared to be clinically irrelevant, with the possible exception of Lyral. However, this data should be interpreted in the light of the relatively small number of patients tested (only 100 in most centres).

Flavor of cold-hardy grapes: impact of berry maturity and environmental conditions.

PubMed

Pedneault, Karine; Dorais, Martine; Angers, Paul

2013-11-06

Since the arrival on the market of high-quality cold-hardy grape varieties, northern winemaking has been developing tremendously in countries traditionally unsuited for grape and wine production. Cold-hardy grapes are mainly interspecific hybrids of Vitis vinifera with Vitis labrusca and Vitis riparia , making their chemical composition distinct from that of V. vinifera varieties traditionally used for winemaking and therefore limiting the use of current knowledge about V. vinifera varieties in the assessment of grape maturity. Consequently, to evaluate the flavor development of cold-hardy grapes in the province of Quebec, Canada, the ripening of Frontenac and Marquette berries in two vineyards located in the southwest (SW) and northeast (NE) areas of the province, starting at the beginning of veraison, was studied. Quality attributes, phenolic compounds, and aroma profiles showed significant changes during maturation. Although full maturity was reached for both Frontenac and Marquette in the SW vineyard (1380 accumulated growing degree days, based on 10 °C), the accumulation of 1035 growing degree days was not sufficient to fully ripen Frontenac and Marquette in the NE vineyard. Principal component analysis showed different ripening patterns for the two studied locations. The longer veraison in the SW vineyard resulted in higher quality attributes and higher flavor development for both Frontenac and Marquette. Under the colder conditions in the NE vineyard, metabolite accumulation was driven primarily by berry growth, and flavor development was limited. Besides growing degree days and technological parameters (total soluble solids, pH, titratable acidity), which provide significant guidelines for maturity assessment in cold climate, phenolic maturity may be followed by the accumulation of hydroxycinnamic esters and flavonoids, although the impact of these compound classes on quality remains to be determined in cold-climate wines. In both Frontenac and Marquette, aromatic maturity was best assessed using the ratio of cis-3-hexenol to trans-2-hexenal, which showed a constant decrease until maturity. Interestingly, a shift in C6 compound profile, illustrated by the progression of the sum of C6 compounds respectively produced from linoleic (C18:2; hexanal and 1-hexanol) and α-linolenic (C18:3; trans-2-hexenol and cis-3-hexenol) acids occurred during ripening, with α-linolenic acid (C18:3) degradation products decreasing in both varieties as maturation approached. At harvest, aroma profiles of both Frontenac and Marquette were dominated by C6 compounds (hexanal, trans-2-hexenal, 1-hexanol, cis-3-hexenol, and hexanoic acid), acetic acid, β-damascenone, and 2-phenylethanol, with Marquette additionally showing significant levels of monoterpenes (linalool, geraniol, and α-citral) and 1-octen-3-ol.

Microstructure of Mixed Surfactant Solutions by Electron Microscopy

NASA Astrophysics Data System (ADS)

Naranjo, Edward

1995-01-01

Surfactant mixtures add a new dimension to the design of complex fluid microstructure. By combining different surfactants it is not only possible to modify aggregate morphology and control the macrascopic properties of colloidal dispersions but also to produce a variety of novel synergistic phases. Mixed systems produce new microstructures by altering the intermolecular and interaggregate forces in ways impossible for single component systems. In this dissertation, we report on the phase behavior and microstructure of several synthetic and biological surfactant mixtures as elucidated by freeze-fracture and cryo-transmission electron microscopy. We have discovered that stable, spontaneous unilamellar vesicles can be prepared from aqueous mixtures of commercially available single-tailed cationic and anionic surfactants. Vesicle stability is determined by the length and volume of the hydrocarbon chains of the "catanionic" pairs. Mixtures containing bulky or branched surfactant pairs (C _{16}/C_{12 -14}) in water produce defect-free fairly monodisperse equilibrium vesicles at high dilution. In contrast, mixtures of catanionic surfactants with highly asymmetric tails (C_{16}/C_8 ) form phases of porous vesicles, dilute lamellar L_{alpha}, and anomalous isotropic L_3 phases. Images of the microstructure by freeze-fracture microscopy show that the L_3 phase consists of multiconnected self-avoiding bilayers with saddle shaped curvature. The forces between bilayers of vesicle-forming cationic and anionic surfactant mixtures were also measured using the Surface Force Apparatus (SFA). We find that the vesicles are stabilized by a long range electrostatic repulsion at large separations (>20 A) and an additional salt-independent repulsive force below 20 A. The measured forces correlate very well with the ternary phase diagram and the vesicle microstructures observed by electron microscopy. In addition to studying ionic surfactants, we have also done original work with biological surfactants. We have found that subtle changes by surfactant additives to phosphatidylcholines (PC) produce dramatic changes in the microstructure of the composite that are impossible to determine from simple scattering experiments. Novel microstructures were observed at mole ratios from 4/1 to 9/1 long chain (Di-C_{16}PC)/short chain lipid (Di-C_7PC), including disc-like micelles and rippled bilayers at room temperature. We have also observed for the first time the formation of single layered ripple phase bilayer fragments. The formation of such fragments eliminates a number of theories of formation of this unique structure that depend on coupling between bilayers. In a similar system, dimyristoyl phosphatidylcholine (DMPC) mixed with the branched alcohol geraniol produces a bluish and extremely viscoelastic phase of giant multilamellar wormy vesicles. This phase shows the Weissenberg effect under flow due to the distortion of the entangled vesicles and may be related to fluid lamellar phases and L _3 phases often seen in surfactant-alcohol -water systems. Lysophosphatidylcholine, the single-chain counterpart of the diacyl phospholipids, can also form bilayer phases when combined with long-chain fatty acids in water. The phase transition characteristics and appearance of the bilayers in equimolar mixtures of lysolipid and fatty acid are similar to those of the diacyl-PC. Electron microscopy reveals large extended multilayers in mixtures with excess lysolipid and multilamellar vesicles in mixtures with excess fatty acid.