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1

Plant Sterols and Stanols  

Microsoft Academic Search

The expanding market of ‘functional foods’ containing plant sterols and stanols has focused interest on their cholesterol-lowering effects as well on possible adverse effects. Trials of cholesterol lowering demonstrate that intake of 2 g\\/day of plant sterols and stanols reduces serum low-density lipoprotein (LDL) cholesterol concentrations by approximately 10%. Safety concerns regarding elevations in serum plant sterol levels, or effects

M. J. Tikkanen

2

Cholesterol-lowering effect of plant sterols.  

PubMed

Plant sterols are plant components that have a chemical structure similar to cholesterol except for the addition of an extra methyl or ethyl group; however, plant sterol absorption in humans is considerably less than that of cholesterol. In fact, plant sterols reduce cholesterol absorption and thus reduce circulating levels of cholesterol. Earlier studies that have tested the efficacy of plant sterols as cholesterol-lowering agents incorporated plant sterols into fat spreads. Later on, plant sterols were added to other food matrices, including juices, nonfat beverages, milk and yogurt, cheese, meat, croissants and muffins, and cereal and chocolate bars. The beneficial physiologic effects of plant sterols could be further enhanced by combining them with other beneficial substances, such as olive and fish oils, fibers, and soy proteins, or with exercise. The addition of plant sterols to the diet is suggested by health experts as a safe and effective way to reduce the risk of coronary heart disease. PMID:18937893

AbuMweis, Suhad S; Jones, Peter J H

2008-12-01

3

Metabolism of plant sterols by nematodes  

Microsoft Academic Search

Parasitic nematodes do not biosynthesize sterolsde novo and therefore possess a nutritional requirement for sterol, which must be obtained from their hosts. Consequently, the metabolism\\u000a of phytosterols by plant-parasitic nematodes is an important process with potential for selective exploitation. The sterol\\u000a compositions of several species of plant-parasitic nematodes were determined by capillary gas chromatography-mass spectrometry\\u000a and compared with the sterol

David J. Chitwood; William R. Lusby

1991-01-01

4

Customary Use of Plant Sterol and Plant Stanol Enriched Margarine Is Associated with Changes in Serum Plant Sterol and Stanol Concentrations in Humans1,2  

Microsoft Academic Search

The consumption of products enriched with plant sterol or stanol esters lowers serum total and LDL-cholesterol con- centrations, thereby most likely reducing the risk of coronary heart disease. However, using plant sterol (not plant stanol) enriched products elevates serum plant sterol concentrations in humans. This may be unwanted because health effects of elevated serum plant sterol concentrations are still controversial.

Heidi P. Fransen; Hans Verhagen; W. M. Monique Verschuren; Dieter Lutjohann; Klaus von Bergmann; Ronald P. Mensink

5

Reminiscences of research on the chemistry and biology of natural sterols in insects, plants and humans.  

PubMed

Natural sterols often occur as a heterogeneous mixture of homologs, which had disturbed the progress of steroid research. Development and application of GC methodology overcame this difficulty and enabled us to obtain detailed sterol profiles. Together, fine synthesis of stereo-defined isomers and homologs of steroids having oxygenated side chains allowed us to compare them with natural samples as well as to investigate structure-activity relationship. Advance of HPLC technology also facilitated the determination of the stereochemical structure of naturally occurring steroidal compounds, which were obtained only in minute amounts. This review highlights three topics out of our steroid research that have been performed mainly at Tokyo Institute of Technology around 1970-1990. These are sterol metabolism in insects focusing on the mechanism of the conversion of plant sterols to cholesterol and ecdysone biosynthesis, the synthesis and biochemical research of active forms of vitamin D3 derivatives, and the synthesis and microanalysis of plant hormone brassinosteroids. PMID:24126284

Ikekawa, Nobuo; Fujimoto, Yoshinori; Ishiguro, Masaji

2013-01-01

6

Reminiscences of research on the chemistry and biology of natural sterols in insects, plants and humans  

PubMed Central

Natural sterols often occur as a heterogeneous mixture of homologs, which had disturbed the progress of steroid research. Development and application of GC methodology overcame this difficulty and enabled us to obtain detailed sterol profiles. Together, fine synthesis of stereo-defined isomers and homologs of steroids having oxygenated side chains allowed us to compare them with natural samples as well as to investigate structure-activity relationship. Advance of HPLC technology also facilitated the determination of the stereochemical structure of naturally occurring steroidal compounds, which were obtained only in minute amounts. This review highlights three topics out of our steroid research that have been performed mainly at Tokyo Institute of Technology around 1970–1990. These are sterol metabolism in insects focusing on the mechanism of the conversion of plant sterols to cholesterol and ecdysone biosynthesis, the synthesis and biochemical research of active forms of vitamin D3 derivatives, and the synthesis and microanalysis of plant hormone brassinosteroids. PMID:24126284

IKEKAWA, Nobuo; FUJIMOTO, Yoshinori; ISHIGURO, Masaji

2013-01-01

7

Plant phloem sterol content: forms, putative functions, and implications for phloem-feeding insects  

E-print Network

was to determine the extent to which phloem sterols occur as free sterols, acylated sterols and/or steryl glycosides in two model plant sys- tems: bean (Phaseolus vulgaris) and tobacco (Nicotiana tabacum). The second objective was to determine, for each sterol... that will advance our understand- ing of both plant phloem sterol physiology/biochemistry, and the nutritional physiology/ecology of phloem-feeding insects. MATERIALS AND METHODS EXPERIMENTAL PLANTS Two plant species were used: Phaseolus vulgaris and Nicotiana...

Behmer, Spencer T.; Olszewski, Nathan; Sebastiani, John; Palka, Sydney; Sparacino, Gina; Sciarrno, Elizabeth; Grebenok, Robert J.

2013-09-24

8

Quantification of sterol lipids in plants by quadrupole time-of-flight mass spectrometry  

PubMed Central

Glycerolipids, sphingolipids, and sterol lipids constitute the major lipid classes in plants. Sterol lipids are composed of free and conjugated sterols, i.e., sterol esters, sterol glycosides, and acylated sterol glycosides. Sterol lipids play crucial roles during adaption to abiotic stresses and plant-pathogen interactions. Presently, no comprehensive method for sterol lipid quantification in plants is available. We used nanospray ionization quadrupole-time-of-flight mass spectrometry (Q-TOF MS) to resolve and identify the molecular species of all four sterol lipid classes from Arabidopsis thaliana. Free sterols were derivatized with chlorobetainyl chloride. Sterol esters, sterol glycosides, and acylated sterol glycosides were ionized as ammonium adducts. Quantification of molecular species was achieved in the positive mode after fragmentation in the presence of internal standards. The amounts of sterol lipids quantified by Q-TOF MS/MS were validated by comparison with results obtained with TLC/GC. Quantification of sterol lipids from leaves and roots of phosphate-deprived A. thaliana plants revealed changes in the amounts and molecular species composition. The Q-TOF method is far more sensitive than GC or HPLC. Therefore, Q-TOF MS/MS provides a comprehensive strategy for sterol lipid quantification that can be adapted to other tandem mass spectrometers. PMID:21382968

Wewer, Vera; Dombrink, Isabel; vom Dorp, Katharina; Dormann, Peter

2011-01-01

9

Effect of plant sterols on the lipid profile of patients with hypercholesterolaemia. Randomised, experimental study  

PubMed Central

Background Studies have been conducted on supplementing the daily diet with plant sterol ester-enriched milk derivatives in order to reduce LDL-cholesterol levels and, consequently, cardiovascular risk. However, clinical practice guidelines on hypercholesterolaemia state that there is not sufficient evidence to recommend their use in subjects with hypercholesterolaemia. The main objective of this study is to determine the efficacy of the intake of 2 g of plant sterol esters a day in lowering LDL-cholesterol levels in patients diagnosed with hypercholesterolaemia. The specific objectives are: 1) to quantify the efficacy of the daily intake of plant sterol esters in lowering LDL-cholesterol, total cholesterol and cardiovascular risk in patients with hypercholesterolaemia; 2) to evaluate the occurrence of adverse effects of the daily intake of plant sterol esters; 3) to identify the factors that determine a greater reduction in lipid levels in subjects receiving plant sterol ester supplements. Methods/Design Randomised, double-blind, placebo controlled experimental trial carried out at family doctors' surgeries at three health centres in the Health Area of Albacete (Spain). The study subjects will be adults diagnosed with "limit" or "defined" hypercholesterolaemia and who have LDL cholesterol levels of 130 mg/dl or over. A dairy product in the form of liquid yoghurt containing 2 g of plant sterol ester per container will be administered daily after the main meal, for a period of 24 months. The control group will receive a daily unit of yogurt not supplemented with plant sterol esters that has a similar appearance to the enriched yoghurt. The primary variable is the change in lipid profile at 1, 3, 6, 12, 18 and 24 months. The secondary variables are: change in cardiovascular risk, adherence to the dairy product, adverse effects, adherence to dietary recommendations, frequency of food consumption, basic physical examination data, health problems, lipid-lowering medication, physical activity, smoking habits and socio-demographic variables. Discussion If plant sterol ester supplements were effective a sounder recommendation for the consumption of plant sterols in subjects with hypercholesterolaemia could be made. Trial Registration Current Controlled Trials NCT01406106. PMID:21910898

2011-01-01

10

Protective Role of Plant Sterol and Stanol Esters in Liver Inflammation: Insights from Mice and Humans  

PubMed Central

The inflammatory component of non–alcoholic steatohepatitis (NASH) can lead to irreversible liver damage. Therefore there is an urgent need to identify novel interventions to combat hepatic inflammation. In mice, omitting cholesterol from the diet reduced hepatic inflammation. Considering the effects of plant sterol/stanol esters on cholesterol metabolism, we hypothesized that plant sterol/stanol esters reduces hepatic inflammation. Indeed, adding plant sterol/stanol esters to a high-fat-diet reduced hepatic inflammation as indicated by immunohistochemical stainings and gene expression for inflammatory markers. Finally, adding sterol/stanol esters lowered hepatic concentrations of cholesterol precursors lathosterol and desmosterol in mice, which were highly elevated in the HFD group similarly as observed in severely obese patients with NASH. In vitro, in isolated LPS stimulated bone marrow derived macrophages desmosterol activated cholesterol efflux whereas sitostanol reduced inflammation. This highly interesting observation that plant sterol/stanol ester consumption leads to complete inhibition of HFD-induced liver inflammation opens new venues in the treatment and prevention of hepatic inflammation. PMID:25356831

Plat, Jogchum; Hendrikx, Tim; Bieghs, Veerle; Jeurissen, Mike L. J.; Walenbergh, Sofie M. A.; van Gorp, Patrick J.; De Smet, Els; Konings, Maurice; Vreugdenhil, Anita C. E.; Guichot, Yasmin Dias; Rensen, Sander S.; Buurman, Wim A.; Greve, Jan Willem M.; Lutjohann, Dieter; Mensink, Ronald P.; Shiri-Sverdlov, Ronit

2014-01-01

11

Plant phloem sterol content: forms, putative functions, and implications for phloem-feeding insects.  

PubMed

All eukaryotes contain sterols, which serve as structural components in cell membranes, and as precursors for important hormones. Plant vegetative tissues are known to contain mixtures of sterols, but very little is known about the sterol composition of phloem. Plants are food for many animals, but plant-feeding arthropods (including phloem-feeding insets) are unique among animals in that they have lost the ability to synthesize sterols, and must therefore acquire these essential nutrients from their food, or via endosymbionts. Our paper starts by providing a very brief overview of variation in plant sterol content, and how different sterols can affect insect herbivores, including those specializing on phloem. We then describe an experiment, where we bulk collected phloem sap exudate from bean and tobacco, and analyzed its sterol content. This approach revealed two significant observations concerning phloem sterols. First, the phloem exudate from each plant was found to contain sterols in three different fractions - free sterols, sterols conjugated to lipids (acylated), and sterols conjugated to carbohydrates (glycosylated). Second, for both plants, cholesterol was identified as the dominant sterol in each phloem exudate fraction; the remaining sterols in each fraction were a mixture of common phytosterols. We discuss our phloem exudate sterol profiles in a plant physiology/biochemistry context, and how it relates to the nutritional physiology/ecology of phloem-feeding insects. We close by proposing important next steps that will advance our knowledge concerning plant phloem sterol biology, and how phloem-sterol content might affect phloem-feeding insects. PMID:24069026

Behmer, Spencer T; Olszewski, Nathan; Sebastiani, John; Palka, Sydney; Sparacino, Gina; Sciarrno, Elizabeth; Grebenok, Robert J

2013-01-01

12

Plant Oxidosqualene Metabolism: Cycloartenol Synthase-Dependent Sterol Biosynthesis in Nicotiana benthamiana  

PubMed Central

The plant sterol pathway exhibits a major biosynthetic difference as compared with that of metazoans. The committed sterol precursor is the pentacyclic cycloartenol (9?,19-cyclolanost-24-en-3?-ol) and not lanosterol (lanosta-8,24-dien-3?-ol), as it was shown in the late sixties. However, plant genome mining over the last years revealed the general presence of lanosterol synthases encoding sequences (LAS1) in the oxidosqualene cyclase repertoire, in addition to cycloartenol synthases (CAS1) and to non-steroidal triterpene synthases that contribute to the metabolic diversity of C30H50O compounds on earth. Furthermore, plant LAS1 proteins have been unambiguously identified by peptidic signatures and by their capacity to complement the yeast lanosterol synthase deficiency. A dual pathway for the synthesis of sterols through lanosterol and cycloartenol was reported in the model Arabidopsis thaliana, though the contribution of a lanosterol pathway to the production of 24-alkyl-?5-sterols was quite marginal (Ohyama et al. (2009) PNAS 106, 725). To investigate further the physiological relevance of CAS1 and LAS1 genes in plants, we have silenced their expression in Nicotiana benthamiana. We used virus induced gene silencing (VIGS) based on gene specific sequences from a Nicotiana tabacum CAS1 or derived from the solgenomics initiative (http://solgenomics.net/) to challenge the respective roles of CAS1 and LAS1. In this report, we show a CAS1-specific functional sterol pathway in engineered yeast, and a strict dependence on CAS1 of tobacco sterol biosynthesis. PMID:25343375

Gas-Pascual, Elisabet; Berna, Anne; Bach, Thomas J.; Schaller, Hubert

2014-01-01

13

Stability of plant sterols in ingredients used in functional foods.  

PubMed

The content of plant sterol (PS) and their oxidation products (POPs) in eight ingredients used to enrich functional foods was studied. A gas chromatographic (GC) technique with mass-spectrometric detection was used for identification, while GC with a flame ionization detector (GC-FID) was used for quantification. ?-Sitosterol was the most abundant phytosterol, and the main POPs found were derived from this compound (7?/?-hydroxysitosterol, 7-ketositosterol, and sitostanetriol). The total amount of POPs found in the ingredients ranged from 29.03 to 110.02 ?g/100 g PS. The ?-sitosterol oxidation rates ranged from 10 to 50 ?g ?-sitosterol oxides/100 g of ?-sitosterol. In view of this low rate of oxidation in the ingredients tested, it can be concluded that the PS remain stable in these ingredients. Significant correlations (p < 0.01) were found between total oxysitosterols versus ?-sitosterol contents (R(2) = 86.5%) and between total POPs and total PS (R(2) = 81.6%). PMID:21395311

González-Larena, Marina; García-Llatas, Guadalupe; Vidal, M Carmen; Sánchez-Siles, Luis Manuel; Barberá, Reyes; Lagarda, María Jesús

2011-04-27

14

Plant sterols as cholesterol-lowering agents: clinical trials in patients with hypercholesterolemia and studies of sterol balance.  

PubMed

We have evaluated the efficacy of plant sterol preparations from two different sources and in two different physical forms in lowering the plasma cholesterol of a total of 46 patients with type II hyperlipoproteinemia when given in addition to appropriate diet therapy. In addition, the mechanisms of the hypocholesterolemic effect were investigated in 7 patients by a sterol balance technique. The maximal mean cholesterol lowering in response to any preparation was 12 percent, although it was much greater in some individual patients. Sterol balance data showed that plant sterols inhibit cholesterol absorption with maximal negative cholesterol balance in adults at a dose of 3 g/day of a tall oil sterol suspension. Interestingly, maximal plasma cholesterol reduction in the adult outpatients on this preparation was seen at the same dose level. Since the tall oil sterol suspension is relatively palatable and is poorly absorbed, it has potential value as an adjunct to dietary therapy in patients with mild hypercholesterolemia for whom long-term drug therapy is deemed advisable. PMID:597345

Lees, A M; Mok, H Y; Lees, R S; McCluskey, M A; Grundy, S M

1977-11-01

15

Plant sterols and host plant suitability for a phloem-feeding insect  

E-print Network

-feeding insects may differ from chewing insect herbivores utilizing the same plant. Atyp- ical steroids, and possible reasons why plants apparently do not use them as defensive com- pounds are considered. KeyPlant sterols and host plant suitability for a phloem- feeding insect Spencer T. Behmer*,1 , Robert

Behmer, Spencer T.

16

Sterols of Delphinium ajacis; production and metabolic relationships in whole plants and callus tissue.  

PubMed

Sterols from whole nonsterile Delphinium ajacis plants and from sterile tissue cultures (callus) were identified and determined quantitatively. The major sterols in the whole plant tissues were sitosterol, campesterol and stigmasterol, whereas those in the callus tissue were stigmastanol, 24-ethylidenelophenol and Delta (7)-stigmastanol. Of the 21 compounds identified in callus tissue, 5 were not present in the whole plant, most notably Delta (7)-stigmastanol. For both sources of tissue, the sterol predominating in one was a minor component in the other (whole plant/tissue cultures: sitosterol 57%/5%; stigmastanol 2%/35%). On a tissue dry-weight basis, the amount of sterols isolated from callus tissue culture was ten to twenty times that obtained from the whole plant. Qualitatively the sterols from both sources fit into a metabolic scheme which proceeds from cycloartenol through 4,4-dimethylsterols and 4-methylsterols to sterols. A proposed metabolic pathway shows the differences in accumulation of sterols in the two types of tissue. The increase in sterol production in cultured cells, especially when favored by growth conditions, has promise for industrial application and in organic synthesis. PMID:17401988

Waller, G R; Mangiafico, S; Foster, R C; Lawrence, R H

1981-08-01

17

Plant Sterols as Dietary Adjuvants in the Reduction of Cardiovascular Risk: Theory and Evidence  

PubMed Central

Plant sterol-enriched foods are an effective dietary adjuvant in reducing cardiovascular risk by lowering total cholesterol and low density lipoprotein-cholesterol (LDL-C) in serum by up to ?15%. The mechanism of action of plant sterols is different from those of 3-hydroxy-3-methylglutaryl coenzyme A inhibitors (statins) and thus their effect is additive. Combining plant sterols with other dietary components known to reduce cholesterol in a portfolio approach has proven to be most effective for reduction of hypercholesterolemia and provide an alternative treatment option for clinicians. Plant sterol-enriched foods provides clinicians with a relatively cheap, safe, and effective way to help patients manage their cardiovascular risk. PMID:17319460

Patch, Craig S; Tapsell, Linda C; Williams, Peter G; Gordon, Michelle

2006-01-01

18

Plant sterols/stanols as cholesterol lowering agents: A meta-analysis of randomized controlled trials  

PubMed Central

Background Consumption of plant sterols has been reported to reduce low density lipoprotein (LDL) cholesterol concentrations by 5–15%. Factors that affect plant sterol efficacy are still to be determined. Objectives To more precisely quantify the effect of plant sterol enriched products on LDL cholesterol concentrations than what is reported previously, and to identify and quantify the effects of subjects’ characteristics, food carrier, frequency and time of intake on efficacy of plant sterols as cholesterol lowering agents. Design Fifty-nine eligible randomized clinical trials published from 1992 to 2006 were identified from five databases. Weighted mean effect sizes were calculated for net differences in LDL levels using a random effect model. Results Plant sterol containing products decreased LDL levels by 0.31 mmol/L (95% CI, –0.35 to –0.27, P=?plant sterols were incorporated into fat spreads, mayonnaise and salad dressing, milk and yoghurt comparing with other food products such as croissants and muffins, orange juice, non-fat beverages, cereal bars, and chocolate. Plant sterols consumed as a single morning dose did not have a significant effect on LDL cholesterol levels. Conclusion Plant sterol containing products reduced LDL concentrations but the reduction was related to individuals’ baseline LDL levels, food carrier, and frequency and time of intake. PMID:19109655

AbuMweis, Suhad S.; Barake, Roula; Jones, Peter J.H.

2008-01-01

19

Plant sterols: factors affecting their efficacy and safety as functional food ingredients  

PubMed Central

Plant sterols are naturally occurring molecules that humanity has evolved with. Herein, we have critically evaluated recent literature pertaining to the myriad of factors affecting efficacy and safety of plant sterols in free and esterified forms. We conclude that properly solubilized 4-desmetyl plant sterols, in ester or free form, in reasonable doses (0.8–1.0 g of equivalents per day) and in various vehicles including natural sources, and as part of a healthy diet and lifestyle, are important dietary components for lowering low density lipoprotein (LDL) cholesterol and maintaining good heart health. In addition to their cholesterol lowering properties, plant sterols possess anti-cancer, anti-inflammatory, anti-atherogenicity, and anti-oxidation activities, and should thus be of clinical importance, even for those individuals without elevated LDL cholesterol. The carotenoid lowering effect of plant sterols should be corrected by increasing intake of food that is rich in carotenoids. In pregnant and lactating women and children, further study is needed to verify the dose required to decrease blood cholesterol without affecting fat-soluble vitamins and carotenoid status. PMID:15070410

Berger, Alvin; Jones, Peter JH; Abumweis, Suhad S

2004-01-01

20

Effects of yoghurt enriched with plant sterols on serum lipids in patients with moderate hypercholesterolaemia.  

PubMed

The objective of the present study was to assess the effect of consumption of a yoghurt-based drink enriched with 1-2 g plant sterols/d on serum lipids, transaminases, vitamins and hormone status in patients with primary moderate hypercholesterolaemia. Thirty patients were randomly assigned to one of two treatment groups: a low-fat low-lactose yoghurt-based drink enriched with 1 g plant sterol extracted from soyabean/d v. a low-fat low-lactose yoghurt, for a period of 4 weeks. After a 2-week wash-out period, patients were crossed over for an additional 4-week period. Second, after a 4-week wash-out period, eleven patients were treated with 2 g plant sterols/d in a second open part of the study for a period of 8 weeks. The yoghurt enriched with plant sterols significantly reduced, in a dose-dependent manner, serum total cholesterol and LDL-cholesterol levels and LDL-cholesterol:HDL-cholesterol (P<0.001), whereas no changes were observed in HDL-cholesterol and triacylglycerol levels, either in the first or the second part of the study. There were only slight, not statistically significant, differences in serum transaminase, vitamin and hormone levels. To conclude, a low-fat yoghurt-based drink moderately enriched with plant sterols may lower total cholesterol and LDL-cholesterol effectively in patients with primary moderate hypercholesterolaemia. PMID:11502237

Volpe, R; Niittynen, L; Korpela, R; Sirtori, C; Bucci, A; Fraone, N; Pazzucconi, F

2001-08-01

21

Plant sterols in seeds of two species of Vaccinium ( V. myrtillus and V. vitis-idaea ) naturally distributed in Finland  

Microsoft Academic Search

Sterols in the seeds of wild Finnish blueberry (Vaccinium myrtillus) and lingonberry (Vaccinium vitis-idaea) were analyzed as TMS derivatives by gas chromatography-mass spectrometry. Free and esterified sterols constituted 0.7% and 0.3% of the seed oil of V. myrtillus, respectively, whereas in the seed oil of V. vitis-idaea the sterols in the two fractions were equally represented at 0.5-0.6%. Sitosterol (85%

Baoru Yang; Jani Koponen; Raija Tahvonen; Heikki Kallio

2003-01-01

22

Effect of plant sterols and tannins on Phytophthora ramorum growth and sporulation.  

PubMed

Elicitin-mediated acquisition of plant sterols is required for growth and sporulation of Phytophthora spp. This study examined the interactions between elicitins, sterols, and tannins. Ground leaf tissue, sterols, and tannin-enriched extracts were obtained from three different plant species (California bay laurel, California black oak, and Oregon white oak) in order to evaluate the effect of differing sterol/tannin contents on Phytophthora ramorum growth. For all three species, high levels of foliage inhibited P. ramorum growth and sporulation, with a steeper concentration dependence for the two oak samples. Phytophthora ramorum growth and sporulation were inhibited by either phytosterols or tannin-enriched extracts. High levels of sterols diminished elicitin gene expression in P. ramorum; whereas the tannin-enriched extract decreased the amount of 'functional' or ELISA-detectable elicitin, but not gene expression. Across all treatment combinations, P. ramorum growth and sporulation correlated strongly with the amount of ELISA-detectable elicitin (R (2)?= 0.791 and 0.961, respectively). PMID:23689874

Stong, Rachel A; Kolodny, Eli; Kelsey, Rick G; González-Hernández, M P; Vivanco, Jorge M; Manter, Daniel K

2013-06-01

23

Differential Modulation of Membrane Structure and Fluctuations by Plant Sterols and Cholesterol  

PubMed Central

We have studied the concentration and temperature dependent influence of cholesterol, stigmasterol, and sitosterol on the global structure and the bending fluctuations of fluid dimyristoyl phosphatidylcholine and palmitoyl oleoyl phosphatidylcholine bilayers applying small-angle x-ray scattering, as well as dilatometry and ultrasound velocimetry. Independent of the lipid matrix, cholesterol was found to be most efficient in modulating bilayer thickness and elasticity, followed by sitosterol and stigmasterol. This can be attributed to the additional ethyl groups and double bond at the C17 alkyl side-chain of the two plant sterols. Hence, it seems that some flexibility of the sterol hydrocarbon chain is needed to accommodate within the lipid bilayer. In addition, we did not observe two populations of membranes within the putative liquid-ordered/liquid-disordered phase coexistence regime of binary sterol/lipid mixtures. Instead, the diffraction patterns could be interpreted in terms of a uniform phase. This lends further support to the idea of compositional fluctuations of unstable sterol rich domains recently brought up by fluorescence microscopy experiments, which contrasts the formation of stable domains within the miscibility gap of binary lipid/sterol mixtures. PMID:18234811

Hodzic, Aden; Rappolt, Michael; Amenitsch, Heinz; Laggner, Peter; Pabst, Georg

2008-01-01

24

Serum sterol responses to increasing plant sterol intake from natural foods in the Mediterranean diet  

Microsoft Academic Search

Background Phytosterols in natural foods are thought to inhibit cholesterol absorption. The Mediterranean diet is rich in phytosterol-containing plant foods. Aim of the study To assess whether increasing phytosterol intake from natural foods was associated with a choles- terol-lowering effect in a substudy of a randomized trial of nutritional intervention with Mediterranean diets for pri- mary cardiovascular prevention (PREDIMED study).

Valentina Ruiz-Gutierrez; Ramon Estruch; Emilio Ros

25

Serum sterol responses to increasing plant sterol intake from natural foods in the Mediterranean diet  

Microsoft Academic Search

Background  Phytosterols in natural foods are thought to inhibit cholesterol absorption. The Mediterranean diet is rich in phytosterol-containing\\u000a plant foods.\\u000a \\u000a \\u000a \\u000a Aim of the study  To assess whether increasing phytosterol intake from natural foods was associated with a cholesterol-lowering effect in a\\u000a substudy of a randomized trial of nutritional intervention with Mediterranean diets for primary cardiovascular prevention\\u000a (PREDIMED study).\\u000a \\u000a \\u000a \\u000a Methods  One hundred and six

Verónica Escurriol; Montserrat Cofán; Mercè Serra; Mónica Bulló; Josep Basora; Jordi Salas-Salvadó; Dolores Corella; Itziar Zazpe; Miguel A. Martínez-González; Valentina Ruiz-Gutiérrez; Ramón Estruch; Emilio Ros

2009-01-01

26

21 CFR 101.83 - Health claims: plant sterol/stanol esters and risk of coronary heart disease (CHD).  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Health claims: plant sterol/stanol esters...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...FOOD LABELING Specific Requirements for Health Claims § 101.83 Health...

2010-04-01

27

Cholesterol absorption: Influence of body weight and the role of plant sterols  

Microsoft Academic Search

Cholesterol absorption and synthesis are inter-regulated, so if one changes then the other changes in the opposite direction.\\u000a The regulation and detailed mechanism of cholesterol absorption have been intensely investigated. Inhibition of cholesterol\\u000a absorption has become an additional factor for cholesterol lowering. Agents inhibiting cholesterol absorption, mainly plant\\u000a stanols and sterols or ezetimibe, usually lower low-density lipoprotein cholesterol in monotherapy

Helena Gylling; Tatu A. Miettinen

2005-01-01

28

The effect of combining plant sterols, soy protein, viscous fibers, and almonds in treating hypercholesterolemia  

Microsoft Academic Search

Reductions in low-density lipoprotein-cholesterol (LDL-C) result from diets containing almonds, or diets that are either low in saturated fat or high in viscous fibers, soy proteins, or plant sterols. We have therefore combined all of these interventions in a single diet (portfolio diet) to determine whether cholesterol reductions could be achieved of similar magnitude to those reported in recent statin

David J. A Jenkins; Cyril W. C Kendall; Augustine Marchie; Dorothea Faulkner; Edward Vidgen; Karen G Lapsley; Elke A Trautwein; Tina L Parker; Robert G Josse; Lawrence A Leiter; Philip W Connelly

2003-01-01

29

Plant sterol esters lower plasma lipids and most carotenoids in mildly hypercholesterolemic adults  

Microsoft Academic Search

The ability of plant sterol esters (PSE) in salad dressing to modify plasma lipids and carotenoids was determined in 26 men\\u000a and 27 women fed controlled, weight-maintaining, isocaloric diets. Diets contained typical American foods that provided 32%\\u000a of energy from fat. Dressings contained 8 g (ranch) or 4 g (Italian) of fat per serving. PSF (3.6 g\\/d) were provided in

Joseph T. Judd; David J. Baer; Shirley C. Chen; Beverly A. Clevidence; Richard A. Muesing; Matthew Kramer; Gert W. Meijer

2002-01-01

30

Enzyme catalyzed synthesis of structured phospholipids with conjugated linoleic acid and plant sterols  

E-print Network

. I would like to thank Dr. Huanbiao Mo for the study of cancer cells. I would like to thank Dr. Ronald MacFarlane and Dr. Zachlyn Farwig for mass spectroscopic analysis of samples and suggestions to identify my new reaction compounds. I also............................................................. 68 18 Suppression of murine B16 melanoma skin tumor cells by CLA-PL................... 87 19 Suppression of Caco-2 colon cancer cells by CLA isomers................................. 87 20 Examples of different dosage forms of plant sterols...

Hossen, Md Monjur

2006-08-16

31

Role of membrane sterols and cortical microtubules in gravity resistance in plants  

NASA Astrophysics Data System (ADS)

Resistance to the gravitational force is a principal graviresponse in plants comparable to gravitropism Nevertheless only limited information has been obtained for this graviresponse We have examined mechanisms of signal perception transformation and transduction of the perceived signal and response to the transduced signal in gravity resistance using hypergravity conditions produced by centrifugation In Arabidopsis hypocotyls hypergravity treatment greatly increased the expression level of 3-hydroxy-3-methylglutaryl-Coenzyme A reductase HMGR which catalyzes a reaction producing mevalonic acid a key precursor of terpenoids such as membrane sterols Geranyl diphosphate synthase gene was also up-regulated by hypergravity whereas the expression of other genes involved in membrane lipid metabolism was not influenced Hypergravity caused an increase in sterol content in azuki bean epicotyls but not in phospholipid glycolipid or fatty acid content Also hypergravity did not influence fatty acid composition in any lipid class Thus the effect of hypergravity on membrane lipid metabolism was specific for sterol synthesis On the other hand alpha- and beta-tubulin genes were up-regulated by hypergravity treatment in Arabidopsis hypocotyls Hypergravity also induced reorientation of cortical microtubules in azuki epicotyls the percentage of epidermal cells with transverse microtubles was decreased whereas that with longitudinal microtubules was increased Inhibitors of HMGR action and microtubule-disrupting agents completely prevented the gravity resistance

Hoson, T.; Koizumi, T.; Matsumoto, S.; Kumasaki, S.; Soga, K.; Wakabayashi, K.; Sakaki, T.

32

Involvement of membrane sterols in hypergravity-induced modifications of growth and cell wall metabolism in plant stems  

NASA Astrophysics Data System (ADS)

Organisms living on land resist the gravitational force by constructing a tough body Plants have developed gravity resistance responses after having first went ashore more than 500 million years ago The mechanisms of gravity resistance responses have been studied under hypergravity conditions which are easily produced on earth by centrifugation In Arabidopsis hypocotyls hypergravity treatment greatly increased the expression level of 3-hydroxy-3-methylglutaryl-Coenzyme A reductase HMGR which is involved in synthesis of terpenoids such as membrane sterols In the present study we examined the role of membrane sterols in gravity resistance in plants by analyzing sterol levels of stem organs grown under hypergravity conditions and by analyzing responses to hypergravity of the organs whose sterol level was modulated Hypergravity inhibited elongation growth but stimulated lateral expansion of Arabidopsis hypocotyls and azuki bean epicotyls Under hypergravity conditions sterol levels were kept high as compared with 1 g controls during incubation Lovastatin an inhibitor HMGR prevented lateral expansion as the gravity resistance response in azuki bean epicotyls Similar results were obtained in analyses with loss of function mutants of HMGR in Arabidopsis It has been shown that sterols play a role in cellulose biosynthesis probably as the primer In wild type Arabidopsis hypocotyls hypergravity increased the cellulose content but it did not influence the content in HMGR mutants These results suggest that hypergravity increases

Koizumi, T.; Soga, K.; Wakabayashi, K.; Suzuki, M.; Muranaka, T.; Hoson, T.

33

Cholesterol-lowering effects of plant sterol esters and non-esterified stanols in margarine, butter and low-fat foods  

Microsoft Academic Search

Objectives: To determine the efficacy on plasma cholesterol-lowering of plant sterol esters or non-esterified stanols eaten within low-fat foods as well as margarine.Design: Randomised, controlled, single-blind study with sterol esters and non-esterified plant stanols provided in breakfast cereal, bread and spreads. Study 1 comprised 12 weeks during which sterol esters (2.4 g) and stanol (2.4 g) -containing foods were eaten

P Nestel; M Cehun; S Pomeroy; M Abbey; G Weldon

2001-01-01

34

Mycoplasma lactucae sp. nov., a sterol-requiring mollicute from a plant surface.  

PubMed

Strain 831-C4T (T = type strain), isolated from the surface of lettuce plants (Lactuca sativa) obtained from a retail food market, was shown to be a sterol-requiring mollicute. Morphological examination of this organism by electron and dark-field microscopic techniques showed that it consists of small, nonhelical, nonmotile, pleomorphic coccoid cells, with individual cells surrounded by a single cytoplasmic membrane. No evidence of a cell wall was observed. The organism grew rapidly in all conventional culture medium formulations for mollicutes in either aerobic or anaerobic environments. The optimum temperature for growth was 30 degrees C, but multiplication occurred at 18 to 37 degrees C. Strain 831-C4T catabolized glucose, but hydrolysis of arginine or urea could not be demonstrated. The genome size of strain 831-C4T was determined to be about 569 megadaltons, while the base composition (guanine-plus-cytosine content) of the DNA was 30.0 mol%. Recent studies in which we compared the 16S rRNA sequences of strain 831-C4T with those of more than 40 other mollicutes indicated that this organism is phylogenetically related to the Spiroplasma-Mycoplasma mycoides clade. Strain 831-C4T was serologically unrelated to the type strains of previously described Mycoplasma species and to 18 other unclassified sterol-requiring isolates cultivated from various animal, plant, or insect sources. Strain 831-C4T (= ATCC 49193) is the type strain of Mycoplasma lactucae sp. nov. PMID:2223606

Rose, D L; Kocka, J P; Somerson, N L; Tully, J G; Whitcomb, R F; Carle, P; Bové, J M; Colflesh, D E; Williamson, D L

1990-04-01

35

Genetic variation in plant CYP51s confers resistance against voriconazole, a novel inhibitor of brassinosteroid-dependent sterol biosynthesis.  

PubMed

Brassinosteroids (BRs) are plant steroid hormones with structural similarity to mammalian sex steroids and ecdysteroids from insects. The BRs are synthesized from sterols and are essential regulators of cell division, cell elongation and cell differentiation. In this work we show that voriconazole, an antifungal therapeutic drug used in human and veterinary medicine, severely impairs plant growth by inhibiting sterol-14?-demethylation and thereby interfering with BR production. The plant growth regulatory properties of voriconazole and related triazoles were identified in a screen for compounds with the ability to alter BR homeostasis. Voriconazole suppressed growth of the model plant Arabidopsis thaliana and of a wide range of both monocotyledonous and dicotyledonous plants. We uncover that voriconazole toxicity in plants is a result of a deficiency in BRs that stems from an inhibition of the cytochrome P450 CYP51, which catalyzes a step of BR-dependent sterol biosynthesis. Interestingly, we found that the woodland strawberry Fragaria vesca, a member of the Rosaceae, is naturally voriconazole resistant and that this resistance is conferred by the specific CYP51 variant of F. vesca. The potential of voriconazole as a novel tool for plant research is discussed. PMID:23335967

Rozhon, Wilfried; Husar, Sigrid; Kalaivanan, Florian; Khan, Mamoona; Idlhammer, Markus; Shumilina, Daria; Lange, Theo; Hoffmann, Thomas; Schwab, Wilfried; Fujioka, Shozo; Poppenberger, Brigitte

2013-01-01

36

Genetic Variation in Plant CYP51s Confers Resistance against Voriconazole, a Novel Inhibitor of Brassinosteroid-Dependent Sterol Biosynthesis  

PubMed Central

Brassinosteroids (BRs) are plant steroid hormones with structural similarity to mammalian sex steroids and ecdysteroids from insects. The BRs are synthesized from sterols and are essential regulators of cell division, cell elongation and cell differentiation. In this work we show that voriconazole, an antifungal therapeutic drug used in human and veterinary medicine, severely impairs plant growth by inhibiting sterol-14?-demethylation and thereby interfering with BR production. The plant growth regulatory properties of voriconazole and related triazoles were identified in a screen for compounds with the ability to alter BR homeostasis. Voriconazole suppressed growth of the model plant Arabidopsis thaliana and of a wide range of both monocotyledonous and dicotyledonous plants. We uncover that voriconazole toxicity in plants is a result of a deficiency in BRs that stems from an inhibition of the cytochrome P450 CYP51, which catalyzes a step of BR-dependent sterol biosynthesis. Interestingly, we found that the woodland strawberry Fragaria vesca, a member of the Rosaceae, is naturally voriconazole resistant and that this resistance is conferred by the specific CYP51 variant of F. vesca. The potential of voriconazole as a novel tool for plant research is discussed. PMID:23335967

Rozhon, Wilfried; Husar, Sigrid; Kalaivanan, Florian; Khan, Mamoona; Idlhammer, Markus; Shumilina, Daria; Lange, Theo; Hoffmann, Thomas; Schwab, Wilfried; Fujioka, Shozo; Poppenberger, Brigitte

2013-01-01

37

Sterol and n-alkane biomarker composition of modern fen plants - potential application for palaeoecological analyses  

NASA Astrophysics Data System (ADS)

Acute and contemporary questions related to human-induced changes in climate have emphasized the importance of peatland research because peatlands store large quantities of carbon. Historically, pristine mires have been long-term sinks for atmospheric carbon because of a slow decomposition rate of the organic matter once below the water table. However, the net carbon balance of mires is highly sensitive and reflects changes in moisture conditions and consequent changes in vegetation assemblages. Historical variations in climate and hydrology are recorded in peat layers as alteration in the assemblages of different biological organisms. Past vegetation assemblages are in a key role when reconstructing the past moisture conditions that control peatland carbon dynamics. In order to evaluate the role of northern peatlands as carbon sinks or sources in changing future climate, it is important to understand the past mechanisms: how mires have earlier responded to climate forcing. An especially useful proxy method to reconstruct past environmental changes is the plant macrofossil method. Large parts of northern peatlands are fens, where, as a result of fast surface decay, major parts of the peat below the surface layer is highly humified. Bog peats, in turn, usually contain relatively well preserved plant material for palaeoecological examination, but highly humified layers can also be found underneath the top layers of bog peats. A high degree of humification constrains palaeo-botanical and -climatical studies because reliable identification of different fossil vegetation components is difficult. Previous work has shown that plant biomarkers (compounds that can be linked to specific plant types) can be successfully applied to indentify modern and fossil plant groups from less-humified bog peat. In this study we apply selected organic geochemistry methods to fen plant species to investigate the potential for biomarkers to characterise different fen plants. We focus on plant types that would give insight into major palaeoecological challenges (e.g. Sphagnum subsecundum, Warnstorfia exannulata, Carex livida). We report n-alkane and sterol distributions and concentrations in shoots, stems and roots from 12 plant species common to fens. The primary results are promising, confirming some previously established relationships in peat-forming plants e.g. n-alkane chain length differs between the main plant types (e.g. Sphagnum versus non-Sphagnum). However, we also find that biomarker composition, and thus interpretation of the chemical fingerprints of fen plants, is not as straightforward as in bog plants. The implications of these results for palaeo-ecological investigations are discussed.

Ronkainen, T.; McClymont, E. L.; Väliranta, M.; Tuittila, E.

2011-12-01

38

Effect of free plant sterols in low-fat milk on serum lipid profile in hypercholesterolemic subjects  

Microsoft Academic Search

Objective: To determine the effect of nonesterified, nonhydrogenated plant sterols solubilized in a partly vegetable oil-filled low-fat milk on serum low-density lipoprotein cholesterol (LDL) in mildly hypercholesterolemic patients.Design: Double-blind, randomized, placebo-controlled three-arm crossover study.Setting: Outpatient clinical trial.Subjects: A total of 138 patients were screened, providing 81 patients for randomization; 71 patients completed the study.Interventions: The study product was a 500

A B Thomsen; H B Hansen; C Christiansen; H Green; A Berger

2004-01-01

39

Additive effect of plant sterol-ester margarine and cerivastatin in lowering low-density lipoprotein cholesterol in primary hypercholesterolemia  

Microsoft Academic Search

The objective of this study was to evaluate whether plant sterol-ester margarine has an additive or interactive effect on low-density lipoprotein (LDL) cholesterol reduction when ingested in combination with a statin drug. This was a multicenter, randomized, double-blind study with 4 parallel treatment arms in a balanced 2 × 2 factorial design. The 4 daily treatment options were: (1) placebo

Leon A Simons

2002-01-01

40

Sterols of the fungi - Distribution and biosynthesis.  

NASA Technical Reports Server (NTRS)

The importance of sterols in the growth and reproduction in fungi is becoming increasingly apparent. This article concerns the composition and biosynthesis of ergosterol in these organisms. Comparison to plant and animal sterol formation are made.

Weete, J. D.

1973-01-01

41

Loci on chromosomes 14 and 2, distinct from ABCG5/ABCG8, regulate plasma plant sterol levels in a C57BL/6J × CASA/Rk intercross  

PubMed Central

Plasma plant sterol levels differ among humans due to genetic and dietary factors. A disease characterized by high plasma plant sterol levels, ?-sitosterolemia, was recently found to be due to mutations at the ABCG5/ABCG8 locus. To detect variants at this and other loci, a genetic cross was carried out between two laboratory mouse strains. Parental C57BL/6J had almost twice the campesterol and sitosterol levels compared with parental CASA/Rk mice, and F1 mice had levels halfway between the parentals. An intercross between F1s was performed and plasma plant sterol levels measured in 102 male and 99 female F2 mice. Plasma plant sterols in F2s displayed a unimodal distribution, suggesting the effects of several rather a single major gene. In the F2 mice, a full genome scan revealed significant linkages on chromosomes 14 and 2. With regard to chromosome 14, analysis showed a single peak for linkage at 17 cM with a logarithm of odds (LOD) score of 9.9, designated plasma plant sterol 14 (Plast14). With regard to chromosome 2, analysis showed two significant peaks for linkage at 18 and 65 cMs with LOD scores of 4.1 and 3.65, respectively, designated Plast2a and Plast2b, respectively. Four interactions between loci, predominantly of an additive nature, were also demonstrated, the most significant between Plast14 and Plast2b (LOD 16.44). No significant linkage or gene interaction was detected for the ABCG5/ABCG8 locus on chromosome 17. Therefore, other genes besides ABCG5/ABCG8 influence plasma plant sterol levels and now become candidates to explain differences in plasma plant sterol levels between humans. PMID:12446833

Sehayek, Ephraim; Duncan, Elizabeth M.; Lutjohann, Dieter; von Bergmann, Klaus; Ono, Jennie G.; Batta, Ashok K.; Salen, Gerald; Breslow, Jan L.

2002-01-01

42

Cholesterol precursors and plant sterols in children with food allergy1,2  

Microsoft Academic Search

Background: The data on lipid metabolism in allergic children is limited. Objective: We investigated lipid and sterol metabolism in young children whose diets were restricted because of food allergy. Design: Children in group A (n = 21; mean (± SD) age: 1.78 ± 0.73 y) were allergic to fish, eggs, and either cow milk or cereals; those in group B

Päivi Joki; Hanna Suomalainen; Kirsi-Marjut Järvinen; Kaisu Juntunen-Backman; Helena Gylling; Tatu A Miettinen; Marjatta Antikainen

43

Fish-oil esters of plant sterols differ from vegetable-oil sterol esters in triglycerides lowering, carotenoid bioavailability and impact on plasminogen activator inhibitor-1 (PAI-1) concentrations in hypercholesterolemic subjects  

Microsoft Academic Search

BACKGROUND: Consumption of plant sterol (PS) esters lower low-density lipoprotein (LDL)-cholesterol levels by suppressing intestinal absorption of cholesterol. Commercially available PS are mainly esterified to omega-6 fatty acid (FA), such as sunflower oil (SO) FA. Emerging trends include using other sources such as olive oil (OO) or omega-3 FA from fish oil (FO), known to exert potent hypotriglyceridemic effects. Our

Peter JH Jones; Isabelle Demonty; Yen-Ming Chan; Yael Herzog; Dori Pelled

2007-01-01

44

Distribution and Functions of Sterols and Sphingolipids  

PubMed Central

Sterols and sphingolipids are considered mainly eukaryotic lipids even though both are present in some prokaryotes, with sphingolipids being more widespread than sterols. Both sterols and sphingolipids differ in their structural features in vertebrates, plants, and fungi. Interestingly, some invertebrates cannot synthesize sterols de novo and seem to have a reduced dependence on sterols. Sphingolipids and sterols are found in the plasma membrane, but we do not have a clear picture of their precise intracellular localization. Advances in lipidomics and subcellular fractionation should help to improve this situation. Genetic approaches have provided insights into the diversity of sterol and sphingolipid functions in eukaryotes providing evidence that these two lipid classes function together. Intermediates in sphingolipid biosynthesis and degradation are involved in signaling pathways, whereas sterol structures are converted to hormones. Both lipids have been implicated in regulating membrane trafficking. PMID:21454248

Hannich, J. Thomas; Umebayashi, Kyohei; Riezman, Howard

2011-01-01

45

Determination of Sterols in Foods: Recovery of Free, Esterified, and Glycosidic Sterols  

Microsoft Academic Search

A reliable method for routine use in the determination of sterols in foods is described. In the sample preparation procedure, acid hydrolysis prior to alkaline saponification was used to liberate glycosidic sterols. Sterols were analyzed by capillary gas chromatography as the trimethylsilyl ether derivatives and quantified using an internal standard (dihydrocholesterol). In method development, the main focus was on optimization

Jari Toivo; Katherine Phillips; Anna-Maija Lampi; Vieno Piironen

2001-01-01

46

Sterol-Dependent Induction of Plant Defense Responses by a Microbe-Associated Molecular Pattern from Trichoderma viride1[W][OPEN  

PubMed Central

Plant-microbe interactions involve numerous regulatory systems essential for plant defense against pathogens. An ethylene-inducing xylanase (Eix) of Trichoderma viride is a potent elicitor of plant defense responses in specific cultivars of tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum). We demonstrate that tomato cyclopropyl isomerase (SlCPI), an enzyme involved in sterol biosynthesis, interacts with the LeEix2 receptor. Moreover, we examined the role of SlCPI in signaling during the LeEix/Eix defense response. We found that SlCPI is an important factor in the regulation of the induction of defense responses such as the hypersensitive response, ethylene biosynthesis, and the induction of pathogenesis-related protein expression in the case of LeEix/Eix. Our results also suggest that changes in the sterol composition reduce LeEix internalization, thereby attenuating the induction of plant defense responses. PMID:24351686

Sharfman, Miya; Bar, Maya; Schuster, Silvia; Leibman, Meirav; Avni, Adi

2014-01-01

47

Effects of Sterol Structure on Insect Herbivore Physiology, Biochemistry and Molecular Biology  

E-print Network

. Cholesterol is the most common sterol in plant-feeding insects, but because plants contain very little cholesterol, plant-feeding insects must convert plant sterols into cholesterol. In this dissertation I investigate the effect of common and novel plant...

Jing, Xiangfeng

2012-02-14

48

Sterols heating: degradation and formation of their ring-structure polar oxidation products.  

PubMed

Cholesterol and phytosterols can be oxidised under heating conditions to give sterol oxidation products (SOPs), known by their toxic effects. This paper studied the degradation of cholesterol and three plant sterols during a 360 min heating treatment (180 °C). The formation and further degradation of SOPs was also analysed by GC-MS. Results revealed a sterol susceptibility to degradation according to the following decreasing order: campesterol??-sitosterol?stigmasterol>cholesterol. The degradation curve fit (R(2)=0.907-0.979) a logarithmic model. SOPs increased their concentration during the first 5-10 min and thereafter, their degradation rate was higher than their formation rate, resulting in a decrease over time. Irrespective of the sterol from which they had derived, 7-keto derivatives presented the highest levels throughout the entire process, and also SOPs with the same type of oxidation followed a similar degradation pattern (R=0.90-0.99). PMID:22868149

Barriuso, Blanca; Otaegui-Arrazola, Ane; Menéndez-Carreño, María; Astiasarán, Iciar; Ansorena, Diana

2012-11-15

49

The plant sterol guggulsterone attenuates inflammation and immune dysfunction in murine models of inflammatory bowel disease.  

PubMed

Inflammatory bowel diseases (IBD) are chronic inflammatory and relapsing diseases of the gut that may manifest as either Crohn's disease (CD) or ulcerative colitis (UC). CD and UC are immunologically different diseases characterized by exacerbated Th1 and Th2 response. T-cell resistance against apoptosis contributes to inappropriate T-cell accumulation and the perpetuation of chronic mucosal inflammation. In the present study we have investigated the effect exerted by guggulsterone (GS) a plant derived steroid isolated from the gum resin of the Commiphora mukul tree, in two models of intestinal inflammation induced in mice by trinitro-benzene sulfonic acid (TNBS) and oxazolone. We provided evidence that E-GS protects mice against development of sign and symptoms of colon inflammation. E-GS effectively attenuated the severity of wasting disease and the fecal score and colon inflammation as assessed by measuring the macroscopic- and microscopic-damage scores. Administration Z-GS failed to ameliorate colon inflammation in TNBS-induced colitis and had a partial effect in oxazolone-induced colitis. In vitro, mechanistic studies carried out using CD4+ cells isolated from the intestinal lamina propria demonstrate that GS effectively regulates the function of effector T cells by modulating cell signaling activation pathway caused by CD3/CD28. The net biological effects resulting from exposure to GS includes attenuation of generation of interleukin-2 and -4 and interferon-gamma as well as T cell proliferation. In conclusion, GS is an anti-inflammatory compound with the capacity to prevent and ameliorate T-cell-induced colitis. These data ground the use of GS, a natural cholesterol-lowering agent, in the treatment of chronic inflammatory diseases. PMID:19555671

Mencarelli, Andrea; Renga, Barbara; Palladino, Giuseppe; Distrutti, Eleonora; Fiorucci, Stefano

2009-11-01

50

Thresholds for Sterol-Limited Growth of Daphnia magna: A Comparative Approach Using 10 Different Sterols.  

PubMed

Arthropods are incapable of synthesizing sterols de novo and thus require a dietary source to cover their physiological demands. The most prominent sterol in animal tissues is cholesterol, which is an indispensable structural component of cell membranes and serves as precursor for steroid hormones. Instead of cholesterol, plants and algae contain a variety of different phytosterols. Consequently, herbivorous arthropods have to metabolize dietary phytosterols to cholesterol to meet their requirements for growth and reproduction. Here, we investigated sterol-limited growth responses of the freshwater herbivore Daphnia magna by supplementing a sterol-free diet with increasing amounts of 10 different phytosterols and comparing thresholds for sterol-limited growth. In addition, we analyzed the sterol composition of D. magna to explore sterol metabolic constraints and bioconversion capacities. We show that dietary phytosterols strongly differ in their potential to support somatic growth of D. magna. The dietary threshold concentrations obtained by supplementing the different sterols cover a wide range (3.5-34.4 ?g mg C(-1)) and encompass the one for cholesterol (8.9 ?g mg C(-1)), indicating that certain phytosterols are more efficient in supporting somatic growth than cholesterol (e.g., fucosterol, brassicasterol) while others are less efficient (e.g., dihydrocholesterol, lathosterol). The dietary sterol concentration gradients revealed that the poor quality of particular sterols can be alleviated partially by increasing dietary concentrations, and that qualitative differences among sterols are most pronounced at low to moderate dietary concentrations. We infer that the dietary sterol composition has to be considered in zooplankton nutritional ecology to accurately assess potential sterol limitations under field conditions. PMID:25228231

Martin-Creuzburg, Dominik; Oexle, Sarah; Wacker, Alexander

2014-09-01

51

Metabolism of conjugated sterols in eggplant. Part 1. UDP-glucose : sterol glucosyltransferase.  

PubMed

A membrane-bound UDP-glucose : sterol glucosyltransferase from Solanum melongena (eggplant) leaves was partially purified and its specificity as well as molecular and kinetic properties were defined. Among a wide spectrum of 3-OH steroids (i.e. typical plant sterols, androstane, pregnane and cholestane derivatives, steroidal alkaloids and sapogenins) and triterpenic alcohols, the highest activity was found with 22-oxycholesterol. UDP-glucose appeared to be the best sugar donor. The enzyme preparation was also able to utilize UDP-galactose, TDP-glucose and CDP-glucose as a sugar source for sterol glucosylation, however, at distinctly lower rates. The investigated glucosyltrasferase was stimulated by 2-mercaptoethanol, Triton X-100 and negatively charged phospholipids, and inhibited in the presence of UDP, mono-, di- and triacylglycerols, divalent cations such as Zn(2+), Co(2+), high ionic strength, cholesteryl glucoside, galactoside and xyloside and some amino acid-modifying reagents (SITS, DIDS, PLP, DEPC, pCMBS, NEM, WRK and HNB). Our results suggest that unmodified residues of lysine, tryptophan, cysteine, histidine and dicarboxylic amino acids are essential for full enzymatic activity and indicate that a glutamic (or aspartic) acid residue is necessary for the binding of sugar donor, i.e. UDP-glucose in the active site of the GT-ase while histidine and cysteine residues are both important for the binding of the nucleotide-sugar as well as of the steroidal aglycone. PMID:18196184

Potocka, Anna; Zimowski, Jan

2008-01-01

52

Effect of a plant sterol, fish oil and B vitamin combination on cardiovascular risk factors in hypercholesterolemic children and adolescents: a pilot study  

PubMed Central

Background Assessment of cardiovascular disease (CVD) risk factors can predict clinical manifestations of atherosclerosis in adulthood. In this pilot study with hypercholesterolemic children and adolescents, we investigated the effects of a combination of plant sterols, fish oil and B vitamins on the levels of four independent risk factors for CVD; LDL-cholesterol, triacylglycerols, C-reactive protein and homocysteine. Methods Twenty five participants (mean age 16 y, BMI 23 kg/m2) received daily for a period of 16 weeks an emulsified preparation comprising plant sterols esters (1300 mg), fish oil (providing 1000 mg eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA)) and vitamins B12 (50 ?g), B6 (2.5 mg), folic acid (800 ?g) and coenzyme Q10 (3 mg). Atherogenic and inflammatory risk factors, plasma lipophilic vitamins, provitamins and fatty acids were measured at baseline, week 8 and 16. Results The serum total cholesterol, LDL- cholesterol, VLDL-cholesterol, subfractions LDL-2, IDL-1, IDL-2 and plasma homocysteine levels were significantly reduced at the end of the intervention period (p<0.05). The triacylglycerols levels decreased by 17.6%, but did not reach significance. No significant changes in high sensitivity C-reactive protein, HDL-cholesterol and apolipoprotein A-1 were observed during the study period. After standardisation for LDL cholesterol, there were no significant changes in the levels of plasma ?-tocopherol, ?-carotene and retinol, except for reduction in ?-tocopherol levels. The plasma levels of n-3 fatty acids increased significantly with the dietary supplementation (p<0.05). Conclusions Daily intake of a combination of plant sterols, fish oil and B vitamins may modulate the lipid profile of hypercholesterolemic children and adolescents. Trial registration Current Controlled Trials ISRCTN89549017 PMID:23297818

2013-01-01

53

Consumption of plant sterols reduces plasma and hepatic triglycerides and modulates the expression of lipid regulatory genes and de novo lipogenesis in C57BL/6J mice.  

PubMed

To investigate emerging clinical data suggesting a triglyceride (TAG)-lowering response to plant sterol (PS) therapy, we characterized changes in TAG metabolism in 16 C57BL/6J mice fed a basal control diet (CON) or the CON diet supplemented with 2% PS for 6 wk. PS consumption reduced (p<0.05) plasma (-28%) and hepatic (-30%) TAG concentrations compared with CON mice. PS consumption increased (p<0.05) hepatic lipogenic gene expression (sterol-regulatory-element-binding protein 1c, 2.4-fold of CON; fatty acid synthase, 6.5-fold of CON) and de novo lipogenesis (4.51+/-0.72 versus 2.82+/-0.61%/day) compared with CON. PS consumption increased (p<0.05) fecal palmitate and stearate excretion and reduced body weight gain compared with CON mice. Although no change in the transcription of intestinal fatty acid absorptive genes was observed, peroxisome proliferator-activated receptor alpha mRNA was reduced (p<0.05, 2.0-fold of CON) in the PS-fed mice. In conclusion, PS-fed C57BL/6J mice showed pronounced reductions in plasma and hepatic TAG concentrations despite increases in hepatic lipogenic gene expression and de novo lipogenesis. Interference with intestinal fatty acid/TAG metabolism as suggested by increased fecal fatty acid loss and reduced weight gain may be associated with the TAG-lowering response to PS consumption. PMID:20333723

Rideout, Todd C; Harding, Scott V; Jones, Peter J H

2010-05-01

54

Plant sterol-enriched margarines and reduction of plasma total- and LDL-cholesterol concentrations in normocholesterolaemic and mildly hypercholesterolaemic subjects  

Microsoft Academic Search

Objectives: To compare effects on plasma total-, LDL-, and HDL-cholesterol concentrations of margarines enriched with different vegetable oil sterols or sitostanol-ester.Design: A randomized double-blind placebo-controlled balanced incomplete Latin square design with five treatments and four periods of 3.5 weeks. Margarines enriched with sterols from soybean, sheanut or ricebran oil or with sitostanol-ester were compared to a non-enriched control margarine. Sterol

JA Weststrate; GW Meijer

1998-01-01

55

Effects of the growth retardant tetcyclacis on the sterol composition of oat (Avena sativa)  

Microsoft Academic Search

The norbornenodiazetine plant growth regulator tetcyclacis, when applied to roots of Avena sativa, caused a substantial increase in the cholesterol content of the shoots. Amounts of the C-24 alkylated sterols campesterol, stigmasterol and sitosterol all declined. A similar alteration in the sterol profile was observed for a plasma membrane preparation from the shoots. Changes in the sterol composition of root

R. S. Burden; D. T. Cooke; P. J. White; C. S. James

1987-01-01

56

Sterols and oxysterols in immune cell function.  

PubMed

Intermediates in the cholesterol-biosynthetic pathway and oxysterol derivatives of cholesterol regulate diverse cellular processes. Recent studies have expanded the appreciation of their roles in controlling the functions of cells of the innate and adaptive immune systems. Here we review recent literature reporting on the biological functions of sterol intermediates and oxysterols, acting through transcription factors such as the liver X receptors (LXRs), sterol regulatory element-binding proteins (SREBPs) and the G protein-coupled receptor EBI2, in regulating the differentiation and population expansion of cells of the innate and adaptive immune systems, their responses to inflammatory mediators, their effects on the phagocytic functions of macrophages and their effects on antiviral activities and the migration of immune cells. Such findings have raised many new questions about the production of endogenous bioactive sterols and oxysterols and their mechanisms of action in the immune system. PMID:23959186

Spann, Nathanael J; Glass, Christopher K

2013-09-01

57

Sterols and sterol glycosides of Bryonia alba  

Microsoft Academic Search

It has been shown that the roots ofBryonia alba contain cholest-7-en-3ß-ol, 24-methylcholest-7-en-3ß-ol, 24-ethylcholest-7-en-3ß-ol, 24-methylenecholest-7-en-3ß-ol, 24-ethylidenecholest-7-en-3ß-ol, 24-ethyl-4-methylcholest-7-en-3ß-ol, 24-ethylidene-4-methylcholest-7-en-3ß-ol, and also previously undescribed 3-O-ß-glucopyranosides of the above-mentioned sterols.

A. G. Panosyan; G. M. Avetisyan; V. A. Mnatsakanyan

1977-01-01

58

Sterol C-24 Methyltransferase Type 1 Controls the Flux of Carbon into Sterol Biosynthesis in Tobacco Seed  

PubMed Central

The first committed step in the conversion of cycloartenol into ?5 C24-alkyl sterols in plants is catalyzed by an S-adenosyl-methionine-dependent sterol-C24-methyltransferase type 1 (SMT1). We report the consequences of overexpressing SMT1 in tobacco (Nicotiana tabacum), under control of either the constitutive carnation etched ring virus promoter or the seed-specific Brassica napus acyl-carrier protein promoter, on sterol biosynthesis in seed tissue. Overexpression of SMT1 with either promoter increased the amount of total sterols in seed tissue by up to 44%. The sterol composition was also perturbed with levels of sitosterol increased by up to 50% and levels of isofucosterol and campesterol increased by up to 80%, whereas levels of cycloartenol and cholesterol were decreased by up to 53% and 34%, respectively. Concomitant with the enhanced SMT1 activity was an increase in endogenous 3-hydroxy-3-methylglutaryl coenzyme A reductase activity, from which one can speculate that reduced levels of cycloartenol feed back to up-regulate 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and thereby control the carbon flux into sterol biosynthesis. This potential regulatory role of SMT1 in seed sterol biosynthesis is discussed. PMID:12226510

Holmberg, Niklas; Harker, Mark; Gibbard, Carl L.; Wallace, Andrew D.; Clayton, John C.; Rawlins, Sally; Hellyer, Amanda; Safford, Richard

2002-01-01

59

Arabidopsis ERG28 Tethers the Sterol C4-Demethylation Complex to Prevent Accumulation of a Biosynthetic Intermediate That Interferes with Polar Auxin Transport[C][W  

PubMed Central

Sterols are vital for cellular functions and eukaryotic development because of their essential role as membrane constituents. Sterol biosynthetic intermediates (SBIs) represent a potential reservoir of signaling molecules in mammals and fungi, but little is known about their functions in plants. SBIs are derived from the sterol C4-demethylation enzyme complex that is tethered to the membrane by Ergosterol biosynthetic protein28 (ERG28). Here, using nonlethal loss-of-function strategies focused on Arabidopsis thaliana ERG28, we found that the previously undetected SBI 4-carboxy-4-methyl-24-methylenecycloartanol (CMMC) inhibits polar auxin transport (PAT), a key mechanism by which the phytohormone auxin regulates several aspects of plant growth, including development and responses to environmental factors. The induced accumulation of CMMC in Arabidopsis erg28 plants was associated with diagnostic hallmarks of altered PAT, including the differentiation of pin-like inflorescence, loss of apical dominance, leaf fusion, and reduced root growth. PAT inhibition by CMMC occurs in a brassinosteroid-independent manner. The data presented show that ERG28 is required for PAT in plants. Furthermore, it is accumulation of an atypical SBI that may act to negatively regulate PAT in plants. Hence, the sterol pathway offers further prospects for mining new target molecules that could regulate plant development. PMID:24326590

Mialoundama, Alexis Samba; Jadid, Nurul; Brunel, Julien; Di Pascoli, Thomas; Heintz, Dimitri; Erhardt, Mathieu; Mutterer, Jérôme; Bergdoll, Marc; Ayoub, Daniel; Van Dorsselaer, Alain; Rahier, Alain; Nkeng, Paul; Geoffroy, Philippe; Miesch, Michel; Camara, Bilal; Bouvier, Florence

2013-01-01

60

Distribution of sterols and the sources of pollution in surface sediments of Ulungur lake, Xinjiang.  

PubMed

Domestic sewage discharged into lakes brings great pressure to the ecological environment. This study selected sediment from an inland lake as a research object to evaluate pollution of the environment. Eight sterols were used to evaluate the content of pollutants, while the ratios of sterols were used as the index to analyze the sources of pollution. The correlations were analyzed between sterols and total organic carbon (TOC), salinity and particle size. The distribution and composition of sterol compounds were determined in 12 surface sediment samples collected from Ulungur lake. The total concentrations of detected sterols in the sediments ranged from 1.3 to 36.3 ?g/g.dw. The most abundant sterol detected was ?-sitosterol (STI) with average concentrations of 2.6 ?g/g.dw, followed by cholesterol (CHOE), stigmasterol (STIG) and stigmastanol (STAN). The concentration of coprostanol (COP) was between 0.03 and 1.66 ?g/g.dw. Through correlation analysis, it was found that there was a significant correlation between fecal sterols and plant sterols. So the plant sterols shall not be neglected in evaluating the sources of pollution for their impact to identify the fecal sources. The study suggests that the composition and distribution of sterols in surface sediment provide useful information for environmental contamination monitoring and assessment in the inland lake. PMID:23676408

Yao, Xiaorui; Lu, Jianjiang; Liu, Zilong; Ran, Dan; Huang, Yating

2013-01-01

61

The physiology of sterol nutrition in the pea aphid Acyrthosiphon pisum Sophie Bouvaine a  

E-print Network

sap of fava bean (Vicia faba) plants utilized by the pea aphid Acyrthosiphon pisum contains three- plementary RNA-seq analysis of pea aphids reared on plants and diets with different sterol contents, 7The physiology of sterol nutrition in the pea aphid Acyrthosiphon pisum Sophie Bouvaine a , Spencer

Behmer, Spencer T.

62

Sterol Biosynthesis Is Required for Heat Resistance but Not Extracellular Survival in Leishmania  

PubMed Central

Sterol biosynthesis is a crucial pathway in eukaryotes leading to the production of cholesterol in animals and various C24-alkyl sterols (ergostane-based sterols) in fungi, plants, and trypanosomatid protozoa. Sterols are important membrane components and precursors for the synthesis of powerful bioactive molecules, including steroid hormones in mammals. Their functions in pathogenic protozoa are not well characterized, which limits the development of sterol synthesis inhibitors as drugs. Here we investigated the role of sterol C14?-demethylase (C14DM) in Leishmania parasites. C14DM is a cytochrome P450 enzyme and the primary target of azole drugs. In Leishmania, genetic or chemical inactivation of C14DM led to a complete loss of ergostane-based sterols and accumulation of 14-methylated sterols. Despite the drastic change in lipid composition, C14DM-null mutants (c14dm?) were surprisingly viable and replicative in culture. They did exhibit remarkable defects including increased membrane fluidity, failure to maintain detergent resistant membrane fraction, and hypersensitivity to heat stress. These c14dm? mutants showed severely reduced virulence in mice but were highly resistant to itraconazole and amphotericin B, two drugs targeting sterol synthesis. Our findings suggest that the accumulation of toxic sterol intermediates in c14dm? causes strong membrane perturbation and significant vulnerability to stress. The new knowledge may help improve the efficacy of current drugs against pathogenic protozoa by exploiting the fitness loss associated with drug resistance. PMID:25340392

Xu, Wei; Hsu, Fong-Fu; Baykal, Eda; Huang, Juyang; Zhang, Kai

2014-01-01

63

Sterol biosynthesis is required for heat resistance but not extracellular survival in leishmania.  

PubMed

Sterol biosynthesis is a crucial pathway in eukaryotes leading to the production of cholesterol in animals and various C24-alkyl sterols (ergostane-based sterols) in fungi, plants, and trypanosomatid protozoa. Sterols are important membrane components and precursors for the synthesis of powerful bioactive molecules, including steroid hormones in mammals. Their functions in pathogenic protozoa are not well characterized, which limits the development of sterol synthesis inhibitors as drugs. Here we investigated the role of sterol C14?-demethylase (C14DM) in Leishmania parasites. C14DM is a cytochrome P450 enzyme and the primary target of azole drugs. In Leishmania, genetic or chemical inactivation of C14DM led to a complete loss of ergostane-based sterols and accumulation of 14-methylated sterols. Despite the drastic change in lipid composition, C14DM-null mutants (c14dm-) were surprisingly viable and replicative in culture. They did exhibit remarkable defects including increased membrane fluidity, failure to maintain detergent resistant membrane fraction, and hypersensitivity to heat stress. These c14dm- mutants showed severely reduced virulence in mice but were highly resistant to itraconazole and amphotericin B, two drugs targeting sterol synthesis. Our findings suggest that the accumulation of toxic sterol intermediates in c14dm- causes strong membrane perturbation and significant vulnerability to stress. The new knowledge may help improve the efficacy of current drugs against pathogenic protozoa by exploiting the fitness loss associated with drug resistance. PMID:25340392

Xu, Wei; Hsu, Fong-Fu; Baykal, Eda; Huang, Juyang; Zhang, Kai

2014-10-01

64

Sterol composition and biosynthesis in Trypanosoma cruzi amastigotes.  

PubMed

A detailed analysis of the endogenous sterols present in the clinically relevant intracellular (amastigote) stages of Trypanosoma cruzi, is presented. The parasites were grown in cultured Vero cells in the absence or presence of different sterol biosynthesis inhibitors, including the C14alpha demethylase inhibitor ketoconazole and two inhibitors of delta24(25)-sterol methyl transferase, 20 piperidin-2-yl-5alpha-pregnan-3beta-20-R-diol (22,26-azasterol) and 24-(R,S),25-epiminolanosterol. Amastigotes were isolated and purified from their host cells and neutral lipids were extracted, separated and analyzed by chromatographic and mass spectrometric methods. Control (untreated) amastigotes contained as main endogenous sterols 24-methyl-cholesta-7-en-3beta-ol (ergosta-7-en-3beta-ol) and its 24-ethyl analog, plus smaller amounts of their precursor, ergosta-7,24(28)dien-3beta-ol; these cells also contained cholesterol (up to 80% by weight of total sterols), probably derived from host cells. Amastigotes that proliferated in the presence of 10 nM ketoconazole (minimal inhibitory concentration, MIC) for 24 h had a sharply reduced content of endogenous 4-desmethyl sterols with a concomitant accumulation of 24-methyl-dihydrolanosterol and 24-methylene-dihydrolanosterol. On the other hand, amastigotes incubated during the same period of time with the two inhibitors of 24(25)-SMT at their respective MICs (100-300 nM) accumulated large amounts of C27 sterols whose structure suggested, in the case of 22,26-azasterol, that delta14 sterol reductase was also inhibited. Ketoconazole produced a dose-dependent reduction in the incorporation of [2-(14)C]-acetate into the parasite's endogenous C4-desmethyl sterols with an IC50 of 50 nM, indistinguishable from the value reported previously for the extracellular epimastigote form. Taken together, the results showed that amastigotes have a simpler sterol biosynthetic pathway than that previously described for epimastigotes, lacking both delta5 and delta22 reductases. They also suggest that the 100-fold higher potency of antifungal azoles as antiproliferative agents against amastigotes, when compared with epimastigotes, is most probably due to a smaller pool of endogenous sterols in the intracellular parasites. PMID:10589983

Liendo, A; Visbal, G; Piras, M M; Piras, R; Urbina, J A

1999-10-25

65

Post-ingestive feedbacks and associative learning regulate the intake of unsuitable sterols in a generalist grasshopper.  

PubMed

Behavioural studies of the grasshopper Schistocerca americana were undertaken to identify the mechanisms that regulate the intake of dietary sterols. In the first experiment, grasshoppers were allowed to feed on spinach, a plant containing only unsuitable sterols; immediately after this first meal, a suitable or unsuitable sterol was injected into the haemolymph. Grasshoppers injected with unsuitable sterols had second meals on spinach that were significantly shorter than those of grasshoppers injected with suitable sterols, indicating that unsuitable dietary sterols are detected post-ingestively. In the second experiment, grasshoppers were fed food containing only unsuitable sterols and were then presented with glass-fibre discs containing different concentrations of a suitable sterol or sucrose only (the control). The results suggest that grasshoppers do not use a direct feedback operating on mouthpart chemoreceptors to regulate their intake of suitable sterols. In the third experiment, grasshoppers were presented with artificial diets containing different sterols and flavours, and feeding was observed over a sequence of meals. The results from both the first and last experiments suggest a role for associative learning in regulating the intake of unsuitable sterols. PMID:10021327

Behmer, S T; Elias, D O; Bernays, E A

1999-03-01

66

Sterol composition and biosynthetic genes of the recently discovered photosynthetic alveolate, Chromera velia (chromerida), a close relative of apicomplexans.  

PubMed

Chromera velia is a recently discovered, photosynthetic, marine alveolate closely related to apicomplexan parasites, and more distantly to perkinsids and dinoflagellates. To date, there are no published studies on the sterols of C. velia. Because apicomplexans and perkinsids are not known to synthesize sterols de novo, but rather obtain them from their host organisms, our objective was to examine the composition of the sterols of C. velia to assess whether or not there is any commonality with dinoflagellates as the closest taxonomic group capable of synthesizing sterols de novo. Furthermore, knowledge of the sterols of C. velia may provide insight into the sterol biosynthetic capabilities of apicomplexans prior to loss of sterol biosynthesis. We have found that C. velia possesses two primary sterols, 24-ethylcholesta-5,22E-dien-3?-ol, and 24-ethylcholest-5-en-3?-ol, not common to dinoflagellates, but rather commonly found in other classes of algae and plants. In addition, we have identified computationally three genes, SMT1 (sterol-24C-methyltransferase), FDFT1 (farnesyl diphosphate farnesyl transferase, squalene synthase), and IDI1 (isopentenyl diphosphate ?-isomerase), predicted to be involved in sterol biosynthesis by their similarity to analogous genes in other sterol-producing eukaryotes, including a number of algae. PMID:22313428

Leblond, Jeffrey D; Dodson, Joshua; Khadka, Manoj; Holder, Sabrina; Seipelt, Rebecca L

2012-01-01

67

Fatty AcidDerived Signals in Plant Defense  

E-print Network

Fatty Acid­Derived Signals in Plant Defense Aardra Kachroo and Pradeep Kachroo Department of Plant in pathogen defense. Historically, FAs were only assigned passive roles in plant defense such as biosynthetic demonstrate more direct roles for FAs and their breakdown products in inducing various modes of plant defenses

Kachroo, Pradeep

68

Molecular pathways: sterols and receptor signaling in cancer.  

PubMed

Accelerated cholesterol and lipid metabolism are the hallmarks of cancer and contribute to malignant transformation due to the obligatory requirement for cholesterol for the function of eukaryotic membranes. To build new membranes and maintain active signaling, cancer cells depend on high intensity of endogenous cholesterol biosynthesis and uptake of lipid particles. This metabolic dependency of cancer cells on cholesterol and other lipids is tightly regulated by the cholesterol homeostasis network, including (i) sterol response element-binding proteins (SREBP), master transcriptional regulators of cholesterol and fatty acid pathway genes; (ii) nuclear sterol receptors (liver X receptors, LXR), which coordinate growth with the availability of cholesterol; and (iii) lipid particle receptors, such as low-density lipid particle (LDL) receptor, providing exogenous sterol and lipids to cancer cells. In addition, activity of oncogenic receptors, such as MUC1 or EGFR, accelerates sterol uptake and biosynthesis. Therefore, a general strategy of reducing the cholesterol pool in cancer cells is challenged by the highly efficient feedback loops compensating for a blockade at a single point in the cholesterol homeostatic network. Besides the well-established structural role of cholesterol in membranes, recent studies have uncovered potent biologic activities of certain cholesterol metabolic precursors and its oxidized derivatives, oxysterols. The former, meiosis-activating sterols, exert effects on trafficking and signaling of oncogenic EGF receptor (EGFR). Cholesterol epoxides, the highly active products of cholesterol oxidation, are being neutralized by the distal sterol pathway enzymes, emopamyl-binding protein (EBP) and dehydrocholesterol-7 reductase (DHCR7). These recently discovered "moonlighting" activities of the cholesterol pathway genes and metabolites expand our understanding of the uniquely conserved roles these sterol molecules play in the regulation of cellular proliferation and in cancer. PMID:24158702

Gabitova, Linara; Gorin, Andrey; Astsaturov, Igor

2014-01-01

69

Sterols as Complex-forming Species  

NASA Astrophysics Data System (ADS)

The formation of complexes of sterols with different compounds determines the biological properties of both sterols and various natural substances such as saponins and polyene antibiotics. Complex formation by sterols with phospholipids, steroid saponins, and polyene antibiotics is determined by the same characteristic features of the structure of the sterol molecule. The principal role in complex formation is played by the hydrophobic reaction of the cyclopentanoperhydrophenanthrene ring. The formation of a hydrogen bond between the hydroxyl group of the sterol and a proton acceptor, which is assumed in most complexes, has been proved only in the complexes of sterols with water and acids. The bibliography contains 122 references.

Ioffe, D. V.

1986-02-01

70

Agrobacterium tumefaciens responses to plant-derived signaling molecules  

PubMed Central

As a special phytopathogen, Agrobacterium tumefaciens infects a wide range of plant hosts and causes plant tumors also known as crown galls. The complexity of Agrobacterium–plant interaction has been studied for several decades. Agrobacterium pathogenicity is largely attributed to its evolved capabilities of precise recognition and response to plant-derived chemical signals. Agrobacterium perceives plant-derived signals to activate its virulence genes, which are responsible for transferring and integrating its Transferred DNA (T-DNA) from its Tumor-inducing (Ti) plasmid into the plant nucleus. The expression of T-DNA in plant hosts leads to the production of a large amount of indole-3-acetic acid (IAA), cytokinin (CK), and opines. IAA and CK stimulate plant growth, resulting in tumor formation. Agrobacterium utilizes opines as nutrient sources as well as signals in order to activate its quorum sensing (QS) to further promote virulence and opine metabolism. Intriguingly, Agrobacterium also recognizes plant-derived signals including ?-amino butyric acid and salicylic acid (SA) to activate quorum quenching that reduces the level of QS signals, thereby avoiding the elicitation of plant defense and preserving energy. In addition, Agrobacterium hijacks plant-derived signals including SA, IAA, and ethylene to down-regulate its virulence genes located on the Ti plasmid. Moreover, certain metabolites from corn (Zea mays) also inhibit the expression of Agrobacterium virulence genes. Here we outline the responses of Agrobacterium to major plant-derived signals that impact Agrobacterium–plant interactions. PMID:25071805

Subramoni, Sujatha; Nathoo, Naeem; Klimov, Eugene; Yuan, Ze-Chun

2014-01-01

71

Tracking the sterol biosynthesis pathway of the diatom Phaeodactylum tricornutum.  

PubMed

Diatoms are unicellular photosynthetic microalgae that play a major role in global primary production and aquatic biogeochemical cycling. Endosymbiotic events and recurrent gene transfers uniquely shaped the genome of diatoms, which contains features from several domains of life. The biosynthesis pathways of sterols, essential compounds in all eukaryotic cells, and many of the enzymes involved are evolutionarily conserved in eukaryotes. Although well characterized in most eukaryotes, the pathway leading to sterol biosynthesis in diatoms has remained hitherto unidentified. Through the DiatomCyc database we reconstructed the mevalonate and sterol biosynthetic pathways of the model diatom Phaeodactylum tricornutum in silico. We experimentally verified the predicted pathways using enzyme inhibitor, gene silencing and heterologous gene expression approaches. Our analysis revealed a peculiar, chimeric organization of the diatom sterol biosynthesis pathway, which possesses features of both plant and fungal pathways. Strikingly, it lacks a conventional squalene epoxidase and utilizes an extended oxidosqualene cyclase and a multifunctional isopentenyl diphosphate isomerase/squalene synthase enzyme. The reconstruction of the P. tricornutum sterol pathway underscores the metabolic plasticity of diatoms and offers important insights for the engineering of diatoms for sustainable production of biofuels and high-value chemicals. PMID:24996048

Fabris, Michele; Matthijs, Michiel; Carbonelle, Sophie; Moses, Tessa; Pollier, Jacob; Dasseville, Renaat; Baart, Gino J E; Vyverman, Wim; Goossens, Alain

2014-11-01

72

Andrographolide: A New Plant-Derived Antineoplastic Entity on Horizon  

Microsoft Academic Search

Plant-derived natural products occupy an important position in the area of cancer chemo- therapy. Molecules such as vincristine, vinblastine, paclitaxel, camptothecin derivatives, epipo- dophyllotoxin, etc. are invaluable contributions of nature to modern medicine. However, the quest to find out novel therapeutic compounds for cancer treatment and management is a never-ending venture; and diverse plant species are persistently being studied for

Astha Varma; Harish Padh; Neeta Shrivastava

2009-01-01

73

Sterol methylation in Saccharomyces cerevisiae.  

PubMed Central

Various nystatin-resistant mutants defective in S-adenosylmethionine: delta 24-sterol-C-methyltransferase (EC 2.1.1.41) were shown to possess alleles of the same gene, erg6. The genetic map location of erg6 was shown to be close to trp1 on chromosome 4. Despite the single locus for erg6, S-adenosylmethionine: delta 24-sterol-C-methyltransferase enzyme activity was found in three separate fractions: mitochondria, microsomes, and the "floating lipid layer." The amount of activity in each fraction could be manipulated by assay conditions. The lipids and lipid synthesis of mutants of Saccharomyces cerevisiae defective in the delta 24-sterol-C-methyltransferase were compared with a C5(6) desaturase mutant and parental wild types. No ergosterol (C28 sterol) could be detected in whole-cell sterol extracts of the erg6 mutants, the limits of detection being less than 10(-11) mol of ergosterol per 10(8) cells. The distribution of accumulated sterols by these mutants varied with growth phase and between free and esterified fractions. The steryl ester concentrations of the mutants were eight times higher than those of the wild type from exponential growth samples. However, the concentration of the ester accumulated by the mutants was not as great in stationary-phase cells. Whereas the head group phospholipid composition was the same between parental and mutant strains, strain-dependent changes in fatty acids were observed, most notably a 40% increase in the oleic acid content of phosphatidylethanolamine of one erg6 mutant, JR5. PMID:6363386

McCammon, M T; Hartmann, M A; Bottema, C D; Parks, L W

1984-01-01

74

Sterols in pumpkin seed oil  

Microsoft Academic Search

and summary  The sterol fraction of unsaponifiable matter obtained from a Yugoslav pumpkin seed ripening was investigated by gas liquid\\u000a chromatography on a glass capillary column. It contained at least 14 different sterols ten of which were identified primarily\\u000a by combined gas chromatography-mass spectrometry as cholesterol, brassicasterol, campesterol, stigmasterol, 24-methylcholest-7-en-3?-ol,\\u000a ?7,22,25-stimastatrien-3?-ol, ?-spinasterol, ?7,25-stigmastadien-3?-ol, ?7,25-stigmastenol, and ?7-avenasterol. It was shown that the

M. Basti?; Lj. Basti?; J. A. Jovanovi?; G. Spiteller

1977-01-01

75

Analysis of unsaturated c27 sterols by nuclear magnetic resonance spectroscopy  

Microsoft Academic Search

Complete 'H and IsC nuclear magnetic reso- nance (NMR) signal assignments have been established for 5a-cholestan-3P-01, 22 unsaturated C27 sterols, and their ace- tate derivatives. Assignments were made from a combination of 1D and 2D spectra and include stereochemical 'H assign- ments for the C-22 and C-23 protons of 5a-cholesta-8,24dien- 3p-01 and other A*' sterols with a Cg side chain.

William K. Wilson; Rhea M. Sumpter; Joshua J. Warren; Peter S. Rogers; Benfang Ruan; George J. Schroepfer

76

The content and composition of sterols and sterol esters in sunflower and poppy seed oils  

Microsoft Academic Search

The composition and proportion of free sterols and sterol esters in crude sunflower and poppy seed oils were determined, using\\u000a preparative thin layer chromatography followed by gas chromatography with cholesterol as an internal standard. Free sterols\\u000a and sterol esters were also isolated in a liquid fraction obtained by low temperature crystallization (?80 C) of the oils\\u000a and enriched with minor

Anna Johansson

1979-01-01

77

Enzymological properties of sterol-C4-methyl-oxidase of yeast sterol biosynthesis  

Microsoft Academic Search

Despite genes of the sterol methyl-oxidase component (SMO) of the sterol-C4-demethylation multienzymatic complex have been identified in a variety of organisms and the key role played by SMO in yeast sterol biosynthesis, the enzymological properties of yeast SMO have not been investigated. An enzymatic assay for measuring specifically sterol 4?-methyl-oxidase activity in Saccharomyces cerevisiae has been developed for the first

Sylvain Darnet; Alain Rahier

2003-01-01

78

Use of capillary gas chromatography for measuring fecal-derived sterols application to stormwater, the sea-surface microlayer, beach greases, regional studies, and distinguishing algal blooms and human and non-human sources of sewage pollution  

Microsoft Academic Search

The sterol composition, including the fecal biomarker coprostanol, from a variety of sample types was determined by capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The coprostanol concentration in field samples readily provided an estimate of human fecal pollution. The technique was successfully used for stormwater, the sea-surface microlayer, beach sands and greases, and in regional studies of coastal

Peter D. Nichols; Rhys Leeming; Mark S. Rayner; Val Latham

1996-01-01

79

Consumption and biochemical impact of commercially available plant-derived nutritional supplements. An observational pilot-study on recreational athletes  

PubMed Central

Background A growing consumption of natural (plant-derived) dietary supplements with ergogenic aims, with particular regard for ecdysteroids, phytoestrogens and vegetal sterols, has been registered over the last years among “recreational” athletes. The present study was carried out in order to evaluate the real knowledge of plant-derived nutritional supplements among physically active people as well as their real consumption. Additional aim was to evaluate the effects of these supplements on the health profile of the users. Methods Twenty-three trained subjects who habitually used natural dietary supplements, and 30 matched controls were analyzed for plasma biochemical markers and hormonal profile. Results The laboratory tests revealed the absence of any sign of organ toxicity/damage in both athletes and controls. On the contrary, hormone profiles revealed marked alterations in 15 (65%) out of the 23 of investigated athletes. Specifically, 10 males presented increased plasma levels of progesterone, 15 subjects presented abnormal estrogen levels, including 5 (2?F and 3?M) presenting a “dramatic” increased estrogen values and 2 two males with increased estrogen levels, increased testosterone levels and associated suppression of luteinizing hormone and follicle-stimulating hormone. Conclusions The results of the present study highlighted that the habitual consumption of plant-derived nutritional supplements is frequently associated with significant hormonal alterations both in male and female subjects. Although these biochemical alterations were not associated with signs or symptoms of organ toxicity/damage at the moment of the study, it cannot be excluded that, in the mid/long-term, these subjects would suffer of health problems secondary to chronic exposure to heavily altered hormonal levels. Further large scale studies are needed to confirm the results of this pilot study as well as to investigate the biological mechanisms at the base of the observed hormonal alterations. PMID:22713127

2012-01-01

80

Analysis of Sterol Glycosides in Biodiesel and Biodiesel Precipitates  

Microsoft Academic Search

Biodiesel is produced by the transesterification of vegetable oils with short chain alcohols, usually in the presence of an\\u000a alkali catalyst. Minor components in biodiesel exist as a result of unreacted reagents, by-products, additives, and auto-oxidation\\u000a products, such as water, free glycerin, bonded glycerin, free fatty acids, catalysts, residual alcohol, unsaponifiable matter\\u000a (plant sterols, antioxidants, and hydrocarbons), soaps and polymers.

Huali Wang; Haiying Tang; Steven Salley; K. Y. Simon Ng

2010-01-01

81

Polymeric derivatives of plant growth regulators: synthesis and properties  

Microsoft Academic Search

The polymeric formulations of plant growth regulators (PGRs) are high molecular weight systems in which the PGR unit is attached to the polymeric chain by a hydrolysable chemical bond. These polymeric derivatives (esters, ethers, or else) of PGRs are characterised by the ability to release the active compound (PGR) from their solutions (mainly aqueous) in certain conditions. The release of

Aristidis M. Tsatsakis; Michail I. Shtilman

1994-01-01

82

Plant-derived virus-like particles as vaccines  

PubMed Central

Virus-like particles (VLPs) are self-assembled structures derived from viral antigens that mimic the native architecture of viruses but lack the viral genome. VLPs have emerged as a premier vaccine platform due to their advantages in safety, immunogenicity, and manufacturing. The particulate nature and high-density presentation of viral structure proteins on their surface also render VLPs as attractive carriers for displaying foreign epitopes. Consequently, several VLP-based vaccines have been licensed for human use and achieved significant clinical and economical success. The major challenge, however, is to develop novel production platforms that can deliver VLP-based vaccines while significantly reducing production times and costs. Therefore, this review focuses on the essential role of plants as a novel, speedy and economical production platform for VLP-based vaccines. The advantages of plant expression systems are discussed in light of their distinctive posttranslational modifications, cost-effectiveness, production speed, and scalability. Recent achievements in the expression and assembly of VLPs and their chimeric derivatives in plant systems as well as their immunogenicity in animal models are presented. Results of human clinical trials demonstrating the safety and efficacy of plant-derived VLPs are also detailed. Moreover, the promising implications of the recent creation of “humanized” glycosylation plant lines as well as the very recent approval of the first plant-made biologics by the U. S. Food and Drug Administration (FDA) for plant production and commercialization of VLP-based vaccines are discussed. It is speculated that the combined potential of plant expression systems and VLP technology will lead to the emergence of successful vaccines and novel applications of VLPs in the near future. PMID:22995837

Chen, Qiang; Lai, Huafang

2013-01-01

83

The mutagenicities of seven coumarin derivatives and a furan derivative (nimbolide) isolated from three medicinal plants  

Microsoft Academic Search

Seven coumarin derivatives (imperatorin, heraclenin, xanthotoxin, marmesin, chelepin, oxypeucedanin, esculin) and a furan derivative (nimbolide) were screened on 6 Ames tester strains (TA92, TA94, TA97, TA98, TA100, TA102). The eight compounds are chemicals isolated from three Nigerian medicinal plants: Afraegle paniculata, Clausena anisata, and Azadirachta indica. Different preparations of the former are taken by Nigerians for gut disturbances, and a

Anthony O. Uwaifo

1984-01-01

84

Sterol Modulation of the Plasma Membrane H+-ATPase Activity from Corn Roots Reconstituted into Soybean Lipids.  

PubMed Central

A partially purified H+-ATPase from the plasma membrane (PM) of corn (Zea mays L.) roots was inserted into vesicles prepared with soybean (Glycine max L.) phospholipids and various concentrations of individual sterols using either a freeze-thaw sonication or an octylglucoside dilution procedure. Both methods yielded a functional enzyme that retained its native characteristics. We have investigated the effects of typical plant sterols (i.e. sitosterol, stigmasterol, and 24-methylcholesterol) on both ATP hydrolysis and H+ pumping by the reconstituted corn root PM ATPase. We have also checked the influence of cholesterol and of two unusual sterols, 24-methylpollinastanol and 14[alpha],24-dimethylcholest-8-en-3[beta]-ol. Here we present evidence for a sterol modulation of the plant PM H+-ATPase activity. In particular, cholesterol and stigmasterol were found to stimulate the pump, especially when present at 5 mol%, whereas all of the other sterols tested behaved as inhibitors at any concentration in proteoliposomes. In all situations H+ pumping was shown to be more sensitive to a sterol environment than was ATP hydrolysis. Our results suggest the occurrence of binding sites for sterols on the plant PM H+-ATPase. PMID:12223599

Grandmougin-Ferjani, A.; Schuler-Muller, I.; Hartmann, M. A.

1997-01-01

85

Regulation of Squalene Synthase, a Key Enzyme of Sterol Biosynthesis, in Tobacco1  

PubMed Central

Squalene synthase (SS) represents a putative branch point in the isoprenoid biosynthetic pathway capable of diverting carbon flow specifically to the biosynthesis of sterols and, hence, is considered a potential regulatory point for sterol metabolism. For example, when plant cells grown in suspension culture are challenged with fungal elicitors, suppression of sterol biosynthesis has been correlated with a reduction in SS enzyme activity. The current study sought to correlate changes in SS enzyme activity with changes in the level of the corresponding protein and mRNA. Using an SS-specific antibody, the initial suppression of SS enzyme activity in elicitor-challenged cells was not reflected by changes in the absolute level of the corresponding polypeptide, implicating a post-translational control mechanism for this enzyme activity. In comparison, the absolute level of the SS mRNA did decrease approximately 5-fold in the elicitor-treated cells, which is suggestive of decreased transcription of the SS gene. Study of SS in intact plants was also initiated by measuring the level of SS enzyme activity, the level of the corresponding protein, and the expression of SS gene promoter-reporter gene constructs in transgenic plants. SS enzyme activity, polypeptide level, and gene expression were all localized predominately to the shoot apical meristem, with much lower levels observed in leaves and roots. These later results suggest that sterol biosynthesis is localized to the apical meristems and that apical meristems may be a source of sterols for other plant tissues. PMID:12114564

Devarenne, Timothy P.; Ghosh, Anirban; Chappell, Joe

2002-01-01

86

Response of ?? T cells to plant-derived tannins  

PubMed Central

Many pharmaceutical drugs are isolated from plants used in traditional medicines. Through screening plant extracts, both traditional medicines and compound libraries, new pharmaceutical drugs continue to be identified. Currently, two plant-derived agonists for ?? T cells are described. These plant-derived agonists impart innate effector functions upon distinct ?? T cell subsets. Plant tannins represent one class of ?? T cell agonist and preferentially activate the mucosal population. Mucosal ?? T cells function to modulate tissue immune responses and induce epithelium repair. Select tannins, isolated from apple peel, rapidly induce immune gene transcription in ?? T cells, leading to cytokine production and increased responsiveness to secondary signals. Activity of these tannin preparations tracks to the procyanidin fraction, with the procyanidin trimer (C1) having the most robust activity defined to date. The response to the procyanidins is evolutionarily conserved in that responses are seen with human, bovine, and murine ?? T cells. Procyanidin-induced responses described in this review likely account for the expansion of mucosal ?? T cells seen in mice and rats fed soluble extracts of tannins. Procyanidins may represent a novel approach for treatment of tissue damage, chronic infection, and autoimmune therpies. PMID:19166386

Holderness, Jeff; Hedges, Jodi F.; Daughenbaugh, Katie; Kimmel, Emily; Graff, Jill; Freedman, Brett; Jutila, Mark A.

2008-01-01

87

Plant-derived epigenetic modulators for cancer treatment and prevention.  

PubMed

Carcinogenesis is a complex and multistep process that involves the accumulation of successive transformational events driven by genetic mutations and epigenetic alterations that affect major cellular processes and pathways such as proliferation, differentiation, invasion and survival. Massive deregulation of all components of the epigenetic machinery is a hallmark of cancer. These alterations affect normal gene regulation and impede normal cellular processes including cell cycle, DNA repair, cell growth, differentiation and apoptosis. Since epigenetic alterations appear early in cancer development and represent potentially initiating events during carcinogenesis, they are considered as promising targets for anti-cancer interventions by chemopreventive and chemotherapeutic strategies using epigenetically active agents. In this field, plant-derived compounds have shown promise. Here, we will give an overview of plant-derived compounds displaying anticancer properties that interfere with the epigenetic machinery. PMID:24699435

Schnekenburger, Michael; Dicato, Mario; Diederich, Marc

2014-11-01

88

California Plant Names, Word Meanings and Name Derivations  

NSDL National Science Digital Library

Created by an enthusiast, this site is a unique compilation of botanical etymology from a broad range of sources. The list focuses on plants found in Southern California, but "many if not most of these names are in general use world-wide." A simple alphabetical listing of botanical words and their meanings and derivations allows for user-friendly navigation. A similar list of botanical terms enhances the usefulness of this resource.

Charters, Michael L.

2008-08-28

89

Sterol Regulation of Metabolism, Homeostasis and Development  

PubMed Central

Sterol metabolites are critical signaling molecules that regulate metabolism, development, and homeostasis. Oxysterols, bile acids, and steroids work primarily through cognate sterol-responsive nuclear hormone receptors to control these processes through feed-forward and feedback mechanisms. These signaling pathways are conserved from simple invertebrates to mammals. Indeed, results from various model organisms have yielded fundamental insights into cholesterol and bile acid homeostasis, lipid and glucose metabolism, protective mechanisms, tissue differentiation, development, reproduction, and even aging. Here, we review how sterols act through evolutionarily ancient mechanisms to control these processes. PMID:21495846

Wollam, Joshua; Antebi, Adam

2014-01-01

90

Cameroonian Medicinal Plants: Pharmacology and Derived Natural Products  

PubMed Central

Many developing countries including Cameroon have mortality patterns that reflect high levels of infectious diseases and the risk of death during pregnancy and childbirth, in addition to cancers, cardiovascular diseases and chronic respiratory diseases that account for most deaths in the developed world. Several medicinal plants are used traditionally for their treatment. In this review, plants used in Cameroonian traditional medicine with evidence for the activities of their crude extracts and/or derived products have been discussed. A considerable number of plant extracts and isolated compounds possess significant antimicrobial, anti-parasitic including antimalarial, anti-proliferative, anti-inflammatory, anti-diabetes, and antioxidant effects. Most of the biologically active compounds belong to terpenoids, phenolics, and alkaloids. Terpenoids from Cameroonian plants showed best activities as anti-parasitic, but rather poor antimicrobial effects. The best antimicrobial, anti-proliferative, and antioxidant compounds were phenolics. In conclusion, many medicinal plants traditionally used in Cameroon to treat various ailments displayed good activities in vitro. This explains the endeavor of Cameroonian research institutes in drug discovery from indigenous medicinal plants. However, much work is still to be done to standardize methodologies and to study the mechanisms of action of isolated natural products. PMID:21833168

Kuete, Victor; Efferth, Thomas

2010-01-01

91

Impaired sterol ester synthesis alters the response of Arabidopsis thaliana to Phytophthora infestans.  

PubMed

Non-host resistance of Arabidopsis thaliana against Phytophthora infestans, the causal agent of late blight disease of potato, depends on efficient extracellular pre- and post-invasive resistance responses. Pre-invasive resistance against P. infestans requires the myrosinase PEN2. To identify additional genes involved in non-host resistance to P. infestans, a genetic screen was performed by re-mutagenesis of pen2 plants. Fourteen independent mutants were isolated that displayed an enhanced response to Phytophthora (erp) phenotype. Upon inoculation with P. infestans, two mutants, pen2-1 erp1-3 and pen2-1 erp1-4, showed an enhanced rate of mesophyll cell death and produced excessive callose deposits in the mesophyll cell layer. ERP1 encodes a phospholipid:sterol acyltransferase (PSAT1) that catalyzes the formation of sterol esters. Consistent with this, the tested T-DNA insertion lines of PSAT1 are phenocopies of erp1 plants. Sterol ester levels are highly reduced in all erp1/psat1 mutants, whereas sterol glycoside levels are increased twofold. Excessive callose deposition occurred independently of PMR4/GSL5 activity, a known pathogen-inducible callose synthase. A similar formation of aberrant callose deposits was triggered by the inoculation of erp1 psat1 plants with powdery mildew. These results suggest a role for sterol conjugates in cell non-autonomous defense responses against invasive filamentous pathogens. PMID:23072470

Kopischke, Michaela; Westphal, Lore; Schneeberger, Korbinian; Clark, Richard; Ossowski, Stephan; Wewer, Vera; Fuchs, René; Landtag, Jörn; Hause, Gerd; Dörmann, Peter; Lipka, Volker; Weigel, Detlef; Schulze-Lefert, Paul; Scheel, Dierk; Rosahl, Sabine

2013-02-01

92

Phylogenetic examination of crude drugs derived from Yunnanese Swertia plants.  

PubMed

Aiming to examine whether the genetic background of the crude drugs derived from four Yunnanese Swertia plants and their chemical constituent profiles correlate, we analyzed the nucleotide sequences of their nuclear ribosomal DNA regions including ITS1, 5.8S ribosomal RNA gene, and ITS2, together with those of Japanese S. japonica and S. pseudochinensis from Hebei Province. The result that two of the Yunnanese Swertia plants, S. binchuanensis and S. punicea, were genetically similar may explain their similarity in chemical constituent profiles. On the other hand, in spite of differences in chemical profile, S. decora and S. pseudochinensis were genetically close. The other Yunnanese Swertia plants, S. delavayi, and S. japonica, stood at intermediate positions between these two genetically similar pairs. The result suggests that although genetic background would have an influence, environmental factors, e.g., soil and weather conditions, might be critical for their production of secondary metabolites. PMID:23653334

Kakiuchi, Nobuko; Iwaki, Naoko; Mikage, Masayuki; Xiao, Huai; Wang, Zhigang; Hattori, Masao

2014-01-01

93

Overview of major classes of plant-derived anticancer drugs.  

PubMed

Cancer is the second leading cause of death worldwide. Conventional cancer therapies cause serious side effects and, at best, merely extend the patient's lifespan by a few years. Cancer control may therefore benefit from the potential that resides in alternative therapies. The demand to utilize alternative concepts or approaches to the treatment of cancer is therefore escalating. There is compelling evidence from epidemiological and experimental studies that highlight the importance of compounds derived from plants "phytochemicals" to reduce the risk of colon cancer and inhibit the development and spread of tumors in experimental animals. More than 25% of drugs used during the last 20 years are directly derived from plants, while the other 25% are chemically altered natural products. Still, only 5-15% of the approximately 250,000 higher plants have ever been investigated for bioactive compounds. The advantage of using such compounds for cancer treatment is their relatively non-toxic nature and availability in an ingestive form. An ideal phytochemical is one that possesses anti-tumor properties with minimal toxicity and has a defined mechanism of action. As compounds that target specific signaling pathways are identified, researchers can envisage novel therapeutic approaches as well as a better understanding of the pathways involved in disease progression. Here, we focus on 4 classes of natural anticancer drugs: methyltransferase inhibitors, DNA damaging/pro-oxidant drugs, HDAC inhibitors (HDACi), and mitotic disrupters, and we will focus on the mode of action for one promising example per group. PMID:23675107

Amin, Amr; Gali-Muhtasib, Hala; Ocker, Matthias; Schneider-Stock, Regine

2009-03-01

94

Overview of Major Classes of Plant-Derived Anticancer Drugs  

PubMed Central

Cancer is the second leading cause of death worldwide. Conventional cancer therapies cause serious side effects and, at best, merely extend the patient’s lifespan by a few years. Cancer control may therefore benefit from the potential that resides in alternative therapies. The demand to utilize alternative concepts or approaches to the treatment of cancer is therefore escalating. There is compelling evidence from epidemiological and experimental studies that highlight the importance of compounds derived from plants “phytochemicals” to reduce the risk of colon cancer and inhibit the development and spread of tumors in experimental animals. More than 25% of drugs used during the last 20 years are directly derived from plants, while the other 25% are chemically altered natural products. Still, only 5-15% of the approximately 250,000 higher plants have ever been investigated for bioactive compounds. The advantage of using such compounds for cancer treatment is their relatively non-toxic nature and availability in an ingestive form. An ideal phytochemical is one that possesses anti-tumor properties with minimal toxicity and has a defined mechanism of action. As compounds that target specific signaling pathways are identified, researchers can envisage novel therapeutic approaches as well as a better understanding of the pathways involved in disease progression. Here, we focus on 4 classes of natural anticancer drugs: methyltransferase inhibitors, DNA damaging/pro-oxidant drugs, HDAC inhibitors (HDACi), and mitotic disrupters, and we will focus on the mode of action for one promising example per group. PMID:23675107

Amin, Amr; Gali-Muhtasib, Hala; Ocker, Matthias; Schneider-Stock, Regine

2009-01-01

95

Analysis of Vascular Development in the hydra Sterol Biosynthetic Mutants of Arabidopsis  

PubMed Central

Background The control of vascular tissue development in plants is influenced by diverse hormonal signals, but their interactions during this process are not well understood. Wild-type sterol profiles are essential for growth, tissue patterning and signalling processes in plant development, and are required for regulated vascular patterning. Methodology/Principal Findings Here we investigate the roles of sterols in vascular tissue development, through an analysis of the Arabidopsis mutants hydra1 and fackel/hydra2, which are defective in the enzymes sterol isomerase and sterol C-14 reductase respectively. We show that defective vascular patterning in the shoot is associated with ectopic cell divisions. Expression of the auxin-regulated AtHB8 homeobox gene is disrupted in mutant embryos and seedlings, associated with variably incomplete vascular strand formation and duplication of the longitudinal axis. Misexpression of the auxin reporter proIAA2?GUS and mislocalization of PIN proteins occurs in the mutants. Introduction of the ethylene-insensitive ein2 mutation partially rescues defective cell division, localization of PIN proteins, and vascular strand development. Conclusions The results support a model in which sterols are required for correct auxin and ethylene crosstalk to regulate PIN localization, auxin distribution and AtHB8 expression, necessary for correct vascular development. PMID:20808926

Pullen, Margaret; Clark, Nick; Zarinkamar, Fatemeh; Topping, Jennifer; Lindsey, Keith

2010-01-01

96

Survey of extrachromosomal circular DNA derived from plant satellite repeats  

PubMed Central

Background Satellite repeats represent one of the most dynamic components of higher plant genomes, undergoing rapid evolutionary changes of their nucleotide sequences and abundance in a genome. However, the exact molecular mechanisms driving these changes and their eventual regulation are mostly unknown. It has been proposed that amplification and homogenization of satellite DNA could be facilitated by extrachromosomal circular DNA (eccDNA) molecules originated by recombination-based excision from satellite repeat arrays. While the models including eccDNA are attractive for their potential to explain rapid turnover of satellite DNA, the existence of satellite repeat-derived eccDNA has not yet been systematically studied in a wider range of plant genomes. Results We performed a survey of eccDNA corresponding to nine different families and three subfamilies of satellite repeats in ten species from various genera of higher plants (Arabidopsis, Oryza, Pisum, Secale, Triticum and Vicia). The repeats selected for this study differed in their monomer length, abundance, and chromosomal localization in individual species. Using two-dimensional agarose gel electrophoresis followed by Southern blotting, eccDNA molecules corresponding to all examined satellites were detected. EccDNA occurred in the form of nicked circles ranging from hundreds to over eight thousand nucleotides in size. Within this range the circular molecules occurred preferentially in discrete size intervals corresponding to multiples of monomer or higher-order repeat lengths. Conclusion This work demonstrated that satellite repeat-derived eccDNA is common in plant genomes and thus it can be seriously considered as a potential intermediate in processes driving satellite repeat evolution. The observed size distribution of circular molecules suggests that they are most likely generated by molecular mechanisms based on homologous recombination requiring long stretches of sequence similarity. PMID:18721471

Navratilova, Alice; Koblizkova, Andrea; Macas, Jiri

2008-01-01

97

Distribution of fecal sterols in surface sediment of Sungai Tebrau, Johor  

NASA Astrophysics Data System (ADS)

Decreasing quality of aquatic environments may harm human health in general. Sewage pollution from human and animal excretions is a major cause of environmental quality depletion. This study investigates the distribution of sewage contamination level in twenty surface sediment samples taken from Sungai Tebrau, Johor. Four principal fecal sterols have been identified and were found in all sediment samples, which are coprostanol, cholesterol, epicoprostanol and also cholestanol. Cholesterol as the major sterol and most abundant compound derived from a variety of sources ranged from 32.92 to 1,100.55 ngg-1 dry weights. Meanwhile, major fecal sterol, coprostanol has the lowest quantity of total sterol in all samples, constituting only 13% of total sterol. It ranged from 12.63 to 565.42 ngg-1 dry weights, but only two stations (ST12 and ST14) are sewage contaminated. Squatters and residential areas are a major contributor of poorly treated sewage into the aquatic environment. Coprostanol concentration alone is not reliable to indicate sewage contamination; diagnostic indices enhance reliability of sterols as a marker for sewage contamination. Indices applied in this study are coprostanol/cholesterol, coprostanol/(coprostanol+cholestanol) and also epicoprostanol/coprostanol. Resultsof coprostanol/cholesterol, coprostanol/(coprostanol+cholestanol) indices supported the findings that both ST12 and ST14 samples are contaminated with sewage. All samples consist of relativelyhigh concentration of epicoprostanol and high ratio value of epicoprostanol/coprostanol. Generally, it can be concluded that these sampling sites are not contaminated with sewage even though fecal sterols were detected in all samples as they were found to be at low concentration.

Nordin, N.; Ali, M. M.

2013-11-01

98

Sterol-binding proteins and endosomal cholesterol transport  

Microsoft Academic Search

Endosomal compartments sort and deliver exogenous lipoprotein-derived cholesterol to the endoplasmic reticulum for regulating\\u000a cellular cholesterol homeostasis. A large number of studies have focused on the removal of endosomal cholesterol, since its\\u000a accumulation leads to devastating human diseases. Recent studies suggest that cytoplasmic sterol-binding proteins may be involved\\u000a in endosomal cholesterol transport. In particular, endosome\\/lysosome-localized or -associated cholesterol-binding proteins\\u000a may

Ximing Du; Hongyuan Yang

2011-01-01

99

Plant-Derived Human Collagen Scaffolds for Skin Tissue Engineering  

PubMed Central

Tissue engineering scaffolds are commonly formed using proteins extracted from animal tissues, such as bovine hide. Risks associated with the use of these materials include hypersensitivity and pathogenic contamination. Human-derived proteins lower the risk of hypersensitivity, but possess the risk of disease transmission. Methods engineering recombinant human proteins using plant material provide an alternate source of these materials without the risk of disease transmission or concerns regarding variability. To investigate the utility of plant-derived human collagen (PDHC) in the development of engineered skin (ES), PDHC and bovine hide collagen were formed into tissue engineering scaffolds using electrospinning or freeze-drying. Both raw materials were easily formed into two common scaffold types, electrospun nonwoven scaffolds and lyophilized sponges, with similar architectures. The processing time, however, was significantly lower with PDHC. PDHC scaffolds supported primary human cell attachment and proliferation at an equivalent or higher level than the bovine material. Interleukin-1 beta production was significantly lower when activated THP-1 macrophages where exposed to PDHC electrospun scaffolds compared to bovine collagen. Both materials promoted proper maturation and differentiation of ES. These data suggest that PDHC may provide a novel source of raw material for tissue engineering with low risk of allergic response or disease transmission. PMID:23298216

Willard, James J.; Drexler, Jason W.; Das, Amitava; Roy, Sashwati; Shilo, Shani; Shoseyov, Oded

2013-01-01

100

Up-regulation of an N-terminal truncated 3-hydroxy-3-methylglutaryl CoA reductase enhances production of essential oils and sterols in transgenic Lavandula latifolia.  

PubMed

Spike lavender (Lavandula latifolia) essential oil is widely used in the perfume, cosmetic, flavouring and pharmaceutical industries. Thus, modifications of yield and composition of this essential oil by genetic engineering should have important scientific and commercial applications. We generated transgenic spike lavender plants expressing the Arabidopsis thaliana HMG1 cDNA, encoding the catalytic domain of 3-hydroxy-3-methylglutaryl CoA reductase (HMGR1S), a key enzyme of the mevalonic acid (MVA) pathway. Transgenic T0 plants accumulated significantly more essential oil constituents as compared to controls (up to 2.1- and 1.8-fold in leaves and flowers, respectively). Enhanced expression of HMGR1S also increased the amount of the end-product sterols, beta-sitosterol and stigmasterol (average differences of 1.8- and 1.9-fold, respectively), but did not affect the accumulation of carotenoids or chlorophylls. We also analysed T1 plants derived from self-pollinated seeds of T0 lines that flowered after growing for 2 years in the greenhouse. The increased levels of essential oil and sterols observed in the transgenic T0 plants were maintained in the progeny that inherited the HMG1 transgene. Our results demonstrate that genetic manipulation of the MVA pathway increases essential oil yield in spike lavender, suggesting a contribution for this cytosolic pathway to monoterpene and sesquiterpene biosynthesis in leaves and flowers of the species. PMID:17714440

Muñoz-Bertomeu, Jesús; Sales, Ester; Ros, Roc; Arrillaga, Isabel; Segura, Juan

2007-11-01

101

Herbal remedies of the Maritime indians: sterols and triterpenes of Tanacetum vulgare L. (Tansy).  

PubMed

Plant sterols and triterpenes exhibit a wide range of pharmacological activities. As part of our ongoing studies of the medicinal aspects of Maritime flora, particularly the herbal remedies of the Micmac and Malecite Indians, we determined the nature of the sterols and triterpenes of Tanacetum vulgare L. (Compositae)-a widely used herbal remedy usually referred to as tansy. By using thin layer and gas chromatographics, nuclear magnetic resonance (NMR) spectroscopy and combined gas chromatography-mass spectrometry, we were able to identify beta-sitosterol as the major sterol and alpha-amyrin as the major triterpene of tansy. We also identified the sterols stigmasterol, campesterol and cholesterol, and the triterpenes beta-amyrin and taraxasterol. A fourth triterpene was tentatively identified as pseudo-taraxasterol. The successful therapeutic application of this herb may be due partly to the presence of one or more of these compounds. The sterols and triterpenes of tansy have not been previously reported; neither, to our knowledge, have the NMR spectra of the amyrins and the NMR and mass spectra of taraxasterol. PMID:7087682

Chandler, R F; Hooper, S N; Hooper, D L; Jamieson, W D; Lewis, E

1982-02-01

102

How sterol tilt regulates properties and organization of lipid membranes and membrane insertions  

PubMed Central

Serving as a crucial component of mammalian cells, cholesterol critically regulates the functions of biomembranes. This review focuses on a specific property of cholesterol and other sterols: the tilt modulus ? that quantifies the energetic cost of tilting sterol molecules inside the lipid membrane. We show how ? is involved in determining properties of cholesterol-containing membranes, and detail a novel approach to quantify its value from atomistic molecular dynamics (MD) simulations. Specifically, we link ? with other structural, thermodynamic, and mechanical properties of cholesterol-containing lipid membranes, and delineate how this useful parameter can be obtained from the sterol tilt probability distributions derived from relatively small-scale unbiased MD simulations. We demonstrate how the tilt modulus quantitatively describes the aligning field that sterol molecules create inside the phospholipid bilayers, and we relate ? to the bending rigidity of the lipid bilayer through effective tilt and splay energy contributions to the elastic deformations. Moreover, we show how ? can conveniently characterize the “condensing effect” of cholesterol on phospholipids. Finally, we demonstrate the importance of this cholesterol aligning field to the proper folding and interactions of membrane peptides. Given the relative ease of obtaining the tilt modulus from atomistic simulations, we propose that ? can be routinely used to characterize the mechanical properties of sterol/lipid bilayers, and can also serve as a required fitting parameter in multi-scaled simulations of lipid membrane models to relate the different levels of coarse-grained details. PMID:23291283

Khelashvili, George; Harries, Daniel

2013-01-01

103

A Dietary Test of Putative Deleterious Sterols for the Aphid Myzus persicae  

E-print Network

A Dietary Test of Putative Deleterious Sterols for the Aphid Myzus persicae Sophie Bouvaine1, College Station, Texas, United States of America Abstract The aphid Myzus persicae displays high mortality on tobacco plants bearing a transgene which results in the accumulation of the ketosteroids cholestan-3-one

Behmer, Spencer T.

104

Visualization of Sterol-Rich Membrane Domains with Fluorescently-Labeled Theonellamides  

PubMed Central

Cholesterol plays important roles in biological membranes. The cellular location where cholesterol molecules work is prerequisite information for understanding their dynamic action. Bioimaging probes for cholesterol molecules would be the most powerful means for unraveling the complex nature of lipid membranes. However, only a limited number of chemical or protein probes have been developed so far for cytological analysis. Here we show that fluorescently-labeled derivatives of theonellamides act as new sterol probes in mammalian cultured cells. The fluorescent probes recognized cholesterol molecules and bound to liposomes in a cholesterol-concentration dependent manner. The probes showed patchy distribution in the plasma membrane, while they stained specific organelle in the cytoplasm. These data suggest that fTNMs will be valuable sterol probes for studies on the role of sterols in the biological membrane under a variety of experimental conditions. PMID:24386262

Nishimura, Shinichi; Ishii, Kumiko; Iwamoto, Kunihiko; Arita, Yuko; Matsunaga, Shigeki; Ohno-Iwashita, Yoshiko; Sato, Satoshi B.; Kakeya, Hideaki; Kobayashi, Toshihide; Yoshida, Minoru

2013-01-01

105

Biofuels. Altered sterol composition renders yeast thermotolerant.  

PubMed

Ethanol production for use as a biofuel is mainly achieved through simultaneous saccharification and fermentation by yeast. Operating at ?40°C would be beneficial in terms of increasing efficiency of the process and reducing costs, but yeast does not grow efficiently at those temperatures. We used adaptive laboratory evolution to select yeast strains with improved growth and ethanol production at ?40°C. Sequencing of the whole genome, genome-wide gene expression, and metabolic-flux analyses revealed a change in sterol composition, from ergosterol to fecosterol, caused by mutations in the C-5 sterol desaturase gene, and increased expression of genes involved in sterol biosynthesis. Additionally, large chromosome III rearrangements and mutations in genes associated with DNA damage and respiration were found, but contributed less to the thermotolerant phenotype. PMID:25278608

Caspeta, Luis; Chen, Yun; Ghiaci, Payam; Feizi, Amir; Buskov, Steen; Hallström, Björn M; Petranovic, Dina; Nielsen, Jens

2014-10-01

106

Biological removal of phyto-sterols in pulp mill effluents.  

PubMed

Phyto-sterols and extractives found in pulp mill effluents are suspected to cause endocrine abnormalities in receiving water fish. The control of sterols in pulp mill effluents through biological secondary wastewater treatment was studied using two lab-scale bioreactor systems. After achieving a stable performance, both bioreactor systems successfully removed (>90%) sterols and the estimated biodegradation was up to 80%. Reactor 1 system operating at 6.7 ± 0.2 pH effectively treated pulp mill effluent sterols spiked up to 4500 ?g/L in 11 h HRT and 11 day SRT. However, Reactor 2 system operating at 7.6 ± 0.2 pH performed relatively poorly. Retention time reductions beyond critical values deteriorated the performance of treatment systems and quickly reduced the sterols biodegradation. The biodegradation loss was indicated by mixed liquor sterols content that started increasing. This biodegradation loss was compensated by the increased role of bio-adsorption and the overall sterols removal remained relatively high. Hence, a relatively small (20-30%) loss in the overall sterols removal efficiency did not fully reflect the associated major (60-70%) loss in the sterols biodegradation because the amount of sterols accumulated in the sludge due to adsorption increased so the estimate of sterols removal through adsorption increased from 30-40% to 70-80% keeping the overall sterols removal still high. PMID:24211569

Mahmood-Khan, Zahid; Hall, Eric R

2013-12-15

107

Transport of Newly Synthesized Sterol to the Sterol-Enriched Plasma Membrane Occurs via Nonvesicular Equilibration †  

Microsoft Academic Search

The mechanism by which newly synthesized sterols are transported from their site of synthesis, the endoplasmic reticulum (ER), to the sterol-enriched plasma membrane (PM) is not fully understood. Studies in mammalian cells suggest that newly synthesized cholesterol is transported to the PM in Golgi- bypassing vesicles and\\/or via a nonvesicular process. Using the yeast Saccharomyces cereVisiae as a model system,

Nikola A. Baumann; David P. Sullivan; Henna Ohvo-Rekilä; Cedric Simonot; Anita Pottekat; Zachary Klaassen; Christopher T. Beh; Anant K. Menon

2005-01-01

108

Lectin cDNA and transgenic plants derived therefrom  

DOEpatents

Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties.

Raikhel, Natasha V. (Okemos, MI)

2000-10-03

109

Assessment of plant-derived hydrocarbons. Final report  

SciTech Connect

A number of hydrocarbon producing plants are evaluated as possible sources of rubber, liquid fuels, and industrial lubricants. The plants considered are Euphorbia lathyris or gopher plant, milkweeds, guayule, rabbit brush, jojoba, and meadow foam. (ACR)

McFadden, K.; Nelson, S.H.

1981-09-30

110

Changes in membrane lipid composition in azuki bean epicotyls under hypergravity conditions: Possible role of membrane sterols in gravity resistance  

NASA Astrophysics Data System (ADS)

Seedlings of azuki bean ( Vigna angularis Ohwi et Ohashi) were cultivated under hypergravity conditions, and changes in membrane lipid composition in their epicotyls were analyzed. Under hypergravity conditions at 300 g, the levels of total sterols, phospholipids, and fatty acids per fresh weight were kept higher, as compared with 1 g controls. In particular, sterol levels were prominently increased by hypergravity. On the other hand, hypergravity did not clearly influence the levels of each phospholipid and glycolipid class, or their fatty acid compositions. Thus, the effect of hypergravity on membrane lipid metabolism was specific for sterol biosynthesis. In various regions of azuki epicotyls, high growth rate was associated with high sterol levels. Hypergravity suppressed elongation growth and stimulated lateral expansion of azuki epicotyls. In the presence of lovastatin, an inhibitor of sterol biosynthesis, at 30 ?M, such changes in growth parameters occurred even under 1 g conditions, suggesting that lovastatin made epicotyls hypersensitive to the gravitational force. These results support the hypothesis that membrane sterols are involved in maintenance of normal growth capacity of plant organs against gravity.

Koizumi, T.; Sakaki, T.; Usui, S.; Soga, K.; Wakabayashi, K.; Hoson, T.

111

Plasma membrane lipid-protein interactions affect signaling processes in sterol-biosynthesis mutants in Arabidopsis thaliana  

PubMed Central

The plasma membrane is an important organelle providing structure, signaling and transport as major biological functions. Being composed of lipids and proteins with different physicochemical properties, the biological functions of membranes depend on specific protein–protein and protein–lipid interactions. Interactions of proteins with their specific sterol and lipid environment were shown to be important factors for protein recruitment into sub-compartmental structures of the plasma membrane. System-wide implications of altered endogenous sterol levels for membrane functions in living cells were not studied in higher plant cells. In particular, little is known how alterations in membrane sterol composition affect protein and lipid organization and interaction within membranes. Here, we conducted a comparative analysis of the plasma membrane protein and lipid composition in Arabidopsis sterol-biosynthesis mutants smt1 and ugt80A2;B1. smt1 shows general alterations in sterol composition while ugt80A2;B1 is significantly impaired in sterol glycosylation. By systematically analyzing different cellular fractions and combining proteomic with lipidomic data we were able to reveal contrasting alterations in lipid–protein interactions in both mutants, with resulting differential changes in plasma membrane signaling status. PMID:24672530

Zauber, Henrik; Burgos, Asdrubal; Garapati, Prashanth; Schulze, Waltraud X.

2014-01-01

112

An Update on Plant Derived Anti-Androgens  

PubMed Central

Anti-androgens are an assorted group of drugs and compounds that reduce the levels or activity of androgen hormones within the human body. Disease states in which this is relevant include polycystic ovarian syndrome, hirsutism, acne, benign prostatic hyperplasia, and endocrine related cancers such as carcinoma of the prostate. We provide an overview and discussion of the use of anti-androgen medications in clinical practice and explore the increasing recognition of the benefits of plant-derived anti-androgens, for example, spearmint tea in the management of PCOS, for which some evidence about efficacy is beginning to emerge. Other agents covered include red reishi, which has been shown to reduce levels 5-alpha reductase, the enzyme that facilitates conversion of testosterone to dihydrotestosterone (DHT); licorice, which has phytoestrogen effects and reduces testosterone levels; Chinese peony, which promotes the aromatization of testosterone into estrogen; green tea, which contains epigallocatechins and also inhibits 5-alpha reductase, thereby reducing the conversion of normal testosterone into the more potent DHT; black cohosh, which has been shown to kill both androgenresponsive and non-responsive human prostate cancer cells; chaste tree, which has a reduces prolactin from the anterior pituitary; and saw palmetto extract, which is used as an anti-androgen although it shown no difference in comparison to placebo in clinical trials. PMID:23843810

Grant, Paul; Ramasamy, Shamin

2012-01-01

113

An update on plant derived anti-androgens.  

PubMed

Anti-androgens are an assorted group of drugs and compounds that reduce the levels or activity of androgen hormones within the human body. Disease states in which this is relevant include polycystic ovarian syndrome, hirsutism, acne, benign prostatic hyperplasia, and endocrine related cancers such as carcinoma of the prostate. We provide an overview and discussion of the use of anti-androgen medications in clinical practice and explore the increasing recognition of the benefits of plant-derived anti-androgens, for example, spearmint tea in the management of PCOS, for which some evidence about efficacy is beginning to emerge. Other agents covered include red reishi, which has been shown to reduce levels 5-alpha reductase, the enzyme that facilitates conversion of testosterone to dihydrotestosterone (DHT); licorice, which has phytoestrogen effects and reduces testosterone levels; Chinese peony, which promotes the aromatization of testosterone into estrogen; green tea, which contains epigallocatechins and also inhibits 5-alpha reductase, thereby reducing the conversion of normal testosterone into the more potent DHT; black cohosh, which has been shown to kill both androgenresponsive and non-responsive human prostate cancer cells; chaste tree, which has a reduces prolactin from the anterior pituitary; and saw palmetto extract, which is used as an anti-androgen although it shown no difference in comparison to placebo in clinical trials. PMID:23843810

Grant, Paul; Ramasamy, Shamin

2012-01-01

114

Mechanisms and genetic determinants regulating sterol absorption, circulating LDL levels, and sterol elimination: implications for classification and disease risk  

PubMed Central

This review integrates historical biochemical and modern genetic findings that underpin our understanding of the low-density lipoprotein (LDL) dyslipidemias that bear on human disease. These range from life-threatening conditions of infancy through severe coronary heart disease of young adulthood, to indolent disorders of middle- and old-age. We particularly focus on the biological aspects of those gene mutations and variants that impact on sterol absorption and hepatobiliary excretion via specific membrane transporter systems (NPC1L1, ABCG5/8); the incorporation of dietary sterols (MTP) and of de novo synthesized lipids (HMGCR, TRIB1) into apoB-containing lipoproteins (APOB) and their release into the circulation (ANGPTL3, SARA2, SORT1); and receptor-mediated uptake of LDL and of intestinal and hepatic-derived lipoprotein remnants (LDLR, APOB, APOE, LDLRAP1, PCSK9, IDOL). The insights gained from integrating the wealth of genetic data with biological processes have important implications for the classification of clinical and presymptomatic diagnoses of traditional LDL dyslipidemias, sitosterolemia, and newly emerging phenotypes, as well as their management through both nutritional and pharmaceutical means. PMID:21862702

Calandra, Sebastiano; Tarugi, Patrizia; Speedy, Helen E.; Dean, Andrew F.; Bertolini, Stefano; Shoulders, Carol C.

2011-01-01

115

Antibiofilm effect of plant derived antimicrobials on Listeria monocytogenes.  

PubMed

The present study investigated the efficacy of sub-inhibitory concentrations (SICs, concentrations not inhibiting bacterial growth) and bactericidal concentrations (MBCs) of four, generally recognized as safe (GRAS), plant-derived antimicrobials (PDAs) in inhibiting Listeria monocytogenes (LM) biofilm formation and inactivating mature LM biofilms, at 37, 25 and 4 °C on polystyrene plates and stainless-steel coupons. In addition, the effect of SICs of PDAs on the expression of LM genes critical for biofilm synthesis was determined by real-time quantitative PCR. The PDAs and their SICs used for inhibition of biofilm were trans-cinnamaldehyde (TC 0.50, 0.75 mM), carvacrol (CR 0.50, 0.65 mM), thymol (TY 0.33, 0.50 mM), and eugenol (EG 1.8, 2.5 mM), whereas the PDA concentrations used for inactivating mature biofilms were 5.0 and 10.0 mM (TC, CR), 3.3 and 5.0 mM (TY), 18.5 and 25.0 mM (EG). All PDAs inhibited biofilm synthesis and inactivated fully formed LM biofilms on both matrices at three temperatures tested (P < 0.05). Real-time quantitative PCR data revealed that all PDAs down-regulated critical LM biofilm-associated genes (P < 0.05). Results suggest that TC, CR, TY, and EG could potentially be used to control LM biofilms in food processing environments, although further studies under commercial settings are necessary. PMID:23764223

Upadhyay, Abhinav; Upadhyaya, Indu; Kollanoor-Johny, Anup; Venkitanarayanan, Kumar

2013-10-01

116

Mutations in UDP-Glucose:sterol glucosyltransferase in Arabidopsis cause transparent testa phenotype and suberization defect in seeds.  

PubMed

In higher plants, the most abundant sterol derivatives are steryl glycosides (SGs) and acyl SGs. Arabidopsis (Arabidopsis thaliana) contains two genes, UGT80A2 and UGT80B1, that encode UDP-Glc:sterol glycosyltransferases, enzymes that catalyze the synthesis of SGs. Lines having mutations in UGT80A2, UGT80B1, or both UGT80A2 and UGT8B1 were identified and characterized. The ugt80A2 lines were viable and exhibited relatively minor effects on plant growth. Conversely, ugt80B1 mutants displayed an array of phenotypes that were pronounced in the embryo and seed. Most notable was the finding that ugt80B1 was allelic to transparent testa15 and displayed a transparent testa phenotype and a reduction in seed size. In addition to the role of UGT80B1 in the deposition of flavanoids, a loss of suberization of the seed was apparent in ugt80B1 by the lack of autofluorescence at the hilum region. Moreover, in ugt80B1, scanning and transmission electron microscopy reveals that the outer integument of the seed coat lost the electron-dense cuticle layer at its surface and displayed altered cell morphology. Gas chromatography coupled with mass spectrometry of lipid polyester monomers confirmed a drastic decrease in aliphatic suberin and cutin-like polymers that was associated with an inability to limit tetrazolium salt uptake. The findings suggest a membrane function for SGs and acyl SGs in trafficking of lipid polyester precursors. An ancillary observation was that cellulose biosynthesis was unaffected in the double mutant, inconsistent with a predicted role for SGs in priming cellulose synthesis. PMID:19641030

DeBolt, Seth; Scheible, Wolf-Rüdiger; Schrick, Kathrin; Auer, Manfred; Beisson, Fred; Bischoff, Volker; Bouvier-Navé, Pierrette; Carroll, Andrew; Hematy, Kian; Li, Yonghua; Milne, Jennifer; Nair, Meera; Schaller, Hubert; Zemla, Marcin; Somerville, Chris

2009-09-01

117

Casein kinase 1 regulates sterol regulatory element-binding protein (SREBP) to control sterol homeostasis.  

PubMed

Sterol homeostasis is tightly controlled by the sterol regulatory element-binding protein (SREBP) transcription factor that is highly conserved from fungi to mammals. In fission yeast, SREBP functions in an oxygen-sensing pathway to promote adaptation to decreased oxygen supply that limits oxygen-dependent sterol synthesis. Low oxygen stimulates proteolytic cleavage of the SREBP homolog Sre1, generating the active transcription factor Sre1N that drives expression of sterol biosynthetic enzymes. In addition, low oxygen increases the stability and DNA binding activity of Sre1N. To identify additional signals controlling Sre1 activity, we conducted a genetic overexpression screen. Here, we describe our isolation and characterization of the casein kinase 1 family member Hhp2 as a novel regulator of Sre1N. Deletion of Hhp2 increases Sre1N protein stability and ergosterol levels in the presence of oxygen. Hhp2-dependent Sre1N degradation by the proteasome requires Hhp2 kinase activity, and Hhp2 binds and phosphorylates Sre1N at specific residues. Our results describe a role for casein kinase 1 as a direct regulator of sterol homeostasis. Given the role of mammalian Hhp2 homologs, casein kinase 1? and 1?, in regulation of the circadian clock, these findings may provide a mechanism for coordinating circadian rhythm and lipid metabolism. PMID:24327658

Brookheart, Rita T; Lee, Chih-Yung S; Espenshade, Peter J

2014-01-31

118

Physiological and proteomic approaches to evaluate the role of sterol binding in elicitin-induced resistance  

PubMed Central

Cryptogein is a proteinaceous elicitor secreted by Phytophthora cryptogea that can induce resistance to P. parasitica in tobacco plants. On the basis of previous computer modelling experiments, by site-directed mutagenesis a series of cryptogein variants was prepared with altered abilities to bind sterols, phospholipids or both. The sterol binding and phospholipid transfer activities corresponded well with the previously reported structural data. Induction of the synthesis of reactive oxygen species (ROS) in tobacco cells in suspension and proteomic analysis of intercellular fluid changes in tobacco leaves triggered by these mutant proteins were not proportional to their ability to bind or transfer sterols and phospholipids. However, changes in the intercellular proteome corresponded to transcription levels of defence genes and resistance to P. parasitica and structure-prediction of mutants did not reveal any significant changes in protein structure. These results suggest, contrary to previous proposals, that the sterol-binding ability of cryptogein and its mutants, and the associated conformational change in the ?-loop, might not be principal factors in either ROS production or resistance induction. Nevertheless, the results support the importance of the ?-loop for the interaction of the protein with the high affinity binding site on the plasma membrane. PMID:22223811

Dokladal, Ladislav; Oboril, Michal; Stejskal, Karel; Zdrahal, Zbynek; Ptackova, Nikola; Chaloupkova, Radka; Damborsky, Jiri; Kasparovsky, Tomas; Jeandroz, Sylvain; Zd'arska, Marketa; Lochman, Jan

2012-01-01

119

Fatty Acid-Derived Signals that Induce or Regulate Plant Defenses Against Herbivory  

Microsoft Academic Search

Jasmonic acid and other derivatives of linolenic acid produced in plants by the octadecanoid pathway, as well as the six-carbon fatty acid derivatives called green leaf compounds, play major roles in regulating plant defenses against herbivores. So do also conjugates of linolenic acid with glutamine and glutamate, found in the regurgitant of several lepidopteran larvae, as well as in crickets

James H. Tumlinson; Juergen Engelberth

120

Early diagenesis of plant-derived dissolved organic matter along a wetland, mangrove, estuary ecotone  

Microsoft Academic Search

We studied the role of photochemical and microbial processes in contributing to the transformation of dissolved organic matter (DOM) derived from various plants that dominate the Florida Everglades. Plant-derived DOM leach- ate samples were exposed to photochemical and microbial degradation and the optical, chemical, and molecular weight characteristics measured over time. Optical parameters such as the synchronous fluorescence intensity be-

Norman M. Scully; Nagamitsu Maie; Susan K. Dailey; Joseph N. Boyer; Ronald D. Jones; Rudolf Jaffé

2004-01-01

121

Lectin cDNA and transgenic plants derived therefrom  

DOEpatents

Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties. GOVERNMENT RIGHTS This application was funded under Department of Energy Contract DE-AC02-76ER01338. The U.S. Government has certain rights under this application and any patent issuing thereon. .

Raikhel, N.V.

1994-01-04

122

Lectin cDNA and transgenic plants derived therefrom  

DOEpatents

Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties. GOVERNMENT RIGHTS This application was funded under Department of Energy Contract DE-AC02-76ER01338. The U.S. Government has certain rights under this application and any patent issuing thereon.

Raikhel, Natasha V. (Okemos, MI)

1994-01-04

123

Distribution of sterols in the fungi. I - Fungal spores  

NASA Technical Reports Server (NTRS)

Mass spectrometry was used to examine freely extractable sterols from spores of several species of fungi. Ergosterol was the most common sterol produced by any individual species, but it was completely absent from two species belonging to apparently distantly related groups of fungi: the aquatic Phycomycetes and the rust fungi. This fact could have taxonomic or phylogenetic implications. The use of glass capillary columns in the resolution of the sterols is shown to eliminate some of the difficulty inherent in this process.

Weete, J. D.; Laseter, J. L.

1974-01-01

124

Seasonal changes in minor membrane phospholipid classes, sterols and tocopherols in overwintering insect, Pyrrhocoris apterus.  

PubMed

Ectotherm animals including insects are known to undergo seasonal restructuring of the cell membranes in order to keep their functionality and/or protect their structural integrity at low body temperatures. Studies on insects so far focused either on fatty acids or on composition of molecular species in major phospholipid classes. Here we extend the scope of analysis and bring results on seasonal changes in minor phospholipid classes, lysophospholipids (LPLs), free fatty acids, phytosterols and tocopherols in heteropteran insect, Pyrrhocoris apterus. We found that muscle tissue contains unusually high amounts of LPLs. Muscle and fat body tissues also contain high amounts of ?-sitosterol and campesterol, two phytosterols derived from plant food, while only small amounts of cholesterol are present. In addition, two isomers (? and ?) of tocopherol (vitamin E) are present in quantities comparable to, or even higher than phytosterols in both tissues. Distinct seasonal patterns of sterol and tocopherol concentrations were observed showing a minimum in reproductively active bugs in summer and a maximum in diapausing, cold-acclimated bugs in winter. Possible adaptive meanings of such changes are discussed including: preventing the unregulated transition of membrane lipids from functional liquid crystalline phase to non-functional gel phase; decreasing the rates of ion/solute leakage; silencing the activities of membrane bound enzymes and receptors; and counteracting the higher risk of oxidative damage to PUFA in winter membranes. PMID:23845405

Koštál, Vladimír; Urban, Tomáš; Rimná?ová, Lucie; Berková, Petra; Simek, Petr

2013-09-01

125

Sterols and Oxidized Sterols in Feed Ingredients Obtained from Chemical and Physical Refining Processes of Fats and Oils  

Microsoft Academic Search

The by-products obtained from conventional chemical and physical refining processes for edible fats and oils are important\\u000a sources of valuable fatty components such as sterols, tocopherols, fatty acids, etc., and are also used as ingredients in\\u000a animal feed formulations. Reports on sterol composition and content are limited, and the levels of oxidized sterols in these\\u000a valuable by-products are unknown. This

Sarojini J. K. A. Ubhayasekera; Paresh C. Dutta

2009-01-01

126

Plant-derived Compounds for the Treatment of Retroviral Diseases  

Cancer.gov

NIH Researchers have identified Englerin A and its derivatives as potent and specific activators of viral replication in infected T cells (with a decrease of about 70% of activated T-reg population following ex-vivo PBMCs treatment).

127

X-ray Structure of 4,4?-Dihydroxybenzophenone Mimicking Sterol Substrate in the Active Site of Sterol 14?-Demethylase (CYP51)*S??  

PubMed Central

A universal step in the biosynthesis of membrane sterols and steroid hormones is the oxidative removal of the 14?-methyl group from sterol precursors by sterol 14?-demethylase (CYP51). This enzyme is a primary target in treatment of fungal infections in organisms ranging from humans to plants, and development of more potent and selective CYP51 inhibitors is an important biological objective. Our continuing interest in structural aspects of substrate and inhibitor recognition in CYP51 led us to determine (to a resolution of 1.95Å) the structure of CYP51 from Mycobacterium tuberculosis (CYP51Mt) co-crystallized with 4,4?-dihydroxybenzophenone (DHBP), a small organic molecule previously identified among top type I binding hits in a library screened against CYP51Mt. The newly determined CYP51Mt-DHBP structure is the most complete to date and is an improved template for three-dimensional modeling of CYP51 enzymes from fungal and prokaryotic pathogens. The structure demonstrates the induction of conformational fit of the flexible protein regions and the interactions of conserved Phe-89 essential for both fungal drug resistance and catalytic function, which were obscure in the previously characterized CYP51Mt-estriol complex. DHBP represents a benzophenone scaffold binding in the CYP51 active site via a type I mechanism, suggesting (i) a possible new class of CYP51 inhibitors targeting flexible regions, (ii) an alternative catalytic function for bacterial CYP51 enzymes, and (iii) a potential for hydroxybenzophenones, widely distributed in the environment, to interfere with sterol biosynthesis. Finally, we show the inhibition of M. tuberculosis growth by DHBP in a mouse macrophage model. PMID:18367444

Eddine, Ali Nasser; von Kries, Jens P.; Podust, Mikhail V.; Warrier, Thulasi; Kaufmann, Stefan H. E.; Podust, Larissa M.

2008-01-01

128

Sterol Carrier Protein 2 Gene Transfer Changes Lipid Metabolism and Enterohepatic Sterol Circulation in Mice  

E-print Network

´gicas, Facultad de Ciencias Biolo´gicas, Pontificia Universidad Cato´lica, Santiago, Chile; §Institute for Human of SCP-2 in hepatic cholesterol and lipid trafficking through the sinusoidal and canalicular secretory the complex function of the liver in cholesterol metabolism, sterol trafficking within the hepatocytes must

Terasaki, Mark

129

Free Fatty Acids and Sterols in Swine Manure  

Microsoft Academic Search

Free fatty acids and sterols were assessed in fresh manure and anaerobic lagoon sludge from swine production facilities in North Carolina. Eight free fatty acids and five sterols were identified and quantified in both manure and sludge samples. Compound identification was performed by gas chromatography\\/mass spectroscopy (GC-MS), and compound quantities were determined by gas chromatography after solid phase extraction with

JOHN H. LOUGHRIN; ARIEL A. SZOGI

2006-01-01

130

STARD4 abundance regulates sterol transport and sensing  

PubMed Central

Nonvesicular transport of cholesterol plays an essential role in the distribution and regulation of cholesterol within cells, but it has been difficult to identify the key intracellular cholesterol transporters. The steroidogenic acute regulatory-related lipid-transfer (START) family of proteins is involved in several pathways of nonvesicular trafficking of sterols. Among them, STARD4 has been shown to increase intracellular cholesteryl ester formation and is controlled at the transcriptional level by sterol levels in cells. We found that STARD4 is very efficient in transporting sterol between membranes in vitro. Cholesterol levels are increased in STARD4-silenced cells, while sterol transport to the endocytic recycling compartment (ERC) and to the endoplasmic reticulum (ER) are enhanced upon STARD4 overexpression. STARD4 silencing attenuates cholesterol-mediated regulation of SREBP-2 activation, while its overexpression amplifies sterol sensing by SCAP/SREBP-2. To analyze STARD4's mode of action, we compared sterol transport mediated by STARD4 with that of a simple sterol carrier, methyl-?-cyclodextrin (MCD), when STARD4 and MCD were overexpressed or injected into cells. Interestingly, STARD4 and cytosolic MCD act similarly by increasing the rate of transfer of sterol to the ERC and to the ER. Our results suggest that cholesterol transport mediated by STARD4 is an important component of the cholesterol homeostasis regulatory machinery. PMID:21900492

Mesmin, Bruno; Pipalia, Nina H.; Lund, Frederik W.; Ramlall, Trudy F.; Sokolov, Anna; Eliezer, David; Maxfield, Frederick R.

2011-01-01

131

STEROLS AS BIOMARKERS IN GYMNODINIUM BREVE DISTRIBUTION IN DINOFLAGELLATES  

EPA Science Inventory

The sterol composition of marine microalgae has been shown to be a chemotaxonomic property potentially of value in distinguishing members of different algal classes. For example, members of the class Dinophyceae display sterol compositions ranging from as few as two (cholesterol ...

132

Regeneration of anther-derived plants of Hyoscyamus niger L.  

PubMed

Anthers of Hyoscyamus niger L. were cultured by two different methods. In the first method anthers were cultured in the dark in the late tetrad stage of microspore development on the basal medium of Nitsch and Nitsch (Science 163, 85-87; 1969) supplemented with 5 or 10 mg/l 2,4-dichlorophenoxyacetic acid. The callus which developed was able to produce a large number of plants under photoperiodic conditions of 16 h light from fluorescent tubes at 28° and 20° during the dark cycle. Cytological analysis revealed that about 50% of these plants were haploid. A further imporvement to raise the level of haploids by the use of p-fluorophenylalanine was not achieved. In the second method anthers were cultured in the early mononucleate stage of microspore development on the basal medium of Nitsch and Nitsch which was little modified under various conditions. The largest number of plants which developed directly by embryoids was observed on the medium of Nitsch without indolylacetic acid under photoperiodic conditions of 16 h fluorescent light at 28° and 8 h dark at 20°. Cytological examination determined that approximately 70% of the plants were diploid. A genetic marker was used to ensure homozygoty of the diploid regenerates. 98% of the regenerates which developed via callus as well as by direct formation of embryoids were found to be homozygous and originated therefore from generative cells. PMID:24430282

Corduan, G

1975-01-01

133

6-methoxybenzoxazolinone: A Plant Derivative that Stimulates Reproduction in Microtus montanus  

Microsoft Academic Search

A plant-derived cyclic carbamate, 6-methoxybenzoxazolinone, that stimulates reproductive activity in Microtus montanus has been isolated. This nonestrogenic compound may be a naturally occurring environmental cue affecting reproductive cycles in many mammals.

Edward H. Sanders; Pete D. Gardner; Patricia J. Berger; Norman C. Negus

1981-01-01

134

A plant-derived edible vaccine against hepatitis B virus.  

PubMed

The infectious hepatitis B virus represents 42 nm spherical double-shelled particles. However, analysis of blood from hepatitis B virus carriers revealed the presence of smaller 22 nm particles consisting of a viral envelope surface protein. These particles are highly immunogenic and have been used in the design of hepatitis B virus vaccine produced in yeast. Upon expression in yeast, these proteins form virus-like particles that are used for parenteral immunization. Therefore, the DNA fragment encoding hepatitis B virus surface antigen was introduced into Agrobacterium tumerifacience LBA4404 and used to obtain transgenic lupin (Lupinus luteus L.) and lettuce (Lactuca sativa L.) cv. Burpee Bibb expressing envelope surface protein. Mice that were fed the transgenic lupin tissue developed significant levels of hepatitis B virus-specific antibodies. Human volunteers, fed with transgenic lettuce plants expressing hepatitis B virus surface antigen, developed specific serum-IgG response to plant produced protein. PMID:10506582

Kapusta, J; Modelska, A; Figlerowicz, M; Pniewski, T; Letellier, M; Lisowa, O; Yusibov, V; Koprowski, H; Plucienniczak, A; Legocki, A B

1999-10-01

135

Mycotoxins biosynthesized by plant-derived Fusarium isolates.  

PubMed

There is little information on secondary metabolites produced by Fusaria infecting crop plants other than cereals. Many members of Fusarium genus have the ability to colonise perennial crops with only scarce infection or disease symptoms or with no symptoms at all while still being detectable. Even in case of such asymptomatic infection, significant mycotoxin contamination of the plant tissues is possible. The aim of this study was to characterise the spectrum of Fusarium species isolates obtained from different plant hosts (like asparagus, garlic, pineapple, banana, rhubarb, peppers, rice, maize, wheat, and oncidium) and evaluate their ability to biosynthesize the most common mycotoxins in vitro. Among the F.proliferatum isolates, up to 57 % of them biosynthesized fumonisins at very high mass fractions, amounting to above 1000 ?g g(-1), while other Fusarium species such as F. verticillioides, F. lactis, F. polyphialydicum, F. concentricum, F. temperatum, and F. fujikuroi formed fumonisins mostly at much lower level. Only F. ananatum and F. oxysporum did not produce these toxins. Co-occurrence of FBs with other mycotoxins [moniliformin (MON) and beauvericin (BEA)] was often observed and it was mainly F. proliferatum species that formed both mycotoxins (0.4 ?g g(-1) to 41.1 ?g g(-1) BEA and 0.1 ?g g(-1) to 158.5 ?g g(-1) MON). PMID:23334038

Wa?kiewicz, Agnieszka; St?pie?, ?ukasz

2012-12-01

136

Effect of sterol side-chain structure on sterol-phosphatidylcholine interactions in monolayers and small unilamellar vesicles.  

PubMed

In this study we have characterized the monolayer behavior of analogues of cholesterol having different side-chain structures and their interaction with phosphatidylcholines in mixed monolayers and small unilamellar vesicles (SUVs). Two series of side-chain analogues of cholesterol were synthesized, one with an unbranched side chain (the n-series, from 3 to 7 carbons in length), and the other with a single methyl-branched side chain (the iso-series, from 5 to 10 carbons in length). The length and conformation of the sterol side chain markedly influenced both the mean molecular area of the pure sterols and their monolayer stability (i.e., collapse pressure). Shorter side chains gave smaller mean molecular areas and decreased monolayer stability. The sterols from the n-series also had smaller mean molecular areas than the corresponding sterols in the iso-series. In mixed 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)/sterol monolayers (equimolar ratio; at 22 degrees C), all of the sterols tested decreased the monolayer stability as judged by the lower collapse pressure with sterol than without sterol. A similar trend was observed in mixed monolayers containing 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC), except that sterols from the iso-series with a chain length of 8 or 10 carbon atoms actually stabilized the monolayer compared with the sterol-free SOPC monolayer. The ability of the sterols to condense the molecular packing of DPPC was similar with all sterols (3-5% condensation at 10 mN/m), irrespective of the length or structure of the side chain. 5-Androsten-3 beta-ol, however, which lacks the side chain, did not at all condense the monolayer packing of DPPC. With SOPC mixed monolayers, all side chain containing sterols caused a 18-20% condensation (at 10 mN/m) of monolayer packing. The condensing effect of 5-androsten-3 beta-ol on SOPC packing was again much smaller (about 10%) compared with that of the side-chain sterols. The rate of sterol oxidation by cholesterol oxidase (at 37 degrees C) in DPPC-containing SUVs increased as a function of increasing the side-chain length (iso-series). With sterols from the n-series, the same trend was seen, except that the n-C7 analogue was oxidized much slower than the n-C4, n-C5, and n-C6 analogues. With SOPC SUVs, a similar side-chain dependent oxidation pattern was observed. Our results support and extend previous knowledge about the importance of the sterol side chain in determining sterol-sterol and sterol-phospholipid interactions, both in mono- and bilayers. PMID:8142447

Slotte, J P; Jungner, M; Vilchèze, C; Bittman, R

1994-03-23

137

Toxicological Actions of Plant-Derived and Anthropogenic Methylenedioxyphenyl-Substituted Chemicals in Mammals and Insects  

Microsoft Academic Search

The methylenedioxyphenyl (MDP) substituent is a structural feature present in many plant chemicals that deter foraging by predatory insects and herbivores. With increasing use of herbal extracts in alternative medicine, human exposure to MDP-derived plant chemicals may also be significant. Early studies found that most MDP agents themselves possess relatively low intrinsic toxicity, but strongly influence the actions of other

Michael Murray

2012-01-01

138

Expression of chimaeric genes transferred into plant cells using a Ti-plasmid-derived vector  

Microsoft Academic Search

Foreign genes introduced into plant cells with Ti-plasmid vectors are not expressed. We have constructed an expression vector derived from the promoter sequence of nopaline synthase, and have inserted the coding sequences of the octopine synthase gene and a chloramphenicol acetyltransferase gene into this vector. These chimaeric genes are functionally expressed in plant cells after their transfer via a Ti-plasmid

Luis Herrera-Estrella; Ann Depicker; Marc van Montagu; Jeff Schell

1983-01-01

139

Biotechnology of flavonoids and other phenylpropanoid-derived natural products. Part II: Reconstruction of multienzyme pathways in plants and microbes  

Microsoft Academic Search

Plant natural products derived from phenylalanine and the phenylpropanoid pathways are im- pressive in their chemical diversity and are the result of plant evolution, which has selected for the acquisition of large repertoires of pigments, structural and defensive compounds, all derived from a phenylpropanoid backbone via the plant-specific phenylpropanoid pathway. These compounds are important in plant growth, development and responses

Filippos Ververidis; Emmanouil Trantas; Carl Douglas; Guenter Vollmer; Georg Kretzschmar; Nickolas Panopoulos

2007-01-01

140

Plant-derived food ingredients for stimulation of energy expenditure.  

PubMed

The development of obesity is related to the regulation of energy intake, energy expenditure, and energy storage in the body. Increasing energy expenditure by inducing lipolysis followed by fat oxidation is one of the alternatives which could help to reverse this increasingly widespread condition. Currently, there is no approved drug targeting on stimulation of energy expenditure available. The use of herbal medicines has become a preferred alternative, supported by the classical consensus on the innocuity of herbal medicine vs synthetic drugs, something that often lacks a scientific basis (ban on Ephedra, for example). The inclusion of functional food in the daily diet has also been promoted although its efficacy requires further investigation. This review summarizes the results of recent work focused on the investigation of edible plant materials targeted at various important pathways related to stimulation of energy expenditure. The aim is to evaluate a number of plants that may be of interest for further studies because of their potential to provide novel lead compounds or functional foods which may be used to combat obesity, but require further studies to evaluate their antiobesity activity in humans. PMID:24188308

Yuliana, Nancy Dewi; Korthout, Henrie; Wijaya, Christofora Hanny; Kim, Hye Kyong; Verpoorte, Robert

2014-01-01

141

Ribulose Bisphosphate Carboxylase Activity in Anther-Derived Plants of Saintpaulia ionantha Wendl. Shag.  

PubMed

Plants obtained from anther culture of the African violet, Saintpaulia ionantha Wendl. ;Shag' and vegetatively cloned copies of the parent anther donor plant were examined for their ploidy and ribulose-1,5-biphosphate carboxylase (RuBPcase) activity. The cloned parent plants were all diploid and did not vary much in their nuclear DNA, chlorophyll, and RuBPcase activity. Some of the anther-derived plants were similar to the parent plants while others were not. Different levels of ploidy were observed among the androgenetic plants. RuBPcase activities higher than that of the parent plants were found in some anther-derived plants. However, there was no direct correlation between ploidy and RuBPcase activity. Expression of nuclear genes from a single parent in the anther-derived plants and it's diploidization or plastid changes during early stages of microsporogenesis or androgenesis are suggested as possible reasons for the variations observed among them. This could be a useful technique to obtain physiological variants which could be agronomically desirable. PMID:16663273

Bhaskaran, S; Smith, R H; Finer, J J

1983-11-01

142

Ribulose Bisphosphate Carboxylase Activity in Anther-Derived Plants of Saintpaulia ionantha Wendl. Shag 1  

PubMed Central

Plants obtained from anther culture of the African violet, Saintpaulia ionantha Wendl. `Shag' and vegetatively cloned copies of the parent anther donor plant were examined for their ploidy and ribulose-1,5-biphosphate carboxylase (RuBPcase) activity. The cloned parent plants were all diploid and did not vary much in their nuclear DNA, chlorophyll, and RuBPcase activity. Some of the anther-derived plants were similar to the parent plants while others were not. Different levels of ploidy were observed among the androgenetic plants. RuBPcase activities higher than that of the parent plants were found in some anther-derived plants. However, there was no direct correlation between ploidy and RuBPcase activity. Expression of nuclear genes from a single parent in the anther-derived plants and it's diploidization or plastid changes during early stages of microsporogenesis or androgenesis are suggested as possible reasons for the variations observed among them. This could be a useful technique to obtain physiological variants which could be agronomically desirable. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:16663273

Bhaskaran, Shyamala; Smith, Roberta H.; Finer, John J.

1983-01-01

143

Efficient chimeric plant promoters derived from plant infecting viral promoter sequences.  

PubMed

In the present study, we developed a set of three chimeric/hybrid promoters namely FSgt-PFlt, PFlt-UAS-2X and MSgt-PFlt incorporating different important domains of Figwort Mosaic Virus sub-genomic transcript promoter (FSgt, -270 to -60), Mirabilis Mosaic Virus sub-genomic transcript promoter (MSgt, -306 to -125) and Peanut Chlorotic Streak Caulimovirus full-length transcript promoter (PFlt-, -353 to +24 and PFlt-UAS, -353 to -49). We demonstrated that these chimeric/hybrid promoters can drive the expression of reporter genes in different plant species including tobacco, Arabidopsis, petunia, tomato and spinach. FSgt-PFlt, PFlt-UAS-2X and MSgt-PFlt promoters showed 4.2, 1.5 and 1.2 times stronger GUS activities compared to the activity of the CaMV35S promoter, respectively, in tobacco protoplasts. Protoplast-derived recombinant promoter driven GFP showed enhanced accumulation compared to that obtained under the CaMV35S promoter. FSgt-PFlt, PFlt-UAS-2X and MSgt-PFlt promoters showed 3.0, 1.3 and 1.0 times stronger activities than the activity of the CaMV35S² (a modified version of the CaMV35S promoter with double enhancer domain) promoter, respectively, in tobacco (Nicotiana tabacum, var. Samsun NN). Alongside, we observed a fair correlation between recombinant promoter-driven GUS accumulation with the corresponding uidA-mRNA level in transgenic tobacco. Histochemical (X-gluc) staining of whole transgenic seedlings and fluorescence images of ImaGene Green™ treated floral parts expressing the GUS under the control of recombinant promoters also support above findings. Furthermore, we confirmed that these chimeric promoters are inducible in the presence of 150 ?M salicylic acid (SA) and abscisic acid (ABA). Taken altogether, we propose that SA/ABA inducible chimeric/recombinant promoters could be used for strong expression of gene(s) of interest in crop plants. PMID:24178585

Acharya, Sefali; Ranjan, Rajiv; Pattanaik, Sitakanta; Maiti, Indu B; Dey, Nrisingha

2014-02-01

144

Theory of the deuterium NMR of sterol-phospholipid membranes  

PubMed Central

A general theoretical model is described for the NMR spectra of mixtures of sterols and deuterium-labeled phospholipids. In the case of homogeneous membranes, the average quadrupole splittings are determined by equilibria between lipids in cholesterol–phospholipid complexes and lipids not in complexes. Chemical exchange of lipids between those in the free state and those in the complex state affects the deuterium resonance line shapes. The lifetime of a phospholipid molecule in an ergosterol–dipalmitoylphosphatidylcholine complex is estimated to be of the order of 10–5 s on the basis of the observed line broadenings. In the vicinity of a critical point of a cholesterol–phospholipid mixture, fluctuations in the concentration of complexes also can contribute to the deuterium nuclear resonance line broadening. At the critical point, the temperature derivative of the concentration of complexes is discontinuous. There is a corresponding jump in the calculated heat capacity as well as in the temperature derivative of the deuterium NMR first moment. PMID:16432189

McConnell, Harden; Radhakrishnan, Arun

2006-01-01

145

Involvement of heme biosynthesis in control of sterol uptake by Saccharomyces cerevisiae.  

PubMed Central

Wild-type Saccharomyces cerevisiae do not accumulate exogenous sterols under aerobic conditions, and a mutant allele conferring sterol auxotrophy (erg7) could be isolated only in strains with a heme deficiency. delta-Aminolevulinic acid (ALA) fed to a hem1 (ALA synthetase-) erg7 (2,3-oxidosqualene cyclase-) sterol-auxotrophic strain of S. cerevisiae inhibited sterol uptake, and growth was negatively affected when intracellular sterol was depleted. The inhibition of sterol uptake (and growth of sterol auxotrophs) by ALA was dependent on the ability to synthesize heme from ALA. A procedure was developed which allowed selection of strains which would take up exogenous sterols but had no apparent defect in heme or ergosterol biosynthesis. One of these sterol uptake control mutants possessed an allele which allowed phenotypic expression of sterol auxotrophy in a heme-competent background. PMID:3891725

Lewis, T A; Taylor, F R; Parks, L W

1985-01-01

146

Combating Pathogenic Microorganisms Using Plant-Derived Antimicrobials: A Minireview of the Mechanistic Basis  

PubMed Central

The emergence of antibiotic resistance in pathogenic bacteria has led to renewed interest in exploring the potential of plant-derived antimicrobials (PDAs) as an alternative therapeutic strategy to combat microbial infections. Historically, plant extracts have been used as a safe, effective, and natural remedy for ailments and diseases in traditional medicine. Extensive research in the last two decades has identified a plethora of PDAs with a wide spectrum of activity against a variety of fungal and bacterial pathogens causing infections in humans and animals. Active components of many plant extracts have been characterized and are commercially available; however, research delineating the mechanistic basis of their antimicrobial action is scanty. This review highlights the potential of various plant-derived compounds to control pathogenic bacteria, especially the diverse effects exerted by plant compounds on various virulence factors that are critical for pathogenicity inside the host. In addition, the potential effect of PDAs on gut microbiota is discussed. PMID:25298964

Upadhyaya, Indu; Kollanoor-Johny, Anup

2014-01-01

147

Lipids of a Sterol-Nonrequiring Mycoplasma  

PubMed Central

The lipids of the sterol nonrequiring Mycoplasma strain S743 were found to include both ester glycerophosphatides (phosphatidylglycerol, acylphosphatidylglycerol, and diphosphatidylglycerol) and ceramide glycerophosphate compounds containing N-hydroxyacyl groups. The major phosphosphingolipid was tentatively identified as a hydroxyceramidephosphorylglycerol containing an O-acyl group. These compounds became labeled during growth in the presence of 32P-orthophosphate, 14C-glycerol, or 14C-palmitate. The lipid fraction also contained free long-chain base. 14C-palmitate was converted to labeled sphinganine. The long-chain base composition of the lipids was modified by growing the organisms in media containing different fatty acids, which were converted to bases containing two more C atoms per molecule. Ninety per cent of the long-chain base from cells grown in medium supplemented with elaidate consisted of monounsaturated C20 base. Images PMID:5489436

Plackett, P.; Smith, P. F.; Mayberry, W. R.

1970-01-01

148

Inoculation of the Nonlegume Capsicum annuum L. with Rhizobium Strains. 2. Changes in Sterols, Triterpenes, Fatty Acids, and Volatile Compounds.  

PubMed

Peppers (Capsicum spp.) are consumed worldwide, imparting flavor, aroma, and color to foods, additionally containing high concentrations of biofunctional compounds. This is the first report about the effect of the inoculation of two Rhizobium strains on sterols, triterpenes, fatty acids, and volatile compounds of leaves and fruits of pepper (Capsicum annuum L.) plants. Generally, inoculation with strain TVP08 led to the major changes, being observed a decrease of sterols and triterpenes and an increase of fatty acids, which are related to higher biomass, growth, and ripening of pepper fruits. The increase of volatile compounds may reflect the elicitation of plant defense after inoculation, since the content on methyl salicylate was significantly increased in inoculated material. The findings suggest that inoculation with Rhizobium strains may be employed to manipulate the content of interesting metabolites in pepper leaves and fruits, increasing potential health benefits and defense abilities of inoculated plants. PMID:24405510

Silva, Luís R; Azevedo, Jessica; Pereira, Maria J; Carro, Lorena; Velazquez, Encarna; Peix, Alvaro; Valentão, Patrícia; Andrade, Paula B

2014-01-22

149

Sterol Profile for Natural Juices Authentification by GC-MS  

SciTech Connect

A GC-MS analytical method is described for some natural juices analysis. The fingerprint of sterols was used to characterize the natural juice. A rapid liquid-liquid extraction method was used. The sterols were separated on a Rtx-5MS capillary column, 15mx0.25mm, 0.25{mu}m film thickness, in a temperature program from 50 deg. C for 1 min, then ramped at 15 deg. C/min to 300 deg. C and held for 15 min. Identification of sterols and their patterns were used for juice characterization. The sterol profile is a useful approach for confirming the presence of juices of orange, grapefruit, pineapple and passion fruit in compounded beverages and for detecting of adulteration of fruit juices.

Culea, M. [Faculty of Physics, Babes-Bolyai University of Cluj-Napoca (Romania)

2007-04-23

150

Functional convergence of hopanoids and sterols in membrane ordering  

PubMed Central

Liquid-ordered phases are one of two biochemically active membrane states, which until now were thought to be a unique consequence of the interactions between eukaryotic membrane lipids. The formation of a liquid-ordered phase depends crucially on the ordering properties of sterols. However, it is not known whether this capacity exists in organisms that lack sterols, such as bacteria. We show that diplopterol, the simplest bacterial hopanoid, has similar properties and that hopanoids are bacterial “sterol surrogates” with the ability to order saturated lipids and to form a liquid-ordered phase in model membranes. These observations suggest that the evolution of an ordered biochemically active liquid membrane could have evolved before the oxygenation of Earth’s surface and the emergence of sterols. PMID:22893685

Saenz, James Peter; Sezgin, Erdinc; Schwille, Petra; Simons, Kai

2012-01-01

151

Composition and biosynthesis of sterols by Mortierella alpina.  

E-print Network

??Sterols from mycelia of Mortierella alpina CBS 210.32. a zygomycetous fungus, were identified by thin layer chromatography, gas-liquid chromatography, reversed phase-high performance liquid chromatography, gas… (more)

Nichols, Shawnn Derrek

1998-01-01

152

Use of plant fatty acyl hydroxylases to produce hydroxylated fatty acids and derivatives in plants  

DOEpatents

The present invention relates to the identification of nucleic acid sequences and constructs, and methods related thereto, and the use of these sequences and constructs to produce genetically modified plants for the purpose of altering the composition of plant oils, waxes and related compounds. 35 figs.

Somerville, C.; Loo, F. van de

1998-09-01

153

Terrestrial Plant-Derived Anticancer Agents and Plant Species Used in Anticancer Research  

Microsoft Academic Search

Cancer is a major cause of death and the number of new cases, as well as the number of individuals living with cancer, is expanding continuously. Due to the enormous propensity of plants that synthesize mixtures of structurally diverse bioactive compounds, the plant kingdom is potentially a very diverse source of chemical constituents with tumor cytotoxic activity. Despite the successful

Spiridon E. Kintzios

2006-01-01

154

Comparison of single cell culture derived Solanum tuberosum L. plants and a model for their application in breeding programs  

Microsoft Academic Search

The techniques of microspore and protoplast regeneration starting from dihaploid Solanum tuberosum plants has been improved to such an extent that the production of more than 2000 microspore derived A1 plant lines and of several hundred protoplast derived plantlets has become possible. Further, from the dihaploid Solanum species S. phureja the regeneration of microspores to plants, and from the species

G. Wenzel; O. Schieder; T. Przewozny; S. K. Sopory; G. Melchers

1979-01-01

155

Sterol Esterification in Yeast: A Two-Gene Process  

Microsoft Academic Search

Unesterified sterol modulates the function of eukaryotic membranes. In human cells, sterol is esterified to a storage form by acyl-coenzyme A (CoA): cholesterol acyl transferase (ACAT). Here, two genes are identified, ARE1 and ARE2, that encode ACAT-related enzymes in yeast. The yeast enzymes are 49 percent identical to each other and exhibit 23 percent identity to human ACAT. Deletion of

Hongyuan Yang; Martin Bard; Debora A. Bruner; Anne Gleeson; Richard J. Deckelbaum; Gordana Aljinovic; Thomas M. Pohl; Rodney Rothstein; Stephen L. Sturley

1996-01-01

156

Microbial assimilation of plant-derived carbon in soil traced by isotope analysis  

Microsoft Academic Search

The flow of new and native plant-derived C in the rhizosphere of an agricultural field during one growing season was tracked, the ratios in different soil C pools were quantified, and the residence times (ts) were estimated. For this the natural differences in 13C abundances of: (1) C4 soil (with a history of C4 plant, Miscanthus sinensis, cultivation), (2) C3

Oliver Pelz; Wolf-Rainer Abraham; Matthias Saurer; Rolf Siegwolf; Josef Zeyer

2005-01-01

157

Sterol/steroid metabolism and absorption in a generalist and specialist caterpillar: Effects of dietary sterol/steroid structure, mixture and ratio  

E-print Network

Sterol/steroid metabolism and absorption in a generalist and specialist caterpillar: Effects of dietary sterol/steroid structure, mixture and ratio Xiangfeng Jing a,b,*, Robert J. Grebenok c , Spencer T insect herbivore sterol/steroid metabolism and absorption; we use two cat- erpillars species e one

Behmer, Spencer T.

158

Sterols in a unicellular relative of the metazoans.  

PubMed

Molecular clocks suggest that animals originated well before they first appear as macroscopic fossils, but geologic tests of these hypotheses have been elusive. A rare steroid hydrocarbon, 24-isopropylcholestane, has been hypothesized to be a biomarker for sponges or their immediate ancestors because of its relatively high abundance in pre-Ediacaran to Early Cambrian sedimentary rocks and oils. Biolipid precursors of this sterane have been reported to be prominent in several demosponges. Whether 24-isopropylcholestane can be interpreted as a sponge (and, hence, animal) biomarker, and so provide clues about early metazoan history, depends on an understanding of the distribution of sterol biosynthesis among animals and their protistan relatives. Accordingly, we characterized the sterol profile of the choanoflagellate Monosiga brevicollis, a representative of the unicellular sister group of animals. M. brevicollis does not produce a candidate sterol precursor for 24-isopropylcholestane under our experimental growth conditions. It does, however, produce a number of other sterols, and comparative genomics confirms its biosynthetic potential to produce the full suite of compounds recovered. Consistent with the phylogenetic position of choanoflagellates, the sterol profile and biosynthetic pathway of M. brevicollis display characteristics of both fungal and poriferan sterol biosynthesis. This is an example in which genomic and biochemical information have been used together to investigate the taxonomic specificity of a fossil biomarker. PMID:18632573

Kodner, Robin B; Summons, Roger E; Pearson, Ann; King, Nicole; Knoll, Andrew H

2008-07-22

159

Structural complex of sterol 14?-demethylase (CYP51) with 14?-methylenecyclopropyl-?7-24, 25-dihydrolanosterol[S  

PubMed Central

Sterol 14?-demethylase (CYP51) that catalyzes the removal of the 14?-methyl group from the sterol nucleus is an essential enzyme in sterol biosynthesis, a primary target for clinical and agricultural antifungal azoles and an emerging target for antitrypanosomal chemotherapy. Here, we present the crystal structure of Trypanosoma (T) brucei CYP51 in complex with the substrate analog 14?-methylenecyclopropyl-?7-24,25-dihydrolanosterol (MCP). This sterol binds tightly to all protozoan CYP51s and acts as a competitive inhibitor of F105-containing (plant-like) T. brucei and Leishmania (L) infantum orthologs, but it has a much stronger, mechanism-based inhibitory effect on I105-containing (animal/fungi-like) T. cruzi CYP51. Depicting substrate orientation in the conserved CYP51 binding cavity, the complex specifies the roles of the contact amino acid residues and sheds new light on CYP51 substrate specificity. It also provides an explanation for the effect of MCP on T. cruzi CYP51. Comparison with the ligand-free and azole-bound structures supports the notion of structural rigidity as the characteristic feature of the CYP51 substrate binding cavity, confirming the enzyme as an excellent candidate for structure-directed design of new drugs, including mechanism-based substrate analog inhibitors. PMID:22135275

Hargrove, Tatiana Y.; Wawrzak, Zdzislaw; Liu, Jialin; Waterman, Michael R.; Nes, W. David; Lepesheva, Galina I.

2012-01-01

160

AHA Science Advisory. Stanol/sterol ester-containing foods and blood cholesterol levels. A statement for healthcare professionals from the Nutrition Committee of the Council on Nutrition, Physical Activity, and Metabolism of the American Heart Association.  

PubMed

Considerable attention in the recent past has focused on the potential benefits or adverse effects of butter versus different types of margarines, usually with respect to their relative content of polyunsaturated, saturated, and trans fatty acids, and the impact of these on low-density lipoprotein (LDL) cholesterol levels. Recently, a new class of margarines and other fat-derived products (eg, salad dressings, mayonnaise) containing plant-derived sterols that are intended for use to lower blood cholesterol levels have been introduced into the food supply. These products are being marketed as adjuncts to low-saturated-fat and low-cholesterol diets to maximize reductions in LDL cholesterol levels achievable by dietary means. PMID:11222485

Lichtenstein, A H; Deckelbaum, R J

2001-02-27

161

Prolific plant regeneration from protoplast-derived tissues of Lotus corniculatus L. (birdsfoot trefoil)  

Microsoft Academic Search

Protoplasts isolated enzymatically from seedling roots, hypocotyls and cotyledons of Lotus corniculatus L. produced callus which underwent prolific shoot regeneration. The rapidity and ease of recovering plants from protoplast-derived tissues makes this forage legume an attractive experimental system for genetic manipulation.

P. S. Ahuja; S. Hadiuzzaman; M. R. Davey; E. C. Cocking

1983-01-01

162

Role of Plant-Derived Omega–3 Fatty Acids in Human Nutrition  

Microsoft Academic Search

An international workshop on the role of plant-derived omega–3 fatty acids in human nutrition took place in Milan on February 9, 2000. The meeting was sponsored by the Nutrition Foundation of Italy and was organized by its Scientific Director, Dr. Andrea Poli. It was attended by experts in polyunsaturated fatty acids and human lipid nutrition. This is the first meeting

Michael Crawford; Claudio Galli; Francesco Visioli; Serge Renaud; Artemis P. Simopoulos; Arthur A. Spector

2000-01-01

163

29-Norcucurbitacin derivatives isolated from the Indonesian medicinal plant, Phaleria macrocarpa (Scheff.) Boerl.  

PubMed

The new 29-norcucurbitacin, desacetylfevicordin A (1), together with three known 29-norcucurbitacin derivatives (2-4) were isolated from seeds of the Indonesian medicinal plant, Phaleria macrocarpa (Scheff.) Boerl. The structures of 1-4 were elucidated on the basis of spectroscopic analyses and chemical transformation. These compounds exhibited toxicity against the brine shrimp (Artemia salina). PMID:18256498

Kurnia, Dikdik; Akiyama, Kohki; Hayashi, Hideo

2008-02-01

164

The role of sterol-C4-methyl oxidase in epidermal biology.  

PubMed

Deficiency of sterol C4 methyl oxidase, encoded by the SC4MOL gene, has recently been described in four patients from three different families. All of the patients presented with microcephaly, congenital cataracts, and growth delay in infancy. The first patient has suffered since the age of six years from severe, diffuse, psoriasiform dermatitis, sparing only her palms. She is now 20 years old. The second patient is a 5 year old girl who has just started to develop dry skin and hair changes. The third and fourth patients are a pair of affected siblings with a severe skin condition since infancy. Quantitative sterol analysis of plasma and skin scales from all four patients showed marked elevation of 4?-methyl- and 4, 4'-dimethylsterols, consistent with a deficiency in the first step of sterol C4 demethylation in cholesterol biosynthesis. Mutations in the SC4MOL have been identified in all of the patients. SC4MOL deficiency is the first autosomal recessive disorder identified in the sterol demethylation complex. Cellular studies with patient-derived fibroblasts have shown a higher mitotic rate than control cells in cholesterol-depleted medium, with increased de novo cholesterol biosynthesis and accumulation of methylsterols. Immunologic analyses of granulocytes and B cells from patients and obligate carriers in the patients' families indicated dysregulation of immune-related receptors. Inhibition of sterol C4 methyl oxidase in human transformed lymphoblasts induced activation of the cell cycle. Additional studies also demonstrated diminished EGFR signaling and disrupted vesicular trafficking in cells from the affected patients. These findings suggest that methylsterols play an important role in epidermal biology by their influence on cell proliferation, intracellular signaling, vesicular trafficking and immune response. SC4MOL is situated within the psoriasis susceptibility locus PSORS9, and may be a genetic risk factor for common skin conditions. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias. PMID:24144731

He, Miao; Smith, Laurie D; Chang, Richard; Li, Xueli; Vockley, Jerry

2014-03-01

165

Derivative Analysis of AVIRIS Hyperspectral Data for the Detection of Plant Stress  

NASA Technical Reports Server (NTRS)

A remote sensing campaign was conducted over a U.S. Department of Agriculture test site at Shelton, Nebraska. The test field was set off in blocks that were differentially treated with nitrogen. Four replicates of 0-kg/ha to 200-kg/ha, in 50-kg/ha increments, were present. Low-altitude AVIRIS hyperspectral data were collected over the site in 224 spectral bands. Simultaneously, ground data were collected to support the airborne imagery. In an effort to evaluate published, derivative-based algorithms for the detection of plant stress, different derivative-based approaches were applied to the collected AVIRIS image cube. The results indicate that, given good quality hyperspectral imagery, derivative techniques compare favorably with simple, well known band ratio algorithms for detection of plant stress.

Estep, Lee; Berglund, Judith

2001-01-01

166

Metabolic interconversion of free sterols and steryl esters in Saccharomyces cerevisiae.  

PubMed Central

The interconversion of free and esterified sterols was followed radioisotopically with [U-14C]acetate and [methyl-14C]methionine. In pulse-chase experiments, radioactivity first appeared mainly in unesterified sterols in exponential-phase cells. Within one generation time, the label equilibrated between the free and esterified sterol pools and subsequently accumulated in steryl esters in stationary-phase cells. When the sterol pools were prelabeled by growing cells aerobically to the stationary phase and the cells were diluted into unlabeled medium, the prelabeled steryl esters returned to the free sterol form under several conditions. (i) During aerobic growth, the prelabeled sterols decreased from 80% to 45% esters in the early exponential phase and then returned to 80% esters as the culture reached the stationary phase. (ii) Under anaerobic conditions, the percentage of prelabeled steryl esters declined continuously. When growth stopped, only 15% of the sterols remained esterified. (iii) In the presence of an inhibitor of sterol biosynthesis, which causes accumulation of a precursor to ergosterol, prelabeled sterols decreased to 40% steryl esters while the precursor was found preferentially in the esterified form. These results indicate that the bulk of the free sterol and steryl ester pools are freely interconvertible, with the steryl esters serving as a supply of free sterols. Furthermore, there is an active cellular control over what types of sterol are found in the free and esterified sterol pools. PMID:361713

Taylor, F R; Parks, L W

1978-01-01

167

The Arabidopsis dwf7/ste1 mutant is defective in the delta7 sterol C-5 desaturation step leading to brassinosteroid biosynthesis.  

PubMed Central

Lesions in brassinosteroid (BR) biosynthetic genes result in characteristic dwarf phenotypes in plants. Understanding the regulation of BR biosynthesis demands continued isolation and characterization of mutants corresponding to the genes involved in BR biosynthesis. Here, we present analysis of a novel BR biosynthetic locus, dwarf7 (dwf7). Feeding studies with BR biosynthetic intermediates and analysis of endogenous levels of BR and sterol biosynthetic intermediates indicate that the defective step in dwf7-1 resides before the production of 24-methylenecholesterol in the sterol biosynthetic pathway. Furthermore, results from feeding studies with 13C-labeled mevalonic acid and compactin show that the defective step is specifically the Delta7 sterol C-5 desaturation, suggesting that dwf7 is an allele of the previously cloned STEROL1 (STE1) gene. Sequencing of the STE1 locus in two dwf7 mutants revealed premature stop codons in the first (dwf7-2) and the third (dwf7-1) exons. Thus, the reduction of BRs in dwf7 is due to a shortage of substrate sterols and is the direct cause of the dwarf phenotype in dwf7. PMID:9927639

Choe, S; Noguchi, T; Fujioka, S; Takatsuto, S; Tissier, C P; Gregory, B D; Ross, A S; Tanaka, A; Yoshida, S; Tax, F E; Feldmann, K A

1999-01-01

168

Screening, isolation and optimization of anti-white spot syndrome virus drug derived from marine plants  

PubMed Central

Objective To screen, isolate and optimize anti-white spot syndrome virus (WSSV) drug derived from various marine floral ecosystems and to evaluate the efficacy of the same in host–pathogen interaction model. Methods Thirty species of marine plants were subjected to Soxhlet extraction using water, ethanol, methanol and hexane as solvents. The 120 plant isolates thus obtained were screened for their in vivo anti-WSSV property in Litopenaeus vannamei. By means of chemical processes, the purified anti-WSSV plant isolate, MP07X was derived. The drug was optimized at various concentrations. Viral and immune genes were analysed using reverse transcriptase PCR to confirm the potency of the drug. Results Nine plant isolates exhibited significant survivability in host. The drug MP07X thus formulated showing 85% survivability in host. The surviving shrimps were nested PCR negative at the end of the 15 d experimentation. The lowest concentration of MP07X required intramuscularly for virucidal property was 10 mg/mL. The oral dosage of 1?000 mg/kg body weight/day survived at the rate of 85%. Neither VP28 nor ie 1 was expressed in the test samples at 42nd hour and 84th hour post viral infection. Conclusions The drug MP07X derived from Rhizophora mucronata is a potent anti-WSSV drug. PMID:25183065

Chakraborty, Somnath; Ghosh, Upasana; Balasubramanian, Thangavel; Das, Punyabrata

2014-01-01

169

Seaweed Polysaccharides and Derived Oligosaccharides Stimulate Defense Responses and Protection Against Pathogens in Plants  

PubMed Central

Plants interact with the environment by sensing “non-self” molecules called elicitors derived from pathogens or other sources. These molecules bind to specific receptors located in the plasma membrane and trigger defense responses leading to protection against pathogens. In particular, it has been shown that cell wall and storage polysaccharides from green, brown and red seaweeds (marine macroalgae) corresponding to ulvans, alginates, fucans, laminarin and carrageenans can trigger defense responses in plants enhancing protection against pathogens. In addition, oligosaccharides obtained by depolymerization of seaweed polysaccharides also induce protection against viral, fungal and bacterial infections in plants. In particular, most seaweed polysaccharides and derived oligosaccharides trigger an initial oxidative burst at local level and the activation of salicylic (SA), jasmonic acid (JA) and/or ethylene signaling pathways at systemic level. The activation of these signaling pathways leads to an increased expression of genes encoding: (i) Pathogenesis-Related (PR) proteins with antifungal and antibacterial activities; (ii) defense enzymes such as pheylalanine ammonia lyase (PAL) and lipoxygenase (LOX) which determine accumulation of phenylpropanoid compounds (PPCs) and oxylipins with antiviral, antifugal and antibacterial activities and iii) enzymes involved in synthesis of terpenes, terpenoids and/or alkaloids having antimicrobial activities. Thus, seaweed polysaccharides and their derived oligosaccharides induced the accumulation of proteins and compounds with antimicrobial activities that determine, at least in part, the enhanced protection against pathogens in plants. PMID:22363237

Vera, Jeannette; Castro, Jorge; Gonzalez, Alberto; Moenne, Alejandra

2011-01-01

170

Seaweed polysaccharides and derived oligosaccharides stimulate defense responses and protection against pathogens in plants.  

PubMed

Plants interact with the environment by sensing "non-self" molecules called elicitors derived from pathogens or other sources. These molecules bind to specific receptors located in the plasma membrane and trigger defense responses leading to protection against pathogens. In particular, it has been shown that cell wall and storage polysaccharides from green, brown and red seaweeds (marine macroalgae) corresponding to ulvans, alginates, fucans, laminarin and carrageenans can trigger defense responses in plants enhancing protection against pathogens. In addition, oligosaccharides obtained by depolymerization of seaweed polysaccharides also induce protection against viral, fungal and bacterial infections in plants. In particular, most seaweed polysaccharides and derived oligosaccharides trigger an initial oxidative burst at local level and the activation of salicylic (SA), jasmonic acid (JA) and/or ethylene signaling pathways at systemic level. The activation of these signaling pathways leads to an increased expression of genes encoding: (i) Pathogenesis-Related (PR) proteins with antifungal and antibacterial activities; (ii) defense enzymes such as pheylalanine ammonia lyase (PAL) and lipoxygenase (LOX) which determine accumulation of phenylpropanoid compounds (PPCs) and oxylipins with antiviral, antifugal and antibacterial activities and iii) enzymes involved in synthesis of terpenes, terpenoids and/or alkaloids having antimicrobial activities. Thus, seaweed polysaccharides and their derived oligosaccharides induced the accumulation of proteins and compounds with antimicrobial activities that determine, at least in part, the enhanced protection against pathogens in plants. PMID:22363237

Vera, Jeannette; Castro, Jorge; Gonzalez, Alberto; Moenne, Alejandra

2011-12-01

171

A Dietary Test of Putative Deleterious Sterols for the Aphid Myzus persicae  

PubMed Central

The aphid Myzus persicae displays high mortality on tobacco plants bearing a transgene which results in the accumulation of the ketosteroids cholestan-3-one and cholest-4-en-3-one in the phloem sap. To test whether the ketosteroids are the basis of the plant resistance to the aphids, M. persicae were reared on chemically-defined diets with different steroid contents at 0.1–10 µg ml?1. Relative to sterol-free diet and dietary supplements of the two ketosteroids and two phytosterols, dietary cholesterol significantly extended aphid lifespan and increased fecundity at one or more dietary concentrations tested. Median lifespan was 50% lower on the diet supplemented with cholest-4-en-3-one than on the cholesterol-supplemented diet. Aphid feeding rate did not vary significantly across the treatments, indicative of no anti-feedant effect of any sterol/steroid. Aphids reared on diets containing equal amounts of cholesterol and cholest-4-en-3-one showed fecundity equivalent to aphids on diets containing only cholesterol. Aphids were reared on diets that reproduced the relative steroid abundance in the phloem sap of the control and modified tobacco plants, and their performance on the two diet formulations was broadly equivalent. We conclude that, at the concentrations tested, plant ketosteroids support weaker aphid performance than cholesterol, but do not cause acute toxicity to the aphids. In plants, the ketosteroids may act synergistically with plant factors absent from artificial diets but are unlikely to be solely responsible for resistance of modified tobacco plants. PMID:24465993

Bouvaine, Sophie; Faure, Marie-Line; Grebenok, Robert J.; Behmer, Spencer T.; Douglas, Angela E.

2014-01-01

172

A dietary test of putative deleterious sterols for the aphid Myzus persicae.  

PubMed

The aphid Myzus persicae displays high mortality on tobacco plants bearing a transgene which results in the accumulation of the ketosteroids cholestan-3-one and cholest-4-en-3-one in the phloem sap. To test whether the ketosteroids are the basis of the plant resistance to the aphids, M. persicae were reared on chemically-defined diets with different steroid contents at 0.1-10 µg ml(-1). Relative to sterol-free diet and dietary supplements of the two ketosteroids and two phytosterols, dietary cholesterol significantly extended aphid lifespan and increased fecundity at one or more dietary concentrations tested. Median lifespan was 50% lower on the diet supplemented with cholest-4-en-3-one than on the cholesterol-supplemented diet. Aphid feeding rate did not vary significantly across the treatments, indicative of no anti-feedant effect of any sterol/steroid. Aphids reared on diets containing equal amounts of cholesterol and cholest-4-en-3-one showed fecundity equivalent to aphids on diets containing only cholesterol. Aphids were reared on diets that reproduced the relative steroid abundance in the phloem sap of the control and modified tobacco plants, and their performance on the two diet formulations was broadly equivalent. We conclude that, at the concentrations tested, plant ketosteroids support weaker aphid performance than cholesterol, but do not cause acute toxicity to the aphids. In plants, the ketosteroids may act synergistically with plant factors absent from artificial diets but are unlikely to be solely responsible for resistance of modified tobacco plants. PMID:24465993

Bouvaine, Sophie; Faure, Marie-Line; Grebenok, Robert J; Behmer, Spencer T; Douglas, Angela E

2014-01-01

173

Dormancy break of celery (Apium graveolens L.) seeds by plant derived smoke extract  

Microsoft Academic Search

Seed dormancy of a highly-dormant cultivar of celery (Apium graveolens L.) was broken by combinations of plant-derived smoke extract or N6-benzyladenine (BA) and gibberellins A4\\/7 (GA4\\/7) in the dark at temperatures between 18 and 26°C. A less dormant cultivar which responded to GA4\\/7 alone showed no additional response to smoke extract or BA. Neither smoke extract nor BA affected either

T. H. Thomas; J. Staden

1995-01-01

174

Herbal plants and their derivatives as growth and health promoters in animal nutrition  

Microsoft Academic Search

The purpose of this review is to summarize the effectiveness, modes of action and commercial application of herbal plants and their derivatives as growth promoters for animal. Feed supplements\\u000a are a group of feed ingredients that can cause a desired animal response in a non-nutrient role such as pH shift, growth,\\u000a or metabolic modifier (Hutjens, 1991). Common feed additives used

Seyed Reza Hashemi; Homa Davoodi

2011-01-01

175

Regeneration of protoplast-derived green plants of Kentucky blue grass ( Poa pratensis L.)  

Microsoft Academic Search

Green plants were repeatedly regenerated from suspension-derived protoplasts of Kentucky blue grass (Poa pratensis L.) cv. “Geronimo”. One suspension was capable of donating competent protoplasts during long-term culture i. e. 10–16 months after its establishment. The plating efficiency of the protoplasts from three different suspension lines varied from 0.004% in the lowest up to 1.5% in the highest responding line,

Kirsten Annette Nielsen; Else Larsen; Elisabeth Knudsen

1993-01-01

176

Annual Variation in the Effect of Red Light on Sterol Biosynthesis in Digitalis purpurea L.  

PubMed

The effect of varying sequences of red and far red light on sterol biosynthesis in etiolated seedlings of Digitalis purpurea L. was examined. Red light caused a marked increase in the amounts of free and glycosidic sterols and a small decrease in esterified sterols during the first 4 hours after illumination. Far red light elicited the same response but to a lesser degree. Exposure to red followed by far red light or the reverse caused little or no increase in the amounts of free and glycosidic sterols. The magnitude of the increase in the amounts of sterols varied, depending upon the season in which the experiments were performed. The largest increments were obtained during the summer and fall, whereas the smallest were observed during the winter and spring. Correlation of these data with previous observations of an annual cycle in the sterol content of Digitalis seedlings showed that the maximum stimulation in sterol biosynthesis occurs when the endogenous level of sterols is minimal.Sterol monoglycosides, acylmonoglycosides, and an unidentified sterol conjugate from the lipid extracts were quantitated. Changes in conjugated sterol content were related to the particular light conditions of each experiment. The results are discussed in terms of physiological cycles and the possible influence of hormones upon the control of sterol biosynthesis in Digitalis. PMID:16660620

Jacobsohn, M K

1978-12-01

177

Annual Variation in the Effect of Red Light on Sterol Biosynthesis in Digitalis purpurea L. 1  

PubMed Central

The effect of varying sequences of red and far red light on sterol biosynthesis in etiolated seedlings of Digitalis purpurea L. was examined. Red light caused a marked increase in the amounts of free and glycosidic sterols and a small decrease in esterified sterols during the first 4 hours after illumination. Far red light elicited the same response but to a lesser degree. Exposure to red followed by far red light or the reverse caused little or no increase in the amounts of free and glycosidic sterols. The magnitude of the increase in the amounts of sterols varied, depending upon the season in which the experiments were performed. The largest increments were obtained during the summer and fall, whereas the smallest were observed during the winter and spring. Correlation of these data with previous observations of an annual cycle in the sterol content of Digitalis seedlings showed that the maximum stimulation in sterol biosynthesis occurs when the endogenous level of sterols is minimal. Sterol monoglycosides, acylmonoglycosides, and an unidentified sterol conjugate from the lipid extracts were quantitated. Changes in conjugated sterol content were related to the particular light conditions of each experiment. The results are discussed in terms of physiological cycles and the possible influence of hormones upon the control of sterol biosynthesis in Digitalis. PMID:16660620

Jacobsohn, Myra K.; Orkwiszewski, Joseph A. J.; Jacobsohn, Gert M.

1978-01-01

178

Characterization of Total and Individual Sterols in Canola Sprouts  

Microsoft Academic Search

In this study, the contents of total and individual phytosterols in sprouts made from seeds of seven canola (Brassica\\u000a napus L.) lines (Acropolis, Banjo, Jetton, KS-7740, KSM3-1-124, Mussette and Virginia), grown at three locations in Virginia (Orange,\\u000a Petersburg and Suffolk), were determined. Canola sprouts contained, on an average, 36.3 g sterols in 100 g of unsaponifiable\\u000a matter (UNSAP), 10.7 mg sterols in 1 g

Anwar A. HamamaHarbans; Harbans L. Bhardwaj

2011-01-01

179

Plant-Derived Phenolics Inhibit the Accrual of Structurally Characterised Protein and Lipid Oxidative Modifications  

PubMed Central

Epidemiological data suggest that plant-derived phenolics beneficial effects include an inhibition of LDL oxidation. After applying a screening method based on 2,4-dinitrophenyl hydrazine- protein carbonyl reaction to 21 different plant-derived phenolic acids, we selected the most antioxidant ones. Their effect was assessed in 5 different oxidation systems, as well as in other model proteins. Mass-spectrometry was then used, evidencing a heterogeneous effect on the accumulation of the structurally characterized protein carbonyl glutamic and aminoadipic semialdehydes as well as for malondialdehyde-lysine in LDL apoprotein. After TOF based lipidomics, we identified the most abundant differential lipids in Cu++-incubated LDL as 1-palmitoyllysophosphatidylcholine and 1-stearoyl-sn-glycero-3-phosphocholine. Most of selected phenolic compounds prevented the accumulation of those phospholipids and the cellular impairment induced by oxidized LDL. Finally, to validate these effects in vivo, we evaluated the effect of the intake of a phenolic-enriched extract in plasma protein and lipid modifications in a well-established model of atherosclerosis (diet-induced hypercholesterolemia in hamsters). This showed that a dietary supplement with a phenolic-enriched extract diminished plasma protein oxidative and lipid damage. Globally, these data show structural basis of antioxidant properties of plant-derived phenolic acids in protein oxidation that may be relevant for the health-promoting effects of its dietary intake. PMID:22952663

Naudi, Alba; Romero, Maria-Paz; Cassanye, Anna; Serrano, Jose C. E.; Arola, Lluis; Valls, Josep; Bellmunt, Maria Josep; Prat, Joan; Pamplona, Reinald; Portero-Otin, Manuel; Motilva, Maria-Jose

2012-01-01

180

50 CFR 23.92 - Are any wildlife or plants, and their parts, products, or derivatives, exempt?  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Are any wildlife or plants, and their parts, products, or derivatives...EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) CONVENTION ON INTERNATIONAL...Species § 23.92 Are any wildlife or plants, and their parts, products, or...

2010-10-01

181

Recombinant plant-derived pharmaceutical proteins: current technical and economic bottlenecks.  

PubMed

Molecular pharming is a cost-effective platform for the production of recombinant proteins in plants. Although the biopharmaceutical industry still relies on a small number of standardized fermentation-based technologies for the production of recombinant proteins there is now a greater awareness of the advantages of molecular pharming particularly in niche markets. Here we discuss some of the technical, economic and regulatory barriers that constrain the clinical development and commercialization of plant-derived pharmaceutical proteins. We also discuss strategies to increase productivity and product quality/homogeneity. The advantages of whole plants should be welcomed by the industry because this will help to reduce the cost of goods and therefore expand the biopharmaceutical market into untapped sectors. PMID:25048244

Sabalza, Maite; Christou, Paul; Capell, Teresa

2014-12-01

182

Metal adsorption by quasi cellulose xanthogenates derived from aquatic and terrestrial plant materials.  

PubMed

The FTIR spectra, SEM-EDXA and copper adsorption capacities of the raw plant materials, alkali-treated straws and cellulose xanthogenate derivatives of Eichhornia crassipes shoot, rape straw and corn stalk were investigated. FTIR spectra indicated that of the three plant materials, the aquatic biomass of E. crassipes shoot contained more OH and CO groups which accounted for the higher Cu(2+) adsorption capacities of the raw and alkali treated plant material. SEM-EDXA indicated the incorporation of sulphur and magnesium in the cellulose xanthogenate. The Cu(2+) adsorption capacities of the xanthogenates increased with their magnesium and sulphur contents. However more copper was adsorbed than that can be explained by exchange of copper with magnesium. Precipitation may contribute to the enhanced uptake of copper by the cellulose xanthogenate. PMID:21123055

Zhou, Wenbing; Ge, Xuan; Zhu, Duanwei; Langdon, Alan; Deng, Li; Hua, Yumei; Zhao, Jianwei

2011-02-01

183

Sorption of ammonium and phosphate from aqueous solution by biochar derived from phytoremediation plants*  

PubMed Central

The study on biochar derived from plant biomass for environmental applications is attracting more and more attention. Twelve sets of biochar were obtained by treating four phytoremediation plants, Salix rosthornii Seemen, Thalia dealbata, Vetiveria zizanioides, and Phragmites sp., sequentially through pyrolysis at 500 °C in a N2 environment, and under different temperatures (500, 600, and 700 °C) in a CO2 environment. The cation exchange capacity and specific surface area of biochar varied with both plant species and pyrolysis temperature. The magnesium (Mg) content of biochar derived from T. dealbata (TC) was obviously higher than that of the other plant biochars. This biochar also had the highest sorption capacity for phosphate and ammonium. In terms of biomass yields, adsorption capacity, and energy cost, T. dealbata biochar produced at 600 °C (TC600) is the most promising sorbent for removing contaminants (N and P) from aqueous solution. Therefore, T. dealbata appears to be the best candidate for phytoremediation application as its biomass can make a good biochar for environmental cleaning. PMID:24302715

Zeng, Zheng; Zhang, Song-da; Li, Ting-qiang; Zhao, Feng-liang; He, Zhen-li; Zhao, He-ping; Yang, Xiao-e; Wang, Hai-long; Zhao, Jing; Rafiq, Muhammad Tariq

2013-01-01

184

Sorption of ammonium and phosphate from aqueous solution by biochar derived from phytoremediation plants.  

PubMed

The study on biochar derived from plant biomass for environmental applications is attracting more and more attention. Twelve sets of biochar were obtained by treating four phytoremediation plants, Salix rosthornii Seemen, Thalia dealbata, Vetiveria zizanioides, and Phragmites sp., sequentially through pyrolysis at 500 °C in a N2 environment, and under different temperatures (500, 600, and 700 °C) in a CO2 environment. The cation exchange capacity and specific surface area of biochar varied with both plant species and pyrolysis temperature. The magnesium (Mg) content of biochar derived from T. dealbata (TC) was obviously higher than that of the other plant biochars. This biochar also had the highest sorption capacity for phosphate and ammonium. In terms of biomass yields, adsorption capacity, and energy cost, T. dealbata biochar produced at 600 °C (TC600) is the most promising sorbent for removing contaminants (N and P) from aqueous solution. Therefore, T. dealbata appears to be the best candidate for phytoremediation application as its biomass can make a good biochar for environmental cleaning. PMID:24302715

Zeng, Zheng; Zhang, Song-da; Li, Ting-qiang; Zhao, Feng-liang; He, Zhen-li; Zhao, He-ping; Yang, Xiao-e; Wang, Hai-long; Zhao, Jing; Rafiq, Muhammad Tariq

2013-12-01

185

Quinuclidine Derivatives as Potential Antiparasitics?  

PubMed Central

There is an urgent need for the development of new drugs for the treatment of tropical parasitic diseases such as Chagas' disease and leishmaniasis. One potential drug target in the organisms that cause these diseases is sterol biosynthesis. This paper describes the design and synthesis of quinuclidine derivatives as potential inhibitors of a key enzyme in sterol biosynthesis, squalene synthase (SQS). A number of compounds that were inhibitors of the recombinant Leishmania major SQS at submicromolar concentrations were discovered. Some of these compounds were also selective for the parasite enzyme rather than the homologous human enzyme. The compounds inhibited the growth of and sterol biosynthesis in Leishmania parasites. In addition, we identified other quinuclidine derivatives that inhibit the growth of Trypanosoma brucei (the causative organism of human African trypanosomiasis) and Plasmodium falciparum (a causative agent of malaria), but through an unknown mode(s) of action. PMID:17709461

Cammerer, Simon B.; Jimenez, Carmen; Jones, Simon; Gros, Ludovic; Lorente, Silvia Orenes; Rodrigues, Carlos; Rodrigues, Juliany C. F.; Caldera, Aura; Ruiz Perez, Luis Miguel; da Souza, Wanderley; Kaiser, Marcel; Brun, Reto; Urbina, Julio A.; Gonzalez Pacanowska, Dolores; Gilbert, Ian H.

2007-01-01

186

Incorporation of Sterols into Cells Using Cholesterol/Cyclodextrin Complexes  

E-print Network

Incorporation of Sterols into Cells Using Cholesterol/Cyclodextrin Complexes Reagents NeededH 7.2 Cholesterol/Cyclodextrin Complexes (6.8 mM cholesterol in 70 mM cyclodextrin) Phosphate to DME. Warm to 37° in the tissue culture incubator. Use 3 ml DME per 60 mm dish. 2 . Add cholesterol

Pike, Linda J.

187

Biostimulant action of a plant-derived protein hydrolysate produced through enzymatic hydrolysis.  

PubMed

The aim of this study was to evaluate the biostimulant action (hormone like activity, nitrogen uptake, and growth stimulation) of a plant-derived protein hydrolysate by means of two laboratory bioassays: a corn (Zea mays L.) coleoptile elongation rate test (Experiment 1), a rooting test on tomato cuttings (Experiment 2); and two greenhouse experiments: a dwarf pea (Pisum sativum L.) growth test (Experiment 3), and a tomato (Solanum lycopersicum L.) nitrogen uptake trial (Experiment 4). Protein hydrolysate treatments of corn caused an increase in coleoptile elongation rate when compared to the control, in a dose-dependent fashion, with no significant differences between the concentrations 0.75, 1.5, and 3.0 ml/L, and inodole-3-acetic acid treatment. The auxin-like effect of the protein hydrolysate on corn has been also observed in the rooting experiment of tomato cuttings. The shoot, root dry weight, root length, and root area were significantly higher by 21, 35, 24, and 26%, respectively, in tomato treated plants with the protein hydrolysate at 6 ml/L than untreated plants. In Experiment 3, the application of the protein hydrolysate at all doses (0.375, 0.75, 1.5, and 3.0 ml/L) significantly increased the shoot length of the gibberellin-deficient dwarf pea plants by an average value of 33% in comparison with the control treatment. Increasing the concentration of the protein hydrolysate from 0 to 10 ml/L increased the total dry biomass, SPAD index, and leaf nitrogen content by 20.5, 15, and 21.5%, respectively. Thus the application of plant-derived protein hydrolysate containing amino acids and small peptides elicited a hormone-like activity, enhanced nitrogen uptake and consequently crop performances. PMID:25250039

Colla, Giuseppe; Rouphael, Youssef; Canaguier, Renaud; Svecova, Eva; Cardarelli, Mariateresa

2014-01-01

188

A Plant-Derived Morphinan as a Novel Lead Compound Active against Malaria Liver Stages  

PubMed Central

Background The global spread of multidrug–resistant malaria parasites has led to an urgent need for new chemotherapeutic agents. Drug discovery is primarily directed to the asexual blood stages, and few drugs that are effective against the obligatory liver stages, from which the pathogenic blood infection is initiated, have become available since primaquine was deployed in the 1950s. Methods and Findings Using bioassay-guided fractionation based on the parasite's hepatic stage, we have isolated a novel morphinan alkaloid, tazopsine, from a plant traditionally used against malaria in Madagascar. This compound and readily obtained semisynthetic derivatives were tested for inhibitory activity against liver stage development in vitro (P. falciparum and P. yoelii) and in vivo (P. yoelii). Tazopsine fully inhibited the development of P. yoelii (50% inhibitory concentration [IC50] 3.1 ?M, therapeutic index [TI] 14) and P. falciparum (IC50 4.2 ?M, TI 7) hepatic parasites in cultured primary hepatocytes, with inhibition being most pronounced during the early developmental stages. One derivative, N-cyclopentyl-tazopsine (NCP-tazopsine), with similar inhibitory activity was selected for its lower toxicity (IC50 3.3 ?M, TI 46, and IC50 42.4 ?M, TI 60, on P. yoelii and P. falciparum hepatic stages in vitro, respectively). Oral administration of NCP-tazopsine completely protected mice from a sporozoite challenge. Unlike the parent molecule, the derivative was uniquely active against Plasmodium hepatic stages. Conclusions A readily obtained semisynthetic derivative of a plant-derived compound, tazopsine, has been shown to be specifically active against the liver stage, but inactive against the blood forms of the malaria parasite. This unique specificity in an antimalarial drug severely restricts the pressure for the selection of drug resistance to a parasite stage limited both in numbers and duration, thus allowing researchers to envisage the incorporation of a true causal prophylactic in malaria control programs. PMID:17194195

Carraz, Maelle; Jossang, Akino; Franetich, Jean-Francois; Siau, Anthony; Ciceron, Liliane; Hannoun, Laurent; Sauerwein, Robert; Frappier, Francois; Rasoanaivo, Philippe; Snounou, Georges; Mazier, Dominique

2006-01-01

189

Derivate  

NSDL National Science Digital Library

In this activity, students input functions in order to calculate the derivative and tangent line of that function. This activity allows students to explore tangent lines of various functions. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet.

2010-01-01

190

Refuse derived soluble bio-organics enhancing tomato plant growth and productivity  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Municipal bio-wastes are a sustainable source of bio-based products. Black-Right-Pointing-Pointer Refuse derived soluble bio-organics promote chlorophyll synthesis. Black-Right-Pointing-Pointer Refuse derived soluble bio-organics enhance plant growth and fruit ripening rate. Black-Right-Pointing-Pointer Sustainable chemistry exploiting urban refuse allows sustainable development. Black-Right-Pointing-Pointer Chemistry, agriculture and the environment benefit from biowaste technology. - Abstract: Municipal bio-refuse (CVD), containing kitchen wastes, home gardening residues and public park trimmings, was treated with alkali to yield a soluble bio-organic fraction (SBO) and an insoluble residue. These materials were characterized using elemental analysis, potentiometric titration, and 13C NMR spectroscopy, and then applied as organic fertilizers to soil for tomato greenhouse cultivation. Their performance was compared with a commercial product obtained from animal residues. Plant growth, fruit yield and quality, and soil and leaf chemical composition were the selected performance indicators. The SBO exhibited the best performance by enhancing leaf chlorophyll content, improving plant growth and fruit ripening rate and yield. No product performance-chemical composition relationship could be assessed. Solubility could be one reason for the superior performance of SBO as a tomato growth promoter. The enhancement of leaf chlorophyll content is discussed to identify a possible link with the SBO photosensitizing properties that have been demonstrated in other work, and thus with photosynthetic performance.

Sortino, Orazio [Dipartimento di Scienze Agronomiche Agrochimiche e delle Produzioni Animali, Universita degli Studi di Catania, Via Valdisavoia 5, 95123 Catania (Italy); Dipasquale, Mauro [Dipartimento di Chimica, Universita di Torino, Via P. Giuria 7, 10125 Torino (Italy); Montoneri, Enzo, E-mail: enzo.montoneri@unito.it [Dipartimento di Chimica, Universita di Torino, Via P. Giuria 7, 10125 Torino (Italy); Tomasso, Lorenzo; Perrone, Daniele G. [Dipartimento di Chimica, Universita di Torino, Via P. Giuria 7, 10125 Torino (Italy); Vindrola, Daniela; Negre, Michele; Piccone, Giuseppe [Dipartimento di Valorizzazione e Protezione delle Risorse Agroforestali, Universita di Torino, Via L. da Vinci 44, 10095 Grugliasco (Italy)

2012-10-15

191

Shellfish: proximate composition, minerals, fatty acids, and sterols.  

PubMed

Proximate composition, minerals, fatty acids, and sterols were determined for eight species of shellfish commonly marketed in the Northwest. Moisture and total lipid content varied with the size of the species, with more variation in mollusca than in crustacea; total lipid content ranged from 0.7% in sea scallops to 3.1% in blue mussels but only from 1.2% in Dungeness crab to 1.3% in pink shrimp. The mineral content was highly variable; the mineral content of Northwest samples tended to be lower than that reported in other studies. Generally, shellfish are good sources of zinc, and Pacific oysters, blue mussels, and Manila clams are also good sources of iron. Five fatty acids (16:0, 16:1, 18:1, 20:5n-3, and 22:6n-3) represented from 60% to 84% of the fatty acid content. Palmitic acid ranged from 13% to 32% of the total fatty acids. Long-chain n-3 polyunsaturated fatty acids were predominant (37.6% to 54.3%), with sea scallops containing more than 50%; n-6 polyunsaturated fatty acids ranged from 1.5% to 6.5%. In crustacea, cholesterol was the primary sterol, and brassicasterol was the only other measurable sterol. In all mollusca except California squid, cholesterol averaged 37 mg/100 gm and ranged from 23% to 39% of the total sterols. In squid, cholesterol, at 231 mg/100 gm, was the only measurable sterol. We conclude that shellfish vary widely in their nutrient content but, in general, are valuable additions to the diet. PMID:2335682

King, I; Childs, M T; Dorsett, C; Ostrander, J G; Monsen, E R

1990-05-01

192

Subverting sterols: rerouting an oxysterol-signaling pathway to promote tumor growth  

PubMed Central

Oxysterols are oxidized derivatives of cholesterol that are generated enzymatically or through autoxidation. Initially identified as important lipid signaling molecules in the context of atherosclerosis and inflammation, accumulated evidence indicates that these lipid-signaling molecules can have pleiotropic effects on the fate and function of the immune system. These effects range from the regulation of immune cell survival and proliferation to chemotaxis and antiviral immunity. New studies now indicate that tumor-derived oxysterols can serve to subvert the immune system by recruiting protumorigenic neutrophils into the tumor microenvironment. The consequence of this recruitment is the generation of proangiogenic factors and matrix metalloproteinase proteins that provide a tumor a significant growth and survival advantage. In combination with other recent studies, these data highlight the ongoing cross talk between sterol metabolism and the immune system, and they raise the intriguing possibility that targeting oxysterol pathways could serve as a novel therapeutic approach in the war on cancer. PMID:23980123

York, Autumn G.

2013-01-01

193

Exserolides A-F, new isocoumarin derivatives from the plant endophytic fungus Exserohilum sp.  

PubMed

Six new isocoumarin derivatives, exserolides A-F (1-6), were isolated from solid cultures of the plant endophytic fungus Exserohilum sp., together with four known metabolites (7-10). The structures of 1-6 were elucidated primarily by NMR experiments. The absolute configuration of the C-3 methine carbon in 1-5 was deduced via the circular dichroism data, whereas that of the 1,3-diol moiety in 6 was assigned from the (1)H NMR data of its (R)- and (S)-MTPA diesters. Compounds 3 and 9 showed antifungal activity against the plant pathogen Fusarium oxysporum, whereas 6 displayed significant inhibitory effects against a small panel of bacteria. PMID:24752143

Li, Ruxin; Chen, Shenxi; Niu, Shubin; Guo, Liangdong; Yin, Jun; Che, Yongsheng

2014-07-01

194

Plant regeneration from cell suspension-derived protoplasts of Saintpaulia ionantha Wendl.  

PubMed

Friable calli were induced on leaf segments of Saintpaulia ionantha Wendl. on B5 medium containing 1 mg l(-1) 2,4-D and 2 g l(-1) casein hydrolysate. Cell suspension cultures were readily established from these friable calli and protoplasts could be isolated from the cells with yields of 1-3×10(7)/g f. wt.. By culturing in 0.1 % gellan gum-solidified B5 medium supplemented with 1 mg l(-1) 2,4-D and 0.1 M each of sucrose and mannitol at a density of 1×10(5)/ml, the protoplasts divided within 6 days and formed macro-colonies after 2 months of culture. Shoot regeneration from protoplast-derived calli was obtained by sequential treatment of the calli with plant growth regulators: initially with 1 mg l(-1) each of NAA and BA for 2 months followed by 0.01 mg l(-1) NAA and 5 mg l(-1) BA for 4 months. Regenerated plants were established after rooting of the shoots on half-strength MS medium, and successfully transferred to the greenhouse. The regenerated plants grew into flowering stage and showed the same phenotype as the parent plant. PMID:24185329

Hoshino, Y; Nakano, M; Mii, M

1995-03-01

195

Targeted Depletion of Hepatic ACAT2-driven Cholesterol Esterification Reveals a Non-biliary Route for Fecal Neutral Sterol Loss*  

PubMed Central

Deletion of acyl-CoA:cholesterol O-acyltransferase 2 (ACAT2) in mice results in resistance to diet-induced hypercholesterolemia and protection against atherosclerosis. Recently, our group has shown that liver-specific inhibition of ACAT2 via antisense oligonucleotide (ASO)-mediated targeting likewise limits atherosclerosis. However, whether this atheroprotective effect was mediated by: 1) prevention of packaging of cholesterol into apoB-containing lipoproteins, 2) augmentation of nascent HDL cholesterol secretion, or 3) increased hepatobiliary sterol secretion was not examined. Therefore, the purpose of these studies was to determine whether hepatic ACAT2 is rate-limiting in all three of these important routes of cholesterol homeostasis. Liver-specific depletion of ACAT2 resulted in reduced packaging of cholesterol into apoB-containing lipoproteins (very low density lipoprotein, intermediate density lipoprotein, and low density lipoprotein), whereas high density lipoprotein cholesterol levels remained unchanged. In the liver of ACAT2 ASO-treated mice, cholesterol ester accumulation was dramatically reduced, yet there was no reciprocal accumulation of unesterified cholesterol. Paradoxically, ASO-mediated depletion of hepatic ACAT2 promoted fecal neutral sterol excretion without altering biliary sterol secretion. Interestingly, during isolated liver perfusion, ACAT2 ASO-treated livers had augmented secretion rates of unesterified cholesterol and phospholipid. Furthermore, we demonstrate that liver-derived cholesterol from ACAT2 ASO-treated mice is preferentially delivered to the proximal small intestine as a precursor to fecal excretion. Collectively, these studies provide the first insight into the hepatic itinerary of cholesterol when cholesterol esterification is inhibited only in the liver, and provide evidence for a novel non-biliary route of fecal sterol loss. PMID:18281279

Brown, J. Mark; Bell, Thomas A.; Alger, Heather M.; Sawyer, Janet K.; Smith, Thomas L.; Kelley, Kathryn; Shah, Ramesh; Wilson, Martha D.; Davis, Matthew A.; Lee, Richard G.; Graham, Mark J.; Crooke, Rosanne M.; Rudel, Lawrence L.

2008-01-01

196

2-Amino-nonyl-6-methoxyl-tetralin muriate inhibits sterol C-14 reductase in the ergosterol biosynthetic pathway  

PubMed Central

Aim: To investigate the action mechanism of a novel chemical structural aminotetralin derivate, 2-Amino-Nonyl-6-Methoxyl-Tetralin Muriate (10b), against Candida albicans (C albicans) in the ergosterol biosynthetic pathway. Methods: Antifungal susceptibility test of 10b was carried out using broth microdilution method, the action mechanism of 10b against C albicans was investigated by GC-MS spectrometry and real-time RT-PCR assay, and cytotoxicity of 10b in vitro was assessed by MTS/PMS reduction assay. Results: 10b reduced the ergosterol content markedly, and the 50% ergosterol content inhibitory concentration (ECIC50 value) was 0.08 ?g/mL. Although the sterol composition of 10b-grown cells was completely identical with that of erg24 strain, the content of ergosta-8,14,22-trienol in 10b-grown cells was much higher than that in erg24 strain. Real-time RT-PCR assay revealed a global upregulation of sterol metabolism genes. In addition, the 50% inhibitory concentration (IC50 value) of 10b was 11.30 ?g/mL for murine embryonic fibroblasts and 35.70 ?g/mL for human normal liver cells. Conclusion: 10b possessed a mode of action different from that of azoles and morpholines, whose targets were sterol C-14 reductase (encoded by ERG24 gene) and sterol C-5 desaturase (encoded by ERG3) related enzyme. Although 10b seemed to reduce MTS/PMS reduction in a dose dependent manner, IC50 value for mammalian cells was much higher than 50% minimum inhibitory concentration (MIC50) value for C albicans. This indicates that the formulation is preliminarily safe and warrants further study for possible human applications. PMID:19915585

Liang, Rong-mei; Cao, Yong-bing; Fan, Kai-hua; Xu, Yi; Gao, Ping-hui; Zhou, You-jun; Dai, Bao-di; Tan, Yong-hong; Wang, Shi-hua; Tang, Hui; Liu, Hong-tao; Jiang, Yuan-ying

2009-01-01

197

Variable Contribution of Soil and Plant Derived Carbon to Dissolved Organic Matter  

NASA Astrophysics Data System (ADS)

The seasonal variation in the amount and sources of dissolved organic matter (DOM) in soil profiles was investigated. In general DOM in soil solution can evolve from the decomposition and mobilization of soil organic matter (SOM), dissolution of dead microbial cells or from the input of plant material such as root exudates or decomposing litter. Here we used vegetation change from C3 to C4 plants to quantify the plant derived carbon in DOM. In 2002 an agricultural field was converted to an experimental grass land. The average carbon isotope value of SOM was -26.5 per mill (sd = 0.2) for the plough horizon. On two independent plots, each 10 x 20 m, we used Amaranthus retroflexus as C4 plant with a carbon isotope label of 13.0 per mill to distinguish unlabeled SOM and plant derived carbon sources. To quantify the contribution of litter input on DOM formation we applied a split plot design. One half had no litter and the other half double amount of above ground litter. Soil water was collected in 10, 20 and 30 cm depth biweekly and DOM concentrations in solution and carbon isotope ratios of the freeze dried and decarbonized material were investigated. During winter uniform concentrations of DOM of about 7 mg/l were measured throughout all depth and treatments. In spring when soil temperatures increase and water availability decreases DOM concentrations increased with similar rates in all depth. Even in the second year of Amaranth growth the carbon isotope ratios of DOM in winter and spring had no C4 signal. The carbon isotope ratios of -26 to -27 per mill suggest SOM as carbon source and contradict a contribution of root exudates to the DOM pool. During summer almost no soil solution was collected. After rewetting in fall DOM concentrations up to 50 mg/l in 10 cm depth and up to 35 mg/l in deeper layers were found. These high concentrations held carbon isotope signals from -25 to -26.5 per mill contradicting carbon input from plant material. With ongoing wetting of the soil the carbon isotope ratios suddenly increased up to -21.7 per mill on the double litter plots and to -24 per mill on no litter plots. However, this signal was not detected in 30 cm depth. Keeling plots proved that the major part of the DOM comes from SOM. In fall and early winter only 36 % and 19 % of plant derived carbon were found in the double litter and no litter plots, respectively. Our results suggest that carbon of the SOM pool is the major source for carbon in DOM. In the spring season root exudates seem to be completely respired by soil organisms suggesting that root and rhizosphere respiration are the same respiratory pool. Only in fall the decomposition of plant litter contributed to carbon in DOM. However, this carbon source is already exhausted in the next spring. In consequence our results may indicate that stored soil carbon is more active than thought and that DOM transport might be a key process to understand carbon sequestration.

Steinbeiss, S.; Gleixner, G.

2005-12-01

198

Phylogenetic and biochemical evidence for sterol synthesis in the bacterium Gemmata obscuriglobus  

PubMed Central

Sterol biosynthesis is viewed primarily as a eukaryotic process, and the frequency of its occurrence in bacteria has long been a subject of controversy. Two enzymes, squalene monooxygenase and oxidosqualene cyclase, are the minimum necessary for initial biosynthesis of sterols from squalene. In this work, 19 protein gene sequences for eukaryotic squalene monooxygenase and 12 protein gene sequences for eukaryotic oxidosqualene cyclase were compared with all available complete and partial prokaryotic genomes. The only unequivocal matches for a sterol biosynthetic pathway were in the proteobacterium, Methylococcus capsulatus, in which sterol biosynthesis is known, and in the planctomycete, Gemmata obscuriglobus. The latter species contains the most abbreviated sterol pathway yet identified in any organism. Analysis shows that the major sterols in Gemmata are lanosterol and its uncommon isomer, parkeol. There are no subsequent modifications of these products. In bacteria, the sterol biosynthesis genes occupy a contiguous coding region and possibly comprise a single operon. Phylogenetic trees constructed for both enzymes show that the sterol pathway in bacteria and eukaryotes has a common ancestry. It is likely that this contiguous reading frame was exchanged between bacteria and early eukaryotes via lateral gene transfer or endosymbiotic events. The primitive sterols produced by Gemmata suggest that this genus could retain the most ancient remnants of the sterol biosynthetic pathway. PMID:14660793

Pearson, Ann; Budin, Meytal; Brocks, Jochen J.

2003-01-01

199

Bioprocessing of plant-derived virus-like particles of Norwalk virus capsid protein under current Good Manufacture Practice regulations.  

PubMed

Despite the success in expressing a variety of subunit vaccine proteins in plants and the recent stride in improving vaccine accumulation levels by transient expression systems, there is still no plant-derived vaccine that has been licensed for human use. The lack of commercial success of plant-made vaccines lies in several technical and regulatory barriers that remain to be overcome. These challenges include the lack of scalable downstream processing procedures, the uncertainty of regulatory compliance of production processes, and the lack of demonstration of plant-derived products that meet the required standards of regulatory agencies in identity, purity, potency and safety. In this study, we addressed these remaining challenges and successfully demonstrate the ability of using plants to produce a pharmaceutical grade Norwalk virus (NV) vaccine under current Good Manufacture Practice (cGMP) guidelines at multiple gram scales. Our results demonstrate that an efficient and scalable extraction and purification scheme can be established for processing virus-like particles (VLPs) of NV capsid protein (NVCP). We successfully operated the upstream and downstream NVCP production processes under cGMP regulations. Furthermore, plant-derived NVCP VLP demonstrates the identity, purity, potency and safety that meet the preset release specifications. This material is being tested in a Phase I human clinical trial. This research provides the first report of producing a plant-derived vaccine at scale under cGMP regulations in an academic setting and an important step for plant-produced vaccines to become a commercial reality. PMID:22134876

Lai, Huafang; Chen, Qiang

2012-03-01

200

Large-scale Gene Ontology analysis of plant transcriptome-derived sequences retrieved by AFLP technology  

PubMed Central

Background After 10-year-use of AFLP (Amplified Fragment Length Polymorphism) technology for DNA fingerprinting and mRNA profiling, large repertories of genome- and transcriptome-derived sequences are available in public databases for model, crop and tree species. AFLP marker systems have been and are being extensively exploited for genome scanning and gene mapping, as well as cDNA-AFLP for transcriptome profiling and differentially expressed gene cloning. The evaluation, annotation and classification of genomic markers and expressed transcripts would be of great utility for both functional genomics and systems biology research in plants. This may be achieved by means of the Gene Ontology (GO), consisting in three structured vocabularies (i.e. ontologies) describing genes, transcripts and proteins of any organism in terms of their associated cellular component, biological process and molecular function in a species-independent manner. In this paper, the functional annotation of about 8,000 AFLP-derived ESTs retrieved in the NCBI databases was carried out by using GO terminology. Results Descriptive statistics on the type, size and nature of gene sequences obtained by means of AFLP technology were calculated. The gene products associated with mRNA transcripts were then classified according to the three main GO vocabularies. A comparison of the functional content of cDNA-AFLP records was also performed by splitting the sequence dataset into monocots and dicots and by comparing them to all annotated ESTs of Arabidopsis and rice, respectively. On the whole, the statistical parameters adopted for the in silico AFLP-derived transcriptome-anchored sequence analysis proved to be critical for obtaining reliable GO results. Such an exhaustive annotation may offer a suitable platform for functional genomics, particularly useful in non-model species. Conclusion Reliable GO annotations of AFLP-derived sequences can be gathered through the optimization of the experimental steps and the statistical parameters adopted. The Blast2GO software was shown to represent a comprehensive bioinformatics solution for an annotation-based functional analysis. According to the whole set of GO annotations, the AFLP technology generates thorough information for angiosperm gene products and shares common features across angiosperm species and families. The utility of this technology for structural and functional genomics in plants can be implemented by serial annotation analyses of genome-anchored fragments and organ/tissue-specific repertories of transcriptome-derived fragments. PMID:18652646

Botton, Alessandro; Galla, Giulio; Conesa, Ana; Bachem, Christian; Ramina, Angelo; Barcaccia, Gianni

2008-01-01

201

Host-plant-derived variation in ultraviolet wing patterns influences mate selection by male butterflies.  

PubMed

We report on the first case in which sequestered secondary plant compounds determine an insect's external appearance in the ultraviolet spectrum and thereby influence visually mediated mate choice. Larvae of the common blue butterfly Polyommatus icarus specifically sequester flavonoids in different amounts and types, depending on the part or species of food plant. During late pupal development the majority of ultraviolet-absorbing flavonoids are deposited in the wing scales. The flavonoid content of the larval diet thereby determines ultraviolet wing patterns. In laboratory and field experiments, male butterflies clearly preferred flavonoid-rich, ultraviolet-absorbing female dummies. This preference is mediated visually by the ultraviolet pattern of the wings. Food-plant parts and species vary in value as a food source, so ultraviolet wing patterns may signal mate quality and are not a species-specific characteristic. We discuss the use of principal component analysis in analysing spectral data in the context of visual communication. We propose the alternative application of confidence intervals of averaged spectra as a novel straightforward statistical method for comparing groups of spectra in a manner that is independent of assumptions about the visual system of the receiver. In addition, they can be used to give confidence intervals to derived measures of colour such as quantum catch by photoreceptors. PMID:11511660

Knüttel, H; Fiedler, K

2001-07-01

202

Structural complex of sterol 14[alpha]-demethylase (CYP51) with 14[alpha]-methylenecyclopropyl-[delta]7-24, 25-dihydrolanosterol[S  

SciTech Connect

Sterol 14{alpha}-demethylase (CYP51) that catalyzes the removal of the 14{alpha}-methyl group from the sterol nucleus is an essential enzyme in sterol biosynthesis, a primary target for clinical and agricultural antifungal azoles and an emerging target for antitrypanosomal chemotherapy. Here, we present the crystal structure of Trypanosoma (T) brucei CYP51 in complex with the substrate analog 14{alpha}-methylenecyclopropyl-{Delta}7-24,25-dihydrolanosterol (MCP). This sterol binds tightly to all protozoan CYP51s and acts as a competitive inhibitor of F105-containing (plant-like) T. brucei and Leishmania (L) infantum orthologs, but it has a much stronger, mechanism-based inhibitory effect on I105-containing (animal/fungi-like) T. cruzi CYP51. Depicting substrate orientation in the conserved CYP51 binding cavity, the complex specifies the roles of the contact amino acid residues and sheds new light on CYP51 substrate specificity. It also provides an explanation for the effect of MCP on T. cruzi CYP51. Comparison with the ligand-free and azole-bound structures supports the notion of structural rigidity as the characteristic feature of the CYP51 substrate binding cavity, confirming the enzyme as an excellent candidate for structure-directed design of new drugs, including mechanism-based substrate analog inhibitors.

Hargrove, Tatiana Y.; Wawrzak, Zdzislaw; Liu, Jialin; Waterman, Michael R.; Nes, W. David; Lepesheva, Galina I. (Vanderbilt); (TTU); (NWU)

2012-06-28

203

Co-opted Oxysterol-Binding ORP and VAP Proteins Channel Sterols to RNA Virus Replication Sites via Membrane Contact Sites.  

PubMed

Viruses recruit cellular membranes and subvert cellular proteins involved in lipid biosynthesis to build viral replicase complexes and replication organelles. Among the lipids, sterols are important components of membranes, affecting the shape and curvature of membranes. In this paper, the tombusvirus replication protein is shown to co-opt cellular Oxysterol-binding protein related proteins (ORPs), whose deletion in yeast model host leads to decreased tombusvirus replication. In addition, tombusviruses also subvert Scs2p VAP protein to facilitate the formation of membrane contact sites (MCSs), where membranes are juxtaposed, likely channeling lipids to the replication sites. In all, these events result in redistribution and enrichment of sterols at the sites of viral replication in yeast and plant cells. Using in vitro viral replication assay with artificial vesicles, we show stimulation of tombusvirus replication by sterols. Thus, co-opting cellular ORP and VAP proteins to form MCSs serves the virus need to generate abundant sterol-rich membrane surfaces for tombusvirus replication. PMID:25329172

Barajas, Daniel; Xu, Kai; de Castro Martín, Isabel Fernández; Sasvari, Zsuzsanna; Brandizzi, Federica; Risco, Cristina; Nagy, Peter D

2014-10-01

204

Co-opted Oxysterol-Binding ORP and VAP Proteins Channel Sterols to RNA Virus Replication Sites via Membrane Contact Sites  

PubMed Central

Viruses recruit cellular membranes and subvert cellular proteins involved in lipid biosynthesis to build viral replicase complexes and replication organelles. Among the lipids, sterols are important components of membranes, affecting the shape and curvature of membranes. In this paper, the tombusvirus replication protein is shown to co-opt cellular Oxysterol-binding protein related proteins (ORPs), whose deletion in yeast model host leads to decreased tombusvirus replication. In addition, tombusviruses also subvert Scs2p VAP protein to facilitate the formation of membrane contact sites (MCSs), where membranes are juxtaposed, likely channeling lipids to the replication sites. In all, these events result in redistribution and enrichment of sterols at the sites of viral replication in yeast and plant cells. Using in vitro viral replication assay with artificial vesicles, we show stimulation of tombusvirus replication by sterols. Thus, co-opting cellular ORP and VAP proteins to form MCSs serves the virus need to generate abundant sterol-rich membrane surfaces for tombusvirus replication. PMID:25329172

Barajas, Daniel; Xu, Kai; de Castro Martin, Isabel Fernandez; Sasvari, Zsuzsanna; Brandizzi, Federica; Risco, Cristina; Nagy, Peter D.

2014-01-01

205

[Microbial models in screening of inhibitors of sterol biosynthesis].  

PubMed

On the base of previously developed microbial models high effective scheme for screening of inhibitors of sterol biosynthesis (ISB) is proposed. It is based on cultivation of halophilic bacteria Halobacterium salinarum (former Halobacterium halobium), possessing mevalonate pathway of sterol biosynthesis, and cultivation of fungus Acremonium fusidioides (former Fusidium coccineum), that is producer of steroid antibiotic fusidin (fusidic acid), which biosynthesis has great similarity (with coincidence of its initial steps till squalene formation) to cholesterol biosynthesis in human organism. In H. salinarum model ISB are revealed as compounds that inhibit test-culture growth, whereas in A. fusidioides test-system they are revealed as compounds that strongly reduce fusidin production without any visible influence on producer's growth. Mevalonate that is one of the crucial intermediates of sterol biosynthesis remove inhibition induced by many microbial metabolites that is the evidence of their action at early stages of sterol biosynthetic pathway, including HMG-CoA reductase step. Both test-systems are developed as micromethod and could be easily mechanized due to miniaturization of microbiological procedures, cultivation in sterile 96-well plates and usage of automatic micropipettes and dispensers. Effectiveness of both test-systems, as well as their sensitiveness, laboriousness and ability to give false-positive or false-negative results in ISB screening work is compared. The proposed scheme of screening of ISB includes microbial models at early steps of screening procedures and Hep G2 test-system at the late step. The preliminary screening of microbial metabolites possessing antifungal activity at initial step is compulsory. Miniaturization and mechanization of microbial processes and purification of producers' culture broth with micro- and ultrafiltration are under consideration as well. PMID:24757827

Trenin, A S

2013-01-01

206

Dietary phosphilipids and sterols protective against peptic ulceration.  

PubMed

The prevalence of duodenal ulceration in regions of developing countries with a stable diet is related to the staple food(s) in that diet. A higher prevalence occurs in areas where the diet is principally milled rice, refined wheat or maize, yams, cassava, sweet potato or green bananas, and a lower prevalence in areas where the staple diet is based on unrefined wheat or maize, soya, certain millets or certain pulses. Experiments using animal peptic ulcer models showed that the lipid fraction in foods from the staple diets of low prevalence areas gave protection against both gastric and duodenal ulceration, including ulceration due to non-steroidal anti-inflammatory drugs (NSAIDs), and also promoted healing of ulceration. The protective activity was found to lie in the phospholipid, sterol and sterol ester fractions of the lipid. Amongst individual phospholipids present in the phospholipid fraction, phosphatidyl ethanolamine (cephalin) and phosphatidyl choline (Lecithin) predominated. The sterol fraction showing activity contained ?-sitosterol, stigmasterol and an unidentified isomer of ?-sitosterol. The evidence shows that dietary phytosterols and phospholipids, both individually and in combination, have a protective effect on gastroduodenal mucosa. These findings may prove to be important in the prevention and management of duodenal and gastric ulceration including ulceration due to NSAIDs. PMID:23097339

Tovey, F I; Bardhan, K D; Hobsley, M

2013-09-01

207

Expression of a fungal sterol desaturase improves tomato drought tolerance, pathogen resistance and nutritional quality  

PubMed Central

Crop genetic engineering mostly aims at improving environmental stress (biotic and abiotic) tolerance as well as nutritional quality. Empowering a single crop with multiple traits is highly demanding and requires manipulation of more than one gene. However, we report improved drought tolerance and fungal resistance along with the increased iron and polyunsaturated fatty acid content in tomato by expressing a single gene encoding C-5 sterol desaturase (FvC5SD) from an edible fungus Flammulina velutipes. FvC5SD is an iron binding protein involved in ergosterol biosynthesis. Morphological and biochemical analyses indicated ?23% more epicuticular wax deposition in leaves of transgenic plants that provides an effective waterproof barrier resulting in improved protection from drought and infection by phytopathogenic fungus Sclerotinia sclerotiorum. Furthermore, the transgenic fruits have improved nutritional value attributed to enhanced level of beneficial PUFA and 2-3 fold increase in total iron content. This strategy can be extended to other economically important crops. PMID:23230516

Kamthan, Ayushi; Kamthan, Mohan; Azam, Mohammad; Chakraborty, Niranjan; Chakraborty, Subhra; Datta, Asis

2012-01-01

208

Dialkylimidazole inhibitors of Trypanosoma cruzi sterol 14?-demethylase as anti-Chagas disease agents  

PubMed Central

New dialkylimidazole based sterol 14?-demethylase inhibitors were prepared and tested as potential anti-Trypanosoma cruzi agents. Previous studies had identified compound 2 as the most potent and selective inhibitor against parasite cultures. In addition, animal studies had demonstrated that compound 2 is highly efficacious in the acute model of the disease. However, compound 2 has a high molecular weight and high hydrophobicity, issues addressed here. Systematic modifications were carried out at four positions on the scaffold and several inhibitors were identified which are highly potent (EC50<1 nM) against T. cruzi in culture. The halogenated derivatives 36j, 36k, and 36p, display excellent activity against T.cruzi amastigotes, with reduced molecular weight and lipophilicity, and exhibit suitable physicochemical properties for an oral drug candidate. PMID:24120539

Suryadevara, Praveen Kumar; Racherla, Kishore Kumar; Olepu, Srinivas; Norcross, Neil R.; Tatipaka, Hari Babu; Arif, Jennifer A.; Planer, Joseph D.; Lepesheva, Galina; Verlinde, Christophe L. M. J.; Buckner, Frederick S.; Gelb, Michael H.

2014-01-01

209

A sterol binding protein integrates endosomal lipid metabolism with TOR signaling and nitrogen sensing  

PubMed Central

SUMMARY Kes1, and other oxysterol binding protein (OSBP) superfamily members, are involved in membrane and lipid trafficking through trans-Golgi network (TGN) and endosomal systems. We demonstrate that Kes1 represents a sterol-regulated antagonist of TGN/endosomal phosphatidylinositol-4-phosphate signaling. This regulation modulates TOR activation by amino acids, and dampens gene expression driven by Gcn4; the primary transcriptional activator of the general amino acid control regulon. Kes1-mediated repression of Gcn4 transcription factor activity is characterized by nonproductive Gcn4 binding to its target sequences, involves TGN/endosome-derived sphingolipid signaling, and requires activity of the cyclin-dependent kinase 8 (CDK8) module of the enigmatic ‘large Mediator’ complex. These data describe a pathway by which Kes1 integrates lipid metabolism with TORC1 signaling and nitrogen sensing. PMID:22341443

Mousley, Carl J.; Yuan, Peihua; Gaur, Naseem A.; Trettin, Kyle D.; Nile, Aaron H.; Deminoff, Stephen J.; Dewar, Brian J.; Wolpert, Max; Macdonald, Jeffrey M.; Herman, Paul K.; Hinnebusch, Alan G.; Bankaitis, Vytas A.

2012-01-01

210

The structure of the human sterol carrier protein X/sterol carrier protein 2 gene (SCP2)  

SciTech Connect

Sterol carrier protein X (SCPx) is a 58-kDa protein that is localized to peroxisomes. The amino acid sequence of the protein suggests that SCPx may function as a thiolase. The gene encoding SCPx also codes for a 15.3-kDa protein called sterol carrier protein 2 (SCP{sub 2}). Here the authors report the structure of this gene (SCP2), which spans approximately 80 kb and consists of 16 exons and 15 introns. Multiple transcription start sites were identified. The 5{prime} flanking region has characteristics of other peroxisomal protein promoters, which include the absence of a TATA box and G+C-enriched region containing several reverse GC boxes. 24 refs., 3 figs., 1 tab.

Ohba, Takashi; Rennert, H.; Pfeifer, S.M. [Univ. of Pennsylvania School of Medicine, Phildelphia, PA (United States)] [and others] [Univ. of Pennsylvania School of Medicine, Phildelphia, PA (United States); and others

1994-11-15

211

Bioactive sterols from marine resources and their potential benefits for human health.  

PubMed

Bioactive agents from marine resources have shown their valuable health beneficial effects. Therefore, increase knowledge on novel functional ingredients with biological activities from marine animal and microbe has gained much attention. Sterols are recognized as potential in development functional food ingredients and pharmaceutical agents. Marine resources, with a great diversity, can be a very interesting natural resource of sterols. This chapter focuses on biological activities of marine animal and microbe sterols with potential health beneficial applications in functional foods and pharmaceuticals. PMID:22361193

Kim, Se-Kwon; Van Ta, Quang

2012-01-01

212

Conversion of exogenous cholesterol into glycoalkaloids in potato shoots, using two methods for sterol solubilisation.  

PubMed

Steroidal glycoalkaloids (SGA) are toxic secondary metabolites naturally occurring in the potato, as well as in certain other Solanaceous plant species, such as tomato, eggplant and pepper. To investigate the steroidal origin of SGA biosynthesis, cut potato shoots were fed cholesterol labelled with deuterium (D) in the sterol ring structure (D5- or D6-labelled), or side chain (D7-labelled), and analysed after three or five weeks. The labelled cholesterol and presence of D-labelled SGA were analysed by GC-MS and LC-MS/MS, respectively. When feeding D-labelled cholesterol solubilised in Tween-80, labelled cholesterol in free form became present in both leaves and stems, although the major part was recovered as steryl esters. Minor amounts of D-labelled SGA (?-solanine and ?-chaconine) were identified in cholesterol-treated shoots, but not in blank controls, or in shoots fed D6-27-hydroxycholesterol. Solubilising the labelled cholesterol in methyl-?-cyclodextrin instead of Tween-80 increased the levels of labelled SGA up to 100-fold, and about 1 mole% of the labelled cholesterol was recovered as labelled SGA in potato leaves. Both side chain and ring structure D labels were retained in SGA, showing that the entire cholesterol molecule is converted to SGA. However, feeding side chain D7-labelled cholesterol resulted in D5-labelled SGA, indicating that two hydrogen atoms were released during formation of the SGA nitrogen-containing ring system. Feeding with D7-sitosterol did not produce any labelled SGA, indicating that cholesterol is a specific SGA precursor. In conclusion, we have demonstrated a superior performance of methyl-?-cyclodextrin for delivery of cholesterol in plant tissue feeding experiments, and given firm evidence for cholesterol as a specific sterol precursor of SGA in potato. PMID:24349406

Petersson, Erik V; Nahar, Nurun; Dahlin, Paul; Broberg, Anders; Tröger, Rikard; Dutta, Paresh C; Jonsson, Lisbeth; Sitbon, Folke

2013-01-01

213

Conversion of Exogenous Cholesterol into Glycoalkaloids in Potato Shoots, Using Two Methods for Sterol Solubilisation  

PubMed Central

Steroidal glycoalkaloids (SGA) are toxic secondary metabolites naturally occurring in the potato, as well as in certain other Solanaceous plant species, such as tomato, eggplant and pepper. To investigate the steroidal origin of SGA biosynthesis, cut potato shoots were fed cholesterol labelled with deuterium (D) in the sterol ring structure (D5- or D6-labelled), or side chain (D7-labelled), and analysed after three or five weeks. The labelled cholesterol and presence of D-labelled SGA were analysed by GC-MS and LC-MS/MS, respectively. When feeding D-labelled cholesterol solubilised in Tween-80, labelled cholesterol in free form became present in both leaves and stems, although the major part was recovered as steryl esters. Minor amounts of D-labelled SGA (?-solanine and ?-chaconine) were identified in cholesterol-treated shoots, but not in blank controls, or in shoots fed D6-27-hydroxycholesterol. Solubilising the labelled cholesterol in methyl-?-cyclodextrin instead of Tween-80 increased the levels of labelled SGA up to 100-fold, and about 1 mole% of the labelled cholesterol was recovered as labelled SGA in potato leaves. Both side chain and ring structure D labels were retained in SGA, showing that the entire cholesterol molecule is converted to SGA. However, feeding side chain D7-labelled cholesterol resulted in D5-labelled SGA, indicating that two hydrogen atoms were released during formation of the SGA nitrogen-containing ring system. Feeding with D7-sitosterol did not produce any labelled SGA, indicating that cholesterol is a specific SGA precursor. In conclusion, we have demonstrated a superior performance of methyl-?-cyclodextrin for delivery of cholesterol in plant tissue feeding experiments, and given firm evidence for cholesterol as a specific sterol precursor of SGA in potato. PMID:24349406

Petersson, Erik V.; Nahar, Nurun; Dahlin, Paul; Broberg, Anders; Tröger, Rikard; Dutta, Paresh C.; Jonsson, Lisbeth; Sitbon, Folke

2013-01-01

214

Posaconazole Is a Potent Inhibitor of Sterol 14?-Demethylation in Yeasts and Molds  

PubMed Central

Posaconazole (POS; SCH 56592) is a novel triazole that is active against a wide variety of fungi, including fluconazole-resistant Candida albicans isolates and fungi that are inherently less susceptible to approved azoles, such as Candida glabrata. In this study, we compared the effects of POS, itraconazole (ITZ), fluconazole (FLZ), and voriconazole (VOR) on sterol biosynthesis in strains of C. albicans (both azole-sensitive and azole-resistant strains), C. glabrata, Aspergillus fumigatus, and Aspergillus flavus. Following exposure to azoles, nonsaponifiable sterols were extracted and resolved by liquid chromatography and sterol identity was confirmed by mass spectroscopy. Ergosterol was the major sterol in all but one of the strains; C. glabrata strain C110 synthesized an unusual sterol in place of ergosterol. Exposure to POS led to a decrease in the total sterol content of all the strains tested. The decrease was accompanied by the accumulation of 14?-methylated sterols, supporting the contention that POS inhibits the cytochrome P450 14?-demethylase enzyme. The degree of sterol inhibition was dependent on both dose and the susceptibility of the strain tested. POS retained activity against C. albicans isolates with mutated forms of the 14?-demethylase that rendered these strains resistant to FLZ, ITZ, and VOR. In addition, POS was a more potent inhibitor of sterol synthesis in A. fumigatus and A. flavus than either ITZ or VOR. PMID:15388421

Munayyer, Hanan K.; Mann, Paul A.; Chau, Andrew S.; Yarosh-Tomaine, Taisa; Greene, Jonathan R.; Hare, Roberta S.; Heimark, Larry; Palermo, Robert E.; Loebenberg, David; McNicholas, Paul M.

2004-01-01

215

Functional Interactions between Sphingolipids and Sterols in Biological Membranes Regulating Cell Physiology  

PubMed Central

Sterols and sphingolipids are limited to eukaryotic cells, and their interaction has been proposed to favor formation of lipid microdomains. Although there is abundant biophysical evidence demonstrating their interaction in simple systems, convincing evidence is lacking to show that they function together in cells. Using lipid analysis by mass spectrometry and a genetic approach on mutants in sterol metabolism, we show that cells adjust their membrane composition in response to mutant sterol structures preferentially by changing their sphingolipid composition. Systematic combination of mutations in sterol biosynthesis with mutants in sphingolipid hydroxylation and head group turnover give a large number of synthetic and suppression phenotypes. Our unbiased approach provides compelling evidence that sterols and sphingolipids function together in cells. We were not able to correlate any cellular phenotype we measured with plasma membrane fluidity as measured using fluorescence anisotropy. This questions whether the increase in liquid order phases that can be induced by sterol–sphingolipid interactions plays an important role in cells. Our data revealing that cells have a mechanism to sense the quality of their membrane sterol composition has led us to suggest that proteins might recognize sterol–sphingolipid complexes and to hypothesize the coevolution of sterols and sphingolipids. PMID:19225153

Guan, Xue Li; Souza, Cleiton M.; Pichler, Harald; Dewhurst, Gisèle; Schaad, Olivier; Kajiwara, Kentaro; Wakabayashi, Hirotomo; Ivanova, Tanya; Castillon, Guillaume A.; Piccolis, Manuele; Abe, Fumiyoshi; Loewith, Robbie; Funato, Kouichi

2009-01-01

216

Deriving a Planting Medium from Solid Waste Compost and Construction, Demolition and Excavation Waste  

NASA Astrophysics Data System (ADS)

Lebanon's very high population density has been increasing since the end of the war in the early 1990s reaching 416.36 people per square kilometer. Furthermore, the influx of refugees from conflicts in the region has increased the resident population significantly. All these are exerting pressure on the country's natural resources, pushing the Lebanese to convert more forest and agricultural land into roads, buildings and houses. This has led to a building boom and rapid urbanization which in turn has created a demand for construction material - mainly rock, gravel, sand, etc. nearly all of which were locally acquired through quarrying to the tune of three million cubic meters annually. This boom has been followed by a war with Israel in 2006 which resulted in thousands of tonnes of debris. The increase in population has also led to an increase in solid waste generation with 1.57 million tonnes of solid waste generated in Lebanon per year. The combination of construction, demolition and excavation (CDE) waste along with the increase in solid waste generation has put a major stress on the country and on the management of its solid waste problem. Compounding this problem are the issues of quarries closure and rehabilitation and a decrease in forest and vegetative cover. The on-going research reported in this paper aims to provide an integrated solution to the stated problem by developing a "soil mix" derived from a mélange of the organic matter of the solid waste (compost), the CDE waste, and soil. In this mix, native and indicator plants are planted (in pots) from which the most productive mix will be selected for further testing at field level in later experiments. The plant species used are Matiolla, a native Lebanese plant and Zea mays, which is commonly known used as an indicator plant due to its sensitivity to environmental conditions. To ensure sustainability and environmental friendliness of the mix, its physical and chemical characteristics are monitored and assessed. The leachate from the irrigation of the pots is also monitored and assessed to ensure that if selected for field trials, the mix will not pose a threat to water bodies. The presentation at the conference will aim to report the latest results from the on-going experiment.

Farajalla, Nadim; Assaf, Eleni; Bashour, Issam; Talhouk, Salma

2014-05-01

217

Inhibitory effects of plant-derived flavonoids and phenolic acids on malonaldehyde formation from ethyl arachidonate.  

PubMed

The antioxidant activities of naturally occurring plant compounds were measured in a lipid peroxidation system consisting of ethyl arachidonate and Fenton's reagent. Inhibitory effects of 24 plant-derived flavonoids and 5 phenolic acids on malonaldehyde (MA) formation from ethyl arachidonate were examined using gas chromatography (GC) with a nitrogen-phosphorus detector (NPD). Luteolin, which showed the strongest antioxidant activity, inhibited MA formation by 94% and 97% at the levels of 0.5 and 1.0 mM, respectively. The antioxidant activities of the flavones and flavonols decreased in the following order: luteolin > rhamnetin > fisetin > kaempferol > morin > quercetin. Among the flavanones tested, hesperitin, taxifolin, and naringenin exhibited appreciable antioxidant activities (61-84%) at the 1.0 mM level. The inhibitory effect of epigallocatechin gallate (82.5% at the 1.0 mM level) was the strongest among the flavan-3-ols tested. Ferulic acid had the most potent antioxidant activity (74.6% at the 1.0 mM level) of the phenolic acids tested. PMID:14611194

Lee, Kwang-Geun; Shibamoto, Takayuki; Takeoka, Gary R; Lee, Sung-Eun; Kim, Jeong-Han; Park, Byeoung-Soo

2003-11-19

218

Central African biomes and forest succession stages derived from modern pollen data and plant functional types  

NASA Astrophysics Data System (ADS)

New detailed vegetation reconstructions are proposed in Atlantic Central Africa from a modern pollen data set derived from 199 sites (Cameroon, Gabon and Congo) including 131 new sites. In this study, the concept of plant functional classification is improved with new and more detailed plant functional types (PFTs) and new aggregations of pollen taxa. Using the biomisation method, we reconstructed (1) modern potential biomes and (2) potential succession stages of forest regeneration, a new approach in Atlantic Central African vegetation dynamics and ecosystem functioning reconstruction. When compared to local vegetation, potential biomes are correctly reconstructed (97.5% of the sites) and tropical rain forest (TRFO biome) is well identified from tropical seasonal forest (TSFO biome). When the potential biomes are superimposed on the White's vegetation map, only 76.4% of the sites are correctly reconstructed. But using botanical data, correspondence and cluster analyses, the 43 sites from Congo (Mayombe) evidence more affinities with those of central Gabon and so they can also be considered as correctly reconstructed as TRFO biome and White's map should be revised. In terms of potential succession stages of forest regeneration, the mature forest (TMFO) is well differentiated from the secondary forest (TSFE), but inside this latter group, the young and the pioneer stages are not clearly identified due probably to their low sampling representation. Moreover, linked to their progressive and mosaic character, the boundaries between two forest biomes or two forest stages are not clearly detected and need also a more intensive sampling in such transitions.

Lebamba, J.; Ngomanda, A.; Vincens, A.; Jolly, D.; Favier, C.; Elenga, H.; Bentaleb, I.

2009-07-01

219

Plant-derived vaccines: an approach for affordable vaccines against cervical cancer.  

PubMed

Several types of human papillomavirus (HPV) are causatively associated with cervical cancer, which is the second most common cancer in women worldwide. HPV-16 and 18 are among the high risk types and responsible for HPV infection in more than 70% of the cases. The majority of cervical cancer cases occur in developing countries. Currently available HPV vaccines are expensive and probably unaffordable for most women in low and middle income countries. Therefore, there is a need to develop cost-effective vaccines for these countries. Due to many advantages, plants offer an attractive platform for the development of affordable vaccines. These include low cost of production, scalability, low health risks and the potential ability to be used as unprocessed or partially processed material. Among several techniques, chloroplast transformation is of eminent interest for the production of vaccines because of high yield of foreign protein and lack of transgene transmission through pollen. In this commentary, we focus on the most relevant aspects of plant-derived vaccines that are decisive for the future development of cost-effective HPV vaccines. PMID:22327500

Waheed, Mohammad Tahir; Gottschamel, Johanna; Hassan, Syed Waqas; Lössl, Andreas Günter

2012-03-01

220

Measurement of hepatic sterol synthesis in the Mongolian gerbil in vivo using (/sup 3/H)water: diurnal variation and effect of type of dietary fat  

SciTech Connect

The hepatic synthesis of sterol was measured in the male Mongolian gerbil (Meriones unguiculatus) in vivo following the administration of (/sup 3/H)water by monitoring the incorporation of radioactivity into digitonin-precipitable sterol. A diurnal rhythm in cholesterol synthesis was exhibited under conditions of ad libitum feeding with alternating 12-hour periods of light (0200 to 1400 hr) and dark (1400 to 0200 hr). The zenith was reached between 1500 and 2100 hr and the nadir approximately 10-12 hours later between 0200 and 0400 hr, which provided a zenith/nadir ratio of 9.6 to 1.0. The in vivo rates of hepatic sterol synthesis and plasma cholesterol levels were measured in gerbils fed semi-purified diets containing either 19.5% beef tallow + 0.5% safflower, 20% lard, or 20% safflower oil and widely differing ratios of polyunsaturated: saturated fatty acids. All diets were equalized to contain 0.01% cholesterol and 0.05% plant sterol. After 3 days on the experimental diets, the mean rates of cholesterol synthesis (nmol/g liver per hr) were 41.5, 26.6, and 13.8 for animals fed the diets containing beef tallow, lard, and safflower oil, respectively. After 7 and 14 days, synthetic rates were lowest in the gerbils fed safflower oil as were also the plasma cholesterol levels. These results indicate that the type of dietary lipid can significantly influence the in vivo rate of sterol biosynthesis in gerbil liver. This response may contribute, at least in part, to the observed differences in plasma cholesterol levels.

Mercer, N.J.; Holub, B.J.

1981-01-01

221

Daily Consumption of a Dark Chocolate Containing Flavanols and Added Sterol Esters Affects Cardiovascular Risk Factors in a Normotensive Population with  

Microsoft Academic Search

Previous studies with plant sterols (PS) and cocoa flavanols (CF) provide support for their dietary use in maintaining cardio- vascular health. This double-blind, placebo-controlled, cross-over study evaluated the efficacy of daily consumption of a cocoa flavanol-containing dark chocolate bar with added PS on serum lipids, blood pressure, and other circulating cardio- vascular health markers in a population with elevated serum

Robin R. Allen; Catherine Kwik-Uribe; Ellen M. Evans; John W. Erdman Jr

222

Spreads enriched with three different levels of vegetable oil sterols and the degree of cholesterol lowering in normocholesterolaemic and mildly hypercholesterolaemic subjects  

Microsoft Academic Search

Objective: To investigate the dose-response relationship between cholesterol lowering and three different, relatively low intake levels of plant sterols (0.83, 1.61, 3.24 g\\/d) from spreads. To investigate the effects on lipid-soluble (pro)vitamins.Design: A randomized double-blind placebo controlled balanced incomplete Latin square design using five spreads and four periods. The five study spreads included butter, a commercially available spread and three

HFJ Hendriks; JA Weststrate; T van Vliet; GW Meijer

1999-01-01

223

Sterol-inhibiting fungicide impacts on soil microbial ecology in Atlantic Coastal Plain soils  

NASA Astrophysics Data System (ADS)

Seventy-five percent of the peanuts (Arachus hypogaia) produced in the United States are grown in the Atlantic Coastal Plain region. Portions of this area, including Alabama and Georgia, exhibit a subtropical climate that promotes soil-borne plant fungal diseases. Most fields receive repeated fungicide applications during the growing season to suppress the disease causing organisms, such as Sclerotium rolfsii, Rhizoctonia solani, and Cylindrocladium parasiticum. Information regarding fungicide effects on the soil microbial community, with components principally responsible for transformation and fate of fungicides and other soil-applied pesticides, is limited. The objectives of the study were to assess soil microbial community response to (1) varying rates of the sterol-inhibiting fungicide tebuconazole (0, single application, season max, 2x season max), and (2) field rates of the sterol-inhibitors cyproconazole, prothioconazole, tebuconazole, and flutriafol, and thiol-competitor chlorothalonil. The sterol-inhibitors exhibited different half lives, as listed in the FOOTPRINT database, ranging from <1 day to >1300 d. Chlorothalonil was chosen because it is the most frequently applied fungicide to peanut. Shifts in the fungi, gram positive and gram negative bacteria, were monitored during the experiments using phospholipid fatty acid (PLFA) profiles. Ergosterol levels and pesticide decay rates were also monitored to evaluate the effectiveness of the fungicide and soil residence time, respectively. In the rate study, the highest rate of tebuconazole reduced the fungal biomarker 18:2?6,9c to 2.6 nmol g-1 dry soil at 17 d, as compared to the control (4.1 nmol g-1 dry soil). However, levels of the fungal PLFA biomarker were similar regardless of rate at 0 and 32 d. The gram negative bacterial PLFA mole percent was greater at 17 d for the two highest rates of tebuconazole, but was similar at 0 and 32 d. Gram positive and fungal mole percents were not affected at any time point. Tebuconazole half life was approximately 10 d regardless of rate. A principle components analysis revealed negligible fungicide impact on PLFA. In the field rate study soil samples were collected immediately following fungicide application to peanut. A laboratory dissipation study, accompanied by PLFA and ergosterol analysis is currently being conducted. Results from the rate experiment indicate that tebuconazole's effect was transient due to rapid dissipation and suggest a gram negative bacterial role. Results obtained from both studies will be useful in predicting the environmental fate and impact of fungicides commonly used for production of peanut and other crops on soil microorganisms.

White, P. M.; Potter, T. L.; Strickland, T. C.

2008-12-01

224

Modulation of Plant Mitochondrial VDAC by Phytosterols  

PubMed Central

We have investigated the effect of cholesterol and two abundant phytosterols (sitosterol and stigmasterol) on the voltage-dependent anion-selective channel (VDAC) purified from mitochondria of bean seeds (Phaseolus coccineus). These sterols differ by the degree of freedom of their lateral chain. We show that VDAC displays sensitivity to the lipid-sterol ratio and to the type of sterol found in the membrane. The main findings of this study are: 1), cholesterol and phytosterols modulate the selectivity but only stigmasterol alters the voltage-dependence of the plant VDAC in the range of sterol fraction found in the plant mitochondrial membrane; 2), VDAC unitary conductance is not affected by the addition of sterols; 3), the effect of sterols on the VDAC is reversible upon sterol depletion with 10 ?M methyl-?-cyclodextrins; and 4), phytosterols are essential for the channel gating at salt concentration prevailing in vivo. A quantitative analysis of the voltage-dependence indicates that stigmasterol inhibits the transition of the VDAC in the lowest subconductance states. PMID:20923643

Mlayeh, Lamia; Chatkaew, Sunita; Léonetti, Marc; Homblé, Fabrice

2010-01-01

225

Structure of dehydroergosterol monohydrate and interaction with sterol carrier protein-2.  

PubMed

Dehydroergosterol [ergosta-5,7,9(11),22-tetraen-3beta-ol] is a naturally-occurring, fluorescent sterol utilized extensively to probe membrane cholesterol distribution, cholesterol-protein interactions, and intracellular cholesterol transport both in vitro and in vivo. In aqueous solutions, the low solubility of dehydroergosterol results in the formation of monohydrate crystals similar to cholesterol. Low temperature X-ray diffraction analysis reveals that dehydroergosterol monohydrate crystallizes in the space group P2(1) with four molecules in the unit cell and monoclinic crystal parameters a = 9.975(1) A, b = 7.4731(9) A, c = 34.054(4) A, and beta = 92.970(2) degrees somewhat similar to ergosterol monohydrate. The molecular arrangement is in a slightly closer packed bilayer structure resembling cholesterol monohydrate. Since dehydroergosterol fluorescence emission undergoes a quantum yield enhancement and red-shift of its maximum wavelength when crystallized, formation or disruption of microcrystals was monitored with high sensitivity using cuvette-based spectroscopy and multi-photon laser scanning imaging microscopy. This manuscript reports on the dynamical effect of sterol carrier protein-2 (SCP-2) interacting between aqueous dispersions of dehydroergosterol monohydrate microcrystal donors and acceptors consisting not only of model membranes but also vesicles derived from plasma membranes isolated by biochemical fractionation and affinity purification from Madin-Darby canine kidney cells. Furthermore, this study provides real-time measurements of the effect of increased SCP-2 levels on the rate of disappearance of dehydroergosterol microcrystals in living cells. PMID:19020914

McIntosh, Avery L; Atshaves, Barbara P; Gallegos, Adalberto M; Storey, Stephen M; Reibenspies, Joseph H; Kier, Ann B; Meyer, Edgar; Schroeder, Friedhelm

2008-12-01

226

Purification, characterization and catalytic properties of human sterol 8-isomerase.  

PubMed Central

CHO 2, encoding human sterol 8-isomerase (hSI), was introduced into plasmids pYX213 or pET23a. The resulting native protein was overexpressed in erg 2 yeast cells and purified to apparent homogeneity. The enzyme exhibited a K (m) of 50 microM and a turnover number of 0.423 s(-1) for zymosterol, an isoelectric point of 7.70, a native molecular mass of 107000 Da and was tetrameric. The structural features of zymosterol provided optimal substrate acceptability. Biomimetic studies of acid-catalysed isomerization of zymosterol resulted in formation of cholest-8(14)-enol, whereas the enzyme-generated product was a Delta(7)-sterol, suggesting absolute stereochemical control of the reaction by hSI. Using (2)H(2)O and either zymosterol or cholesta-7,24-dienol as substrates, the reversibility of the reaction was confirmed by GC-MS of the deuterated products. The positional specific incorporation of deuterium at C-9alpha was established by a combination of (1)H- and (13)C-NMR analyses of the enzyme-generated cholesta-7,24-dienol. Kinetic analyses indicated the reaction equilibrium ( K (eq)=14; DeltaG(o')=-6.5 kJ/mol) for double-bond isomerization favoured the forward direction, Delta(8) to Delta(7). Treatment of hSI with different high-energy intermediate analogues produced the following dissociation constants ( K (i)): emopamil (2 microM)=tamoxifen (1 microM)=tridemorph (1 microM)<25-azacholesterol (21 microM) sterol formation in cholesterol synthesis. PMID:12133002

Nes, W David; Zhou, Wenxu; Dennis, Allen L; Li, Haoxia; Jia, Zhonghua; Keith, Richard A; Piser, Timothy M; Furlong, Stephen T

2002-01-01

227

Antitumor sterols from the mycelia of Cordyceps sinensis  

Microsoft Academic Search

Activity guided fractionations led to the isolation of two antitumor compounds 5?,8?-epidioxy-24(R)-methylcholesta-6,22-dien-3?-d-glucopyranoside and 5,6-epoxy-24(R)-methylcholesta-7,22-dien-3?-ol from the methanol extract of Cordyceps sinensis. Two previously known compounds, ergosteryl-3-O-?-d-glucopyranoside and 22-dihydroergosteryl-3-O-?-d-glucopyranoside were also isolated. The structures of hitherto unknown sterols were established by 1D and 2D NMR spectroscopic techniques with the former synthesized in order to confirm the identity of the sugar moiety

Jin Woo Bok; Leonard Lermer; Jeff Chilton; Hans G Klingeman; G. H. Neil Towers

1999-01-01

228

Antitumor sterols from the mycelia of Cordyceps sinensis  

Microsoft Academic Search

Activity guided fractionations led to the isolation of two antitumor compounds 5a,8a-epidioxy-24(R)-methylcholesta-6,22- dien-3b-D-glucopyranoside and 5,6-epoxy-24(R)-methylcholesta-7,22-dien-3b-ol from the methanol extract of Cordyceps sinensis. Two previously known compounds, ergosteryl-3-O-b-D-glucopyranoside and 22-dihydroergosteryl-3-O-b-D-glucopyranoside were also isolated. The structures of hitherto unknown sterols were established by 1D and 2D NMR spectroscopic techniques with the former synthesized in order to confirm the identity of the sugar

Jin Woo Boka; Hans G. Klingeman; G. H. Neil Towers

229

Effect of sterol esters on lipid composition and antioxidant status of erythrocyte membrane of hypercholesterolemic rats.  

PubMed

Hypercholesterolemia is a major cause of coronary heart disease. Erythrocyte membrane is affected during hypercholesterolemia. The effect of EPA-DHA rich sterol ester and ALA rich sterol ester on erythrocyte membrane composition, osmotic fragility in normal and hypercholesterolemic rats and changes in antioxidant status of erythrocyte membrane were studied. Erythrocyte membrane composition, osmotic fragility of the membrane and antioxidant enzyme activities was analyzed. Osmotic fragility data suggested that the erythrocyte membrane of hypercholesterolemia was relatively more fragile than that of the normal rats' membrane which could be reversed with the addition of sterol esters in the diet. The increased plasma cholesterol in hypercholesterolemic rats could also be lowered by the sterol ester administration. There was also marked changes in the antioxidant enzyme activities of the erythrocyte membrane. Antioxidant enzyme levels decreased in the membrane of the hypercholesterolemic subjects were increased with the treatment of the sterol esters. The antioxidative activity of ALA rich sterol ester was better in comparison to EPA-DHA rich sterol ester. In conclusion, rat erythrocytes appear to be deformed and became more fragile in cholesterol rich blood. This deformity and fragility was partially reversed by sterol esters by virtue of their ability to lower the extent of hypercholesterolemia. PMID:24770475

Sengupta, Avery; Ghosh, Mahua

2014-01-01

230

Phylogenetic and biochemical evidence for sterol synthesis in the bacterium Gemmata obscuriglobus  

E-print Network

bacteria and early eukaryotes via lateral gene transfer or endosymbiotic events. The primitive sterols epoxide, this would require the prior evolution of oxygenic photosynthesis. For sterol biosynthesis an exhaustive search of all microbial genetic sequence data currently in the public domain to (i) identify

Brocks, Jochen J.

231

Processes of recovering fatty acids and sterols from tall oil pitch  

SciTech Connect

An improved process of enhancing the recovery of fatty acids from tall oil pitch is disclosed. The process includes a hydrolysis step for increasing the free fatty acid available for recovery from tall oil pitch during the distillation process. The hydrolysis step also enables the recovery of sterols where the tall oil pitch is of the type which is rich in sterol esters.

Hughes, R. E.

1985-06-18

232

Inhaled tobacco sterols: uptake by the lungs and disposition to selected organs of rats  

SciTech Connect

Tobacco sterols (cholesterol, beta-sitosterol, campesterol, and stigmasterol) are present in tobacco smoke and appear in plasma of mammals exposed to cigarette smoke. Because tobacco sterols may be important in the pathogenesis of smoking-induced lung and vascular diseases, we studied the pattern of deposition of cigarette sterols in the lungs and appearance of cigarette sterols in plasma and body organs of rats. After exposure to twenty 5 ml puffs of smoke from tobacco labeled with (4-/sup 14/C)cholesterol or beta-(4-/sup 14/C)sitosterol, rats were killed just after exposure (day 0) and on days 2, 5, 8, 11, 15, and 30, and the lungs and selected body organs analyzed for activity. We found that cigarette sterols are associated with particulates in cigarette smoke, deposited mostly in distal airspaces and parenchyma of the lungs, and appear in plasma and several body organs for more than 30 days after this single exposure to cigarette smoke. Bronchoalveolar lavage fluid contained relatively small amounts of radiolabel for only the first few days, suggesting that most of the sterols were rapidly incorporated in lung parenchyma. Because disorders of sterol metabolism have been implicated in a variety of diseases including atherosclerosis and cancer, the significance of tobacco sterols to human smoking-induced diseases deserves further study.

Holden, W.E.; Maier, J.M.; Liebler, J.M.; Malinow, M.R.

1988-08-01

233

Effect of Sterol Structure on Chain Ordering of an Unsaturated Phospholipid: A 2H-NMR Study of POPC/Sterol Membranes  

NASA Astrophysics Data System (ADS)

The physical properties of biological membranes are considerably altered by the presence of sterols. In particular, sterols help to maintain the integrity of the cell by adjusting the fluidity of the plasma membrane. Cholesterol is in addition an important component of lipid rafts which are hypothesized to compartmentalize the cell membrane surface thereby making it possible for certain proteins to function. Using 2H-NMR spectroscopy, we studied the effect of a series of different sterols on the chain ordering of POPC, an unsaturated phospholipid present in eukaryotic cell membranes. We were able to assigned specific roles to the structural differences between the sterols by comparing the manner in which they affect the average lipid chain conformation of POPC.

Shaghaghi, Mehran; Thewalt, Jenifer; Zuckermann, Martin

2012-10-01

234

Host Defense against Viral Infection Involves Interferon Mediated Down-Regulation of Sterol Biosynthesis  

PubMed Central

Little is known about the protective role of inflammatory processes in modulating lipid metabolism in infection. Here we report an intimate link between the innate immune response to infection and regulation of the sterol metabolic network characterized by down-regulation of sterol biosynthesis by an interferon regulatory loop mechanism. In time-series experiments profiling genome-wide lipid-associated gene expression of macrophages, we show a selective and coordinated negative regulation of the complete sterol pathway upon viral infection or cytokine treatment with IFN? or ? but not TNF, IL1?, or IL6. Quantitative analysis at the protein level of selected sterol metabolic enzymes upon infection shows a similar level of suppression. Experimental testing of sterol metabolite levels using lipidomic-based measurements shows a reduction in metabolic output. On the basis of pharmacologic and RNAi inhibition of the sterol pathway we show augmented protection against viral infection, and in combination with metabolite rescue experiments, we identify the requirement of the mevalonate-isoprenoid branch of the sterol metabolic network in the protective response upon statin or IFN? treatment. Conditioned media experiments from infected cells support an involvement of secreted type 1 interferon(s) to be sufficient for reducing the sterol pathway upon infection. Moreover, we show that infection of primary macrophages containing a genetic knockout of the major type I interferon, IFN?, leads to only a partial suppression of the sterol pathway, while genetic knockout of the receptor for all type I interferon family members, ifnar1, or associated signaling component, tyk2, completely abolishes the reduction of the sterol biosynthetic activity upon infection. Levels of the proteolytically cleaved nuclear forms of SREBP2, a key transcriptional regulator of sterol biosynthesis, are reduced upon infection and IFN? treatment at both the protein and de novo transcription level. The reduction in srebf2 gene transcription upon infection and IFN treatment is also found to be strictly dependent on ifnar1. Altogether these results show that type 1 IFN signaling is both necessary and sufficient for reducing the sterol metabolic network activity upon infection, thereby linking the regulation of the sterol pathway with interferon anti-viral defense responses. These findings bring a new link between sterol metabolism and interferon antiviral response and support the idea of using host metabolic modifiers of innate immunity as a potential antiviral strategy. PMID:21408089

Blanc, Mathieu; Hsieh, Wei Yuan; Robertson, Kevin A.; Watterson, Steven; Shui, Guanghou; Lacaze, Paul; Khondoker, Mizanur; Dickinson, Paul; Sing, Garwin; Rodriguez-Martin, Sara; Phelan, Peter; Forster, Thorsten; Strobl, Birgit; Muller, Matthias; Riemersma, Rudolph; Osborne, Timothy; Wenk, Markus R.; Angulo, Ana; Ghazal, Peter

2011-01-01

235

Male-derived butterfly anti-aphrodisiac mediates induced indirect plant defense  

Microsoft Academic Search

Plants can recruit parasitic wasps in response to egg deposition by herbivorous insects¿a sophisticated indirect plant defense mechanism. Oviposition by the Large Cabbage White butterfly Pieris brassicae on Brussels sprout plants induces phytochemical changes that arrest the egg parasitoid Trichogramma brassicae. Here, we report the identification of an elicitor of such an ovipositioninduced plant response. Eliciting activity was present in

Nina E. Fatouros; Colette Broekgaarden; G. Bukovinszkine-Kiss; Loon van J. J. A; Roland Mumm; Martinus E. Huigens; Marcel Dicke; Monika Hilker

2008-01-01

236

Dynamic molecular structure of plant biomass-derived black carbon (biochar)  

SciTech Connect

Char black carbon (BC), the solid residue of incomplete combustion, is continuously being added to soils and sediments due to natural vegetation fires, anthropogenic pollution, and new strategies for carbon sequestration ('biochar'). Here we present a molecular-level assessment of the physical organization and chemical complexity of biomass-derived chars and, specifically, that of aromatic carbon in char structures. BET-N{sub 2} surface area, X-ray diffraction (XRD), synchrotron-based Near-edge X-ray Absorption Fine Structure (NEXAFS), and Fourier transform infrared (FT-IR) spectroscopy are used to show how two plant materials (wood and grass) undergo analogous, but quantitatively different physical-chemical transitions as charring temperature increases from 100 to 700 C. These changes suggest the existence of four distinct categories of char consisting of a unique mixture of chemical phases and physical states: (i) in transition chars the crystalline character of the precursor materials is preserved, (ii) in amorphous chars the heat-altered molecules and incipient aromatic polycondensates are randomly mixed, (iii) composite chars consist of poorly ordered graphene stacks embedded in amorphous phases, and (iv) turbostratic chars are dominated by disordered graphitic crystallites. The molecular variations among the different char categories translate into differences in their ability to persist in the environment and function as environmental sorbents.

Keiluweit, M.; Nico, P.S.; Johnson, M.G.; Kleber, M.

2009-11-15

237

Metabolism of a plant derived galactose-containing polysaccharide by Bifidobacterium breve UCC2003  

PubMed Central

Summary In this study, we describe the functional characterization of the Bifidobacterium breve UCC2003 gal locus, which is dedicated to the utilization of galactan, a plant?derived polysaccharide. Using a combination of molecular approaches we conclude that the galA gene of B. breve UCC2003 encodes a ??1,4?endogalactanase producing galacto?oligosaccharides, which are specifically internalized by an ABC transport system, encoded by galBCDE, and which are then hydrolysed to galactose moieties by a dedicated intracellular ??galactosidase, specified by galG. The generated galactose molecules are presumed to be fed into the fructose?6?phosphate phosphoketolase pathway via the Leloir pathway, thereby allowing B. breve UCC2003 to use galactan as its sole carbon and energy source. In addition to these findings we demonstrate that GalR is a LacI?type DNA?binding protein, which not only appears to control transcription of the galCDEGR operon, but also that of the galA gene. PMID:21375716

O'Connell Motherway, Mary; Fitzgerald, Gerald F.; van Sinderen, Douwe

2011-01-01

238

Antibacterial Activities of Plant-Derived Compounds and Essential Oils Toward Cronobacter sakazakii and Cronobacter malonaticus.  

PubMed

Abstract Cronobacter sakazakii and C. malonaticus are opportunistic pathogens that cause infections in children and immunocompromised adults. In the present study, the antibacterial activity of 19 plant-derived compounds, 5 essential oils, and an extract of propolis were assessed against C. sakazakii and C. malonaticus. The effects of most of these antimicrobials have not been reported previously. Both strains were susceptible to thymol, carvacrol, thymoquinone, p-cymene, linalool, camphor, citral, eugenol, and trans-cinnamaldehyde as well as cinnamon, lemongrass, oregano, clove, and laurel essential oils; their minimum inhibitory concentrations varied between 0.1 and 2.0?mg/mL. As an alternative treatment method, vapors of the volatiles were tested as an indirect treatment. Vapors of trans-cinnamaldehyde, eugenol, oregano, and cinnamon essential oils inhibited both tested strains, while vapors of linalool were only active against C. sakazakii. To our knowledge, this study is the first time that the inhibitory activity of the vapors of these compounds and essential oils has been reported against Cronobacter spp. PMID:25062020

Fra?ková, Adéla; Marounek, Milan; Mozrová, V?ra; Weber, Jaroslav; Klou?ek, Pavel; Lukešová, Daniela

2014-10-01

239

Annual Variation in the Sterol Content of Digitalis purpurea L. Seedlings.  

PubMed

Seedings from a single lot of Digitalis purpurea L. seeds were germinated in batches over a period of 13 months. A total lipid extract was made which was resolved into esterified and unconjugated plus glycosylated sterol fractions. The amounts of sterol in each fraction and in the total were compared for seedlings germinated at different times of the year. The amount of esterified sterols reached a maximum value from March until June, and a low value from July until January. In January, a sharp increase began which lasted until March. Amounts of unconjugated and glycosylated sterols were elevated from March until June, low from July until October, and on the rise from November until March. These data correlate with an annual cycle in seed germination. The phase of maximum sterol content of seedlings is followed by a period of null germination. PMID:16659713

Jacobsohn, M K; Jacobsohn, G M

1976-10-01

240

Fungal genomes mining to discover novel sterol esterases and lipases as catalysts  

PubMed Central

Background Sterol esterases and lipases are enzymes able to efficiently catalyze synthesis and hydrolysis reactions of both sterol esters and triglycerides and due to their versatility could be widely used in different industrial applications. Lipases with this ability have been reported in the yeast Candida rugosa that secretes several extracellular enzymes with a high level of sequence identity, although different substrate specificity. This versatility has also been found in the sterol esterases from the ascomycetes Ophiostoma piceae and Melanocarpus albomyces. Results In this work we present an in silico search of new sterol esterase and lipase sequences from the genomes of environmental fungi. The strategy followed included identification and search of conserved domains from these versatile enzymes, phylogenetic studies, sequence analysis and 3D modeling of the selected candidates. Conclusions Six potential putative enzymes were selected and their kinetic properties and substrate selectivity are discussed on the basis of their similarity with previously characterized sterol esterases/lipases with known structures. PMID:24138290

2013-01-01

241

Annual Variation in the Sterol Content of Digitalis purpurea L. Seedlings 1  

PubMed Central

Seedings from a single lot of Digitalis purpurea L. seeds were germinated in batches over a period of 13 months. A total lipid extract was made which was resolved into esterified and unconjugated plus glycosylated sterol fractions. The amounts of sterol in each fraction and in the total were compared for seedlings germinated at different times of the year. The amount of esterified sterols reached a maximum value from March until June, and a low value from July until January. In January, a sharp increase began which lasted until March. Amounts of unconjugated and glycosylated sterols were elevated from March until June, low from July until October, and on the rise from November until March. These data correlate with an annual cycle in seed germination. The phase of maximum sterol content of seedlings is followed by a period of null germination. PMID:16659713

Jacobsohn, Myra K.; Jacobsohn, Gert M.

1976-01-01

242

Direct and stereospecific interaction of amphidinol 3 with sterol in lipid bilayers.  

PubMed

Amphidinol 3 (AM3), a polyhydroxy-polyene metabolite from the dinoflagellate Amphidinium klebsii, possesses potent antifungal activity. Although AM3 permeabilizes phospholipid membranes only in the presence of sterol, the detailed molecular basis by which AM3 recognizes sterols in membranes remains unknown. Here, we investigated the molecular interaction between sterols and AM3 in membranes from the viewpoint of stereospecific molecular recognition using ergosterol, cholesterol, and epicholesterol, which is the 3-OH epimer of cholesterol. Dye leakage assays, surface plasmon resonance experiments, (2)H and (31)P NMR measurements, and microscopic observations revealed that AM3 directly interacts with membrane sterols through the strict molecular recognition of the stereochemistry of the sterol 3-OH group. The direct interaction enhances the membrane binding efficiency of AM3, which subsequently permeabilizes membranes without altering membrane integrity. PMID:24773476

Espiritu, Rafael Atillo; Matsumori, Nobuaki; Tsuda, Masashi; Murata, Michio

2014-05-27

243

Derivation of plant-soil relationships for dose assessment on Bikini Atoll. [Radiation dose to returning population  

Microsoft Academic Search

A radiological survey of the terrestrial environment of Bikini and Eneu Islands (Bikini Atoll) was conducted in June 1975 to evaluate the potential radiation dose to the returning Bikini population. This report presents measurements of the radionuclide concentration in soil profiles and in dominant species of edible and nonedible indicator plants and describes the use of these data to derive

Colsher

1976-01-01

244

Trace analysis of selected hormones and sterols in river sediments by liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry.  

PubMed

In this paper, development and optimization of new LC-MS method for determination of twenty selected hormones, human/animal and plant sterols in river sediments were described. Sediment samples were prepared using ultrasonic extraction and clean up with silica gel/anhydrous sodium sulphate cartridge. Extracts were analyzed by liquid chromatography-linear ion trap-tandem mass spectrometry, with atmospheric pressure chemical ionization. The optimized extraction parameters were extraction solvent (methanol), weight of the sediment (2g) and time of ultrasonic extraction (3× 10min). Successful chromatographic separation of hormones (estriol and estrone, 17?- and 17?-estradiol) and four human/animal sterols (epicoprostanol, coprostanol, ?-cholestanol and ?-cholestanol) that have identical fragmentation reactions was achieved. The developed and optimized method provided high recoveries (73-118%), low limits of detection (0.8-18ngg(-1)) and quantification (2.5-60ngg(-1)) with the RSDs generally lower than 20%. Applicability of the developed method was confirmed by analysis of six river sediment samples. A widespread occurrence of human/animal and plant sterols was found. The only detected hormone was mestranol in just one sediment sample. PMID:25182857

Mati?, Ivana; Gruji?, Svetlana; Jaukovi?, Zorica; Lauševi?, Mila

2014-10-17

245

Boosting Crop Yields with Plant Steroids[W  

PubMed Central

Plant sterols and steroid hormones, the brassinosteroids (BRs), are compounds that exert a wide range of biological activities. They are essential for plant growth, reproduction, and responses to various abiotic and biotic stresses. Given the importance of sterols and BRs in these processes, engineering their biosynthetic and signaling pathways offers exciting potentials for enhancing crop yield. In this review, we focus on how alterations in components of sterol and BR metabolism and signaling or application of exogenous steroids and steroid inhibitors affect traits of agronomic importance. We also discuss areas for future research and identify the fine-tuning modulation of endogenous BR content as a promising strategy for crop improvement. PMID:22438020

Vriet, Cecile; Russinova, Eugenia; Reuzeau, Christophe

2012-01-01

246

Carotenoid Biosynthesis in Photo-Synthetic Bacteria and Higher Plants.  

National Technical Information Service (NTIS)

Investigation on the biosynthesis of plant sterols are described. A number of possible phytosterol precursors were identified in peas and larch and include squalene, cycloartenol, 24-methylene cycloartenol, 24-methylene lophenol. The incorporation of (2-1...

T. W. Goodwin, L. J. Goad

1966-01-01

247

Constitutive expression of transgenes encoding derivatives of the synthetic antimicrobial peptide BP100: impact on rice host plant fitness  

PubMed Central

Background The Biopeptide BP100 is a synthetic and strongly cationic ?-helical undecapeptide with high, specific antibacterial activity against economically important plant-pathogenic bacteria, and very low toxicity. It was selected from a library of synthetic peptides, along with other peptides with activities against relevant bacterial and fungal species. Expression of the BP100 series of peptides in plants is of major interest to establish disease-resistant plants and facilitate molecular farming. Specific challenges were the small length, peptide degradation by plant proteases and toxicity to the host plant. Here we approached the expression of the BP100 peptide series in plants using BP100 as a proof-of-concept. Results Our design considered up to three tandemly arranged BP100 units and peptide accumulation in the endoplasmic reticulum (ER), analyzing five BP100 derivatives. The ER retention sequence did not reduce the antimicrobial activity of chemically synthesized BP100 derivatives, making this strategy possible. Transformation with sequences encoding BP100 derivatives (bp100der) was over ten-fold less efficient than that of the hygromycin phosphotransferase (hptII) transgene. The BP100 direct tandems did not show higher antimicrobial activity than BP100, and genetically modified (GM) plants constitutively expressing them were not viable. In contrast, inverted repeats of BP100, whether or not elongated with a portion of a natural antimicrobial peptide (AMP), had higher antimicrobial activity, and fertile GM rice lines constitutively expressing bp100der were produced. These GM lines had increased resistance to the pathogens Dickeya chrysanthemi and Fusarium verticillioides, and tolerance to oxidative stress, with agronomic performance comparable to untransformed lines. Conclusions Constitutive expression of transgenes encoding short cationic ?-helical synthetic peptides can have a strong negative impact on rice fitness. However, GM plants expressing, for example, BP100 based on inverted repeats, have adequate agronomic performance and resistant phenotypes as a result of a complex equilibrium between bp100der toxicity to plant cells, antimicrobial activity and transgene-derived plant stress response. It is likely that these results can be extended to other peptides with similar characteristics. PMID:22947243

2012-01-01

248

Fecal sterols, seasonal variability, and probable sources along the ring of cenotes, Yucatan, Mexico.  

PubMed

Rapid development in Yucatan has had a dramatic impact on the environment, especially the water supply. Groundwater is the only source of water in Yucatan, since surface water is virtually absent due to the karstic nature of the soil. The ring of cenotes (RC) is a geological feature which functions as a source of water and as nodes in the underground river system that canalizes water towards the coast. Numerous productive and domestic activities take place around the RC in the absence of wastewater treatment or sewage systems. Consequently, a number of researchers have hypothesized that pollutants could migrate from the land surface to the underlying aquifer and, eventually, to the coast. Therefore, the present study investigates the relationship among sources of fecal sterols and their levels in cenotes, using the expected levels of fecal sterols obtained by a spatial analysis of the sources and a Pollution Source Index. Accordingly, expected levels are compared with the detected levels of fecal sterols in 5 areas around the RC. Regarding levels, observed during a sampling campaign carried out along the RC during September 2011 (rainy season) and May 2012 (dry season), varied from low to high concentrations of sterols (0.5-2396.42?gg(-1)) and fecal sterols (0.3-1690.18?gg(-1)). These concentrations showed no relationship between neighboring cenotes, where similar fecal sterol concentrations or gradients were expected. When comparing expected fecal sterols levels with the detected ones, only two of the five analyzed areas concur, suggesting that no clear relationship exists among sources and fecal sterols levels at the regional scale. Multivariate analysis showed that fecal sterols were associated with sterols and fine grain particulates during the rainy season, which suggests co-transport. During the dry season, fecal sterols associated with fine grain particulate and organic matter, which indicates a change to a deposition phenomenon. These findings indicate that defining a relationship among sources and fecal sterols levels is highly difficult and this could be the result of the absorption or migration through an intricate conduit, crack, or fracture karst system. Nevertheless, the "source-levels approach", used in this study, was consistent for the northeast edge and the middle western part of the RC. New and more extensive research should be done to assess the environmental fate of fecal sterols, especially considering the intricate karstic system and its compound retention capacity. PMID:25282019

Arcega-Cabrera, F; Velázquez-Tavera, N; Fargher, L; Derrien, M; Noreña-Barroso, E

2014-11-01

249

Fecal sterols, seasonal variability, and probable sources along the ring of cenotes, Yucatan, Mexico  

NASA Astrophysics Data System (ADS)

Rapid development in Yucatan has had a dramatic impact on the environment, especially the water supply. Groundwater is the only source of water in Yucatan, since surface water is virtually absent due to the karstic nature of the soil. The ring of cenotes (RC) is a geological feature which functions as a source of water and as nodes in the underground river system that canalizes water towards the coast. Numerous productive and domestic activities take place around the RC in the absence of wastewater treatment or sewage systems. Consequently, a number of researchers have hypothesized that pollutants could migrate from the land surface to the underlying aquifer and, eventually, to the coast. Therefore, the present study investigates the relationship among sources of fecal sterols and their levels in cenotes, using the expected levels of fecal sterols obtained by a spatial analysis of the sources and a Pollution Source Index. Accordingly, expected levels are compared with the detected levels of fecal sterols in 5 areas around the RC. Regarding levels, observed during a sampling campaign carried out along the RC during September 2011 (rainy season) and May 2012 (dry season), varied from low to high concentrations of sterols (0.5-2396.42 ?g g- 1) and fecal sterols (0.3-1690.18 ?g g- 1). These concentrations showed no relationship between neighboring cenotes, where similar fecal sterol concentrations or gradients were expected. When comparing expected fecal sterols levels with the detected ones, only two of the five analyzed areas concur, suggesting that no clear relationship exists among sources and fecal sterols levels at the regional scale. Multivariate analysis showed that fecal sterols were associated with sterols and fine grain particulates during the rainy season, which suggests co-transport. During the dry season, fecal sterols associated with fine grain particulate and organic matter, which indicates a change to a deposition phenomenon. These findings indicate that defining a relationship among sources and fecal sterols levels is highly difficult and this could be the result of the absorption or migration through an intricate conduit, crack, or fracture karst system. Nevertheless, the “source-levels approach”, used in this study, was consistent for the northeast edge and the middle western part of the RC. New and more extensive research should be done to assess the environmental fate of fecal sterols, especially considering the intricate karstic system and its compound retention capacity.

Arcega-Cabrera, F.; Velázquez-Tavera, N.; Fargher, L.; Derrien, M.; Noreña-Barroso, E.

2014-11-01

250

CHROMOPHORIC DISSOLVED ORGANIC MATTER (CDOM) DERIVED FROM DECOMPOSITION OF VARIOUS VASCULAR PLANT AND ALGAL SOURCES  

EPA Science Inventory

Chromophoric dissolved organic (CDOM) in aquatic environments is derived from the microbial decomposition of terrestrial and microbial organic matter. Here we present results of studies of the spectral properties and photoreactivity of the CDOM derived from several organic matter...

251

Galloyl moieties enhance the dentin biomodification potential of plant-derived catechins.  

PubMed

Proanthocyanidin-rich plant-derived agents have been shown to enhance dentin biomechanical properties and resistance to collagenase degradation. This study systematically investigated the interaction of chemically well-defined monomeric catechins with dentin extracellular matrix components by evaluating dentin mechanical properties as well as activities of matrix metalloproteinases (MMPs) and cysteine-cathepsins (CTs). Demineralized dentin beams (n=15) were incubated for 1h with 0.65% (+)-catechin (C), (-)-catechin gallate (CG), (-)-gallocatechin gallate (GCG), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin-3-gallate (EGCG). The modulus of elasticity (E) and the fold increase in E were determined by comparing specimens at baseline and after treatment. Biodegradation rates were assessed by differences in percentage of dry mass before and after incubation with bacterial collagenase. The inhibition of MMP-9 and CT-B by 0.65, 0.065 and 0.0065% of each catechin was determined using fluorimetric proteolytic assay kits. All monomeric catechins led to a significant increase in E. EGCG showed the highest fold increase in E, followed by ECG, CG and GCG. EGCG, ECG, GCG and CG significantly lowered biodegradation rates and inhibited both MMP-9 and CT-B at a concentration of 0.65%. Overall, the 3-O-galloylated monomeric catechins are clearly more potent than their non-galloylated analogues in improving dentin mechanical properties, stabilizing collagen against proteolytic degradation, and inhibiting the activity of MMPs and CTs. The results indicate that galloylation is a key pharmacophore in the monomeric and likely also in the oligomeric proanthocyanidins that exhibit high cross-linking potential for dentin extracellular matrix. PMID:24721612

Vidal, Cristina M P; Aguiar, Thaiane R; Phansalkar, Rasika; McAlpine, James B; Napolitano, José G; Chen, Shao-Nong; Araújo, Larissa S N; Pauli, Guido F; Bedran-Russo, Ana

2014-07-01

252

Suppression of allergic and inflammatory responses by essential oils derived from herbal plants and citrus fruits.  

PubMed

The aim of the present study was to investigate the biological activity of 20 essential oils (EOs) derived from herbal plants and citrus fruits. The in vitro anti-allergic and anti-inflammatory activities of these oils were investigated, and the EO which was found to have the strongest activity of the 20 EOs examined, was investigated further to identify its components and bioactive compounds. The in vitro anti-allergic activity was determined by measuring the release of ?-hexosaminidase from rat basophilic leukemia (RBL-2H3) cells treated with the calcium ionophore, A23187. The in vitro anti-inflammatory activity was determined by measuring the production of tumor necrosis factor-? (TNF-?) in RAW264.7 murine macrophages treated with lipopolysaccharide. Among the EOs examined, lemongrass [Cymbopogon citratus (DC.) Stapf] elicited the strongest anti-allergic and anti-inflammatory effects. A principal component of this EO is citral (3,7-dimethyl-2,6-octadien-1-al) (74.5%), a mixture of the stereoisomers, geranial (trans-citral, 40.16%) and neral (cis-citral, 34.24%), as determined by chromatography-mass spectrometry analysis. The activities of citral and geranial are similar to those of lemongrass EO. These compounds elicited significant in vivo anti-allergic and anti-inflammatory effects, suppressing an immunoglobulin E (IgE)-induced passive cutaneous anaphylactic reaction in mice and a 12-O-tetradecanoylphorbol-13-acetate-induced inflammatory mouse ear edema, respectively. Our data demonstrate that lemongrass EO and its constituents, citral and geranial, may be a therapeutic candidate for allergic and inflammatory diseases. PMID:24682420

Mitoshi, Mai; Kuriyama, Isoko; Nakayama, Hiroto; Miyazato, Hironari; Sugimoto, Keiichiro; Kobayashi, Yuko; Jippo, Tomoko; Kuramochi, Kouji; Yoshida, Hiromi; Mizushina, Yoshiyuki

2014-06-01

253

1504 VOLUME 24 NUMBER 12 DECEMBER 2006 NATURE BIOTECHNOLOGY Prospects for plant-derived antibacterials  

E-print Network

1504 VOLUME 24 NUMBER 12 DECEMBER 2006 NATURE BIOTECHNOLOGY Prospects for plant, both groups sacrifice infected tis- sues through apoptosis; produce numerous antimicrobial peptides. Plants as a source of antimicrobials Plants make over 100,000 small-molecule compounds1, many if not most

Ausubel, Frederick M.

254

Effect of biologically active plants used as netst material and the derived benefit to starling nestlings  

Microsoft Academic Search

The European starling Sturnus vulgaris preferentially incorporates fresh sprigs of particular plant species for use as nesting material. Chemicals found in these plants may act to reduce pathogen and ectoparasite populations normally found in nest environments. The present experiments were performed to test this Nest Protection Hypothesis. In the fild, we experimentally determined that wild carrot Daucus carota, a plant

Larry Clark; J. Russell Mason

1988-01-01

255

Effects of phytoestrogens and other plant-derived compounds on mesenchymal stem cells, bone maintenance and regeneration.  

PubMed

Phytoestrogens and other plant-derived compounds and extracts have been developed for the treatment of menopause-related complaints and disorders, e.g. hot flushes and osteoporosis. Since estrogens have been discussed to enhance the risk for hormone-sensitive cancers, research activities try to find alternatives. Phytoestrogens like genistein and resveratrol as well as other plant-derived compounds are capable of substituting for estrogens to some extent. Their effects on mesenchymal stem cells and the tissues derived therefrom have been investigated in vitro and in preclinical settings. Besides their well-known estrogenic, i.e. mainly antiresorptive effects on bone via estrogen receptor (ER) signalling, they also directly or indirectly affect osteogenic and adipogenic pathways. As a novel mechanism, phytoestrogens and plant-derived saponins and flavonoids like kaempferol and xanthohumol have been described to reciprocally affect the osteogenic versus the adipogenic differentiation pathway. Both, ER-mediated and other pathways mediate a shift towards osteogenesis by inhibiting PPAR? and C/EBP?, the key adipogenic transcription factors (TFs), while stimulating the key osteogenic TFs Runx2 and Sp7. Besides ER signalling, the broad spectrum of molecular mechanisms supporting osteogenesis comprises the modulation of PPAR?, Wnt/?-catenin, and Sirt1 signalling, which inversely influence the transcription or transactivation of osteogenic versus adipogenic TFs. Preventing the age- and hormone deficiency-related shift towards adipogenesis without provoking adverse estrogenic effects represents a very promising strategy for treating bone loss and other metabolic diseases beyond bone. Research on plant-derived compounds will have to be pursued in vitro as well as in preclinical studies and controlled clinical trials in humans are urgently needed. This article is part of a Special Issue entitled 'Phytoestrogens'. PMID:23262262

Schilling, Tatjana; Ebert, Regina; Raaijmakers, Nadja; Schütze, Norbert; Jakob, Franz

2014-01-01

256

Endogenous sterol biosynthesis is important for mitochondrial function and cell morphology in procyclic forms of Trypanosoma brucei.  

PubMed

Sterol biosynthesis inhibitors are promising entities for the treatment of trypanosomal diseases. Insect forms of Trypanosoma brucei, the causative agent of sleeping sickness, synthesize ergosterol and other 24-alkylated sterols, yet also incorporate cholesterol from the medium. While sterol function has been investigated by pharmacological manipulation of sterol biosynthesis, molecular mechanisms by which endogenous sterols influence cellular processes remain largely unknown in trypanosomes. Here we analyse by RNA interference, the effects of a perturbation of three specific steps of endogenous sterol biosynthesis in order to dissect the role of specific intermediates in proliferation, mitochondrial function and cellular morphology in procyclic cells. A decrease in the levels of squalene synthase and squalene epoxidase resulted in a depletion of cellular sterol intermediates and end products, impaired cell growth and led to aberrant morphologies, DNA fragmentation and a profound modification of mitochondrial structure and function. In contrast, cells deficient in sterol methyl transferase, the enzyme involved in 24-alkylation, exhibited a normal growth phenotype in spite of a complete abolition of the synthesis and content of 24-alkyl sterols. Thus, the data provided indicates that while the depletion of squalene and post-squalene endogenous sterol metabolites results in profound cellular defects, bulk 24-alkyl sterols are not strictly required to support growth in insect forms of T. brucei in vitro. PMID:22964455

Pérez-Moreno, Guiomar; Sealey-Cardona, Marco; Rodrigues-Poveda, Carlos; Gelb, Michael H; Ruiz-Pérez, Luis Miguel; Castillo-Acosta, Víctor; Urbina, Julio A; González-Pacanowska, Dolores

2012-10-01

257

Derivatives of diterpen labdane-8?,15-diol as photosynthetic inhibitors in spinach chloroplasts and growth plant inhibitors.  

PubMed

In a search of new efficient herbicides of natural origin, four derivatives were prepared from labdane-8?,15-diol (1) and 15-O-acetyl-8?-hydroxy labdane (2) isolated from Croton ciliatoglanduliferus. Their inhibitory activity on photosynthetic electron transport on fresh, broken spinach chloroplasts and on the growth of plants were determined. Derivative 15-O-benzoyl-8?-hydroxy labdane (5) was seven times more active than 2 as reaction Hill inhibitor. Complex of 5 with the adjuvant 2-hydroxypropyl-?-cyclodextrin (5:HPB) (200 ?M) was sprayed on Physalys ixocarpa (green tomato) plants; 48 h later the complex inhibited PS II by transforming the active reaction centers to silent reaction centers or "heat sinks". After 72 h this effect disappeared, probably 5:HPB was metabolized by the plant. Chlorophyll a fluorescence of Trifolium alexandrinum (clover) leaves was affected with 5:HPB at the level of PQ pool reduction. 5:HPB decreases the tomato and clover dry-biomass, without affecting Lolium perenne (grass) plants, suggesting that complex 5 acts as selective herbicide for dicotyledonous plants. PMID:23733160

Morales-Flores, Félix; Aguilar, María Isabel; King-Díaz, Beatriz; Lotina-Hennsen, Blas

2013-08-01

258

Improved stability of TMS derivatives for the robust quantification of plant polar metabolites by gas chromatography-mass spectrometry.  

PubMed

Plant metabolite profiling is commonly carried out by GC-MS of methoximated trimethylsilyl (TMS) derivatives. This technique is robust and enables a library search for spectra produced by electron ionization. However, recent articles have described problems associated with the low stability of some TMS derivatives. This limits the use of GC-MS for metabolomic studies that need large sets of qualitative and quantitative analyses. The aim of this work is to determine the experimental conditions in which the stability of TMS derivatives could be improved. This would facilitate the analysis of the large-scale experimental designs needed in the metabolomics approach. For good repeatability, the sampling conditions and the storage temperature of samples during analysis were investigated. Multiple injections of one sample from one vial led to high variations while injection of one sample from different vials improved the analysis. However, before injection, some amino acid TMS derivatives were degraded during the storage of vials in the autosampler. Only 10% of the initial quantity of glutamine 3 TMS and glutamate 3 TMS and 66% of ?-alanine 2 TMS was detected 48h after derivatization. When stored at 4°C until injection, all TMS derivatives remained stable for 12h; at -20°C, they remained stable for 72h. From the integration of all these results, a detailed analytical procedure is thus proposed. It enables a robust quantification of polar metabolites, useful for further plant metabolomics studies using GC-MS. PMID:25237783

Quéro, Anthony; Jousse, Cyril; Lequart-Pillon, Michelle; Gontier, Eric; Guillot, Xavier; Courtois, Bernard; Courtois, Josiane; Pau-Roblot, Corinne

2014-11-01

259

Lipid acyl chain-dependent effects of sterols in Acholeplasma laidlawii membranes.  

PubMed Central

Acholeplasma laidlawii was grown with different fatty acids for membrane lipid synthesis (saturated straight- and branched-chain acids and mono- and di-unsaturated acids). The ability of 12 different sterols to affect cell growth, lipid head group composition, the order parameter of the acyl chains, and the phase equilibria of in vivo lipid mixtures was studied. The following two effects were observed with respect to cell growth: with a given acyl chain composition of the membrane lipids, growth was stimulated, unaffected, reduced, or completely inhibited (lysis), depending on the sterol structure; and the effect of a certain sterol depended on the acyl chain composition (most striking for epicoprostanol, cholest-4-en-3-one, and cholest-5-en-3-one, which stimulated growth with saturated acyl chains but caused lysis with unsaturated chains). The three lytic sterols were the only sterols that caused a marked decrease in the ratio between the major lipids monoglucosyldiglyceride and diglucosyldiglyceride and hence a decrease in bilayer stability when the membranes were enriched in saturated (palmitoyl) chains. With these chains correlations were found for several sterols between the glucolipid ratio and the order parameter of the acyl chains, as well as the lamellar-reversed hexagonal phase transition, in model systems. A shaft experiment revealed a marked decrease in the ratio of monoglucosyldiglyceride to diglucosyldiglyceride with the lytic sterols in unsaturated (oleoyl) membranes. The two cholestenes induced nonlamellar phases in in vivo mixtures of oleoyl A. laidlawii lipids. The order parameters of the oleoyl chains were almost unaffected by the sterols. Generally, the observed effects cannot be explained by an influence of the sterols on the gel-to-liquid crystalline phase transition. PMID:3027049

Rilfors, L; Wikander, G; Wieslander, A

1987-01-01

260

Enzymatic removal of free and conjugated sterols forming pitch deposits in environmentally sound bleaching of eucalypt paper pulp.  

PubMed

Free and conjugated sterols are among the main compounds responsible for pitch deposition in the manufacture of wood chemical pulps, making difficult the implementation of totally chlorine free bleaching (TCF) and closure of bleach plant circuits. In this work, the suitability of oxidative enzymes in efficiently removing sterols from eucalypt pulps is revealed. The enzymatic treatment was applied as an additional stage of an industrial-type TCF sequence for bleaching eucalypt kraft pulp. The pulp obtained after oxygen delignification was treated with a high-redox potential and thermostable fungal laccase using 1-hydroxybenzotriazole as an enzyme mediator. This pulp was further submitted to chelation and peroxide stages and compared with a control TCF pulp obtained using chemical reagents. The composition of the lipophilic extractives in the pulps and the corresponding liquids after the different stages was analyzed by gas chromatography and gas chromatography--mass spectrometry. Free sitosterol and sitosterol esters and glucosides, the major lipophilic compounds in eucalypt pulps, were completely removed during the laccase-mediator treatment. Only some intermediate products from sitosterol oxidation remained after the laccase stage, as well as in the final pulp. Pulp brightness was also improved due to the simultaneous removal of lignin by the laccase-mediator treatment. PMID:16749715

Gutiérrez, Ana; Del Rio, José C; Ibarra, David; Rencoret, Jorge; Romero, Javier; Speranza, Mariela; Camarero, Susana; Martínez, María Jesus; Martínez, Angel T

2006-05-15

261

Gas chromatography-mass spectrometry study of sterols from Pinus elliotti tissues.  

NASA Technical Reports Server (NTRS)

A comparative study of the sterol components of slash pine (Pinus elliotti) callus tissue cultures, seeds, and seedlings was carried out using GC-MS techniques. Cholesterol, desmosterol, campesterol, stigmasterol, sitosterol and cycloeucalenol were identified in all tissues while lophenol and 24-methylenelophenol were identified in only the seed and seedlings. 24-Ethylidenelophenol was detected in trace concentrations in only the seedlings. Sitosterol was the predominant sterol component, i.e., 80.8, 38.1 and 47.8% of the tissue culture, seed and seedling sterols, respectively.

Laseter, J. L.; Evans, R.; Weete, J. D.; Walkinshaw, C. H.

1973-01-01

262

Derivation of medicinal preparations from plants and development of medicinal-plant culture during the years of Soviet rule  

Microsoft Academic Search

At the beginning of the 30th year, a large portion of the procurement of wild medicinal stock and product\\/on of raw material from cultivated plants fell to the consumer cooperative and a special organization, the All-Union Society \\

G. T. Shul'gin; P. T. Kondratenko

1967-01-01

263

Heterologous production of plant-derived isoprenoid products in microbes and the application of metabolic engineering and synthetic biology.  

PubMed

The value associated with plant-derived products has spurred efforts to engineer new production routes. One such option is heterologous biosynthesis which requires reconstitution of a biosynthetic pathway in a host that provides both innate and developed cellular advantages relative to the native producer. This review will summarize success to date in heterologously producing plant-derived isoprenoid products when using hosts such as E. coli and yeast. The article will also address the significant challenges that face such efforts, the approaches that have been used to overcome obstacles, and the tools of metabolic engineering and synthetic biology being applied both in the course of establishing heterologous biosynthesis and optimizing final production metrics. PMID:24631884

Li, Yi; Pfeifer, Blaine A

2014-06-01

264

GLUCAN SYNTHASE-LIKE8 and STEROL METHYLTRANSFERASE2 Are Required for Ploidy Consistency of the Sexual Reproduction System in Arabidopsis[C][W][OA  

PubMed Central

In sexually reproducing plants, the meiocyte-producing archesporal cell lineage is maintained at the diploid state to consolidate the formation of haploid gametes. In search of molecular factors that regulate this ploidy consistency, we isolated an Arabidopsis thaliana mutant, called enlarged tetrad2 (et2), which produces tetraploid meiocytes through the stochastic occurrence of premeiotic endomitosis. Endomitotic polyploidization events were induced by alterations in cell wall formation, and similar cytokinetic defects were sporadically observed in other tissues, including cotyledons and leaves. ET2 encodes GLUCAN SYNTHASE-LIKE8 (GSL8), a callose synthase that mediates the deposition of callose at developing cell plates, root hairs, and plasmodesmata. Unlike other gsl8 mutants, in which defects in cell plate formation are seedling lethal, cytokinetic defects in et2 predominantly occur in flowers and have little effect on vegetative growth and development. Similarly, mutations in STEROL METHYLTRANSFERASE2 (SMT2), a major sterol biosynthesis enzyme, also lead to weak cytokinetic defects, primarily in the flowers. In addition, SMT2 allelic mutants also generate tetraploid meiocytes through the ectopic induction of premeiotic endomitosis. These observations demonstrate that appropriate callose and sterol biosynthesis are required for maintaining the ploidy level of the premeiotic germ lineage and that subtle defects in cytokinesis may lead to diploid gametes and polyploid offspring. PMID:23404886

De Storme, Nico; De Schrijver, Joachim; Van Criekinge, Wim; Wewer, Vera; Dormann, Peter; Geelen, Danny

2013-01-01

265

Rapid inactivation of Salmonella Enteritidis on shell eggs by plant-derived antimicrobials.  

PubMed

Salmonella Enteritidis is a common foodborne pathogen transmitted to humans largely by consumption of contaminated eggs. The external surface of eggs becomes contaminated with Salmonella Enteritidis from various sources on farms, the main sources being hens' droppings and contaminated litter. Therefore, effective egg surface disinfection is critical to reduce pathogens on eggs and potentially control egg-borne disease outbreaks. This study investigated the efficacy of GRAS (generally recognized as safe) status, plant-derived antimicrobials (PDA), namely trans-cinnamaldehyde (TC), carvacrol (CR), and eugenol (EUG), as an antimicrobial wash for rapidly killing Salmonella Enteritidis on shell eggs in the presence or absence of chicken droppings. White-shelled eggs inoculated with a 5-strain mixture of nalidixic acid (NA) resistant Salmonella Enteritidis (8.0 log cfu/mL) were washed in sterile deionized water containing each PDA (0.0, 0.25, 0.5, or 0.75%) or chlorine (200 mg/kg) at 32 or 42°C for 30 s, 3 min, or 5 min. Approximately 6.0 log cfu/mL of Salmonella Enteritidis was recovered from inoculated and unwashed eggs. The wash water control and chlorine control decreased Salmonella Enteritidis on eggs by only 2.0 log cfu/mL even after washing for 5 min. The PDA were highly effective in killing Salmonella Enteritidis on eggs compared with controls (P < 0.05). All treatments containing CR and EUG reduced Salmonella Enteritidis to undetectable levels as rapidly as within 30 s of washing, whereas TC (0.75%) completely inactivated Salmonella Enteritidis on eggs washed at 42°C for 30 s (P < 0.05). No Salmonella Enteritidis was detected in any PDA or chlorine wash solution; however, substantial pathogen populations (~4.0 log cfu/mL) survived in the antibacterial-free control wash water (P < 0.05). The CR and EUG were also able to eliminate Salmonella Enteritidis on eggs to undetectable levels in the presence of 3% chicken droppings at 32°C (P < 0.05). This study demonstrates that PDA could effectively be used as a wash treatment to reduce Salmonella Enteritidis on shell eggs. Sensory and quality studies of PDA-washed eggs need to be conducted before recommending their use. PMID:24235233

Upadhyaya, Indu; Upadhyay, Abhinav; Kollanoor-Johny, Anup; Baskaran, Sangeetha Ananda; Mooyottu, Shankumar; Darre, Michael J; Venkitanarayanan, Kumar

2013-12-01

266

Characterization of some new insect-derived acholeplasmas.  

PubMed

Further analysis of three sterol-nonrequiring Mollicutes (strains PS-1, TAC, and YJS) isolated from gut fluids of insects confirms their similarity to Acholeplasma. They are serologically distinct from acholeplasmas of vertebrates and several other sterol nonrequiring Mollicutes isolated from plant surfaces. The PS-1 strain had a DNA G + C content of 31 mol % and a genome size of 1,030 megadaltons (MDa). Optimum temperature is in the range of 23 to 30 C. Thirty-two new nonhelical Mollicutes isolated from a much wider range of insect hosts were examined for acholeplasmas. Twenty-five of the insect isolates were grown consistently in serum-free broth, with or without Tween 80 supplements. Two of the acholeplasmas were serologically related to Acholeplasma florum, 13 strains were serologically identical to the TAC isolate reported earlier, and 10 of the putative acholeplasmas could not be identified with current reference antisera. Seven of the new nonhelical insect isolates appeared to be sterol-requiring Mollicutes. One sterol-requiring isolate (ELCN-1) was recovered from the hemolymph of a firefly, and is the first report of nonhelical Mollicutes in the insect hemocoel. Two of the seven sterol-requiring Mollicutes, which were nonhelical in earlier passages in broth, later reverted to typically helical spiroplasmas. Confirmation of sterol-requiring, nonhelical Mollicutes in insects would provide an important ecological finding that insects constitute an important reservoir for both acholeplasmas and mycoplasmas. PMID:3667237

Tully, J G; Rose, D L; Whitcomb, R F; Hackett, K J; Clark, T B; Henegar, R B; Clark, E; Carle, P; Bove, J M

1987-06-01

267

High-sensitivity measurement of diverse vascular plant-derived biomarkers in high-altitude ice cores  

Microsoft Academic Search

Semi-volatile organic compounds derived from burned and fresh vascular plant sources and preserved in high-altitude ice fields were detected and identified through use of recently developed analytical tools. Specifically, stir bar sorptive extraction and thermal desorption coupled with gas chromatography\\/time-of-flight mass spectrometry allowed measurement of multiple biomarkers in small sample volumes (?30 ml). Among other compounds of interest, several diterpenoids,

Matthew C. Makou; Lonnie G. Thompson; Daniel B. Montluçon; Timothy I. Eglinton

2009-01-01

268

Plant Virus-Derived Small Interfering RNAs Originate Predominantly from Highly Structured Single-Stranded Viral RNAs  

Microsoft Academic Search

characterized by a sequence analysis of siRNAs from plants infected with Cymbidium ringspot tombusvirus (CymRSV). CymRSV siRNA sequences have a nonrandom distribution along the length of the viral genome, suggesting that there are hot spots for virus-derived siRNA generation. CymRSV siRNAs bound to the CymRSV p19 suppressor protein have the same asymmetry in strand polarity as the sequenced siRNAs and

Attila Molnar; Tibor Csorba; Lorant Lakatos; Eva Varallyay; Christophe Lacomme; Jozsef Burgyan

2005-01-01

269

Does plant-derived smoke affect seed germination in dominant woody species of the Mediterranean matorral of central Chile?  

Microsoft Academic Search

Studies performed in the fire-prone Mediterranean-type climate shrublands of Australia, California, and South Africa have shown that plant-derived smoke enhances seed germination in many species. Unlike other areas with similar climate, central Chile stands out for the absence of natural fires, suggesting that smoke may not be expected to promote germination. However, anthropogenic fires have been frequent since several millennia,

S. Gómez-González; A. Sierra-Almeida; L. A. Cavieres

2008-01-01

270

Dietary vegetable oil and wood derived plant stanol esters reduce atherosclerotic lesion size and severity in apoE*3Leiden transgenic mice  

Microsoft Academic Search

The hypolipidemic and anti-atherosclerotic effects of vegetable oil- and wood-based dietary plant stanol esters were compared in female apoE*3-Leiden transgenic mice at relevant plasma cholesterol levels. The plant stanol esters derived from vegetable oil (sitostanol 65.7%, campestanol 30.1%) had different contents of sitostanol and campestanol than the plant stanol esters derived from wood (sitostanol 87.6%, campestanol 9.5%) or from a

O. L. Volger; R. P. Mensink; J. Plat; G. Hornstra; L. M. Havekes; H. M. G. Princen

2001-01-01

271

Lamin B receptor (LBR) regulates the growth and maturation of myeloid progenitors via its sterol reductase domain: Implications for cholesterol biosynthesis in regulating myelopoiesis  

PubMed Central

Lamin B receptor (LBR) is a bifunctional nuclear membrane protein with N-terminal lamin B and chromatin binding domains plus a C-terminal sterol ?14 reductase domain. LBR expression increases during neutrophil differentiation and deficient expression disrupts neutrophil nuclear lobulation characteristic of Pelger-Huët anomaly. Thus LBR plays a critical role in regulating myeloid differentiation, but how the two functional domains of LBR support this role is currently unclear. We previously identified abnormal proliferation and deficient functional maturation of promyelocytes (EPRO cells) derived from EML-ic/ic cells, a myeloid model of ichthyosis (ic) bone marrow that lacks Lbr expression. Here we provide new evidence that cholesterol biosynthesis is important to myeloid cell growth and is supported by the sterol reductase domain of Lbr. Cholesterol biosynthesis inhibitors caused growth inhibition of EML cells that increased in EPRO cells, whereas cells lacking Lbr exhibited complete growth arrest at both stages. Lipid production increased during wild-type neutrophil maturation, but ic/ic cells exhibited deficient levels of lipid and cholesterol production. Ectopic expression of a full length Lbr in EML-ic/ic cells rescued both nuclear lobulation and growth arrest in cholesterol starvation conditions. Lipid production also was rescued, and a deficient respiratory burst was corrected. Expression of just the C-terminal sterol reductase domain of Lbr in ic/ic cells also improved each of these phenotypes. Our data support the conclusion that the sterol ?14 reductase domain of LBR plays a critical role in cholesterol biosynthesis, and that this process is essential to both myeloid cell growth and functional maturation. PMID:22140257

Subramanian, Gayathri; Chaudhury, Pulkit; Malu, Krishnakumar; Fowler, Samantha; Manmode, Rahul; Gotur, Deepali; Zwerger, Monika; Ryan, David; Roberti, Rita; Gaines, Peter

2011-01-01

272

Laboratory and field evaluations of chemical and plant-derived potential repellents against Culicoides biting midges in northern Spain.  

PubMed

The efficacy of 23 compounds in repelling Culicoides biting midges (Diptera: Ceratopogonidae), particularly Culicoides obsoletus (Meigen) females, was determined by means of a Y-tube olfactometer. The 10 most effective compounds were further evaluated in landing bioassays. The six most promising compounds (including chemical and plant-derived repellents) were evaluated at 10% and 25% concentrations in field assays using Centers for Disease Control (CDC) light traps. At least three compounds showed promising results against Culicoides biting midges with the methodologies used. Whereas olfactometer assays indicated DEET at 1?µg/µL to be the most effective repellent, filter paper landing bioassays showed plant-derived oils to be better. Light traps fitted with polyester mesh impregnated with a mixture of octanoic, decanoic and nonanoic fatty acids at 10% and 25% concentrations collected 2.2 and 3.6 times fewer midges than control traps and were as effective as DEET, which is presently considered the reference standard insect repellent. The best plant-derived product was lemon eucalyptus oil. Although these have been reported as safe potential repellents, the present results indicate DEET and the mixture of organic fatty acids to be superior and longer lasting. PMID:25079042

González, M; Venter, G J; López, S; Iturrondobeitia, J C; Goldarazena, A

2014-12-01

273

Comprehensive molecular characterization of tissue-culture-derived Hordeum marinum plants  

Microsoft Academic Search

Scuttelar calli of Hordeum marinum readily and efficiently regenerate functional plants. In order to assess genetic variability among the regenerants we employed multiple analytic tools, which included molecular and biochemical assays. Total DNA extract from regenerated plants was digested with at least two restriction enzymes and hybridized to four nuclear and six mitochondrial coding sequences, in addition to one nuclear

D. Shimron-Abarbanell; A. Breiman

1991-01-01

274

Field Evaluation of Mosquito Coils Derived from Plants against Night-Biting Mosquitoes in Thailand  

Microsoft Academic Search

Nine plants namely greater galangale (Alpinia galanga), fingerroot (Boesenbergia pandurata), turmeric (Curcuma longa), cardamom (Elettaria cardamomum), neem (Azadirachta indica), Siamese cassia (Cassia siamea), citronella grass (Cymbopogon nardus), eucalyptus (Eucalyptus citriodora) and Siam weed (Eupatorium odoratum) were studies for their efficacy in reducing human-mosquito contact when used in mosquito coils. Each plant material was prepared as 25% in each mosquito coil

Apiwat Tawatsin; Usavadee Thavara; Jakkrawarn Chompoosri

275

Prevention of bubonic and pneumonic plague using plant-derived vaccines  

Microsoft Academic Search

Yersinia pestis, the causative agent of bubonic and pneumonic plague, is an extremely virulent bacterium but there are currently no approved vaccines for protection against this organism. Plants represent an economical and safer alternative to fermentation-based expression systems for the production of therapeutic proteins. The recombinant plague vaccine candidates produced in plants are based on the two most immunogenic antigens

M. Lucrecia Alvarez; Guy A. Cardineau

2010-01-01

276

Plant regeneration and biochemical accumulation of hydroxybenzoic and hydroxycinnamic acid derivatives in Hypoxis hemerocallidea organ and callus cultures.  

PubMed

Micropropagation of Hypoxis hemerocallidea Fisch. and C.A. Mey was used as a model system to study the influence of cytokinins (CKs) on plant regeneration and biochemical accumulation of hydroxybenzoic and hydroxycinnamic acid derivatives in organ and callus cultures and their antioxidant activity. Fourteen free phenolic acids were detected using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) while antioxidant activity was evaluated using oxygen radical absorbance capacity (ORAC) and 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity. Cytokinins had a significant effect on the biochemical accumulation of hydroxybenzoic and hydroxycinnamic acid derivatives in H. hemerocallidea organ cultures. In particular, meta-topolin-treated organ cultures produced high concentrations of gallic, protocatechuic, gentisic, p-hydroxybenzoic, m-hydroxybenzoic, salicylic, chlorogenic and trans-cinnamic acids. The isoprenoid CK, N(6)-(2-isopentenyl)-adenine significantly increased the accumulation of hydroxycinnamic acid derivatives, namely, caffeic, p-coumaric, sinapic and ferulic acids. Cytokinin-treated organ cultures exhibited a significant increase in antioxidant activity, particularly in the ORAC model. In callus cultures, CKs decreased the concentrations of hydroxycinnamic acid derivatives and antioxidant activity when compared to the control. Overall, both CK type and concentration had a significant effect on plant regeneration, callus proliferation, biochemical accumulation of free phenolic acids and antioxidant activity of the resultant extracts. PMID:25219317

Moyo, Mack; Amoo, Stephen O; Aremu, Adeyemi O; Gruz, Ji?í; Subrtová, Michaela; Doležal, Karel; Van Staden, Johannes

2014-10-01

277

Effect of Sterols on the Permeability of Alcohol-Treated Red Beet Tissue 12  

PubMed Central

Alcohols and hydrogen peroxide altered the permeability of membranes of Beta vulgaris root cells. Generally alcohols increased the permeability of membranes without going through an induction period except methanol which required a 10- to 15-hour induction period. The membrane effect of methanol could be inhibited with CaCl2, cholesterol, ?-sitosterol, and stigmasterol. Cholesterol was the most effective inhibitor, followed by ?-sitosterol and stigmasterol; and at the same concentration, the sterols were more effective than CaCl2, the classic membrane stabilizer. Ergosterol increased the methanol-initiated betacyanin leakage. Since none of the tested sterols reversed the betacyanin efflux induced by hydrogen peroxide, the sterols do not apparently act as antioxidants. The results are explained in terms of sterol-phospholipid interaction, based on stereochemistry and charge distribution. PMID:16656796

Grunwald, C.

1968-01-01

278

Isolation of a biodegradable sterol-rich fraction from industrial wastes.  

PubMed

Several industrial waste materials were screened for their sterol content. The possibility of using these industrial by-products as sterol sources for the microbiological production of 4-androsten-3,17-dione (AD) and 1,4-androsta-diene-3,17-dione (ADD) was investigated. Two methods of obtaining the sterol fraction from wastes were developed. Sterol-rich (96-98%) fractions were isolated in a yield above 70%, from a tall-oil effluent of a paper pulp industry and from edible-oil deodorizates. These fractions were subsequently used as a substrate for microbial degradation by a Mycobacterium sp. strain and proved to be easily converted to AD and ADD. PMID:11991074

Dias, A C P; Fernandes, P; Cabral, J M S; Pinheiro, H M

2002-05-01

279

Azole Fungicides Affect Mammalian Steroidogenesis by Inhibiting Sterol 14?-Demethylase and Aromatase  

Microsoft Academic Search

Azole compounds play a key role as antifungals in agriculture and in human mycoses and as non- steroidal antiestrogens in the treatment of estrogen-responsive breast tumors in postmenopausal women. This broad use of azoles is based on their inhibition of certain pathways of steroidogenesis by high-affinity binding to the enzymes sterol 14?-demethylase and aromatase. Sterol 14?- demethylase is crucial for

Jürg A. Zarn; Beat J. Brüschweiler; Josef R. Schlatter

2002-01-01

280

An efficient diethyl ether-based soxhlet protocol to quantify faecal sterols from catchment waters  

Microsoft Academic Search

A study was conducted to evaluate the efficiency and reproducibility of a diethyl ether-based soxhlet extraction procedure for faecal sterols occurring from catchment waters. Water samples spiked with a mixture of faecal sterols were filtered and analytes were extracted using the diethyl ether-based soxhlet method and the Bligh and Dyer chloroform extraction process. For diethyl ether-based soxhlet extraction procedure, solvent

Vikas Kumar G. Shah; Hugh Dunstan; Warren Taylor

2006-01-01

281

ATP binding cassette transporter G1 (ABCG1) is an intracellular sterol transporter  

PubMed Central

Four members of the mammalian ATP binding cassette (ABC) transporter G subfamily are thought to be involved in transmembrane (TM) transport of sterols. The residues responsible for this transport are unknown. The mechanism of action of ABCG1 is controversial and it has been proposed to act at the plasma membrane to facilitate the efflux of cellular sterols to exogenous high-density lipoprotein (HDL). Here we show that ABCG1 function is dependent on localization to intracellular endosomes. Importantly, localization to the endosome pathway distinguishes ABCG1 and/or ABCG4 from all other mammalian members of this superfamily, including other sterol transporters. We have identified critical residues within the TM domains of ABCG1 that are both essential for sterol transport and conserved in some other members of the ABCG subfamily and/or the insulin-induced gene 2 (INSIG-2). Our conclusions are based on studies in which (i) biotinylation of peritoneal macrophages showed that endogenous ABCG1 is intracellular and undetectable at the cell surface, (ii) a chimeric protein containing the TM of ABCG1 and the cytoplasmic domains of the nonsterol transporter ABCG2 is both targeted to endosomes and functional, and (iii) ABCG1 colocalizes with multiple proteins that mark late endosomes and recycling endosomes. Mutagenesis studies identify critical residues in the TM domains that are important for ABCG1 to alter sterol efflux, induce sterol regulatory element binding protein-2 (SREBP-2) processing, and selectively attenuate the oxysterol-mediated repression of SREBP-2 processing. Our data demonstrate that ABCG1 is an intracellular sterol transporter that localizes to endocytic vesicles to facilitate the redistribution of specific intracellular sterols away from the endoplasmic reticulum (ER). PMID:22095132

Tarling, Elizabeth J.; Edwards, Peter A.

2011-01-01

282

Sterol Regulatory Element Binding Protein Is a Principal Regulator of Anaerobic Gene Expression in Fission Yeast  

Microsoft Academic Search

Fission yeast sterol regulatory element binding protein (SREBP), called Sre1p, functions in an oxygen- sensing pathway to allow adaptation to fluctuating oxygen concentrations. The Sre1p-Scp1p complex responds to oxygen-dependent sterol synthesis as an indirect measure of oxygen availability. To examine the role of Sre1p in anaerobic gene expression in Schizosaccharomyces pombe, we performed transcriptional profiling experi- ments after a shift

Bridget L. Todd; Emerson V. Stewart; John S. Burg; Adam L. Hughes; Peter J. Espenshade

2006-01-01

283

Azole fungicides affect mammalian steroidogenesis by inhibiting sterol 14 alpha-demethylase and aromatase.  

PubMed

Azole compounds play a key role as antifungals in agriculture and in human mycoses and as non-steroidal antiestrogens in the treatment of estrogen-responsive breast tumors in postmenopausal women. This broad use of azoles is based on their inhibition of certain pathways of steroidogenesis by high-affinity binding to the enzymes sterol 14-alpha-demethylase and aromatase. Sterol 14-alpha-demethylase is crucial for the production of meiosis-activating sterols, which recently were shown to modulate germ cell development in both sexes of mammals. Aromatase is responsible for the physiologic balance of androgens and estrogens. At high doses, azole fungicides and other azole compounds affect reproductive organs, fertility, and development in several species. These effects may be explained by inhibition of sterol 14-alpha-demethylase and/or aromatase. In fact, several azole compounds were shown to inhibit these enzymes in vitro, and there is also strong evidence for inhibiting activity in vivo. Furthermore, the specificity of the enzyme inhibition of several of these compounds is poor, both with respect to fungal versus nonfungal sterol 14-alpha-demethylases and versus other P450 enzymes including aromatase. To our knowledge, this is the first review on sterol 14-alpha-demethylase and aromatase as common targets of azole compounds and the consequence for steroidogenesis. We conclude that many azole compounds developed as inhibitors of fungal sterol 14-alpha-demethylase are inhibitors also of mammalian sterol 14-alpha-demethylase and mammalian aromatase with unknown potencies. For human health risk assessment, data on comparative potencies of azole fungicides to fungal and human enzymes are needed. PMID:12611652

Zarn, Jürg A; Brüschweiler, Beat J; Schlatter, Josef R

2003-03-01

284

Generation and Analysis of Novel Plant-Derived Antibody-Based Therapeutic Molecules against West Nile Virus  

PubMed Central

Previously, our group engineered a plant-derived monoclonal antibody (MAb) (pHu-E16) that efficiently treated West Nile virus (WNV) infection in mice. In this study, we developed several pHu-E16 variants to improve its efficacy. These variants included a single-chain variable fragment (scFv) of pHu-E16 fused to the heavy chain (HC) constant domains (CH1-3) of human IgG (pHu-E16scFv-CH1-3) and a tetravalent molecule (Tetra pHu-E16) assembled from pHu-E16scFv-CH1-3 with a second pHu-E16scFv fused to the light chain (LC) constant region. pHu-E16scFv-CH1-3 and Tetra pHu-E16 were efficiently expressed and assembled in plants. To assess the impact of differences in N-linked glycosylation on pHu-E16 variant assembly and function, we expressed additional pHu-E16 variants with various combinations of HC and LC components. Our study revealed that proper pairing of HC and LC was essential for the complete N-glycan processing of antibodies in both plant and animal cells. Associated with their distinct N-glycoforms, pHu-E16, pHu-E16scFv-CH1-3 and Tetra pHu-E16 exhibited differential binding to C1q and specific Fc? receptors (Fc?R). Notably, none of the plant-derived Hu-E16 variants showed antibody-dependent enhancement (ADE) activity in CD32A+ human cells, suggesting the potential of plant-produced antibodies to minimize the adverse effect of ADE. Importantly, all plant-derived MAb variants exhibited at least equivalent in vitro neutralization and in vivo protection in mice compared to mammalian cell-produced Hu-E16. This study demonstrates the capacity of plants to express and assemble a large, complex and functional IgG-like tetravalent mAb variant and also provides insight into the relationship between MAb N-glycosylation, Fc?R and C1q binding, and ADE. These new insights may allow the development of safer and cost effective MAb-based therapeutics for flaviviruses, and possibly other pathogens. PMID:24675995

He, Junyun; Lai, Huafang; Engle, Michael; Gorlatov, Sergey; Gruber, Clemens; Steinkellner, Herta; Diamond, Michael S.; Chen, Qiang

2014-01-01

285

Synthesis of Plant Auxin Derivatives and Their Effects on Ceratopteris Richardii  

ERIC Educational Resources Information Center

Bioassays are commonly used to test the biological activity of chemicals and other exercises are presented in which students synthesize plant hormones. Lab exercise is conducted using commercially available auxins and auxin regulating compounds.

Stilts, Corey E.; Fisher, Roxanne

2007-01-01

286

Characterization of plant-derived lactococci on the basis of their volatile compounds profile when grown in milk.  

PubMed

A total of twelve strains of lactococci were isolated from grass and vegetables (baby corn and fresh green peas). Ten of the isolates were classified as Lactococcus lactis subsp. lactis and two as Lactococcus lactis subsp. cremoris based on 16S rDNA sequencing. Most of the plant-derived strains were capable of metabolising a wide range of carbohydrates in that they fermented D-mannitol, amygdalin, potassium gluconate, l-arabinose, d-xylose, sucrose and gentibiose. None of the dairy control strains (i.e. L. lactis subsp. cremoris HP, L. lactis subsp. lactis IL1403 and Lactococcus lactis 303) were able to utilize any of these carbohydrates. The technological potential of the isolates as flavour-producing lactococci was evaluated by analysing their growth in milk and their ability to produce volatile compounds using solid phase micro-extraction of the headspace coupled to gas chromatography-mass spectrometry (SPME GC-MS). Principal component analysis (PCA) of the volatile compounds clearly separated the dairy strains from the plant derived strains, with higher levels of most flavour rich compounds. The flavour compounds produced by the plant isolates among others included; fatty acids such as 2- and 3-methylbutanoic acids, and hexanoic acid, several esters (e.g. butyl acetate and ethyl butanoate) and ketones (e.g. acetoin, diacetyl and 2-heptanone), all of which have been associated with desirable and more mature flavours in cheese. As such the production of a larger number of volatile compounds is a distinguishing feature of plant-derived lactococci and might be a desirable trait for the production of dairy products with enhanced flavour and/or aroma. PMID:24361833

Alemayehu, Debebe; Hannon, John A; McAuliffe, Olivia; Ross, R Paul

2014-02-17

287

Quantitation of fatty acids, sterols, and tocopherols in turpentine (Pistacia terebinthus Chia) growing wild in Turkey.  

PubMed

The chemical composition (fatty acids, tocopherols, and sterols) of the oil from 14 samples of turpentine (Pistacia terebinthus L.) fruits is presented in this study. The oil content of the samples varied in a relatively small range between 38.4 g/100 g and 45.1 g/100 g. The dominating fatty acid of the oil is oleic acid, which accounted for 43.0 to 51.3% of the total fatty acids. The total content of vitamin E active compounds in the oils ranged between 396.8 and 517.7 mg/kg. The predominant isomers were alpha- and gamma-tocopherol, with approximate equal amounts between about 110 and 150 mg/kg. The seed oil of P. terebinthus also contained different tocotrienols, with gamma-tocotrienol as the dominate compound of this group, which amounted to between 79 and 114 mg/kg. The total content of sterols of the oils was determined to be between 1341.3 and 1802.5 mg/kg, with beta-sitosterol as the predominent sterol that accounted for more than 80% of the total amount of sterols. Other sterols in noteworthy amounts were campesterol, Delta5-avenasterol, and stigmasterol, which came to about 3-5% of the total sterols. PMID:17002437

Matthäus, Bertrand; Ozcan, Mehmet Musa

2006-10-01

288

Fluconazole Binding and Sterol Demethylation in Three CYP51 Isoforms Indicate Differences in Active Site Topology  

SciTech Connect

14{alpha}-Demethylase (CYP51) is a key enzyme in all sterol biosynthetic pathways (animals, fungi, plants, protists, and some bacteria), catalyzing the removal of the C-14 methyl group following cyclization of squalene. Based on mutations found in CYP51 genes from Candida albicans azole-resistant isolates obtained after fluconazole treatment of fungal infections, and using site-directed mutagenesis, we have found that fluconazole binding and substrate metabolism vary among three different CYP51 isoforms: human, fungal, and mycobacterial. In C. albicans, the Y132H mutant from isolates shows no effect on fluconazole binding, whereas the F145L mutant results in a 5-fold increase in its IC{sub 50} for fluconazole, suggesting that F145 (conserved only in fungal 14{alpha}-demethylases) interacts with this azole. In C. albicans, F145L accounts, in part, for the difference in fluconazole sensitivity reported between mammals and fungi, providing a basis for treatment of fungal infections. The C. albicans Y132H and human Y145H CYP51 mutants show essentially no effect on substrate metabolism, but the Mycobacterium tuberculosis F89H CYP51 mutant loses both its substrate binding and metabolism. Because these three residues align in the three isoforms, the results indicate that their active sites contain important structural differences, and further emphasize that fluconazole and substrate binding are uncoupled properties.

Bellamine, A.; Lepesheva, Galina I.; Waterman, Mike (Vanderbilt)

2010-11-16

289

Bayesian reconstruction of ancestral expression of the LEA gene families reveals propagule-derived desiccation tolerance in resurrection plants.  

PubMed

Desiccation tolerance is a complex trait that is broadly but infrequently present throughout the evolutionary tree of life. Desiccation tolerance has played a significant role in land plant evolution, in both the vegetative and reproductive life history stages. In the land plants, the late embryogenesis abundant (LEA) gene families are involved in both abiotic stress tolerance and the development of reproductive propagules. They are also a major component of vegetative desiccation tolerance. Phylogenies were estimated for four families of LEA genes from Arabidopsis, Physcomitrella, and the desiccation tolerant plants Tortula ruralis, Craterostigma plantagineum, and Xerophyta humilis. Microarray expression data from Arabidopsis and a subset of the Physcomitrella LEAs were used to estimate ancestral expression patterns in the LEA families and to evaluate alternative hypotheses for the origins of vegetative desiccation tolerance in the flowering plants. The results contradict the idea that vegetative desiccation tolerance in the resurrection angiosperms Craterostigma and Xerophyta arose through the co-option of genes exclusively related to stress tolerance, and support the propagule-derived origin of vegetative desiccation tolerance in the resurrection plants. PMID:21632376

Fisher, Kirsten M

2008-04-01

290

Plant-Derived Anti-Inflammatory Compounds: Hopes and Disappointments regarding the Translation of Preclinical Knowledge into Clinical Progress  

PubMed Central

Many diseases have been described to be associated with inflammatory processes. The currently available anti-inflammatory drug therapy is often not successful or causes intolerable side effects. Thus, new anti-inflammatory substances are still urgently needed. Plants were the first source of remedies in the history of mankind. Since their chemical characterization in the 19th century, herbal bioactive compounds have fueled drug development. Also, nowadays, new plant-derived agents continuously enrich our drug arsenal (e.g., vincristine, galantamine, and artemisinin). The number of new, pharmacologically active herbal ingredients, in particular that of anti-inflammatory compounds, rises continuously. The major obstacle in this field is the translation of preclinical knowledge into evidence-based clinical progress. Human trials of good quality are often missing or, when available, are frequently not suitable to really prove a therapeutical value. This minireview will summarize the current situation of 6 very prominent plant-derived anti-inflammatory compounds: curcumin, colchicine, resveratrol, capsaicin, epigallocatechin-3-gallate (EGCG), and quercetin. We will highlight their clinical potential and/or pinpoint an overestimation. Moreover, we will sum up the planned trials in order to provide insights into the inflammatory disorders that are hypothesized to be beneficially influenced by the compound. PMID:24987194

Furst, Robert; Zundorf, Ilse

2014-01-01

291

Plant growth in Arabidopsis is assisted by compost soil-derived microbial communities  

PubMed Central

Plants in natural and agricultural environments are continuously exposed to a plethora of diverse microorganisms resulting in microbial colonization of roots and the rhizosphere. This process is believed to be accompanied by an intricate network of ongoing simultaneous interactions. In this study, we examined Arabidopsis thaliana roots and shoots in the presence or absence of whole microbial communities extracted from compost soil. The results show a clear growth promoting effect on Arabidopsis shoots in the presence of soil microbes compared to plants grown in microbe-free soil under otherwise identical conditions. Element analyses showed that iron uptake was facilitated by these mixed microbial communities which also led to transcriptional downregulation of genes required for iron transport. In addition, soil microbial communities suppressed the expression of marker genes involved in nitrogen uptake, oxidative stress/redox signaling, and salicylic acid (SA)-mediated plant defense while upregulating jasmonate (JA) signaling, cell wall organization/biosynthesis and photosynthesis. Multi-species analyses such as simultaneous transcriptional profiling of plants and their interacting microorganisms (metatranscriptomics) coupled to metagenomics may further increase our understanding of the intricate networks underlying plant-microbe interactions. PMID:23847639

Carvalhais, Lilia C.; Muzzi, Frederico; Tan, Chin-Hong; Hsien-Choo, Jin; Schenk, Peer M.

2013-01-01

292

Active root-inhabiting microbes identified by rapid incorporation of plant-derived carbon into RNA  

PubMed Central

Plant roots harbor a large diversity of microorganisms that have an essential role in ecosystem functioning. To better understand the level of intimacy of root-inhabiting microbes such as arbuscular mycorrhizal fungi and bacteria, we provided 13CO2 to plants at atmospheric concentration during a 5-h pulse. We expected microbes dependent on a carbon flux from their host plant to become rapidly labeled. We showed that a wide variety of microbes occurred in roots, mostly previously unknown. Strikingly, the greatest part of this unsuspected diversity corresponded to active primary consumers. We found 17 bacterial phylotypes co-occurring within roots of a single plant, including five potentially new phylotypes. Fourteen phylotypes were heavily labeled with the 13C. Eight were phylogenetically close to Burkholderiales, which encompass known symbionts; the others were potentially new bacterial root symbionts. By analyzing unlabeled and 13C-enriched RNAs, we demonstrated differential activity in C consumption among these root-inhabiting microbes. Arbuscular mycorrhizal fungal RNAs were heavily labeled, confirming the high carbon flux from the plant to the fungal compartment, but some of the fungi present appeared to be much more active than others. The results presented here reveal the possibility of uncharacterized root symbioses. PMID:17939995

Vandenkoornhuyse, Philippe; Mahe, Stephane; Ineson, Philip; Staddon, Phil; Ostle, Nick; Cliquet, Jean-Bernard; Francez, Andre-Jean; Fitter, Alastair H.; Young, J. Peter W.

2007-01-01

293

Plant-Derived Natural Products as Sources of Anti-Quorum Sensing Compounds  

PubMed Central

Quorum sensing is a system of stimuli and responses in relation to bacterial cell population density that regulates gene expression, including virulence determinants. Consequently, quorum sensing has been an attractive target for the development of novel anti-infective measures that do not rely on the use of antibiotics. Anti-quorum sensing has been a promising strategy to combat bacterial infections as it is unlikely to develop multidrug resistant pathogens since it does not impose any selection pressure. A number of anti-quorum sensing approaches have been documented and plant-based natural products have been extensively studied in this context. Plant matter is one of the major sources of chemicals in use today in various industries, ranging from the pharmaceutical, cosmetic, and food biotechnology to the textile industries. Just like animals and humans, plants are constantly exposed to bacterial infections, it is therefore logical to expect that plants have developed sophisticated of chemical mechanisms to combat pathogens. In this review, we have surveyed the various types of plant-based natural products that exhibit anti-quorum sensing properties and their anti-quorum sensing mechanisms. PMID:23669710

Koh, Chong-Lek; Sam, Choon-Kook; Yin, Wai-Fong; Tan, Li Ying; Krishnan, Thiba; Chong, Yee Meng; Chan, Kok-Gan

2013-01-01

294

TOXICOLOGICAL EVALUATION OF REALISTIC EMISSIONS OF SOURCE AEROSOLS (TERESA): APPLICATION TO POWER PLANT-DERIVED PM2.5  

SciTech Connect

TERESA (Toxicological Evaluation of Realistic Emissions of Source Aerosols) involves exposing laboratory rats to realistic coal-fired power plant and mobile source emissions to help determine the relative toxicity of these PM sources. There are three coal-fired power plants in the TERESA program; this report describes the results of fieldwork conducted at the first plant, located in the Upper Midwest. The project was technically challenging by virtue of its novel design and requirement for the development of new techniques. By examining aged, atmospherically transformed aerosol derived from power plant stack emissions, we were able to evaluate the toxicity of PM derived from coal combustion in a manner that more accurately reflects the exposure of concern than existing methodologies. TERESA also involves assessment of actual plant emissions in a field setting--an important strength since it reduces the question of representativeness of emissions. A sampling system was developed and assembled to draw emissions from the stack; stack sampling conducted according to standard EPA protocol suggested that the sampled emissions are representative of those exiting the stack into the atmosphere. Two mobile laboratories were then outfitted for the study: (1) a chemical laboratory in which the atmospheric aging was conducted and which housed the bulk of the analytical equipment; and (2) a toxicological laboratory, which contained animal caging and the exposure apparatus. Animal exposures were carried out from May-November 2004 to a number of simulated atmospheric scenarios. Toxicological endpoints included (1) pulmonary function and breathing pattern; (2) bronchoalveolar lavage fluid cytological and biochemical analyses; (3) blood cytological analyses; (4) in vivo oxidative stress in heart and lung tissue; and (5) heart and lung histopathology. Results indicated no differences between exposed and control animals in any of the endpoints examined. Exposure concentrations for the scenarios utilizing secondary particles (oxidized emissions) ranged from 70-256 {micro}g/m{sup 3}, and some of the atmospheres contained high acidity levels (up to 49 {micro}g/m{sup 3} equivalent of sulfuric acid). However, caution must be used in generalizing these results to other power plants utilizing different coal types and with different plant configurations, as the emissions may vary based on these factors.

Annette Rohr

2006-03-01

295

Screening of anti- Helicobacter pylori herbs deriving from Taiwanese folk medicinal plants  

Microsoft Academic Search

In this study, extracts from 50 Taiwanese folk medicinal plants were examined and screened for anti-Helicobacter pylori activity. Ninety-five percent ethanol was used for herbal extraction. Paederia scandens (Lour.) Merr. (PSM), Plumbago zeylanica L. (PZL), Anisomeles indica (L.) O. Kuntze (AIOK), Bombax malabaricum DC. (BMDC) and Alpinia speciosa (J. C. Wendl.) K. Schum. (ASKS) and Bombax malabaricum DC. (BMDC) all

Yuan-Chuen Wang; Tung-Liang Huang

2005-01-01

296

The influence of humic acids derived from earthworm-processed organic wastes on plant growth  

Microsoft Academic Search

Some effects of humic acids, formed during the breakdown of organic wastes by earthworms (vermicomposting), on plant growth were evaluated. In the first experiment, humic acids were extracted from pig manure vermicompost using the classic alkali\\/acid fractionation procedure and mixed with a soilless container medium (Metro-Mix 360), to provide a range of 0, 50, 100, 150, 200, 250, 500, 1000,

R. M. Atiyeh; S. Lee; C. A. Edwards; N. Q. Arancon; J. D. Metzger

2002-01-01

297

The methylation status of DNA derived from potato plants recovered from slow growth  

Microsoft Academic Search

The in vitro conservation of potato using tissue culture medium supplemented with the growth retardant mannitol causes morphological changes in the propagated material. These culture conditions seem to have an affect on the DNA extracted from the regenerated plants, when it is digested by the methylation sensitive restriction enzymes Hpa II\\/Msp I and Eco RII\\/Bst NI, compared to the control

Keith Harding

1994-01-01

298

Aromatic plant-derived essential oil: An alternative larvicide for mosquito control  

Microsoft Academic Search

Five aromatic plants, Carum carvi (caraway), Apium graveolens (celery), Foeniculum vulgare (fennel), Zanthoxylum limonella (mullilam) and Curcuma zedoaria (zedoary) were selected for investigating larvicidal potential against mosquito vectors. Two laboratory-reared mosquito species, Anopheles dirus, the major malaria vector in Thailand, and Aedes aegypti, the main vector of dengue and dengue hemorrhagic fever in urban areas, were used. All of the

B. Pitasawat; D. Champakaew; W. Choochote; A. Jitpakdi; U. Chaithong; D. Kanjanapothi; E. Rattanachanpichai; P. Tippawangkosol; D. Riyong; B. Tuetun; D. Chaiyasit

2007-01-01

299

Plant-derived phenolic compounds impair the remediation of acid mine drainage using treatment wetlands  

Microsoft Academic Search

The use of wetlands to remediate acid mine drainage has expanded rapidly since the realisation that acid coal mine drainage running into natural sphagnum wetlands undergoes an increase in pH and a precipitation of metals. However, our study suggests that the inclusion of plants in the acid mine drainage treatment system may be questionable, due to inefficiencies caused by exudation

Rachel A. White; Chris Freeman; Hojeong Kang

2011-01-01

300

Sex and ploidy of anther culture derived papaya ( Carica papaya L.) plants  

Microsoft Academic Search

Summary  To improve the efficiency of papaya anther culture, we investigated (1) hormonal medium conditions for inducing haploids or dihaploids; (2) identified the sex of established plantlets using a sex-specific DNA molecular marker and (3) estimated their ploidy by flow cytometry analysis of DNA content. Anthers with a mixture of uninucleate, mitotic, and binucleate microspores were collected from a male plant,

Fredah K. Rimberia; Shinichi Adaniya; Takeomi Etoh; Yukio Ishimine

2006-01-01

301

Derivatives of the Antimicrobial Peptide BP100 for Expression in Plant Systems  

PubMed Central

Production of antimicrobial peptides in plants constitutes an approach for obtaining them in high amounts. However, their heterologous expression in a practical and efficient manner demands some structural requirements such as a minimum size, the incorporation of retention signals to assure their accumulation in specific tissues, and the presence of protease cleavage amino acids and of target sequences to facilitate peptide detection. Since any sequence modification may influence the biological activity, peptides that will be obtained from the expression must be screened prior to the synthesis of the genes for plant transformation. We report herein a strategy for the modification of the antimicrobial undecapeptide BP100 that allowed the identification of analogues that can be expressed in plants and exhibit optimum biological properties. We prepared 40 analogues obtained by incorporating repeated units of the antimicrobial undecapeptide, fragments of natural peptides, one or two AGPA hinges, a Gly or Ser residue at the N-terminus, and a KDEL fragment and/or the epitope tag54 at the C-terminus. Their antimicrobial, hemolytic and phytotoxic activities, and protease susceptibility were evaluated. Best sequences contained a magainin fragment linked to the antimicrobial undecapeptide through an AGPA hinge. Moreover, since the presence of a KDEL unit or of tag54 did not influence significantly the biological activity, these moieties can be introduced when designing compounds to be retained in the endoplasmic reticulum and detected using a complementary epitope. These findings may contribute to the design of peptides to be expressed in plants. PMID:24376887

Badosa, Esther; Moiset, Gemma; Montesinos, Laura; Talleda, Montserrat; Bardaji, Eduard; Feliu, Lidia; Planas, Marta; Montesinos, Emilio

2013-01-01

302

INFLUENCE OF TWO PLANT EXTRACTS DERIVED FROM THYME AND CINNAMON ON BROILER PERFORMANCE  

Microsoft Academic Search

This study was conducted to explore the use of essential oil (EO) in broiler nutrition as a natural growth promoter. Different levels of EO derived from thyme and cinnamon were added to a standard diet to determine its effects on feed intake, live weight gain, feed conversion ratio and blood constituents. Three hundred day-old broiler chicks (Arbor-Acres) were divided into

G. A. M. AL-KASSIE

2009-01-01

303

Design of green concrete made of plant-derived aggregates and a pumice–lime binder  

Microsoft Academic Search

The use of particles from agricultural lignocellulosic resources in concrete gives it desirable environmental and multiphysics qualities. In this study, parallels are drawn between particles derived from hemp and sunflower stems, in terms of their morphological and physical properties. A pumice–lime binder is proposed as an alternative to the traditional cement or lime based solutions for both environmentally friendly and

V. Nozahic; S. Amziane; G. Torrent; K. Saïdi; H. De Baynast

304

The Strigolactone Germination Stimulants of the Plant-Parasitic Striga and Orobanche spp. Are Derived from the Carotenoid Pathway1  

PubMed Central

The seeds of parasitic plants of the genera Striga and Orobanche will only germinate after induction by a chemical signal exuded from the roots of their host. Up to now, several of these germination stimulants have been isolated and identified in the root exudates of a series of host plants of both Orobanche and Striga spp. In most cases, the compounds were shown to be isoprenoid and belong to one chemical class, collectively called the strigolactones, and suggested by many authors to be sesquiterpene lactones. However, this classification was never proven; hence, the biosynthetic pathways of the germination stimulants are unknown. We have used carotenoid mutants of maize (Zea mays) and inhibitors of isoprenoid pathways on maize, cowpea (Vigna unguiculata), and sorghum (Sorghum bicolor) and assessed the effects on the root exudate-induced germination of Striga hermonthica and Orobanche crenata. Here, we show that for these three host and two parasitic plant species, the strigolactone germination stimulants are derived from the carotenoid pathway. Furthermore, we hypothesize how the germination stimulants are formed. We also discuss this finding as an explanation for some phenomena that have been observed for the host-parasitic plant interaction, such as the effect of mycorrhiza on S. hermonthica infestation. PMID:16183851

Matusova, Radoslava; Rani, Kumkum; Verstappen, Francel W.A.; Franssen, Maurice C.R.; Beale, Michael H.; Bouwmeester, Harro J.

2005-01-01

305

Structure-activity relationship study of the plant-derived decapeptide OSIP108 inhibiting Candida albicans biofilm formation.  

PubMed

We performed a structure-activity relationship study of the antibiofilm plant-derived decapeptide OSIP108. Introduction of positively charged amino acids R, H, and K resulted in an up-to-5-fold-increased antibiofilm activity against Candida albicans compared to native OSIP108, whereas replacement of R9 resulted in complete abolishment of its antibiofilm activity. By combining the most promising amino acid substitutions, we found that the double-substituted OSIP108 analogue Q6R/G7K had an 8-fold-increased antibiofilm activity. PMID:24913176

Delattin, Nicolas; De Brucker, Katrijn; Craik, David J; Cheneval, Olivier; De Coninck, Barbara; Cammue, Bruno P A; Thevissen, Karin

2014-08-01

306

Global Analyses of Small Interfering RNAs Derived from Bamboo mosaic virus and Its Associated Satellite RNAs in Different Plants  

Microsoft Academic Search

BackgroundSatellite RNAs (satRNAs), virus parasites, are exclusively associated with plant virus infection and have attracted much interest over the last 3 decades. Upon virus infection, virus-specific small interfering RNAs (vsiRNAs) are produced by dicer-like (DCL) endoribonucleases for anti-viral defense. The composition of vsiRNAs has been studied extensively; however, studies of satRNA-derived siRNAs (satsiRNAs) or siRNA profiles after satRNA co-infection are

Kuan-Yu Lin; Chi-Ping Cheng; Bill Chia-Han Chang; Wei-Chi Wang; Ying-Wen Huang; Yun-Shien Lee; Hsien-Da Huang; Yau-Heiu Hsu; Na-Sheng Lin; Baohong Zhang

2010-01-01

307

High frequency plant regeneration from zygotic-embryo-derived embryogenic cell suspension cultures of watershield ( Brasenia schreberi )  

Microsoft Academic Search

An improved protocol for high frequency plant regeneration via somatic embryogenesis from zygotic embryo-derived cell suspension\\u000a cultures of watershield (Brasenia schreberi) was developed. Zygotic embryos formed pale-yellow globular structures and white friable callus at a frequency of 80% when\\u000a cultured on half-strength MS medium supplemented with 0.3 mg l?1 2,4-D. However, the frequency of formation of pale-yellow globular structures and white friable

Myung Jin Oh; Hye Ryun Na; Hong-Keun Choi; Jang Ryol Liu; Suk Weon Kim

2008-01-01

308

Characterization of Small Interfering RNAs Derived from Sugarcane Mosaic Virus in Infected Maize Plants by Deep Sequencing  

PubMed Central

RNA silencing is a conserved surveillance mechanism against viruses in plants. It is mediated by Dicer-like (DCL) proteins producing small interfering RNAs (siRNAs), which guide specific Argonaute (AGO)-containing complexes to inactivate viral genomes and may promote the silencing of host mRNAs. In this study, we obtained the profile of virus-derived siRNAs (vsiRNAs) from Sugarcane mosaic virus (SCMV) in infected maize (Zea mays L.) plants by deep sequencing. Our data showed that vsiRNAs which derived almost equally from sense and antisense SCMV RNA strands accumulated preferentially as 21- and 22-nucleotide (nt) species and had an adenosine bias at the 5?-terminus. The single-nucleotide resolution maps revealed that vsiRNAs were almost continuously but heterogeneously distributed throughout the SCMV genome and the hotspots of sense and antisense strands were mainly distributed in the HC-Pro coding region. Moreover, dozens of host transcripts targeted by vsiRNAs were predicted, several of which encode putative proteins involved in ribosome biogenesis and in biotic and abiotic stresses. We also found that ZmDCL2 mRNAs were up-regulated in SCMV-infected maize plants, which may be the cause of abundant 22-nt vsiRNAs production. However, ZmDCL4 mRNAs were down-regulated slightly regardless of the most abundant 21-nt vsiRNAs. Our results also showed that SCMV infection induced the accumulation of AGO2 mRNAs, which may indicate a role for AGO2 in antiviral defense. To our knowledge, this is the first report on vsiRNAs in maize plants. PMID:24819114

Xia, Zihao; Peng, Jun; Li, Yongqiang; Chen, Ling; Li, Shuai; Zhou, Tao; Fan, Zaifeng

2014-01-01

309

TOXICOLOGICAL EVALUATION OF REALISTIC EMISSIONS OF SOURCE AEROSOLS (TERESA): APPLICATION TO POWER PLANT-DERIVED PM2.5  

SciTech Connect

Determining the health impacts of different sources and components of fine particulate matter (PM2.5) is an important scientific goal, because PM is a complex mixture of both inorganic and organic constituents that likely differ in their potential to cause adverse health outcomes. The TERESA (Toxicological Evaluation of Realistic Emissions of Source Aerosols) study focused on two PM sources - coal-fired power plants and mobile sources - and sought to investigate the toxicological effects of exposure to realistic emissions from these sources. The DOE-EPRI Cooperative Agreement covered the performance and analysis of field experiments at three power plants. The mobile source component consisted of experiments conducted at a traffic tunnel in Boston; these activities were funded through the Harvard-EPA Particulate Matter Research Center and will be reported separately in the peer-reviewed literature. TERESA attempted to delineate health effects of primary particles, secondary (aged) particles, and mixtures of these with common atmospheric constituents. The study involved withdrawal of emissions directly from power plant stacks, followed by aging and atmospheric transformation of emissions in a mobile laboratory in a manner that simulated downwind power plant plume processing. Secondary organic aerosol (SOA) derived from the biogenic volatile organic compound {alpha}-pinene was added in some experiments, and in others ammonia was added to neutralize strong acidity. Specifically, four scenarios were studied at each plant: primary particles (P); secondary (oxidized) particles (PO); oxidized particles + secondary organic aerosol (SOA) (POS); and oxidized and neutralized particles + SOA (PONS). Extensive exposure characterization was carried out, including gas-phase and particulate species. Male Sprague Dawley rats were exposed for 6 hours to filtered air or different atmospheric mixtures. Toxicological endpoints included (1) breathing pattern; (2) bronchoalveolar lavage (BAL) fluid cytology and biochemistry; (3) blood cytology; (4) in vivo oxidative stress in heart and lung tissue; and (5) heart and lung histopathology. In addition, at one plant, cardiac arrhythmias and heart rate variability (HRV) were evaluated in a rat model of myocardial infarction. Statistical analyses included analyses of variance (ANOVA) to determine differences between exposed and control animals in response to different scenario/plant combinations; univariate analyses to link individual scenario components to responses; and multivariate analyses (Random Forest analyses) to evaluate component effects in a multipollutant setting. Results from the power plant studies indicated some biological responses to some plant/scenario combinations. A number of significant breathing pattern changes were observed; however, significant clinical changes such as specific irritant effects were not readily apparent, and effects tended to be isolated changes in certain respiratory parameters. Some individual exposure scenario components appeared to be more strongly and consistently related to respiratory parameter changes; however, the specific scenario investigated remained a better predictor of response than individual components of that scenario. Bronchoalveolar lavage indicated some changes in cellularity of BAL fluid in response to the POS and PONS scenarios; these responses were considered toxicologically mild in magnitude. No changes in blood cytology were observed at any plant or scenario. Lung oxidative stress was increased with the POS scenario at one plant, and cardiac oxidative stress was increased with the PONS scenario also at one plant, suggesting limited oxidative stress in response to power plant emissions with added atmospheric constituents. There were some mild histological findings in lung tissue in response to the P and PONS scenarios. Finally, the MI model experiments indicated that premature ventricular beat frequency was increased at the plant studied, while no changes in heart rate, HRV, or electrocardiographic intervals were observed. Overall, the

Annette C. Rohr; Petros Koutrakis; John Godleski

2011-03-31

310

Independent regulation of sterol regulatory element-binding proteins 1 and 2 in hamster liver.  

PubMed Central

Two sterol regulatory element-binding proteins (SREBPs, designated SREBP-1 and SREBP-2), each approximately 1150 amino acids in length, are attached to membranes of the endoplasmic reticulum and nuclear envelope in human and hamster tissue culture cells. In the absence of sterols, soluble fragments of approximately 470 amino acids are released from both proteins by proteolytic cleavage. The soluble fragments enter the nucleus, where they bind to sterol regulatory elements in the promoters of genes encoding the low density lipoprotein receptor and 3-hydroxy-3-methylglutaryl CoA synthase, thereby activating transcription. Proteolytic processing of both SREBPs is blocked coordinately by sterol overloading and enhanced coordinately when sterols are depleted by treatment with an inhibitor of cholesterol synthesis. In contrast to these findings in cultured cells, the current data show that SREBP-1 and -2 are not coordinately regulated in hamster liver. In untreated animals the soluble fragment of SREBP-1, but not of SREBP-2, was detected by immunoblotting of a liver nuclear extract. Depletion of sterols by treatment with a bile acid-binding resin (colestipol) and a cholesterol synthesis inhibitor (mevinolin) led to a marked increase in the nuclear form of SREBP-2 and a reciprocal decline in the nuclear form of SREBP-1. These findings suggest that SREBP-1 is responsible for basal transcription of the low density lipoprotein receptor and 3-hydroxy-3-methylglutaryl CoA synthase genes in hamster liver and that SREBP-2 is responsible for the increased transcription that follows sterol depletion with a bile acid-binding resin and a cholesterol synthesis inhibitor. Images Fig. 1 Fig. 2 Fig. 3 PMID:7862668

Sheng, Z; Otani, H; Brown, M S; Goldstein, J L

1995-01-01

311

Observing plants dealing with soil water stress: Daily soil moisture fluctuations derived from polymer tensiometers  

NASA Astrophysics Data System (ADS)

Periods of soil water deficit often occur within a plant's life cycle, even in temperate deciduous and rain forests (Wilson et al. 2001, Grace 1999). Various experiments have shown that roots are able to sense the distribution of water in the soil, and produce signals that trigger changes in leaf expansion rate and stomatal conductance (Blackman and Davies 1985, Gollan et al. 1986, Gowing et al. 1990 Davies and Zhang 1991, Mansfield and De Silva 1994, Sadras and Milroy 1996). Partitioning of water and air in the soil, solute distribution in soil water, water flow through the soil, and water availability for plants can be determined according to the distribution of the soil water potential (e.g. Schröder et al. 2013, Kool et al. 2014). Understanding plant water uptake under dry conditions has been compromised by hydrological instrumentation with low accuracy in dry soils due to signal attenuation, or a compromised measurement range (Whalley et al. 2013). Development of polymer tensiometers makes it possible to study the soil water potential over a range meaningful for studying plant responses to water stress (Bakker et al. 2007, Van der Ploeg et al. 2008, 2010). Polymer tensiometer data obtained from a lysimeter experiment (Van der Ploeg et al. 2008) were used to analyse day-night fluctuations of soil moisture in the vicinity of maize roots. To do so, three polymer tensiometers placed in the middle of the lysimeter from a control, dry and very dry treatment (one lysimeter per treatment) were used to calculate water content changes over 12 hours. These 12 hours corresponded with the operation of the growing light. Soil water potential measurements in the hour before the growing light was turned on or off were averaged. The averaged value was used as input for the van Genuchten (1980) model. Parameters for the model were obtained from laboratory determination of water retention, with a separate model parameterization for each lysimeter setup. Results show daily fluctuations in water content changes, with both root water uptake and root water excretion. The magnitude of the water content change was in the same order for all treatments, thus suggesting compensatory uptake. References Bakker G, Van der Ploeg MJ, de Rooij GH, Hoogendam CW, Gooren HPA, Huiskes C, Koopal LK and Kruidhof H. New polymer tensiometers: Measuring matric pressures down to the wilting point. Vadose Zone J. 6: 196-202, 2007. Blackman PG and Davies WJ. Root to shoot communication in maize plants of the effects of soil drying. J. Exp. Bot. 36: 39-48, 1985. Davies WJ and Zhang J. Root signals and the regulation of growth and development of plants in drying soil. Annu. Rev. Plant Physiol. Plant Mol. Biol. 42: 55-76, 1991. Gollan T, Passioura JB and Munns R. Soil water status affects the stomatal conductance of fully turgid wheat and sunflower leafs. Aust. J. Plant Physiol. 13: 459-464, 1986. Gowing DJG, Davies WJ and Jones HG. A Positive Root-sourced Signal as an Indicator of Soil Drying in Apple, Malus x domestica Borkh. J. Exp. Bot. 41: 1535-1540, 1990. Grace J. Environmental controls of gas exchange in tropical rain forests. In: Press, M.C, J.D. Scholes and M.G. Barker (ed.). Physiological plant ecology: the 39th Symposium of the British Ecological Society. Blackwell Science, United Kingdom, 1999. Kool D, Agam N, Lazarovitch N, Heitman JL, Sauer TJ, Ben-Gal A. A review of approaches for evapotranspiration partitioning. Agricultural and Forest Meteorology 184: 56- 70, 2014. Mansfield TA and De Silva DLR. Sensory systems in the roots of plants and their role in controlling stomatal function in the leaves. Physiol. Chem. Phys. & Med. 26: 89-99, 1994. Sadras VO and Milroy SP. Soil-water thresholds for the responses of leaf expansion and gas exchange: a review. Field Crops Res. 47: 253-266, 1996. Schröder N, Lazarovitch N, Vanderborcht J, Vereecken H, Javaux M. Linking transpiration reduction to rhizosphere salinity using a 3D coupled soil-plant model. Plant Soil 2013, doi: 10.1007/s11104-013-1990-8 Van der Ploeg MJ, Gooren HPA, Bakker G and de Rooij GH.

van der Ploeg, Martine; de Rooij, Gerrit

2014-05-01

312

Plant extracts, isolated phytochemicals, and plant-derived agents which are lethal to arthropod vectors of human tropical diseases--a review.  

PubMed

The recent scientific literature on plant-derived agents with potential or effective use in the control of the arthropod vectors of human tropical diseases is reviewed. Arthropod-borne tropical diseases include: amebiasis, Chagas disease (American trypanosomiasis), cholera, cryptosporidiosis, dengue (hemorrhagic fever), epidemic typhus (Brill-Zinsser disease), filariasis (elephantiasis), giardia (giardiasis), human African trypanosomiasis (sleeping sickness), isosporiasis, leishmaniasis, Lyme disease (lyme borreliosis), malaria, onchocerciasis, plague, recurrent fever, sarcocystosis, scabies (mites as causal agents), spotted fever, toxoplasmosis, West Nile fever, and yellow fever. Thus, coverage was given to work describing plant-derived extracts, essential oils (EOs), and isolated chemicals with toxic or noxious effects on filth bugs (mechanical vectors), such as common houseflies (Musca domestica Linnaeus), American and German cockroaches (Periplaneta americana Linnaeus, Blatella germanica Linnaeus), and oriental latrine/blowflies (Chrysomya megacephala Fabricius) as well as biting, blood-sucking arthropods such as blackflies (Simulium Latreille spp.), fleas (Xenopsylla cheopis Rothschild), kissing bugs (Rhodnius Stål spp., Triatoma infestans Klug), body and head lice (Pediculus humanus humanus Linnaeus, P. humanus capitis De Geer), mosquitoes (Aedes Meigen, Anopheles Meigen, Culex L., and Ochlerotatus Lynch Arribálzaga spp.), sandflies (Lutzomyia longipalpis Lutz & Neiva, Phlebotomus Loew spp.), scabies mites (Sarcoptes scabiei De Geer, S. scabiei var hominis, S. scabiei var canis, S. scabiei var suis), and ticks (Ixodes Latreille, Amblyomma Koch, Dermacentor Koch, and Rhipicephalus Koch spp.). Examples of plant extracts, EOs, and isolated chemicals exhibiting noxious or toxic activity comparable or superior to the synthetic control agents of choice (pyrethroids, organophosphorous compounds, etc.) are provided in the text for many arthropod vectors of tropical diseases. PMID:21432748

Pohlit, Adrian Martin; Rezende, Alex Ribeiro; Lopes Baldin, Edson Luiz; Lopes, Norberto Peporine; Neto, Valter Ferreira de Andrade

2011-04-01

313

A mathematical basis for plant patterning derived from physico-chemical phenomena.  

PubMed

The position of leaves and flowers along the stem axis generates a specific pattern, known as phyllotaxis. A growing body of evidence emerging from recent computational modeling and experimental studies suggests that regulators controlling phyllotaxis are chemical, e.g. the plant growth hormone auxin and its dynamic accumulation pattern by polar auxin transport, and physical, e.g. mechanical properties of the cell. Here we present comprehensive views on how chemical and physical properties of cells regulate the pattern of leaf initiation. We further compare different computational modeling studies to understand their scope in reproducing the observed patterns. Despite a plethora of experimental studies on phyllotaxis, understanding of molecular mechanisms of pattern initiation in plants remains fragmentary. Live imaging of growth dynamics and physicochemical properties at the shoot apex of mutants displaying stable changes from one pattern to another should provide mechanistic insights into organ initiation patterns. PMID:23386477

Beleyur, Thejasvi; Abdul Kareem, Valiya Kadavu; Shaji, Anil; Prasad, Kalika

2013-04-01

314

Purification of crude glycerol derived from waste used-oil methyl ester plant  

Microsoft Academic Search

The purification of crude glycerol from a biodiesel plant using waste used-oil as a raw material was carried out on a laboratory\\u000a scale by using the combined chemical and physical treatments based upon repeated cycles of acidification to the desired pH\\u000a within the range of 1–6 using 1.19 M H2SO4, allowing phase separation and harvesting of the glycerol-rich middle phase

Sangkorn Kongjao; Somsak Damronglerd; Mali Hunsom

2010-01-01

315

Plant Regeneration and Somatic Embryogenesis from Immature Embryos Derived through Interspecific Hybridization among Different Carica Species  

PubMed Central

Plant regeneration and somatic embryogenesis through interspecific hybridization among different Carica species were studied for the development of a papaya ringspot virus-resistant variety. The maximum fruit sets were recorded from the cross of the native variety C. papaya cv. Shahi with the wild species C. cauliflora. The highest hybrid embryos were recorded at 90 days after pollination and the embryos were aborted at 150 days after pollination. The immature hybrid embryos were used for plant regeneration and somatic embryogenesis. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora showed the highest percentage of germination, as well as plant regeneration on growth regulators free culture medium after 7 days pre-incubation on half-strength MS medium supplemented with 0.2 mg/L BAP, 0.5 mg/L NAA and 60 g/L sucrose. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora produced maximum callus, as well as somatic embryos when cultured on half-strength MS medium containing 5 mg/L 2,4-D, 100 mg/L glutamine, 100 mg/L casein hydrolysate and 60 g/L sucrose. The somatic embryos were transferred into half-strength MS medium containing 0.5 mg/L BAP and 0.2 mg/L NAA and 60 g/L sucrose for maturation. The highest number of regenerated plants per hybrid embryo (10.33) was recorded from the cross of C. papaya cv. Shahi × C. cauliflora. Isoenzyme and dendrogram cluster analysis using UPGMA of the regenerated F1 plantlets confirmed the presence of the hybrid plantlets. PMID:23235330

Azad, Md. Abul Kalam; Rabbani, Md. Golam; Amin, Latifah

2012-01-01

316

Plant Regeneration and Somatic Embryogenesis from Immature Embryos Derived through Interspecific Hybridization among Different Carica Species.  

PubMed

Plant regeneration and somatic embryogenesis through interspecific hybridization among different Carica species were studied for the development of a papaya ringspot virus-resistant variety. The maximum fruit sets were recorded from the cross of the native variety C. papaya cv. Shahi with the wild species C. cauliflora. The highest hybrid embryos were recorded at 90 days after pollination and the embryos were aborted at 150 days after pollination. The immature hybrid embryos were used for plant regeneration and somatic embryogenesis. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora showed the highest percentage of germination, as well as plant regeneration on growth regulators free culture medium after 7 days pre-incubation on half-strength MS medium supplemented with 0.2 mg/L BAP, 0.5 mg/L NAA and 60 g/L sucrose. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora produced maximum callus, as well as somatic embryos when cultured on half-strength MS medium containing 5 mg/L 2,4-D, 100 mg/L glutamine, 100 mg/L casein hydrolysate and 60 g/L sucrose. The somatic embryos were transferred into half-strength MS medium containing 0.5 mg/L BAP and 0.2 mg/L NAA and 60 g/L sucrose for maturation. The highest number of regenerated plants per hybrid embryo (10.33) was recorded from the cross of C. papaya cv. Shahi × C. cauliflora. Isoenzyme and dendrogram cluster analysis using UPGMA of the regenerated F(1) plantlets confirmed the presence of the hybrid plantlets. PMID:23235330

Azad, Md Abul Kalam; Rabbani, Md Golam; Amin, Latifah

2012-01-01

317

Characterization of plant-derived water extractable organic matter by multiple spectroscopic techniques  

Microsoft Academic Search

Water extractable organic matter (WEOM) derived from fresh- or early-stage decomposing soil amendment materials may play an\\u000a important role in the process of organic matter accumulation. In this study, eight WEOM samples extracted with a 40:1 (v\\/w) water to sample ratio from alfalfa (Medicago sativa L.), corn (Zea mays L.), crimson clover (Trifolium incarnatum L.), hairy vetch (Vicia villosa L.),

Zhongqi He; Jingdong Mao; C. Wayne Honeycutt; Tsutomu Ohno; James F. Hunt; Barbara J. Cade-Menun

2009-01-01

318

Stochastic approach to the derivation of emission limits for wastewater treatment plants.  

PubMed

Stochastic approach to the derivation of WWTP emission limits meeting probabilistically defined environmental quality standards (EQS) is presented. The stochastic model is based on the mixing equation with input data defined by probability density distributions and solved by Monte Carlo simulations. The approach was tested on a study catchment for total phosphorus (P(tot)). The model assumes input variables independency which was proved for the dry-weather situation. Discharges and P(tot) concentrations both in the study creek and WWTP effluent follow log-normal probability distribution. Variation coefficients of P(tot) concentrations differ considerably along the stream (c(v)=0.415-0.884). The selected value of the variation coefficient (c(v)=0.420) affects the derived mean value (C(mean)=0.13 mg/l) of the P(tot) EQS (C(90)=0.2 mg/l). Even after supposed improvement of water quality upstream of the WWTP to the level of the P(tot) EQS, the WWTP emission limits calculated would be lower than the values of the best available technology (BAT). Thus, minimum dilution ratios for the meaningful application of the combined approach to the derivation of P(tot) emission limits for Czech streams are discussed. PMID:19542635

Stransky, D; Kabelkova, I; Bares, V

2009-01-01

319

The role of carbon starvation in the induction of enzymes that degrade plant-derived carbohydrates in Aspergillus niger  

PubMed Central

Fungi are an important source of enzymes for saccharification of plant polysaccharides and production of biofuels. Understanding of the regulation and induction of expression of genes encoding these enzymes is still incomplete. To explore the induction mechanism, we analysed the response of the industrially important fungus Aspergillus niger to wheat straw, with a focus on events occurring shortly after exposure to the substrate. RNA sequencing showed that the transcriptional response after 6 h of exposure to wheat straw was very different from the response at 24 h of exposure to the same substrate. For example, less than half of the genes encoding carbohydrate active enzymes that were induced after 24 h of exposure to wheat straw, were also induced after 6 h exposure. Importantly, over a third of the genes induced after 6 h of exposure to wheat straw were also induced during 6 h of carbon starvation, indicating that carbon starvation is probably an important factor in the early response to wheat straw. The up-regulation of the expression of a high number of genes encoding CAZymes that are active on plant-derived carbohydrates during early carbon starvation suggests that these enzymes could be involved in a scouting role during starvation, releasing inducing sugars from complex plant polysaccharides. We show, using proteomics, that carbon-starved cultures indeed release CAZymes with predicted activity on plant polysaccharides. Analysis of the enzymatic activity and the reaction products, indicates that these proteins are enzymes that can degrade various plant polysaccharides to generate both known, as well as potentially new, inducers of CAZymes. PMID:24792495

van Munster, Jolanda M.; Daly, Paul; Delmas, Stephane; Pullan, Steven T.; Blythe, Martin J.; Malla, Sunir; Kokolski, Matthew; Noltorp, Emelie C.M.; Wennberg, Kristin; Fetherston, Richard; Beniston, Richard; Yu, Xiaolan; Dupree, Paul; Archer, David B.

2014-01-01

320

Ion-Channel Genosensor for the Detection of Specific DNA Sequences Derived from Plum Pox Virus in Plant Extracts  

PubMed Central

A DNA biosensor for detection of specific oligonucleotides sequences of Plum Pox Virus (PPV) in plant extracts and buffer is proposed. The working principles of a genosensor are based on the ion-channel mechanism. The NH2-ssDNA probe was deposited onto a glassy carbon electrode surface to form an amide bond between the carboxyl group of oxidized electrode surface and amino group from ssDNA probe. The analytical signals generated as a result of hybridization were registered in Osteryoung square wave voltammetry in the presence of [Fe(CN)6]3?/4? as a redox marker. The 22-mer and 42-mer complementary ssDNA sequences derived from PPV and DNA samples from plants infected with PPV were used as targets. Similar detection limits of 2.4 pM (31.0 pg/mL) and 2.3 pM (29.5 pg/mL) in the concentration range 1–8 pM were observed in the presence of the 22-mer ssDNA and 42-mer complementary ssDNA sequences of PPV, respectively. The genosensor was capable of discriminating between samples consisting of extracts from healthy plants and leaf extracts from infected plants in the concentration range 10–50 pg/mL. The detection limit was 12.8 pg/mL. The genosensor displayed good selectivity and sensitivity. The 20-mer partially complementary DNA sequences with four complementary bases and DNA samples from healthy plants used as negative controls generated low signal. PMID:25302809

Malecka, Kamila; Michalczuk, Lech; Radecka, Hanna; Radecki, Jerzy

2014-01-01

321

A multi-component LC-MS/MS method for detection of ten plant-derived psychoactive substances in urine.  

PubMed

A sensitive and specific LC-MS/MS method for simultaneous detection of 10 plant-derived psychoactive substances (atropine, N,N-dimethyltryptamine, ephedrine, harmaline, harmine, ibogaine, lysergic acid amide, psilocin, scopolamine and yohimbine) in urine was developed. Direct injection of urine diluted with 3 deuterated internal standards allowed for a readily accessible method suitable for application in clinical intoxication cases. Separation was achieved using reversed phase chromatography and gradient elution with a total analysis time of 14 min. Electrospray ionization was used and ions were monitored in the positive selected reaction monitoring mode. The calibration curves were linear (r(2)>0.999) and the total imprecision at high (1000 microg/L) and low (50 microg/L) substance concentrations were 4.9-13.8% and 8.3-26%, respectively. Infusing the analytes post column and injecting matrix samples showed limited influence by ion suppression. The multi-component method proved to be useful for investigation of authentic cases of intoxication with plant-derived psychoactive drugs and was indicated to cover the clinically relevant concentration ranges. PMID:19332394

Björnstad, Kristian; Beck, Olof; Helander, Anders

2009-04-15

322

Bioprocessing of plant in vitro systems for the mass production of pharmaceutically important metabolites: paclitaxel and its derivatives.  

PubMed

Taxol (paclitaxel) and its derivatives are microtubule-stabilizing drugs widely used in the treatment of several types of cancer, including mammary, prostate, ovarian and non-small-cell lung carcinoma, as well as AIDS-associated Kaposi's sarcoma and other types of tumor. Taxanes stabilize microtubules by enhancing their polymerization and inhibiting depolymerization. Microtubule dynamics are crucial to mitotic spindle formation and function; therefore, cells exposed to taxanes are unable to undergo chromosomal separation during mitosis, become arrested in the G2/M phases of the cell cycle, and are subsequently targeted for apoptosis. Plant cell cultures are used for industrial-scale biotechnological production of important bioactive plant secondary metabolites, including the anticancer agent paclitaxel. In the last two decades, there have been numerous empirical approaches to improve the biotechnological production of taxanes, leading to the conclusion that treatment of Taxus sp. cells with methyl jasmonate or other elicitors is the most effective strategy. However, little insight has been gained into how the elicitors increase taxane biosynthesis or how this process is regulated. In recent years, with the help of "omics" tools, a rational approach has provided new information about taxane metabolism and its control. Once pathway bottlenecks have been identified, it will be possible to engineer Taxus sp. cell lines with overexpression of genes that control the flux-limiting steps, thus boosting taxane productivity. This review describes the chemical and biological characterization of paclitaxel and its derivatives and discusses future prospects for their biotechnological production. PMID:23210777

Onrubia, M; Cusidó, R M; Ramirez, K; Hernández-Vázquez, L; Moyano, E; Bonfill, M; Palazon, J

2013-01-01

323

Development of New Environment Friendly Natural Colored Preservatives for Wood Surface Dying Derived from Different Tree and Herbaceous Plant Extracts and Determination of Their Color Parameters  

Microsoft Academic Search

In this study, the aim is to derive some water-based wood surface dyes which are extracted from different trees and herbaceous plants. For this purpose, wood specimens were prepared from yellow pine (Pinus sylvestris) and beech (Fagus orientalis). The extracts for dyings were derived from walnut (Juglans regia) shells skins, oleander (Nerium oleander), saffron (Crocus sativus) and madder root (Rubia

Mehmet Emin DURU; Ergün BAYSAL; Ayþen Melda ÇOLAK; Ertan ÖZEN

324

Sterol composition in field-grown and cultured mycelia of Inonotus obliquus.  

PubMed

Sterols are one of the active classes of compounds in Inonotus obliquus for their effective therapy of many diseases. In field environment, this fungus accumulates large amount of sterols. In cultured mycelia, however, this class of compounds is less accumulated. For analyzing the factors responsible for differing sterol composition, the field-grown and cultured mycelia were extracted with 80% ethanol at room temperature and total sterols were prepared using silicon gel column chromatography followed by identification using either GC-MS or spectroscopic methods. For culturing Inonotus obliquus, the seed culture was grown either in basic medium consisting of glucose (2%), yeast extract (0.5%), KH2PO4 (0.01%), MgSO4.7H20 (0.05%) and distilled water at pH 6.5, or the basic medium supplemented with serial concentrations of AgNO3. The results indicated that field-grown mycelia contained lanosterol and inotodiol (comprised 45. 47% and 25. 36% of the total sterols, respectively) and other 10 sterols (comprising the remaining 30.17%) including ergosterol biosynthetic intermediates such as 24-methylene dihydrolanosterol, 4,4-dimethylfecosterol, 4-methyl fecosterol, fecosterol and episterol. Column chromatography also led to the isolation of lanosterol, Inotodiol, trametenolic acid, foscoparianol B and a new triterpenoid foscoparianol D in field-grown mycelia. In comparison, the cultured mycelia only contained three sterols with ergosterol as the predominant one (82.20%). Lanosterol only accounted for 3.68%. Supplementing Ag+ into the culture at 0.28 micromol x L(-1) greatly enhanced content of lanosterol (accounting for 56.81%) and decreased the content of ergosterol (18.5%) together with the presence of intermediates for ergosterol biosynthesis. These results suggested that the sterol composition in mycelia of the fungus can be diversified by supplementing substances inhibiting enzymatic process towards the synthesis of ergosterol. Harsh growth conditions in field environment (i.e. temperature variation, UV irradiation etc.) can delay the synthesis of ergosterol and hereby diversify the sterol composition in the mycelia of Inonotus obliquus. PMID:17882960

Zheng, Wei-fa; Liu, Tong; Xiang, Xiao-yan; Gu, Qi

2007-07-01

325

C-24-methylation of 26-fluorocycloartenols by recombinant sterol C-24-methyltransferase from soybean: evidence for channel switching and its phylogenetic implications.  

PubMed

The tightly coupled nature of the electrophilic alkylation reaction sequence catalysed by 24-SMT (sterol C-24-methyltransferase) of land plants and algae can be distinguished by the formation of cationic intermediates that yield phyla-specific product profiles. C-24-methylation of the cycloartenol substrate by the recombinant Glycine max (soybean) 24-SMT proceeds to a single product 24(28)-methylenecycloartanol, whereas the 24-SMT from green algae converts cycloartenol into two products cyclolaudenol [?(25(27))-olefin] and 24(28)-methylenecycloartanol [(?24(28))-olefin]. Substrate analogues that differed in the steric-electronic features at either end of the molecule, 26-homocycloartenol or 3?-fluorolanostadiene, were converted by G. max SMT into a single 24(28)-methylene product. Alternatively, incubation of the allylic 26-fluoro cyclosteroid with G. max SMT afforded a bound intermediate that converted in favour of the ?(25(27))-olefin product via the cyclolaudenol cation formed initially during the C-24-methylation reaction. A portion of the 26-fluorocycloartenol substrate was also intercepted by the enzyme and the corresponding hydrolysis product identified by GC-MS as 26-fluoro-25-hydroxy-24-methylcycloartanol. Finally, the 26-fluorocycloartenols are competitive inhibitors for the methylation of cycloartenol and 26-monofluorocycloartenol generated timedependent inactivation kinetics exhibiting a kinact value of 0.12 min(-1). The ability of soybean 24-SMT to generate a 25-hydroxy alkylated sterol and fluorinated ?(25(27))-olefins is consistent with our hypothesis that (i) achieving the cyclolaudenyl cation intermediate by electrophilic alkylation of cycloartenol is significant to the overall reaction rate, and (ii) the evolution of variant sterol C-24-methylation patterns is driven by competing reaction channels that have switched in algae from formation of primarily ?(25(27)) products that convert into ergosterol to, in land plants, formation of ?(24(28)) products that convert into sitosterol. PMID:23984880

Patkar, Presheet; Haubrich, Brad A; Qi, Ming; Nguyen, T Thuy Minh; Thomas, Crista D; Nes, W David

2013-12-01

326

TOXICOLOGICAL EVALUATION OF REALISTIC EMISSIONS OF SOURCE AEROSOLS (TERESA): APPLICATION TO POWER PLANT-DERIVED PM2.5  

SciTech Connect

This report documents progress made on the subject project during the period of March 1, 2004 through August 31, 2004. The TERESA Study is designed to investigate the role played by specific emissions sources and components in the induction of adverse health effects by examining the relative toxicity of coal combustion and mobile source (gasoline and/or diesel engine) emissions and their oxidative products. The study involves on-site sampling, dilution, and aging of coal combustion emissions at three coal-fired power plants, as well as mobile source emissions, followed by animal exposures incorporating a number of toxicological endpoints. The DOE-EPRI Cooperative Agreement (henceforth referred to as ''the Agreement'') for which this technical progress report has been prepared covers the analysis and interpretation of the field data collected at the first power plant (henceforth referred to as Plant 0, and located in the Upper Midwest), followed by the performance and analysis of similar field experiments at two additional coal-fired power plants (Plants 1 and 2) utilizing different coal types and with different plant configurations. Significant progress was made on the Project during this reporting period, with field work being initiated at Plant 0. Initial testing of the stack sampling system and reaction apparatus revealed that primary particle concentrations were lower than expected in the emissions entering the mobile chemical laboratory. Initial animal exposures to primary emissions were carried out (Scenario 1) to ensure successful implementation of all study methodologies and toxicological assessments. Results indicated no significant toxicological effects in response to primary emissions exposures. Exposures were then carried out to diluted, oxidized, neutralized emissions with the addition of secondary organic aerosol (Scenario 5), both during the day and also at night when primary particle concentrations in the sampled stack emissions tended to be slightly higher. Exposure concentrations were about 249 {micro}g/m{sup 3} PM, of which 87 {micro}g/m{sup 3} was sulfate and approximately 110 {micro}g/m{sup 3} was secondary organic material ({approx}44%). Results indicated subtle differences in breathing pattern between exposed and control (sham) animals, but no differences in other endpoints (in vivo chemiluminescence, blood cytology, bronchoalveolar lavage fluid analysis). It was suspected that primary particle losses may have been occurring in the venturi aspirator/orifice sampler; therefore, the stack sampling system was redesigned. The modified system resulted in no substantial increase in particle concentration in the emissions, leading us to conclude that the electrostatic precipitator at the power plant has high efficiency, and that the sampled emissions are representative of those exiting the stack into the atmosphere. This is important, since the objective of the Project is to carry out exposures to realistic coal combustion-derived secondary PM arising from power plants. During the next reporting period, we will document and describe the remainder of the fieldwork at Plant 0, which we expect to be complete by mid-November 2004. This report will include detailed Phase I toxicological findings for all scenarios run, and Phase II toxicological findings for one selected scenario. Depending upon the outcome of the ongoing fieldwork at Plant 0 (i.e. the biological effects observed), not all the proposed scenarios may be evaluated. The next report is also expected to include preliminary field data for Plant 1, located in the Southeast.

Annette Rohr

2004-12-02

327

Androgens stimulate lipogenic gene expression in prostate cancer cells by activation of the sterol regulatory element-binding protein cleavage activating protein/sterol regulatory element-binding protein pathway.  

PubMed

Using two independent prostate cancer cell lines (LNCaP and MDA-PCa-2a), we demonstrate that coordinated stimulation of lipogenic gene expression by androgens is a common phenomenon in androgen-responsive prostate tumor lines and involves activation of the sterol regulatory element-binding protein (SREBP) pathway. We show 1) that in both cell lines, androgens stimulate the expression of fatty acid synthase and hydroxymethylglutaryl-coenzyme A synthase, two key lipogenic genes representative for the fatty acid and the cholesterol synthesis pathway, respectively; 2) that treatment with androgens results in increased nuclear levels of active SREBP; 3) that the effects of androgens on promoter-reporter constructs derived from both lipogenic genes (fatty acid synthase and hydroxymethylglutaryl-coenzyme A synthase) depend on the presence of intact SREBP-binding sites; and 4) that cotransfection with dominant-negative forms of SREBPs abolishes the effects of androgens. Related to the mechanism underlying androgen activation of the SREBP pathway, we show that in addition to minor effects on SREBP precursor levels, androgens induce a major increase in the expression of sterol regulatory element-binding protein cleavage-activating protein (SCAP), an escort protein that transports SREBPs from their site of synthesis in the endoplasmic reticulum to their site of proteolytical activation in the Golgi. Both time course studies and overexpression experiments showing that increasing levels of SCAP enhance the production of mature SREBP and stimulate lipogenic gene expression support the contention that SCAP plays a pivotal role in the lipogenic effects of androgens in tumor cells. PMID:11579213

Heemers, H; Maes, B; Foufelle, F; Heyns, W; Verhoeven, G; Swinnen, J V

2001-10-01

328

High-Throughput Screening to Identify Plant Derived Human LDH-A Inhibitors  

PubMed Central

Aims Lactate dehydrogenase (LDH)-A is highly expressed in diverse human malignant tumors, parallel to aggressive metastatic disease, resistance to radiation/chemotherapy and clinically poor outcome. Although this enzyme constitutes a plausible target in treatment of advanced cancer, there are few known LDH-A inhibitors. Study Design In this work, we utilized a high-throughput enzyme micro-array format to screen and evaluate > 900 commonly used medicinal plant extracts (0.00001-.5 mg/ml) for capacity to inhibit activity of recombinant full length human LDHA; EC .1.1.1.27. Methodology The protein sequence of purified enzyme was confirmed using 1D gel electrophoresis- MALDI-TOF-MS/MS, enzyme activity was validated by oxidation of NADH (500?M) and kinetic inhibition established in the presence of a known inhibitor (Oxalic Acid). Results Of the natural extracts tested, the lowest IC50s [<0.001 mg/ml] were obtained by: Chinese Gallnut (Melaphis chinensis gallnut), Bladderwrack (Fucus vesiculosus), Kelp (Laminaria Japonica) and Babul (Acacia Arabica). Forty-six additional herbs contained significant LDH-A inhibitory properties with IC50s [<0.07 mg/ml], some of which have common names of Arjun, Pipsissewa, Cinnamon, Pink Rose Buds/Petals, Wintergreen, Cat’s Claw, Witch Hazel Root and Rhodiola Root. Conclusion These findings reflect relative potency by rank of commonly used herbs and plants that contain human LDH-A inhibitory properties. Future research will be required to isolate chemical constituents within these plants responsible for LDH-A inhibition and investigate potential therapeutic application. PMID:24478981

Deiab, S.; Mazzio, E.; Messeha, S.; Mack, N.; Soliman, K. F. A.

2014-01-01

329

Diversity and population structure of sewage derived microorganisms in wastewater treatment plant influent  

PubMed Central

The release of untreated sewage introduces non-indigenous microbial populations of uncertain composition into surface waters. We used massively parallel 454 sequencing of hypervariable regions in rRNA genes to profile microbial communities from eight untreated sewage influent samples of two wastewater treatment plants (WWTP) in metropolitan Milwaukee. The sewage profiles included a discernable human fecal signature made up of several taxonomic groups including multiple Bifidobacteriaceae, Coriobacteriaceae, Bacteroidaceae, Lachnospiraceae, and Ruminococcaceae genera. The fecal signature made up a small fraction of the taxa present in sewage but the relative abundance of these sequence tags mirrored the population structures of human fecal samples. These genera were much more prevalent in the sewage influent than standard indicators species. High-abundance sequences from taxonomic groups within the Beta- and Gammaproteobacteria dominated the sewage samples but occurred at very low levels in fecal and surface water samples, suggesting that these organisms proliferate within the sewer system. Samples from Jones Island (JI – servicing residential plus a combined sewer system) and South Shore (SS – servicing a residential area) WWTPs had very consistent community profiles, with greater similarity between WWTPs on a given collection day than the same plant collected on different days. Rainfall increased influent flows at SS and JI WWTPs, and this corresponded to greater diversity in the community at both plants. Overall, the sewer system appears to be a defined environment with both infiltration of rainwater and stormwater inputs modulating community composition. Microbial sewage communities represent a combination of inputs from human fecal microbes and enrichment of specific microbes from the environment to form a unique population structure. PMID:19840106

McLellan, S.L.; Huse, S.M.; Mueller-Spitz, S.R.; Andreishcheva, E.N.; Sogin, M.L.

2009-01-01

330

Efficacy of Euphorbia hirta latex as plant derived molluscicides against freshwater snails.  

PubMed

The toxic effect of binary and tertiary combinations of Euphorbia hirta Linn latex powder with other plant molluscicidal compounds, were evaluated against the freshwater snails Lymnaea (Radix) acuminata and Indoplanorbis exustus in pond. These combinations showed significant time and dose dependent effect against both the snails. These compounds at higher doses were also lethal to freshwater fish Channa punctatus (Bloch) (Channidae {Ophicephalidae}), which shares the habitat with these snails, but the LC90 (24h) doses of snails have no apparent killing properties in fish populations when treated in mixed population of snails and fish. PMID:21537758

Yadav, Ram P; Singh, Ajay

2011-01-01

331

Sterol-resistant transcription in CHO cells caused by gene rearrangement that truncates SREBP-2.  

PubMed

Sterol-resistant CHO cells (SRD-1 cells) fail to repress sterol synthesis and LDL receptor gene transcription when incubated with 25-hydroxycholesterol. Here we trace the defect to a rearrangement in the gene encoding SREBP-2, a membrane-bound transcription factor that regulates cholesterol homeostasis. SREBP-2 is an 1139-amino acid protein that is bound to extranuclear membranes via a carboxy-terminal attachment domain. In sterol-depleted cells a protease liberates the amino-terminal fragment (approximately 480 amino acids). This fragment, which contains the transcriptional activation and bHLH-Zip domains, translocates to the nucleus. 25-Hydroxycholesterol abolishes protease activity and halts transcription. SRD-1 cells produce a soluble, truncated form of SREBP-2 (amino acids 1-460) that lacks the membrane attachment domain and activates transcription directly, bypassing the sterol-regulated proteolytic step. Although SRD-1 cells produce full-length SREBP-2 from the wild-type allele and a related transcription factor, SREBP-1, they fail to cleave both of these precursors, indicating that the truncated form of SREBP-2 down-regulates the protease through a form of end-product feedback inhibition. The current data provide genetic evidence for the previously proposed model in which cholesterol homeostasis is controlled by sterol-regulated proteolysis of a membrane-bound bHLH-Zip transcription factor. PMID:7958866

Yang, J; Sato, R; Goldstein, J L; Brown, M S

1994-08-15

332

Elicitation of induced resistance against Pectobacterium carotovorum and Pseudomonas syringae by specific individual compounds derived from native Korean plant species.  

PubMed

Plants have developed general and specific defense mechanisms for protection against various enemies. Among the general defenses, induced resistance has distinct characteristics, such as broad-spectrum resistance and long-lasting effectiveness. This study evaluated over 500 specific chemical compounds derived from native Korean plant species to determine whether they triggered induced resistance against Pectobacterium carotovorum supsp. carotovorum (Pcc) in tobacco (Nicotiana tabacum) and Pseudomonas syringae pv. tomato (Pst) in Arabidopsis thaliana. To select target compound(s) with direct and indirect (volatile) effects, a new Petri-dish-based in vitro disease assay system with four compartments was developed. The screening assay showed that capsaicin, fisetin hydrate, jaceosidin, and farnesiferol A reduced the disease severity significantly in tobacco. Of these four compounds, capsaicin and jaceosidin induced resistance against Pcc and Pst, which depended on both salicylic acid (SA) and jasmonic acid (JA) signaling, using Arabidopsis transgenic and mutant lines, including npr1 and NahG for SA signaling and jar1 for JA signaling. The upregulation of the PR2 and PDF1.2 genes after Pst challenge with capsaicin pre-treatment indicated that SA and JA signaling were primed. These results demonstrate that capsaicin and jaceosidin can be effective triggers of strong induced resistance against both necrotrophic and biotrophic plant pathogens. PMID:24135942

Song, Geun Cheol; Ryu, Shi Yong; Kim, Young Sup; Lee, Ji Young; Choi, Jung Sup; Ryu, Choong-Min

2013-01-01

333

Matrix-derived combination effect and risk assessment for estragole from basil-containing plant food supplements (PFS).  

PubMed

Basil-containing plant food supplements (PFS) can contain estragole which can be metabolised into a genotoxic and carcinogenic 1'-sulfoxymetabolite. This study describes the inhibition of sulfotransferase (SULT)-mediated bioactivation of estragole by compounds present in basil-containing PFS. Results reveal that PFS consisting of powdered basil material contain other compounds with considerable in vitro SULT-inhibiting activity, whereas the presence of such compounds in PFS consisting of basil essential oil was limited. The inhibitor in powdered basil PFS was identified as nevadensin. Physiologically based kinetic (PBK) modeling was performed to elucidate if the observed inhibitory effects can occur in vivo. Subsequently, risk assessment was performed using the Margin of Exposure (MOE) approach. Results suggest that the consequences of the in vivo matrix-derived combination effect are significant when estragole would be tested in rodent bioassays with nevadensin at ratios detected in PFS, thereby increasing MOE values. However, matrix-derived combination effects may be limited at lower dose levels, indicating that the importance of matrix-derived combination effects for risk assessment of individual compounds should be done on a case-by-case basis considering dose-dependent effects. Furthermore, this study illustrates how PBK modeling can be used in risk assessment of PFS, contributing to further reduction in the use of experimental animals. PMID:23959103

van den Berg, Suzanne J P L; Klaus, Verena; Alhusainy, Wasma; Rietjens, Ivonne M C M

2013-12-01

334

Screening of anti-Helicobacter pylori herbs deriving from Taiwanese folk medicinal plants.  

PubMed

In this study, extracts from 50 Taiwanese folk medicinal plants were examined and screened for anti-Helicobacter pylori activity. Ninety-five percent ethanol was used for herbal extraction. Paederia scandens (Lour.) Merr. (PSM), Plumbago zeylanica L. (PZL), Anisomeles indica (L.) O. Kuntze (AIOK), Bombax malabaricum DC. (BMDC) and Alpinia speciosa (J. C. Wendl.) K. Schum. (ASKS) and Bombax malabaricum DC. (BMDC) all demonstrated strong anti-H. pylori activities. The minimum inhibitory concentration values of the anti-H. pylori activity given by the five ethanol herb extracts ranged from 0.64 to 10.24 mg ml(-1). Twenty-six herbs, including Artemisia argvi Levl. et Vant (AALEV), Phyla nodiflora (Linn.) Greene (PNG) and others, showed moderate anti-H. pylori activity. The additional 19 herbs, including Areca catechu Linn. (ACL), Euphorbia hirta Linn. (EHL) and Gnaphalium adnatum Wall. ex DC. (GAWEDC), possessed lower anti-H. pylori effects. About half of the Taiwanese folk medicinal plants tested, demonstrated to possess higher anti-H. pylori activity. PMID:15681161

Wang, Yuan-Chuen; Huang, Tung-Liang

2005-02-01

335

Complexes of Trypanosoma cruzi Sterol 14?-Demethylase (CYP51) with Two Pyridine-based Drug Candidates for Chagas Disease  

PubMed Central

Chagas disease, caused by the eukaryotic (protozoan) parasite Trypanosoma cruzi, is an alarming emerging global health problem with no clinical drugs available to treat the chronic stage. Azole inhibitors of sterol 14?-demethylase (CYP51) were proven effective against Chagas, and antifungal drugs posaconazole and ravuconazole have entered clinical trials in Spain, Bolivia, and Argentina. Here we present the x-ray structures of T. cruzi CYP51 in complexes with two alternative drug candidates, pyridine derivatives (S)-(4-chlorophenyl)-1-(4-(4-(trifluoromethyl)phenyl)-piperazin-1-yl)-2-(pyridin-3-yl)ethanone (UDO; Protein Data Bank code 3ZG2) and N-[4-(trifluoromethyl)phenyl]-N-[1-[5-(trifluoromethyl)-2-pyridyl]-4-piperi-dyl]pyridin-3-amine (UDD; Protein Data Bank code 3ZG3). These compounds have been developed by the Drugs for Neglected Diseases initiative (DNDi) and are highly promising antichagasic agents in both cellular and in vivo experiments. The binding parameters and inhibitory effects on sterol 14?-demethylase activity in reconstituted enzyme reactions confirmed UDO and UDD as potent and selective T. cruzi CYP51 inhibitors. Comparative analysis of the pyridine- and azole-bound CYP51 structures uncovered the features that make UDO and UDD T. cruzi CYP51-specific. The structures suggest that although a precise fit between the shape of the inhibitor molecules and T. cruzi CYP51 active site topology underlies their high inhibitory potency, a longer coordination bond between the catalytic heme iron and the pyridine nitrogen implies a weaker influence of pyridines on the iron reduction potential, which may be the basis for the observed selectivity of these compounds toward the target enzyme versus other cytochrome P450s, including human drug-metabolizing P450s. These findings may pave the way for the development of novel CYP51-targeted drugs with optimized metabolic properties that are very much needed for the treatment of human infections caused by eukaryotic microbial pathogens. PMID:24047900

Hargrove, Tatiana Y.; Wawrzak, Zdzislaw; Alexander, Paul W.; Chaplin, Jason H.; Keenan, Martine; Charman, Susan A.; Perez, Catherine J.; Waterman, Michael R.; Chatelain, Eric; Lepesheva, Galina I.

2013-01-01

336

7-Dehydrocholesterol metabolites produced by sterol 27-hydroxylase (CYP27A1) modulate liver X receptor activity.  

PubMed

7-Dehydrocholesterol (7-DHC) is a common precursor of vitamin D3 and cholesterol. Although various oxysterols, oxygenated cholesterol derivatives, have been implicated in cellular signaling pathways, 7-DHC metabolism and potential functions of its metabolites remain poorly understood. We examined 7-DHC metabolism by various P450 enzymes and detected three metabolites produced by sterol 27-hydroxylase (CYP27A1) using high-performance liquid chromatography. Two were further identified as 25-hydroxy-7-DHC and 26/27-hydroxy-7-DHC. These 7-DHC metabolites were detected in serum of a patient with Smith-Lemli-Opitz syndrome. Luciferase reporter assays showed that 25-hydroxy-7-DHC activates liver X receptor (LXR) ?, LXR? and vitamin D receptor and that 26/27-hydroxy-7-DHC induces activation of LXR? and LXR?, although the activities of both compounds on LXRs were weak. In a mammalian two-hybrid assay, 25-hydroxy-7-DHC and 26/27-hydroxy-7-DHC induced interaction between LXR? and a coactivator fragment less efficiently than a natural LXR agonist, 22(R)-hydroxycholesterol. These 7-DHC metabolites did not oppose agonist-induced LXR activation and interacted directly to LXR? in a manner distinct from a potent agonist. These findings indicate that the 7-DHC metabolites are partial LXR activators. Interestingly, 25-hydroxy-7-DHC and 26/27-hydroxy-7-DHC suppressed mRNA expression of sterol regulatory element-binding protein 1c, an LXR target gene, in HepG2 cells and HaCaT cells, while they weakly increased mRNA levels of ATP-binding cassette transporter A1, another LXR target, in HaCaT cells. Thus, 7-DHC is catabolized by CYP27A1 to metabolites that act as selective LXR modulators. PMID:24269243

Endo-Umeda, Kaori; Yasuda, Kaori; Sugita, Kazuyuki; Honda, Akira; Ohta, Miho; Ishikawa, Minoru; Hashimoto, Yuichi; Sakaki, Toshiyuki; Makishima, Makoto

2014-03-01

337

Repellent activity of plant-derived compounds against Amblyomma cajennense (Acari: Ixodidae) nymphs.  

PubMed

Repellence responses of Amblyomma cajennense nymphs to callicarpenal, intermedeol, Hyptis suaveolens essential oil, extract of Melia azedarach, Cymbopogon nardus, Spiranthera odoratissima, Chenopodium ambrosioides, Ageratum conyzoides, Mentha pulegium, Ruta graveolens, and Memora nodosa were studied. Among these the extract of C. nardus stood out because of the long-lasting repellence, maintaining, in the highest concentration, 35h of protection against 90% of the nymphs. The essential oil of H. suaveolens and the extracts of C. ambrosioides and A. conyzoides showed good repellence index (66%) when applied in high concentrations. However, greater protection could be obtained at higher concentrations but with a shorter repellence time. Callicarpenal, intermedeol, extract of M. Pulegium, and M. nodosa leaves showed moderate repellence in high concentrations. Extracts from M. azedarach, R. graveolens, S. odoratissima, and M. nodosa roots showed little or no repellent effect. These results show that some plant extracts may represent a promising alternative in the control of infestations by A. cajennense. PMID:19897309

Soares, Sara Fernandes; Borges, Lígia Miranda Ferreira; de Sousa Braga, Raquel; Ferreira, Lorena Lopes; Louly, Carla Cristina Braz; Tresvenzol, Leonice Manrique Faustino; de Paula, José Realino; Ferri, Pedro Henrique

2010-01-20

338

Carbohydrate storage in meadow plants and its depletion after disturbance: do roots and stem-derived organs differ in their roles?  

PubMed

Storage of carbohydrates in organs protected from disturbance is an important adaptation of plants in disturbed habitats. We carried out a field experiment involving 31 herbaceous plant species in two cultural meadows to find out whether roots or belowground stem-derived organs (stem bases, stem tubers and rhizomes) are the main storage organs, to study how reserves accumulate in individual organs in the long term (growing season) and to ascertain whether meadow abandonment affects the distribution of carbohydrate reserves in plants. We also conducted a 22-day pot experiment with four meadow plant species to determine how removal of roots and aboveground parts affects the use of carbohydrates stored in roots and stem-derived organs in the short term. From the long-term perspective of the field experiment, mowing had a positive effect on the concentration of carbohydrate reserves. From the short-term perspective of the pot experiment, however, the effect on concentration and pools of carbohydrates was negative. In the field experiment, carbohydrate concentrations before winter were generally higher than in mid-season, and more often higher in roots than in stem-derived organs. Roots and stem-derived organs of plants in the pot experiment were depleted similarly after both types of disturbance. Our results indicate a need for including both types of belowground plant organs in future studies of the carbon economy of plants from disturbed habitats. PMID:24525791

Jane?ek, St?pán; Klimešová, Jitka

2014-05-01

339

The Major Cellular Sterol Regulatory Pathway Is Required for Andes Virus Infection  

PubMed Central

The Bunyaviridae comprise a large family of RNA viruses with worldwide distribution and includes the pathogenic New World hantavirus, Andes virus (ANDV). Host factors needed for hantavirus entry remain largely enigmatic and therapeutics are unavailable. To identify cellular requirements for ANDV infection, we performed two parallel genetic screens. Analysis of a large library of insertionally mutagenized human haploid cells and a siRNA genomic screen converged on components (SREBP-2, SCAP, S1P and S2P) of the sterol regulatory pathway as critically important for infection by ANDV. The significance of this pathway was confirmed using functionally deficient cells, TALEN-mediated gene disruption, RNA interference and pharmacologic inhibition. Disruption of sterol regulatory complex function impaired ANDV internalization without affecting virus binding. Pharmacologic manipulation of cholesterol levels demonstrated that ANDV entry is sensitive to changes in cellular cholesterol and raises the possibility that clinically approved regulators of sterol synthesis may prove useful for combating ANDV infection. PMID:24516383

Riblett, Amber M.; Didigu, Chukwuka A.; Wilen, Craig B.; Malani, Nirav; Male, Frances; Lee, Fang-Hua; Bushman, Frederic D.; Cherry, Sara; Doms, Robert W.; Bates, Paul; Briley, Kenneth

2014-01-01

340

Synthesis of steryl ferulates with various sterol structures and comparison of their antioxidant activity.  

PubMed

Steryl ferulates synthesised from commercial sterols as well as commercial oryzanol were used to better understand how structural features affect antioxidant activity in vitro by the ABTS(+) radical decolorization assay, by oxidative stability index (OSI) of soybean oil, and by analysis of antioxidant activity during frying. Steryl ferulates inhibited the ABTS(+) radical by 6.5-56.6%, depending on their concentration, but were less effective, especially at lower concentrations, than ferulic acid. Ferulic acid and steryl ferulates had either no effect, or lowered the OSI of soybean oil by up to 25%, depending on the concentration. In their evaluation as frying oil antioxidants, steryl ferulates with a saturated sterol group had the best antioxidant activity, followed by sterols with one double bond in the C5 position. The results indicate that a dimethyl group at C4 as well as a C9,C19 cyclopropane group, as found in oryzanol, negatively affects antioxidant activity in frying oils. PMID:25236203

Winkler-Moser, Jill K; Hwang, Hong-Sik; Bakota, Erica L; Palmquist, Debra A

2015-02-15

341

A rapid method to determine sterol, erythrodiol, and uvaol concentrations in olive oil.  

PubMed

A rapid, accurate, and efficient method for determining the sterol, uvaol, and erythrodiol concentrations was developed to meet International Olive Council (IOC) certification criteria for extra virgin olive oil (EVOO). The unsaponifiable fraction of the sample (0.2 g) was separated with a diatomaceous earth column, and the sterol and triterpenic dialcohols were isolated with a novel base-activated silica solid-phase extraction (SPE) cartridge cleanup protocol. The improved method and the IOC method provided identical pass/fail results (n = 34) for each of the six sterol and erythrodiol/uvaol IOC criteria used to assess olive oil. This method was validated, and recoveries of stigmasterol (88%) and ?-sitosterol (84%) were greater than previously published values obtained using the IOC method. This method requires approximately one-third the time required to complete the IOC method and has great utility for the rapid screening of EVOO to detect adulteration, false labeling, and an inferior product. PMID:23587059

Mathison, Brian; Holstege, Dirk

2013-05-15

342

Lipid [corrected] classes, fatty acids, and sterols in seafood from Gilbert Bay, southern labrador.  

PubMed

Seafood from Gilbert Bay, southern Labrador, was sampled for lipid classes, fatty acid, and sterol composition. Gilbert Bay is a proposed Marine Protected Area, and the composition of seafood from this region is interesting from both human health and ecological perspectives. Analyses included four species of bivalves and flesh and liver samples from four fish species. Lipids from a locally isolated population of northern cod (Gadus morhua) were also compared to lipids from other cod populations. Lipid classes were analyzed by Chromarod/Iatroscan TLC-FID, fatty acids by GC, and sterols by GC-MS. Three cod populations had similar levels of total lipid per wet weight (0.6%) with triacylglycerols (TAG), sterols, and phospholipids comprising on average 13, 11, and 51%, respectively, of their total lipids. Fatty fish such as capelin and herring contained on average 8.4% lipid with 86% present as TAG. Fish livers from cod and herring showed opposite trends, with cod having elevated lipid (27%) and TAG (63%) and herring containing only 3.8% lipid and 20% TAG. Shellfish averaged 0.6% lipid; however, significant lipid class differences existed among species. Fatty acid analysis showed few significant differences in cod populations with on average 57% polyunsaturated fatty acids (PUFA), 18% monounsaturated fatty acids (MUFA), and 24% saturated fatty acids (SFA). Cod livers had lower PUFA (34%) and elevated MUFA (44%) relative to flesh. Bivalves averaged 25% SFA, 18% MUFA, and 57% PUFA, whereas scallop adductor muscle had the highest PUFA levels (63%). Bivalves contained 20 different sterols with cholesterol present as the major sterol (19-39%). trans-22-Dehydrocholesterol, brassicasterol, 24-methylenecholesterol, and campesterol individually accounted for >10% in at least one species. High levels of PUFA and non-cholesterol sterols observed in Gilbert Bay seafood demonstrate their positive attributes for human nutrition. PMID:15264928

Copeman, Louise A; Parrish, Christopher C

2004-07-28

343

Effect of sterol side chain on ion channel formation by amphotericin B in lipid bilayers.  

PubMed

Amphotericin B (AmB) is one of the most efficient antimycotic drugs used in clinical practice. AmB interacts with membrane sterols increasing permeability of fungal membranes; however, it is still unclear how AmB selectively recognizes the fungal sterol, ergosterol (Erg), over other sterols in cell membranes. In this study, we investigated the effect of an Erg side chain on AmB activity by testing a series of Erg analogues that shared the same alicyclic structure as Erg but varied in the side chain structure by using the K(+) influx assay. The results clearly showed that the sterol side chain is essential for AmB selectivity toward Erg and for the activity of AmB-sterol ion channels. In agreement with our previous findings showing the direct interaction between the drug and Erg, these data suggested that AmB directly recognizes the sterol side chain structure, consequently promoting the formation of ion channels by AmB. Furthermore, the C24 methyl group and ?22 double bond in the side chain of Erg are equally important for the interaction with AmB. Conformational analysis revealed that the C24 methyl group contributes to the interaction by increasing the van der Waals (VDW) contact area of the side chain, while the ?22 double bond restricts the side chain conformation to maximize the VDW contact with the rigid AmB aglycone. This study provides direct experimental evidence of the mechanism of AmB selectivity toward fungal Erg. PMID:24762132

Nakagawa, Yasuo; Umegawa, Yuichi; Takano, Tetsuro; Tsuchikawa, Hiroshi; Matsumori, Nobuaki; Murata, Michio

2014-05-20

344

[Apoptosis induced by the C21 sterols in Baishouwu and its mechanism of action in hepatoma].  

PubMed

This study is to investigate the effect of the C21 sterols on inducing apoptosis of hepatocellular cancer cells and its potential mechanism. The transplanted model of hepatoma substantiality (Heps) was established in mice, and the mice were divided into four groups: negative controls group and C21 sterols groups (10, 20, 40 mg x kg(-1)) , treated with drugs separately once a day for 9 days. Then the mice were sacrificed, the tumor growth inhibition rate (IR) was calculated and tumor tissue samples were taken and examined under electron microscope. The tumor cells were harvested and cell viability or apoptosis was analyzed by acridine orange and ethidium bromide (AO/EB) stain. B-cell lymphoma/leukemia-2 gene (bcl-2) in tumor cells was inspected by immunohistochemistry. After treatment with C21 sterols (10, 20, 40 mg x kg(-1)), inhibitory effect on the transplanted Heps was observed. The IR was 34.79%, 47.08% and 50.23%, respectively. Apoptosis induced by the C21 sterols was observed, low growth density and some apoptotic cells were observed in tumor under the electron microscope. The expression of bcl-2 gene on tumor cells decreased in the C21 sterols groups, but the percentage of positive area is higher in 40 mg x kg(-1) group than that in 20 mg x kg(-1) group, which differed from apoptosis results. Inhibiting the excessive expression of bcl-2 gene to promote apoptosis may be one of anti-tumor mechanisms for the C21 sterols in Baishouwu. PMID:17633201

Wang, Dong-yan; Zhang, Hong-quan; Li, Xin

2007-04-01

345

Plant-derived decapeptide OSIP108 interferes with Candida albicans biofilm formation without affecting cell viability.  

PubMed

We previously identified a decapeptide from the model plant Arabidopsis thaliana, OSIP108, which is induced upon fungal pathogen infection. In this study, we demonstrated that OSIP108 interferes with biofilm formation of the fungal pathogen Candida albicans without affecting the viability or growth of C. albicans cells. OSIP108 displayed no cytotoxicity against various human cell lines. Furthermore, OSIP108 enhanced the activity of the antifungal agents amphotericin B and caspofungin in vitro and in vivo in a Caenorhabditis elegans-C. albicans biofilm infection model. These data point to the potential use of OSIP108 in combination therapy with conventional antifungal agents. In a first attempt to unravel its mode of action, we screened a library of 137 homozygous C. albicans mutants, affected in genes encoding cell wall proteins or transcription factors important for biofilm formation, for altered OSIP108 sensitivity. We identified 9 OSIP108-tolerant C. albicans mutants that were defective in either components important for cell wall integrity or the yeast-to-hypha transition. In line with these findings, we demonstrated that OSIP108 activates the C. albicans cell wall integrity pathway and that its antibiofilm activity can be blocked by compounds inhibiting the yeast-to-hypha transition. Furthermore, we found that OSIP108 is predominantly localized at the C. albicans cell surface. These data point to interference of OSIP108 with cell wall-related processes of C. albicans, resulting in impaired biofilm formation. PMID:24566179

Delattin, Nicolas; De Brucker, Katrijn; Craik, David J; Cheneval, Olivier; Fröhlich, Mirjam; Veber, Matija; Girandon, Lenart; Davis, Talya R; Weeks, Anne E; Kumamoto, Carol A; Cos, Paul; Coenye, Tom; De Coninck, Barbara; Cammue, Bruno P A; Thevissen, Karin

2014-05-01

346

Naturally occurring radionuclides in materials derived from urban water treatment plants in southeast Queensland, Australia.  

PubMed

An assessment of radiologically enhanced residual materials generated during treatment of domestic water supplies in southeast Queensland, Australia, was conducted. Radioactivity concentrations of U-238, Th-232, Ra-226, Rn-222, and Po-210 in water, sourced from both surface water catchments and groundwater resources were examined both pre- and post-treatment under typical water treatment operations. Surface water treatment processes included sedimentation, coagulation, flocculation and filtration, while the groundwater was treated using cation exchange, reverse osmosis, activated charcoal or methods similar to surface water treatment. Waste products generated as a result of treatment included sediments and sludges, filtration media, exhausted ion exchange resin, backwash and wastewaters. Elevated residual concentrations of radionuclides were identified in these waste products. The waste product activity concentrations were used to model the radiological impact of the materials when either utilised for beneficial purposes, or upon disposal. The results indicate that, under current water resource exploitation programs, reuse or disposal of the treatment wastes from large scale urban water treatment plants in Australia do not pose a significant radiological risk. PMID:17980468

Kleinschmidt, Ross; Akber, Riaz

2008-04-01

347

Selective determination of mimosine and its dihydroxypyridinyl derivative in plant systems.  

PubMed

Our observations on the growth stimulatory nature of mimosine, (beta-(3-hydroxy-4-pyridon-1-yl)-L-alanine), the toxic non-protein plant amino acid, in some model experimental systems, warranted sensitive and selective routine estimations. For the determination of both mimosine and DHP, an indirect spectrophotometric method was developed based on their individual reaction with known excess of DZSAM and by estimating the remaining DZSAM with N-(1-naphthyl)ethylene-diamine (NEDA). The resultant decrease in the secondary coupled product was measured at 540 nm. On equimolar basis, DHP had 40% of the reactivity of mimosine while interference from other relevant compounds was 15-35%. The determination of mimosine and DHP in tissue samples under different physiological conditions was effected after paper chromatographic separation of mimosine and DHP with distinctly differing Rf, from other compounds. The indirect method is superior in terms of absolute selectivity, sensitivity and ease of applicability with linear decreases in absorbance, proportional to increasing concentrations of mimosine from 0.1 to 0.75 microM or DHP from 0.2 to 1.5 microM and with recoveries of 99.2 to 100.5%. PMID:16988910

Lalitha, K; Rajendra Kulothungan, S

2006-10-01

348

Plant-Derived Decapeptide OSIP108 Interferes with Candida albicans Biofilm Formation without Affecting Cell Viability  

PubMed Central

We previously identified a decapeptide from the model plant Arabidopsis thaliana, OSIP108, which is induced upon fungal pathogen infection. In this study, we demonstrated that OSIP108 interferes with biofilm formation of the fungal pathogen Candida albicans without affecting the viability or growth of C. albicans cells. OSIP108 displayed no cytotoxicity against various human cell lines. Furthermore, OSIP108 enhanced the activity of the antifungal agents amphotericin B and caspofungin in vitro and in vivo in a Caenorhabditis elegans-C. albicans biofilm infection model. These data point to the potential use of OSIP108 in combination therapy with conventional antifungal agents. In a first attempt to unravel its mode of action, we screened a library of 137 homozygous C. albicans mutants, affected in genes encoding cell wall proteins or transcription factors important for biofilm formation, for altered OSIP108 sensitivity. We identified 9 OSIP108-tolerant C. albicans mutants that were defective in either components important for cell wall integrity or the yeast-to-hypha transition. In line with these findings, we demonstrated that OSIP108 activates the C. albicans cell wall integrity pathway and that its antibiofilm activity can be blocked by compounds inhibiting the yeast-to-hypha transition. Furthermore, we found that OSIP108 is predominantly localized at the C. albicans cell surface. These data point to interference of OSIP108 with cell wall-related processes of C. albicans, resulting in impaired biofilm formation. PMID:24566179

Delattin, Nicolas; De Brucker, Katrijn; Craik, David J.; Cheneval, Olivier; Frohlich, Mirjam; Veber, Matija; Girandon, Lenart; Davis, Talya R.; Weeks, Anne E.; Kumamoto, Carol A.; Cos, Paul; Coenye, Tom; De Coninck, Barbara; Thevissen, Karin

2014-01-01

349

Expression of a plant-derived peptide harboring water-cleaning and antimicrobial activities.  

PubMed

Drinking water is currently a scarce world resource, the preparation of which requires complex treatments that include clarification of suspended particles and disinfection. Seed extracts of Moringa oleifera Lam., a tropical tree, have been proposed as an environment-friendly alternative, due to their traditional use for the clarification of drinking water. However, the precise nature of the active components of the extract and whether they may be produced in recombinant form are unknown. Here we show that recombinant or synthetic forms of a cationic seed polypeptide mediate efficient sedimentation of suspended mineral particles and bacteria. Unexpectedly, the polypeptide was also found to possesses a bactericidal activity capable of disinfecting heavily contaminated water. Furthermore, the polypeptide has been shown to efficiently kill several pathogenic bacteria, including antibiotic-resistant isolates of Staphylococcus, Streptococcus, and Legionella species. Thus, this polypeptide displays the unprecedented feature of combining water purification and disinfectant properties. Identification of an active principle derived from the seed extracts points to a range of potential for drinking water treatment or skin and mucosal disinfection in clinical settings. PMID:12432576

Suarez, M; Entenza, J M; Doerries, C; Meyer, E; Bourquin, L; Sutherland, J; Marison, I; Moreillon, P; Mermod, N

2003-01-01

350

System of handling refuse derived fuel utilizing same to fire power plants  

SciTech Connect

This patent describes an apparatus for supplying refuse derived fuel, that has been shredded to a predetermined nominal size to a furnace fuel supply chute that is open to the furnace fire chamber, in a continuous and uninterrupted flow, for heating the furnace boiler. The apparatus consists of: a large primary surge capacity bin. The bin includes an upper intake port and a lower discharge port, means for continuously storing the fuel in the bin at a rate that is substantially in excess of the flow rate of the flow, means for vibrating the primary bin for feeding from the stored fuel quantity the fuel at a predetermined lesser flow rate, a vibrating conveyor including means for receiving the fuel at the lesser flow rate and including a fuel flow conducting through for vibrationally feeding the fuel received from the primary bin to the locale of the furnace, a metering bin mounted at the locale of the furnace and including an upper intake port and a lower discharge port, means for supplying the fuel from the vibrating conveyor to the metering bin through the upper intake port of the metering bin.

Dumbaugh, G.D.

1988-10-04

351

Formulating blackberry leaf mixtures for preparation of infusions with plant derived sources of sweeteners.  

PubMed

Herbal mixtures composed of blackberry leaf and natural sweeteners (dried apples, prunes, figs, raisins, apricots, carrot and sweet potato, stevia leaves and liquorice root) were developed. Their nutritive and bioactive profile, biological activity and sensory properties were determined. Formulated mixtures exhibited lower total polyphenol content (259.09-350.00 mg GAE/L) when compared to plain blackberry leaf, but contained higher content of chlorogenic, ferulic, p-coumaric, rosmarinic acids and quercetin, as well as some macroelements (Ca, K, Mg) and microelements (Ba, Na). Stevia addition to formulated mixtures ensured higher polyphenolic content. Dried carrot exhibited the highest (0.988 g/g) and liquorice the lowest (0.087 g/g) content of total sugars but it contributed to the sweetness with 574.48 mg/L of glycyrrhizic acid derivatives. Plain blackberry leaf extract exhibited cytotoxic and antioxidative activity on human colon cancer cells. Formulated mixtures exhibited improved flavour profile and balanced sweetness in relation to plain blackberry leaf infusion. PMID:24423548

Komes, Draženka; Belš?ak-Cvitanovi?, Ana; Ljubi?i?, Ivan; Durgo, Ksenija; Cindri?, Iva Juranovi?; Buši?, Arijana; Vojvodi?, Aleksandra

2014-05-15

352

Recoverable Pd/C catalyst mediated dehydrogenation of sterols and an improved synthesis of 1?-hydroxydehydroepiandrosterone.  

PubMed

A novel recyclable Pd/C catalyst mediated dehydrogenation of sterols is developed. The conversion of sterols to 1,4,6-trien-3-ones is best achieved with Pd/C as a catalyst (10%) in the presence of six equivalents of allyl diethyl phosphate (ADP) and excess amount of sodium carbonate in DMF under vigorous reflux conditions. This transformation gives 17,17-ethylenedioxyandrost-1,4,6-trien-3-one in better yield than that of DDQ oxidation and thus provides an improved synthesis of 1?-hydroxydehydroepiandrosterone from DHEA. PMID:23000152

Yin, Yi-Zhen; Liu, Chao; Tang, Long-Qian; Liu, Zhao-Peng

2012-11-01

353

Dominance of ? 7 -sterols in the family caryophyllaceaein the family caryophyllaceae  

Microsoft Academic Search

The predominant 4-desmethylsterols from the leaves of 12 species in 11 genera of the family Caryophyllaceae are 24-ethyl-?7-sterols. In eight species,Scleranthus annus L.,Paronychia virginica Spreng.,Lychnis alba Mill.,Silene cucubalus Wibel,Dianthus armeria L.,Gypsophilia paniculata L.,Saponaria officinales L. andMyosoton aquaticum (L.) Moench, the major sterols are spinasterol (24?-ethylcholesta-7,22E-dien-3?-ol) and 22-dihydrospinasterol (24?-ethylcholest-7-en-3?-ol),\\u000a with spinasterol at more than 60% of the desmethylsterol in the latter

Thomas A. Salt; John H. Adler

1986-01-01

354

Plants  

NSDL National Science Digital Library

Get ready to explore plants! Let's Learn About Plants! Question: What do plants need to live? Watch the video to find out! What does it need to grow? Question: What are the parts of a plant? Click to find out! Parts of a Plant Question: What is the life cycle of a plant? Watch the video to find out! Plant Life Cycle Video Question: ...

Berneski, Miss

2011-12-10

355

Cytotoxicity of three new triazolo-pyrimidine derivatives against the plant trypanosomatid: Phytomonas sp. isolated from Euphorbia characias.  

PubMed

There is no effective chemotherapy against diseases caused by Phytomonas sp., a plant trypanosomatid responsible for economic losses in major crops. We tested three triazolo-pyrimidine complexes [two with Pt(II), and another with Ru(III)] against promastigotes of Phytomonas sp. isolated from Euphorbia characias. The incorporation of radiolabelled precursors, ultrastructural alterations and changes in the pattern of metabolite excretion were examined. Different degrees of toxicity were found for each complex: the platinum compound showed an inhibition effect on nucleic acid synthesis, provoking alterations on the levels of mitochondria, nucleus and glycosomes. These results, together with others reported previously in our laboratory about the activity of pyrimidine derivatives, reflect the potential of these compounds as agents in the treatment of Phytomonas sp. PMID:15558180

Magán, Rosa; Marín, Clotilde; Salas, Juan M; Barrera-Pérez, Mario; Rosales, Maria J; Sánchez-Moreno, Manuel

2004-10-01

356

Effects of dietary plant-derived phytonutrients on the genome-wide profiles and coccidiosis resistance in the broiler chickens  

PubMed Central

Background The present study was conducted to investigate the effects of dietary plant-derived phytonutrients, carvacrol, cinnamaldehyde and Capsicum oleoresin, on the translational regulation of genes associated with immunology, physiology and metabolism using high-throughput microarray analysis and in vivo disease challenge model of avian coccidiosis. Methods In this study, we used nutrigenomics technology to investigate the molecular and genetic mechanisms of dietary modulation of host innate immunity and metabolism by three phytonutrients. To validate their immunomodulatory effects in a disease model, young broiler chickens fed a standard diet supplemented with three phytochemicals (carvacrol, cinnamaldehyde, and Capsicum oleoresin) from one day post-hatch were orally challenged with E. acervulina. The body weight gain and fecal oocyst production were used to evaluate coccidiosis disease parameters. Results Analysis of global gene expression profiles of intestinal tissues from phytonutrient-fed birds indicated that Capsicum oleoresin induced the most gene changes compared to the control group where many of these genes were associated with those of metabolism and immunity. The most reliable network induced by dietary cinnamaldehyde treatment was related with the functions of antigen presentation, humoral immune response, and inflammatory disease. Furthermore, dietary supplementation with these phytonutrients significantly protected broiler chickens against live coccidiosis challenge infection based on body weight and parasite fecundity. Conclusions The results of this study provide clear evidence to support the idea that plant-derived phytochemicals possess immune-enhancing properties in chickens and these new findings create a new possibility to develop effective drug-free alternative strategies for disease control for poultry infectious diseases. PMID:21645315

2011-01-01

357

A new plant-derived antibacterial is an inhibitor of efflux pumps in Staphylococcus aureus.  

PubMed

An in-depth evaluation was undertaken of a new antibacterial natural product (1) recently isolated and characterised from the plant Hypericum olympicum L. cf. uniflorum. Minimum inhibitory concentrations (MICs) were determined for a panel of bacteria, including: meticillin-resistant and -susceptible strains of Staphylococcus aureus, Staphylococcus epidermidis and Staphylococcus haemolyticus; vancomycin-resistant and -susceptible Enterococcus faecalis and Enterococcus faecium; penicillin-resistant and -susceptible Streptococcus pneumoniae; group A streptococci (Streptococcus pyogenes); and Clostridium difficile. MICs were 2-8 mg/L for most staphylococci and all enterococci, but were ?16 mg/L for S. haemolyticus and were >32 mg/L for all species in the presence of blood. Compound 1 was also tested against Gram-negative bacteria, including Escherichia coli, Pseudomonas aeruginosa and Salmonella enterica serovar Typhimurium but was inactive. The MIC for Mycobacterium bovis BCG was 60 mg/L, and compound 1 inhibited the ATP-dependent Mycobacterium tuberculosis MurE ligase [50% inhibitory concentration (IC(50)) = 75 ?M]. In a radiometric accumulation assay with a strain of S. aureus overexpressing the NorA multidrug efflux pump, the presence of compound 1 increased accumulation of (14)C-enoxacin in a concentration-dependent manner, implying inhibition of efflux. Only moderate cytotoxicity was observed, with IC50 values of 12.5, 10.5 and 8.9 ?M against human breast, lung and fibroblast cell lines, respectively, highlighting the potential value of this chemotype as a new antibacterial agent and efflux pump inhibitor. PMID:24119569

Shiu, Winnie K P; Malkinson, John P; Rahman, M Mukhlesur; Curry, Jonathan; Stapleton, Paul; Gunaratnam, Mekala; Neidle, Stephen; Mushtaq, Shazad; Warner, Marina; Livermore, David M; Evangelopoulos, Dimitrios; Basavannacharya, Chandrakala; Bhakta, Sanjib; Schindler, Bryan D; Seo, Susan M; Coleman, David; Kaatz, Glenn W; Gibbons, Simon

2013-12-01

358

Toxic inhibition of smooth muscle contractility by plant-derived sesquiterpenes caused by their chemically reactive alpha-methylenebutyrolactone functions.  

PubMed Central

1. Previous studies have shown that extracts of feverfew (Tanacetum parthenium) and parthenolide, a sesquiterpene alpha-methylenebutyrolactone obtained from it, inhibit smooth muscle contractility in a time-dependent, non-specific and irreversible manner. 2. The hypothesis that this toxic effect is due specifically to the presence in the sesquiterpene lactone of the potentially reactive alpha-methylene function was tested on rabbit isolated aortic ring preparations. This was done (a) by comparing the effects of two plant-derived sesquiterpene lactones purified from yellow star thistle (Centaurea solstitialis): cynaropicrin (an alpha-methylenebutyrolactone) and solstitialin 13-acetate (lacking the alpha-methylene function), and (b) by chemically inactivating the alpha-methylene functions in cynaropicrin and parthenolide by reaction with cysteine. 3. The results show that the characteristic smooth muscle inhibitory profile is demonstrated by the two alpha-methylenebutyrolactones (parthenolide and cynaropicrin), but not by the compound lacking this functional group (solstitialin 13-acetate), or by those previously active compounds in which it has been inactivated with cysteine. 4. Thus the alpha-methylene function is critical for this aspect of the toxic pharmacological profile of the sesquiterpene butyrolactones, which are natural products widely distributed in the Compositae family of flowering plants. PMID:8032668

Hay, A. J.; Hamburger, M.; Hostettmann, K.; Hoult, J. R.

1994-01-01

359

Toxic inhibition of smooth muscle contractility by plant-derived sesquiterpenes caused by their chemically reactive alpha-methylenebutyrolactone functions.  

PubMed

1. Previous studies have shown that extracts of feverfew (Tanacetum parthenium) and parthenolide, a sesquiterpene alpha-methylenebutyrolactone obtained from it, inhibit smooth muscle contractility in a time-dependent, non-specific and irreversible manner. 2. The hypothesis that this toxic effect is due specifically to the presence in the sesquiterpene lactone of the potentially reactive alpha-methylene function was tested on rabbit isolated aortic ring preparations. This was done (a) by comparing the effects of two plant-derived sesquiterpene lactones purified from yellow star thistle (Centaurea solstitialis): cynaropicrin (an alpha-methylenebutyrolactone) and solstitialin 13-acetate (lacking the alpha-methylene function), and (b) by chemically inactivating the alpha-methylene functions in cynaropicrin and parthenolide by reaction with cysteine. 3. The results show that the characteristic smooth muscle inhibitory profile is demonstrated by the two alpha-methylenebutyrolactones (parthenolide and cynaropicrin), but not by the compound lacking this functional group (solstitialin 13-acetate), or by those previously active compounds in which it has been inactivated with cysteine. 4. Thus the alpha-methylene function is critical for this aspect of the toxic pharmacological profile of the sesquiterpene butyrolactones, which are natural products widely distributed in the Compositae family of flowering plants. PMID:8032668

Hay, A J; Hamburger, M; Hostettmann, K; Hoult, J R

1994-05-01

360

Properties of the plant- and manure-derived biochars and their sorption of dibutyl phthalate and phenanthrene  

PubMed Central

The properties of plant residue-derived biochars (PLABs) and animal waste-derived biochars (ANIBs) obtained at low and high heating treatment temperatures (300 and 450°C) as well as their sorption of dibutyl phthalate (DBP) and phenanthrene (PHE) were investigated in this study. The higher C content of PLABs could explain that CO2-surface area (CO2-SA) of PLABs was remarkably high relative to ANIBs. OC and aromatic C were two key factors influencing the CO2-SA of the biochars. Much higher surface C content of the ANIBs than bulk C likely explained that the ANIBs exhibited higher sorption of DBP and PHE compared to the PLABs. H-bonding should govern the adsorption of DBP by most of the tested biochars and ?-? interaction play an important role in the adsorption of PHE by biochars. High CO2-SA (>200?m2 g?1) demonstrated that abundant nanopores of OC existed within the biochars obtained 450°C (HTBs), which likely result in high and nonlinear sorption of PHE by HTBs. PMID:24924925

Qiu, Mengyi; Sun, Ke; Jin, Jie; Gao, Bo; Yan, Yu; Han, Lanfang; Wu, Fengchang; Xing, Baoshan

2014-01-01

361

Models of Experimentally Derived Competitive Effects Predict Biogeographical Differences in the Abundance of Invasive and Native Plant Species  

PubMed Central

Mono-dominance by invasive species provides opportunities to explore determinants of plant distributions and abundance; however, linking mechanistic results from small scale experiments to patterns in nature is difficult. We used experimentally derived competitive effects of an invader in North America, Acroptilon repens, on species with which it co-occurs in its native range of Uzbekistan and on species with which it occurs in its non-native ranges in North America, in individual-based models. We found that competitive effects yielded relative abundances of Acroptilon and other species in models that were qualitatively similar to those observed in the field in the two ranges. In its non-native range, Acroptilon can occur in nearly pure monocultures at local scales, whereas such nearly pure stands of Acroptilon appear to be much less common in its native range. Experimentally derived competitive effects of Acroptilon on other species predicted Acroptilon to be 4–9 times more proportionally abundant than natives in the North American models, but proportionally equal to or less than the abundance of natives in the Eurasian models. Our results suggest a novel way to integrate complex combinations of interactions simultaneously, and that biogeographical differences in the competitive effects of an invader correspond well with biogeographical differences in abundance and impact. PMID:24265701

Xiao, Sa; Ni, Guangyan; Callaway, Ragan M.

2013-01-01

362

Models of experimentally derived competitive effects predict biogeographical differences in the abundance of invasive and native plant species.  

PubMed

Mono-dominance by invasive species provides opportunities to explore determinants of plant distributions and abundance; however, linking mechanistic results from small scale experiments to patterns in nature is difficult. We used experimentally derived competitive effects of an invader in North America, Acroptilon repens, on species with which it co-occurs in its native range of Uzbekistan and on species with which it occurs in its non-native ranges in North America, in individual-based models. We found that competitive effects yielded relative abundances of Acroptilon and other species in models that were qualitatively similar to those observed in the field in the two ranges. In its non-native range, Acroptilon can occur in nearly pure monocultures at local scales, whereas such nearly pure stands of Acroptilon appear to be much less common in its native range. Experimentally derived competitive effects of Acroptilon on other species predicted Acroptilon to be 4-9 times more proportionally abundant than natives in the North American models, but proportionally equal to or less than the abundance of natives in the Eurasian models. Our results suggest a novel way to integrate complex combinations of interactions simultaneously, and that biogeographical differences in the competitive effects of an invader correspond well with biogeographical differences in abundance and impact. PMID:24265701

Xiao, Sa; Ni, Guangyan; Callaway, Ragan M

2013-01-01

363

Properties of the plant- and manure-derived biochars and their sorption of dibutyl phthalate and phenanthrene  

NASA Astrophysics Data System (ADS)

The properties of plant residue-derived biochars (PLABs) and animal waste-derived biochars (ANIBs) obtained at low and high heating treatment temperatures (300 and 450°C) as well as their sorption of dibutyl phthalate (DBP) and phenanthrene (PHE) were investigated in this study. The higher C content of PLABs could explain that CO2-surface area (CO2-SA) of PLABs was remarkably high relative to ANIBs. OC and aromatic C were two key factors influencing the CO2-SA of the biochars. Much higher surface C content of the ANIBs than bulk C likely explained that the ANIBs exhibited higher sorption of DBP and PHE compared to the PLABs. H-bonding should govern the adsorption of DBP by most of the tested biochars and ?-? interaction play an important role in the adsorption of PHE by biochars. High CO2-SA (>200 m2 g-1) demonstrated that abundant nanopores of OC existed within the biochars obtained 450°C (HTBs), which likely result in high and nonlinear sorption of PHE by HTBs.

Qiu, Mengyi; Sun, Ke; Jin, Jie; Gao, Bo; Yan, Yu; Han, Lanfang; Wu, Fengchang; Xing, Baoshan

2014-06-01

364

The Calvin cycle inevitably produces sugar-derived reactive carbonyl methylglyoxal during photosynthesis: a potential cause of plant diabetes.  

PubMed

Sugar-derived reactive carbonyls (RCs), including methylglyoxal (MG), are aggressive by-products of oxidative stress known to impair the functions of multiple proteins. These advanced glycation end-products accumulate in patients with diabetes mellitus and cause major complications, including arteriosclerosis and cardiac insufficiency. In the glycolytic pathway, the equilibration reactions between dihydroxyacetone phosphate and glyceraldehyde 3-phosphate (GAP) have recently been shown to generate MG as a by-product. Because plants produce vast amounts of sugars and support the same reaction in the Calvin cycle, we hypothesized that MG also accumulates in chloroplasts. Incubating isolated chloroplasts with excess 3-phosphoglycerate (3-PGA) as the GAP precursor drove the equilibration reaction toward MG production. The rate of oxygen (O2) evolution was used as an index of 3-PGA-mediated photosynthesis. The 3-PGA- and time-dependent accumulation of MG in chloroplasts was confirmed by HPLC. In addition, MG production increased with an increase in light intensity. We also observed a positive linear relationship between the rates of MG production and O2 evolution (R = 0.88; P < 0.0001). These data provide evidence that MG is produced by the Calvin cycle and that sugar-derived RC production is inevitable during photosynthesis. Furthermore, we found that MG production is enhanced under high-CO2 conditions in illuminated wheat leaves. PMID:24406631

Takagi, Daisuke; Inoue, Hironori; Odawara, Mizue; Shimakawa, Ginga; Miyake, Chikahiro

2014-02-01

365

The composition and flux of vascular-plant derived organic matter export from small mountainous rivers during typhoon event  

NASA Astrophysics Data System (ADS)

Small mountainous rivers, which suffer from landslides triggered by tropical cyclones, may transfer particulate organic carbon (POC) from land to the ocean in an express way, hyperpycnal flow. A significant amount of organic carbon produced by biosphere was channeled to the deep sea during flash flood. The OC source characterization is essential to understand the biosphere denudation and the responses of river basin to the growing climate extremes. Lignin phenols had been widely used in the geochemical studies to trace the terrestrial POC transport as it is unique to the vascular plants. In present study, we first measured lignin phenols in samples collected from three stations in a Taiwan river, Chuoshui River, during the Typhoon Mindulle in 2004 with high time resolution (every 3 hours) to explore the source variation and accurately quantify vascular plant derived OM throughout the flood. In the mainstream, ?8 (Lignin concentration normalized to POC) varied from approximately 0.4 mg/100mg OC at the flood rising and up to 2.4 mg/100mg OC at the peak discharge. A significant positive correlation between water discharge and ?8 was observed (r=0.93, p<0.001) suggesting that precipitation, thus discharge is the primary control for the transport of the vascular plant OM. Moreover, a significant negative relation observed between ?8 and degradation indicator (P/(V+S)) (r=0.62, p<0.001)revealed that freshly produced vascular POC was diluted by highly degraded OC. We calculated that approximately 1.3 Gg of particulate lignin was exported within 84h from Chuoshui River to the ocean, in which ~50% was achieved during the 3 hours discharge peak. The event exporting particulate lignin from Chuoshui River was ~10% of annual export from Changjiang, which is 600x larger in watershed size. Moreover, >90% particulate lignin in Chuoshui River was delivered via hyperpycnal flow, representing an efficient sequestration of terrestrial OC in deep ocean.

Bao, Hongyan; Kao, Shuh-Ji

2014-05-01

366

Production of phytosterols by mature Digitalis purpurea L. plants.  

PubMed

The relative rates of production by mature Digitalis purpurea plants of cholesterol, campesterol, stigmasterol and sitosterol isolated from the glycoside and lipid fractions of the plant extract, were estimated. Plants were exposed to an atmosphere of (14)CO2 in a growth chamber and the radioactivity of the individual sterols assessed at intervals over 25 days on a gas-liquid radio chemical chromatography (GLRC). Incorporation of (14)CO2 occurred within 12 hours into both fractions of the extract. The 5-ene sterols were produced at a similar rate over a period of 25 days but the lipid fraction was about 100% more radioactive than the glycoside fraction. PMID:24469415

Evans, F J

1973-03-01

367

Fatty Acid and Sterol Composition of Mucor genevensis in Relation to Dimorphism and Anaerobic Growth  

PubMed Central

Fatty acid and sterol content and composition were determined for the dimorphic mold, Mucor genevensis, grown under a variety of experimental conditions. Fatty acids account for 6 to 9% of the dry weight of aerobically grown mycelium, and 70 to 80% of these are unsaturated. The organism contains ?-linolenic acid which is characteristic for Phycomycetes, and in sporangiospores this compound represents 40% of the total fatty acids. Of the sterols found in mycelium, 80% is ergosterol, and stigmasterol was positively identified as one of the minor components. In anaerobically grown yeastlike cells, sterol content is less than 10% of the level found in aerobically grown cells, and fatty acids amount to less than 2% of the dry weight. These fatty acids are predominantly short chain and less than 10% are unsaturated. Yeastlike cells obtained under aerobic conditions by growth in the presence of phenethyl alcohol have fatty acid and sterol compositions characteristic of aerobically grown mycelium. It is concluded that the dimorphology of the organism is not directly related to lipid composition. PMID:4327506

Gordon, P. A.; Stewart, P. R.; Clark-Walker, G. D.

1971-01-01

368

Degradation of sterols and terrigenous organic matter in waters of the Mackenzie Shelf, Canadian Arctic  

E-print Network

June 2014 Available online 18 June 2014 Keywords: Mackenzie shelf Mackenzie River SPM Sterols particulate matter (SPM) from surface waters in the Mackenzie River mouth to the Beaufort Sea shelf (Canadian. Laboratory incubation of Mackenzie River SPM in Milli-Q water and seawater confirmed this proposal

369

Effect of food fatty acid and sterol quality on Pecten maximus gonad composition and reproduction process  

Microsoft Academic Search

Spawning individuals of the scallop Pecten maximus were conditioned on three test diets: Tahiti Isochrysis, a mixture (PTSC) and Chaetoceros calcitrans. The scallops fed T-Isochrysis showed a better hatching rate and lower atresia than those fed the other two diets. Proximate composition of the female gonads was not modified by the differences in the diets. Enrichment of gonads with sterol

Philippe Soudant; Yanic Marty; Jeanne Moal; René Robert; Claudie Quéré; Jean René Le Coz; Jean François Samain

1996-01-01

370

[Microbial model of Halobacterium salinarum for screening inhibitors of sterol biosynthesis].  

PubMed

A highly effective and simple microbial test system for screening inhibitors of sterol biosynthesis (ISB) is described. The system is based on cultivation of the bacterial strain Halobacterium salinarum (former Halobacterium halobium), that possesses mevalonate pathway of sterol biosynthesis and is much similar in the biosynthesis to cholesterol formation in humans. In the H. salinarum test system the ISB were found as compounds that inhibited the test culture growth. Mevalonate which is one of the crucial intermediates of sterol biosynthesis dismissed the inhibitory effect of many microbial metabolites thus being evident of their action at the early stages of the sterol biosynthesis, including the HMG-CoA reductase stage. The H. salinarum test system was developed as a micromethod and could be easily mechanized by miniaturization of the microbiological procedures, cultivation in sterile 96-well plates and using automatic micropipettes and dispensers. The H. salinarum test system was effective in testing crude extracts of the culture broths and advantageous at early stage of screening. The use of the H. salinarum test system was shown possible for screening antitumor antibiotics. PMID:24757819

Trenin, A S

2013-01-01

371

Selective visualization of fluorescent sterols in Caenorhabditis elegans by bleach-rate-based image segmentation.  

PubMed

The nematode Caenorhabditis elegans is a genetically tractable model organism to investigate sterol transport. In vivo imaging of the fluorescent sterol, dehydroergosterol (DHE), is challenged by C. elegans' high autofluorescence in the same spectral region as emission of DHE. We present a method to detect DHE selectively, based on its rapid bleaching kinetics compared to cellular autofluorescence. Worms were repeatedly imaged on an ultraviolet-sensitive wide field (UV-WF) microscope, and bleaching kinetics of DHE were fitted on a pixel-basis to mathematical models describing the intensity decay. Bleach-rate constants were determined for DHE in vivo and confirmed in model membranes. Using this method, we could detect enrichment of DHE in specific tissues like the nerve ring, the spermateca and oocytes. We confirm these results in C. elegans gut-granule-loss (glo) mutants with reduced autofluorescence and compare our method with three-photon excitation microscopy of sterol in selected tissues. Bleach-rate-based UV-WF imaging is a useful tool for genetic screening experiments on sterol transport, as exemplified by RNA interference against the rme-2 gene coding for the yolk receptor and for worm homologues of Niemann-Pick C disease proteins. Our approach is generally useful for identifying fluorescent probes in the presence of high cellular autofluorescence. PMID:20070610

Wüstner, Daniel; Landt Larsen, Ane; Faergeman, Nils J; Brewer, Jonathan R; Sage, Daniel

2010-04-01

372

Identification and Biosynthetic Origins of Sterols in the Marine Bryozoan Bugula neritina  

E-print Network

in vitro techniques indicated that 24-alkylated sterols (4, 5, 7, and 8) are produced by alkylation of polyketide macrolides with potent anticancer activity.4 Bryostatin 1 is currently in clinical development; however, only a very few populations contain the clinical agent bryostatin 1.9,10 In the study described

Kerr, Russell G.

373

Selective delipidation of the plasma membrane by surfactants: Enrichment of sterols and activation of ATPase  

SciTech Connect

The influence of plasma membrane lipid components on the activity of the H{sup +}-ATPase has been studied by determining the effect of surfactants on membrane lipids and ATPase activity of oat (Avena sativa L.) root plasma membrane vesicles purified by a two-phase partitioning procedure. Triton X-100, at 25 to 1 (weight/weight) Triton to plasma membrane protein, an amount that causes maximal activation of the ATPase in the ATPase assay, extracted 59% of the membrane protein but did not solubilize the bulk of the ATPase. The Triton-insoluble proteins had associated with them, on a micromole per milligram protein basis, only 14% as much phospholipid, but 38% of the glycolipids and sterols, as compared with the native membranes. The Triton insoluble ATPase could still be activated by Triton X-100. When solubilized by lysolecithin, there were still sterols associated with the ATPase fraction. Free sterols were found associated with the ATPase in the same relative proportions, whether treated with surfactants or not. We suggest that surfactants activate the ATPase by altering the hydrophobic environment around the enzyme. We propose that sterols, through their interaction with the ATPase, may be essential for ATPase activity.

Sandstrom, R.P.; Cleland, R. (Portland State Univ., OR (USA) Univ. of Washington, Seattle (USA))

1989-08-01

374

Plants  

NSDL National Science Digital Library

Use these links to find out more about plants. This site will help you determine what a plant needs to grow. Michigan's 4-H Children's Garden This site will send you through an adventure where you try to discover if you can grow plants on the moon. Adventures of the agronauts These 2 sites are teacher resource sites on plants. Light Plants and Dark Plants, Wet Plants and Dry Ones The New York Times Daily Lesson Plan: Growing Pains ...

Quinn, Miss

2005-05-02

375

Trypanosoma cruzi Response to Sterol Biosynthesis Inhibitors: Morphophysiological Alterations Leading to Cell Death  

PubMed Central

The protozoan parasite Trypanosoma cruzi displays similarities to fungi in terms of its sterol lipid biosynthesis, as ergosterol and other 24-alkylated sterols are its principal endogenous sterols. The sterol pathway is thus a potential drug target for the treatment of Chagas disease. We describe here a comparative study of the growth inhibition, ultrastructural and physiological changes leading to the death of T. cruzi cells following treatment with the sterol biosynthesis inhibitors (SBIs) ketoconazole and lovastatin. We first calculated the drug concentration inhibiting epimastigote growth by 50% (EC50/72 h) or killing all cells within 24 hours (EC100/24 h). Incubation with inhibitors at the EC50/72 h resulted in interesting morphological changes: intense proliferation of the inner mitochondrial membrane, which was corroborated by flow cytometry and confocal microscopy of the parasites stained with rhodamine 123, and strong swelling of the reservosomes, which was confirmed by acridine orange staining. These changes to the mitochondria and reservosomes may reflect the involvement of these organelles in ergosterol biosynthesis or the progressive autophagic process culminating in cell lysis after 6 to 7 days of treatment with SBIs at the EC50/72 h. By contrast, treatment with SBIs at the EC100/24 h resulted in rapid cell death with a necrotic phenotype: time-dependent cytosolic calcium overload, mitochondrial depolarization and reservosome membrane permeabilization (RMP), culminating in cell lysis after a few hours of drug exposure. We provide the first demonstration that RMP constitutes the “point of no return” in the cell death cascade, and propose a model for the necrotic cell death of T. cruzi. Thus, SBIs trigger cell death by different mechanisms, depending on the dose used, in T. cruzi. These findings shed new light on ergosterol biosynthesis and the mechanisms of programmed cell death in this ancient protozoan parasite. PMID:23383204

Kessler, Rafael Luis; Soares, Maurilio José; Probst, Christian Macagnan; Krieger, Marco Aurélio

2013-01-01

376

Sterols in red and green algae: quantification, phylogeny, and relevance for the interpretation of geologic steranes.  

PubMed

Steroids, a class of triterpenoid lipids with high preservation potential, are widely distributed in sedimentary rocks. All eukaryotes have a physiological requirement for these molecules, making steroids important biomarkers for aiding our understanding of eukaryote molecular evolution and geologic history. C(26)-C(30) sterols are the molecules most commonly incorporated or synthesized by eukaryotes, and correspond to C(26)-C(30) steranes ubiquitously and abundantly preserved in petroleums and sedimentary bitumens. Because these sterols occur in evolutionarily diverse taxa, it can be difficult to associate any particular compound with a single group of organisms. Nevertheless, geochemists have still been able to draw parallels between the empirical patterns in geologic sterane abundances and the age of petroleum source rocks. Paleobiologists have also used sterane data, in particular the patterns in C(29) and C(28) steranes, to support fossil evidence of an early radiation of green algae in latest Proterozoic and Paleozoic and the succession of the major modern phytoplankton groups in the Mesozoic. Although C(29) sterols are found in many eukaryotes, organisms that produce them in proportional abundances comparable to those preserved in Proterozoic and Paleozoic rocks are limited. Based on a large, phylogenetically based survey of sterol profiles from the kingdom Plantae, we conclude that modern ulvophyte and early diverging prasinophyte green algae produce high abundances of C(29) relative to C(27) and C(28) sterols most consistent with the sterane profiles observed in Paleozoic rocks. Our analysis also suggests that ancestral stem groups among the Plantae, including the glaucocystophytes and early divergent red algae are also plausible candidates. PMID:18624688

Kodner, R B; Pearson, A; Summons, R E; Knoll, A H

2008-08-01

377

Acetate-Mediated Growth Inhibition in Sterol 14?-Demethylation-Deficient Cells of Candida albicans  

PubMed Central

Candida albicans is a fungus thought to be viable in the presence of a deficiency in sterol 14?-demethylation. We showed in a strain of this species that the deficiency, caused either by a mutation or by an azole antifungal agent, made the cells susceptible to growth inhibition by acetate included in the culture medium. Studies with a mutant demonstrated that the inhibition was complete at a sodium acetate concentration of 0.24 M (20 g/liter) and was evident even at a pH of 8, the latter result indicating the involvement of acetate ions rather than the undissociated form of acetic acid. In fluconazole-treated cells, sterol profiles determined by thin-layer chromatography revealed that the minimum sterol 14?-demethylation-inhibitory concentrations (MDICs) of the drug, thought to be the most important parameter for clinical purposes, were practically identical in the media with and without 0.24 M acetate and were equivalent to the MIC in the acetate-supplemented medium. The acetate-mediated growth inhibition of azole-treated cells was confirmed with two additional strains of C. albicans and four different agents, suggesting the possibility of generalization. From these results, it was surmised that the acetate-containing medium may find use in azole susceptibility testing, for which there is currently no method capable of measuring MDICs directly for those fungi whose viability is not lost as a result of sterol 14?-demethylation deficiency. Additionally, the acetate-supplemented agar medium was found to be useful in detecting reversions from sterol 14?-demethylation deficiency to proficiency. PMID:9869573

Shimokawa, Osamu; Nakayama, Hiroaki

1999-01-01

378

Cleavage of sterol regulatory element binding proteins (SREBPs) by CPP32 during apoptosis.  

PubMed Central

Cellular cholesterol homeostasis is controlled by sterol-regulated proteolysis of membrane-bound transcription factors called sterol-regulatory element binding proteins (SREBPs). CPP32, a cysteine protease, was shown previously to cleave SREBP-1 and SREBP-2 in vitro at an aspartic acid between the basic helix-loop-helix leucine zipper domain and the first trans-membrane domain, liberating a transcriptionally active fragment. Here, we show that CPP32 exists in an inactive 32 kDa form in Chinese hamster ovary (CHO) cells. When apoptosis was induced with the protein kinase inhibitor staurosporine, CPP32 was cleaved to subunits of 20 and 10 kDa to form the active protease. Under these conditions membrane-bound SREBP-1 and SREBP-2 were both cleaved, and the transcriptionally active N-terminal fragments were found in nuclear extracts. Similar results were obtained in human U937 cells induced to undergo apoptosis by anti-Fas and etoposide. The apoptosis-induced cleavage of SREBPs was not suppressed by sterols, indicating that apoptosis-induced cleavage and sterol-regulated cleavage are mediated by different proteases. CHO cells expressing a mutant SREBP-2 with an Asp--> Ala mutation at the CPP32 cleavage site showed sterol-regulated cleavage but no apoptosis-induced cleavage. These data are consistent with the emerging concept that CPP32 is a central mediator in apoptosis. They also indicate that SREBPs, like poly (ADP) ribose polymerase, are cleaved by CPP32 during programmed cell death. Images PMID:8605870

Wang, X; Zelenski, N G; Yang, J; Sakai, J; Brown, M S; Goldstein, J L

1996-01-01

379

The Origin of Sterol Biosynthesis: A Time-Point for the Evolution of Eukaryotes and the Presence of O2  

NASA Astrophysics Data System (ADS)

The evolution of sterol biosynthesis is of critical interest to geoscientists as well as to evolutionary biologists. The first enzyme in the pathway, squalene monooxygenase (Sqmo), requires molecular oxygen (O2), suggesting that this process post-dates the evolution of Cyanobacteria. Additionally, the presence of steranes in ancient rocks marks the suggested time-point of eukaryogenesis(1). Sterol biosynthesis is viewed primarily as a eukaryotic process, and the frequency of its occurrence in bacteria long has been a subject of controversy. In this work, 19 protein gene sequences for Sqmo from eukaryotes were compared to all available complete and partial prokaryotic genomes. Twelve protein gene sequences representing oxidosqualene cyclase (Osc), the second enzyme of the sterol biosynthetic pathway, also were examined. The only unequivocal matches among the bacteria were the alpha-proteobacterium, Methylococcus capsulatus, in which sterol biosynthesis already is known, and the planctomycete, Gemmata obscuriglobus. The latter species contains the most abbreviated sterol pathway yet identified in any organism. Experiments show that the major sterols in Gemmata are lanosterol and its uncommon isomer, parkeol. In bacteria, the sterol biosynthesis genes occupy a contiguous coding region and may represent a single operon. Phylogenetic trees show that the sterol pathway in bacteria and eukaryotes has a common ancestry. Gemmata may retain the most ancient remnants of the pathway's origin, and it is likely that sterol biosynthesis in eukaryotes was acquired through gene transfer from bacteria. However, this work indicates that no known prokaryotes could produce the 24-ethyl steranes found in Archaean rocks(1). Therefore these compounds remain indicative of the presence of both eukaryotes and O2 at 2.7 Ga. 1. J. J. Brocks, G. A. Logan, R. Buick, R. E. Summons, (1999) Science 285, 1033-1036.

Pearson, A.; Budin, M.; Brocks, J. J.

2003-12-01

380

Present and future potential of plant-derived products to control arthropods of veterinary and medical significance  

PubMed Central

The use of synthetic pesticides and repellents to target pests of veterinary and medical significance is becoming increasingly problematic. One alternative approach employs the bioactive attributes of plant-derived products (PDPs). These are particularly attractive on the grounds of low mammalian toxicity, short environmental persistence and complex chemistries that should limit development of pest resistance against them. Several pesticides and repellents based on PDPs are already available, and in some cases widely utilised, in modern pest management. Many more have a long history of traditional use in poorer areas of the globe where access to synthetic pesticides is often limited. Preliminary studies support that PDPs could be more widely used to target numerous medical and veterinary pests, with modes of action often specific to invertebrates. Though their current and future potential appears significant, development and deployment of PDPs to target veterinary and medical pests is not without issue. Variable efficacy is widely recognised as a restraint to PDPs for pest control. Identifying and developing natural bioactive PDP components in place of chemically less-stable raw or 'whole’ products seems to be the most popular solution to this problem. A limited residual activity, often due to photosensitivity or high volatility, is a further drawback in some cases (though potentially advantageous in others). Nevertheless, encapsulation technologies and other slow-release mechanisms offer strong potential to improve residual activity where needed. The current review provides a summary of existing use and future potential of PDPs against ectoparasites of veterinary and medical significance. Four main types of PDP are considered (pyrethrum, neem, essential oils and plant extracts) for their pesticidal, growth regulating and repellent or deterrent properties. An overview of existing use and research for each is provided, with direction to more extensive reviews given in many sections. Sections to highlight potential issues, modes of action and emerging and future potential are also included. PMID:24428899

2014-01-01

381

A reconstruction of Atlantic Central African biomes and forest succession stages derived from modern pollen data and plant functional types  

NASA Astrophysics Data System (ADS)

New detailed vegetation reconstructions are proposed in Atlantic Central Africa from a modern pollen data set derived from 199 sites (Cameroon, Gabon and Congo) including 131 new sites. In this study, the concept of plant functional classification is improved with new and more detailed plant functional types (PFTs) and new aggregations of pollen taxa. Using the biomisation method, we reconstructed (1) modern potential biomes and (2) potential succession stages of forest regeneration, a new approach in Atlantic Central African vegetation dynamics and ecosystem functioning reconstruction. When compared to local vegetation, potential biomes are correctly reconstructed (97.5% of the sites) and tropical evergreen to semi-evergreen forest (TRFO biome) is well identified from semi-deciduous forest (TSFO biome). When the potential biomes are superimposed on the White's vegetation map, only 76.4% of the sites are correctly reconstructed. But using botanical data, correspondence and cluster analyses, the 43 sites from Congo (Mayombe) evidence more affinities with those of central Gabon and so they can also be considered as correctly reconstructed as TRFO biome and White's map must be revised. In terms of potential succession stages of forest regeneration, the mature forest (TMFO) is well differentiated from the secondary forest (TSFE), but inside this latter group, the young and the pioneer stages are not clearly identified due probably to their low sampling representation. Moreover, linked to their progressive and mosaic character, the boundaries between two forest biomes or two forest stages are not clearly detected and need also a more intensive sampling in such transitions.

Lebamba, J.; Ngomanda, A.; Vincens, A.; Jolly, D.; Favier, C.; Elenga, H.; Bentaleb, I.

2009-01-01

382

Plant-derived compatible solutes proline betaine and betonicine confer enhanced osmotic and temperature stress tolerance to Bacillus subtilis.  

PubMed

l-Proline is a widely used compatible solute and is employed by Bacillus subtilis, through both synthesis and uptake, as an osmostress protectant. Here, we assessed the stress-protective potential of the plant-derived l-proline derivatives N-methyl-l-proline, l-proline betaine (stachydrine), trans-4-l-hydroxproline and trans-4-hydroxy-l-proline betaine (betonicine) for cells challenged by high salinity or extremes in growth temperature. l-Proline betaine and betonicine conferred salt stress protection, but trans-4-l-hydroxyproline and N-methyl-l-proline was unable to do so. Except for l-proline, none of these compounds served as a nutrient for B. subtilis. l-Proline betaine was a considerably better osmostress protectant than betonicine, and its import strongly reduced the l-proline pool produced by B. subtilis under osmotic stress conditions, whereas a supply of betonicine affected the l-proline pool only modestly. Both compounds downregulated the transcription of the osmotically inducible opuA operon, albeit to different extents. Mutant studies revealed that l-proline betaine was taken up via the ATP-binding cassette transporters OpuA and OpuC, and the betaine-choline-carnitine-transporter-type carrier OpuD; betonicine was imported only through OpuA and OpuC. l-Proline betaine and betonicine also served as temperature stress protectants. A striking difference between these chemically closely related compounds was observed: l-proline betaine was an excellent cold stress protectant, but did not provide heat stress protection, whereas the reverse was true for betonicine. Both compounds were primarily imported in temperature-challenged cells via the high-capacity OpuA transporter. We developed an in silico model for the OpuAC-betonicine complex based on the crystal structure of the OpuAC solute receptor complexed with l-proline betaine. PMID:25012968

Bashir, Abdallah; Hoffmann, Tamara; Kempf, Bettina; Xie, Xiulan; Smits, Sander H J; Bremer, Erhard

2014-10-01

383

Plants  

NSDL National Science Digital Library

What is the cycle plants go through? First use Write out the Plant Cycle Watch the Plant Powerpoint write down what you learned. Next watch the movie Plant Cycle Movie What did you think was interesting? Next, search around on the website and write down facts about plants. LIfe Cycle of Plants Next, play around with the part of the plants http://www.sciencekids.co.nz/gamesactivities/lifecycles.htmlFinally learn all about growing a plant. Growing a plant After you are finished come see me ...

Barron, Anne

2011-04-14

384

Derivation of power loss factors to evaluate the impact of postcombustion CO 2 capture processes on steam power plant performance  

Microsoft Academic Search

When integrating a post-combustion CO2 capture process and a CO2 compressor into a steam power plant, the heat duty for the regeneration of the solvent (and the corresponding steam extraction) shows to be the largest contributor to the overall net efficiency penalty of the power plant. One parameter which varies from plant to plant and which significantly affects the impact

Sebastian Linnenberg; Ulrich Liebenthal; Jochen Oexmann; Alfons Kather

2011-01-01

385

Radiocesium derived from the Fukushima Daiichi Nuclear Power Plant accident in seabed sediments: initial deposition and inventories.  

PubMed

Since the accident at Fukushima Daiichi Nuclear Power Plant (1FNPP), significant levels of anthropogenic radionuclides have been detected in seabed sediments off the east coast of Japan. In this paper, the approximate amount of accident-derived radiocesium in seabed sediments off Fukushima, Miyagi and Ibaraki prefectures was estimated from a sediment integration algorithm. As of October 2011, about half a year after the accident, the total amount of sedimentary 134Cs was 0.20±0.06 PBq (decay corrected to March 11, 2011) and more than 90% of the radiocesium was accumulated in the regions shallower than 200 m depth. The large inventory in the coastal sediments was attributed to effective adsorption of dissolved radiocesium onto suspended particles and directly to sediments in the early post-accident stage. Although rivers are also an important source to supply radiocesium to the coastal regions, this flux was much lower than that of the above-mentioned process within half a year after the accident. PMID:24743987

Otosaka, Shigeyoshi; Kato, Yoshihisa

2014-05-01

386

Antifungal and antioxidative potential of oil and extracts derived from leaves of Indian spice plant Cinnamomum tamala.  

PubMed

Plant—based antimicrobials and antioxidants represent a vast untapped source for medicines and food supplements and hence have enormous therapeutic potential. Present work reports the fungicidal potential of Cinnamomum tamala Nees & Eberm (Lauraceae) leaf oil against five food spoilage and pathogenic fungi. In addition antioxidant efficacy of seven different solvent extracts derived from leaf was also evaluated using in vitro models. The oil demonstrated potent antifungal activity against Aspergillus niger, A. fumigatus, Candida albicans, Rhizopus stolonifer and Penicillium spp. in agar diffusion assay. Zone of inhibition ranged from 17-25 mm. The MFC values of oil against all the test fungi were found to be 230?g/ml. Phytochemicals present in C. tamala leaf were extracted in several solvents for assessing their effect in oxidative defense. The extracts exhibited appreciable antioxidant activity in ?-carotene bleaching assay and reducing power assay. The antioxidative activities of extracts were compared with the activities of standard antioxidant compounds BHA and ascorbic acid. Petroleum ether, ethanol, acetone and chloroform extracts exhibited about 30-67% antioxidant activity in ?-carotene bleaching assay. Aqueous and ethanol extracts exhibited better reducing power which increased gradually with increasing amount of the extract concentration showing dose dependent response. Results indicated that natural phytochemicals present in C. tamala leaf extracts have potential to prevent growth of food spoilage/pathogenic fungi. In addition they also have capability to mitigate the oxidative stress by antioxidant response. PMID:23273204

Pandey, A K; Mishra, A K; Mishra, A

2012-01-01

387

Effects of plant-derived polyphenols on TNF-alpha and nitric oxide production induced by advanced glycation endproducts.  

PubMed

Advanced glycation endproducts (AGEs) accumulate on protein deposits including the beta-amyloid plaques in Alzheimer's disease. AGEs interact with the "receptor for advanced glycation endproducts", and transmit their signals using intracellular reactive oxygen species as second messengers. Ultimately, AGEs induce the expression of a variety of pro-inflammatory markers including the tumor necrosis factor (TNF-alpha) and inducible nitric oxide (NO) synthase. Antioxidants that act intracellularly, including polyphenols, have been shown to scavenge these "signaling" reactive oxygen species, and thus perform in an anti-inflammatory capacity. This study tested the pure compounds apigenin and diosmetin as well as extracts from silymarin, uva ursi (bearberry) and green olive leaf for their ability to attenuate AGE-induced NO and TNF-alpha production. All five tested samples inhibited BSA-AGE-induced NO production in a dose-dependent manner. Apigenin and diosmetin were most potent, and exhibited EC(50) values approximately 10 microM. In contrast, TNF-alpha expression was only reduced by apigenin, diosmetin and silymarin; not by the bearberry and green olive leaf extracts. In addition, the silymarin and bearberry extracts caused significant cell death at concentrations >or=10 microg/mL and >or=50 microg/mL, respectively. In conclusion, we suggest that plant-derived polyphenols might offer therapeutic opportunities to delay the progression of AGE-mediated and receptor for advanced glycation endproducts-mediated neuro-inflammatory diseases including Alzheimer's disease. PMID:20540146

Chandler, Dave; Woldu, Ameha; Rahmadi, Anton; Shanmugam, Kirubakaran; Steiner, Nicole; Wright, Elise; Benavente-García, Obdulio; Schulz, Oliver; Castillo, Julián; Münch, Gerald

2010-07-01

388

Efficacy of plant-derived and synthetic compounds on clothing as repellents against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae).  

PubMed

We conducted field trials to compare the relative repellent activity of two natural product compounds (nootkatone and carvacrol) with commercially available plant-derived (EcoSMART organic insect repellent) and permethrin-based (Repel Permanone) repellents against adult Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae) by using treated coveralls. One day after treatment, nootkatone and carvacrol provided 100% repellency of I. scapularis adults, with nootkatone maintaining complete protection through 3 d, whereas carvacrol showed steadily declining repellency against I. scapularis during the 7-d course of the trials. Nootkatone was at least as effective against host-seeking A. americanum as against I. scapularis through 3 d. Carvacrol provided little protection agains