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Sample records for metabolites

  1. Metabolite

    MedlinePlus

    A metabolite is any substance produced during metabolism (digestion or other bodily chemical processes). The term metabolite may also refer to the product that remains after a drug is broken down (metabolized) by the body.

  2. Volatile Metabolites

    PubMed Central

    Rowan, Daryl D.

    2011-01-01

    Volatile organic compounds (volatiles) comprise a chemically diverse class of low molecular weight organic compounds having an appreciable vapor pressure under ambient conditions. Volatiles produced by plants attract pollinators and seed dispersers, and provide defense against pests and pathogens. For insects, volatiles may act as pheromones directing social behavior or as cues for finding hosts or prey. For humans, volatiles are important as flavorants and as possible disease biomarkers. The marine environment is also a major source of halogenated and sulfur-containing volatiles which participate in the global cycling of these elements. While volatile analysis commonly measures a rather restricted set of analytes, the diverse and extreme physical properties of volatiles provide unique analytical challenges. Volatiles constitute only a small proportion of the total number of metabolites produced by living organisms, however, because of their roles as signaling molecules (semiochemicals) both within and between organisms, accurately measuring and determining the roles of these compounds is crucial to an integrated understanding of living systems. This review summarizes recent developments in volatile research from a metabolomics perspective with a focus on the role of recent technical innovation in developing new areas of volatile research and expanding the range of ecological interactions which may be mediated by volatile organic metabolites. PMID:24957243

  3. Reactive metabolites and agranulocytosis.

    PubMed

    Uetrecht, J P

    1996-01-01

    Central to most hypotheses of the mechanism of idiosyncratic drug-induced blood dyscrasias is the involvement of reactive metabolites. In view of the reactive nature of the majority of such metabolites, it is likely that they are formed by, or in close proximity to the blood cells affected. The major oxidative system of neutrophils generates hypochlorous acid. We have demonstrated that the drugs associated with the highest incidence of agranulocytosis are oxidized to reactive metabolites by hypochlorous acid and/or activated neutrophils. There are many mechanisms by which such reactive metabolites could induce agranulocytosis. In the case of aminopyrine-induced agranulocytosis, most cases appear to involve drug-dependent anti-neutrophil antibodies, and these are likely to be induced by cell membrane antigens modified by the reactive metabolite of aminopyrine. The target of agranulocytosis associated with many other drugs is usually neutrophil precursors and may involve cytotoxicity or a cell-mediated immune reaction induced by a reactive metabolite. In the case of aplastic anaemia, there is evidence in some cases for involvement of cytotoxic T cells, which could either be induced by metabolites generated by neutrophils, or more likely, by reactive metabolites generated by stem cells. PMID:8987247

  4. Advances in metabolite identification.

    PubMed

    Wishart, David S

    2011-08-01

    One of the central challenges to metabolomics is metabolite identification. Regardless of whether one uses so-called 'targeted' or 'untargeted' metabolomics, eventually all paths lead to the requirement of identifying (and quantifying) certain key metabolites. Indeed, without metabolite identification, the results of any metabolomic analysis are biologically and chemically uninterpretable. Given the chemical diversity of most metabolomes and the character of most metabolomic data, metabolite identification is intrinsically difficult. Consequently a great deal of effort in metabolomics over the past decade has been focused on making metabolite identification better, faster and cheaper. This review describes some of the newly emerging techniques or technologies in metabolomics that are making metabolite identification easier and more robust. In particular, it focuses on advances in metabolite identification that have occurred over the past 2 to 3 years concerning the technologies, methodologies and software as applied to NMR, MS and separation science. The strengths and limitations of some of these approaches are discussed along with some of the important trends in metabolite identification. PMID:21827274

  5. Enhanced metabolite generation

    DOEpatents

    Chidambaram, Devicharan

    2012-03-27

    The present invention relates to the enhanced production of metabolites by a process whereby a carbon source is oxidized with a fermentative microbe in a compartment having a portal. An electron acceptor is added to the compartment to assist the microbe in the removal of excess electrons. The electron acceptor accepts electrons from the microbe after oxidation of the carbon source. Other transfers of electrons can take place to enhance the production of the metabolite, such as acids, biofuels or brewed beverages.

  6. Secondary metabolites from Ganoderma.

    PubMed

    Baby, Sabulal; Johnson, Anil John; Govindan, Balaji

    2015-06-01

    Ganoderma is a genus of medicinal mushrooms. This review deals with secondary metabolites isolated from Ganoderma and their biological significance. Phytochemical studies over the last 40years led to the isolation of 431 secondary metabolites from various Ganoderma species. The major secondary compounds isolated are (a) C30 lanostanes (ganoderic acids), (b) C30 lanostanes (aldehydes, alcohols, esters, glycosides, lactones, ketones), (c) C27 lanostanes (lucidenic acids), (d) C27 lanostanes (alcohols, lactones, esters), (e) C24, C25 lanostanes (f) C30 pentacyclic triterpenes, (g) meroterpenoids, (h) farnesyl hydroquinones (meroterpenoids), (i) C15 sesquiterpenoids, (j) steroids, (k) alkaloids, (l) prenyl hydroquinone (m) benzofurans, (n) benzopyran-4-one derivatives and (o) benzenoid derivatives. Ganoderma lucidum is the species extensively studied for its secondary metabolites and biological activities. Ganoderma applanatum, Ganoderma colossum, Ganoderma sinense, Ganoderma cochlear, Ganoderma tsugae, Ganoderma amboinense, Ganoderma orbiforme, Ganoderma resinaceum, Ganoderma hainanense, Ganoderma concinna, Ganoderma pfeifferi, Ganoderma neo-japonicum, Ganoderma tropicum, Ganoderma australe, Ganoderma carnosum, Ganoderma fornicatum, Ganoderma lipsiense (synonym G. applanatum), Ganoderma mastoporum, Ganoderma theaecolum, Ganoderma boninense, Ganoderma capense and Ganoderma annulare are the other Ganoderma species subjected to phytochemical studies. Further phytochemical studies on Ganoderma could lead to the discovery of hitherto unknown biologically active secondary metabolites. PMID:25975187

  7. Understanding and Classifying Metabolite Space and Metabolite-Likeness

    PubMed Central

    Peironcely, Julio E.; Reijmers, Theo; Coulier, Leon; Bender, Andreas; Hankemeier, Thomas

    2011-01-01

    While the entirety of ‘Chemical Space’ is huge (and assumed to contain between 1063 and 10200 ‘small molecules’), distinct subsets of this space can nonetheless be defined according to certain structural parameters. An example of such a subspace is the chemical space spanned by endogenous metabolites, defined as ‘naturally occurring’ products of an organisms' metabolism. In order to understand this part of chemical space in more detail, we analyzed the chemical space populated by human metabolites in two ways. Firstly, in order to understand metabolite space better, we performed Principal Component Analysis (PCA), hierarchical clustering and scaffold analysis of metabolites and non-metabolites in order to analyze which chemical features are characteristic for both classes of compounds. Here we found that heteroatom (both oxygen and nitrogen) content, as well as the presence of particular ring systems was able to distinguish both groups of compounds. Secondly, we established which molecular descriptors and classifiers are capable of distinguishing metabolites from non-metabolites, by assigning a ‘metabolite-likeness’ score. It was found that the combination of MDL Public Keys and Random Forest exhibited best overall classification performance with an AUC value of 99.13%, a specificity of 99.84% and a selectivity of 88.79%. This performance is slightly better than previous classifiers; and interestingly we found that drugs occupy two distinct areas of metabolite-likeness, the one being more ‘synthetic’ and the other being more ‘metabolite-like’. Also, on a truly prospective dataset of 457 compounds, 95.84% correct classification was achieved. Overall, we are confident that we contributed to the tasks of classifying metabolites, as well as to understanding metabolite chemical space better. This knowledge can now be used in the development of new drugs that need to resemble metabolites, and in our work particularly for assessing the metabolite

  8. Microalgal metabolites: a new perspective.

    PubMed

    Shimizu, Y

    1996-01-01

    Occurrence of secondary metabolites in microalgae (protoctista) is discussed with respect to the phylogenic or taxonomic relationships of organisms. Biosynthetic mechanisms of certain metabolites such as paralytic shellfish poisoning toxins and polyether toxins are also discussed, and genetic aspects of the secondary metabolite production as well. PMID:8905087

  9. Metabolite Damage and Metabolite Damage Control in Plants.

    PubMed

    Hanson, Andrew D; Henry, Christopher S; Fiehn, Oliver; de Crécy-Lagard, Valérie

    2016-04-29

    It is increasingly clear that (a) many metabolites undergo spontaneous or enzyme-catalyzed side reactions in vivo, (b) the damaged metabolites formed by these reactions can be harmful, and (c) organisms have biochemical systems that limit the buildup of damaged metabolites. These damage-control systems either return a damaged molecule to its pristine state (metabolite repair) or convert harmful molecules to harmless ones (damage preemption). Because all organisms share a core set of metabolites that suffer the same chemical and enzymatic damage reactions, certain damage-control systems are widely conserved across the kingdoms of life. Relatively few damage reactions and damage-control systems are well known. Uncovering new damage reactions and identifying the corresponding damaged metabolites, damage-control genes, and enzymes demands a coordinated mix of chemistry, metabolomics, cheminformatics, biochemistry, and comparative genomics. This review illustrates the above points using examples from plants, which are at least as prone to metabolite damage as other organisms. PMID:26667673

  10. [Antiviral properties of basidiomycetes metabolites].

    PubMed

    Avtonomova, A V; Krasnopolskaya, L M

    2014-01-01

    The data on the antiviral action of the Ganoderma lucidum, Lentinus edodes, Grifola frondosa, Agaricus brasiliensis and other basidiomycetes metabolites are summurized. The metabolites of these species of basidiomycetes exhibit a direct antiviral effect on herpes simplex virus types I and II, human immunodeficiency virus (HIV), hepatitis B virus, vesicular stomatitis virus, influenza virus, Epstein-Barr virus, and others. Moreover, metabolites of basidiomycetes increased antiviral immunity. PMID:25975107

  11. Sun, shade, and secondary metabolites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    My research program focuses on understanding plant primary and secondary metabolites. Grape secondary metabolites, such as phenolics, have long been valuable for the organoleptic properties they impart to fruit and wine, and, more recently, for their possible health benefits. These compounds develop...

  12. Synthesis Of Labeled Metabolites

    DOEpatents

    Martinez, Rodolfo A.; Silks, III, Louis A.; Unkefer, Clifford J.; Atcher, Robert

    2004-03-23

    The present invention is directed to labeled compounds, for example, isotopically enriched mustard gas metabolites including: [1,1',2,2'-.sup.13 C.sub.4 ]ethane, 1,1'-sulfonylbis[2-(methylthio); [1,1',2,2'-.sup.13 C.sub.4 ]ethane, 1-[[2-(methylsulfinyl)ethyl]sulfonyl]-2-(methylthio); [1,1',2,2'-.sup.13 C.sub.4 ]ethane, 1,1'-sulfonylbis[2-(methylsulfinyl)]; and, 2,2'-sulfinylbis([1,2-.sup.13 C.sub.2 ]ethanol of the general formula ##STR1## where Q.sup.1 is selected from the group consisting of sulfide (--S--), sulfone (--S(O)--), sulfoxide (--S(O.sub.2)--) and oxide (--O--), at least one C* is .sup.13 C, X is selected from the group consisting of hydrogen and deuterium, and Z is selected from the group consisting of hydroxide (--OH), and --Q.sup.2 --R where Q.sup.2 is selected from the group consisting of sulfide (--S--), sulfone(--S(O)--), sulfoxide (--S(O.sub.2)--) and oxide (--O--), and R is selected from the group consisting of hydrogen, a C.sub.1 to C.sub.4 lower alkyl, and amino acid moieties, with the proviso that when Z is a hydroxide and Q.sup.1 is a sulfide, then at least one X is deuterium.

  13. Toxicological significance of dihydrodiol metabolites

    SciTech Connect

    Hsia, M.T.

    1982-01-01

    Dihydrodiols are often found as the major organic-extractable metabolites of various olefinic or aromatic xenobiotics in many biological samples. Studies on the chemistry of dihydrodiol metabolites have provided insight into the pharmacokinetic behavior and the mode of action of the parent compound. The toxicology of dihydrodiol is more complex than what can be deduced solely on the basis of diminished bioavailability of the epoxide precursor, and the increased hydrophilicity associated with the dihydrodiol moiety. Dihydrodiols can be intrinsically toxic and may even represent metabolically activated species. Some of the dihydrodiol metabolites may still retain sufficient lipophilic character to serve again as substrates for microsomal oxygenases. Because of the tremendous chemical and biological diversity that existed among the various dihydrodiols, more mechanistic studies are needed to examine the toxicological properties of these compounds. It may be premature to conclude dihydrodiol formation as purely a detoxification route for xenobioties.

  14. Deleterious effects of reactive metabolites

    PubMed Central

    2010-01-01

    A number of drugs have been withdrawn from the market or severely restricted in their use because of unexpected toxicities that become apparent only after the launch of new drug entities. Circumstantial evidence suggests that, in most cases, reactive metabolites are responsible for these unexpected toxicities. In this review, a general overview of the types of reactive metabolites and the consequences of their formation are presented. The current approaches to evaluate bioactivation potential of new compounds with particular emphasis on the advantages and limitation of these procedures will be discussed. Reasonable reasons for the excellent safety record of certain drugs susceptible to bioactivation will also be explored and should provide valuable guidance in the use of reactive-metabolite assessments when nominating drug candidates for development. This will, in turn, help us to design and bring safer drugs to the market. PMID:20972370

  15. Sphingolipid metabolites in inflammatory disease

    PubMed Central

    Maceyka, Michael; Spiegel, Sarah

    2015-01-01

    Sphingolipids are ubiquitous building blocks of eukaryotic cell membranes. Progress in our understanding of sphingolipid metabolism, state-of-the-art sphingolipidomic approaches and animal models have generated a large body of evidence demonstrating that sphingolipid metabolites, particularly ceramide and sphingosine-1-phosphate, are signalling molecules that regulate a diverse range of cellular processes that are important in immunity, inflammation and inflammatory disorders. Recent insights into the molecular mechanisms of action of sphingolipid metabolites and new perspectives on their roles in regulating chronic inflammation have been reported. The knowledge gained in this emerging field will aid in the development of new therapeutic options for inflammatory disorders. PMID:24899305

  16. Microbial production of primary metabolites

    NASA Astrophysics Data System (ADS)

    Demain, Arnold L.

    1980-12-01

    Microbial production of primary metabolites contributes significantly to the quality of life. Through fermentation, microorganisms growing on inexpensive carbon sources can produce valuable products such as amino acids, nucleotides, organic acids, and vitamins which can be added to food to enhance its flavor or increase its nutritive value. The contribution of microorganisms will go well beyond the food industry with the renewed interest in solvent fermentations. Microorganisms have the potential to provide many petroleum-derived products as well as the ethanol necessary for liquid fuel. The role of primary metabolites and the microbes which produce them will certainly increase in importance.

  17. Primary expectations of secondary metabolites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant secondary metabolites (e.g., phenolics) are important for human health, in addition to the organoleptic properties they impart to fresh and processed foods. Consumer expectations such as appearance, taste, or texture influence their purchasing decisions. Thorough identification of phenolic com...

  18. Natural products: Hunting microbial metabolites

    NASA Astrophysics Data System (ADS)

    Schmidt, Eric W.

    2015-05-01

    Symbiotic bacteria synthesize many specialized small molecules; however, establishing the role these chemicals play in human health and disease has been difficult. Now, the chemical structure and mechanism of the Escherichia coli product colibactin provides insight into the link between this secondary metabolite and colorectal cancer.

  19. METABOLITE PROFILING OF ECHINACEA GENOTYPES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Echinacea extracts have historically been used as herbal remedies to treat colds, coughs and snake bites. Echinacea products are currently sold as a popular herbal-remedy used for general enhancement of the immune system. However, the genetic variation in metabolites has not been systematically ch...

  20. Automated analysis of oxidative metabolites

    NASA Technical Reports Server (NTRS)

    Furner, R. L. (Inventor)

    1974-01-01

    An automated system for the study of drug metabolism is described. The system monitors the oxidative metabolites of aromatic amines and of compounds which produce formaldehyde on oxidative dealkylation. It includes color developing compositions suitable for detecting hyroxylated aromatic amines and formaldehyde.

  1. Identification of Epoxide-Derived Metabolite(s) of Benzbromarone.

    PubMed

    Wang, Kai; Wang, Hui; Peng, Ying; Zheng, Jiang

    2016-04-01

    Benzbromarone (BBR) is a benzofuran derivative that has been quite useful for the treatment of gout; however, it was withdrawn from European markets in 2003 because of reported serious incidents of drug-induced liver injury. BBR-induced hepatotoxicity has been suggested to be associated with the formation of a quinone intermediate. The present study reported epoxide-derived intermediate(s) of BBR. An N-acetylcysteine (NAC) conjugate derived from epoxide metabolite(s) was detected in both microsomal incubations of BBR and urine samples of mice treated with BBR. The NAC conjugate was identified as 6-NAC BBR. Ketoconazole suppressed the bioactivation of BBR to the epoxide intermediate(s), and the CYP3A subfamily was the primary enzyme responsible for the formation of the epoxide(s). The present study provided new information on metabolic activation of BBR. PMID:26792818

  2. Global Perspectives of Fungal Secondary Metabolite Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fungi produce a wide range of unusual metabolites, termed secondary metabolites because they play no role in the normal, basic metabolic pathways used for growth and energy production, etc. Some of these secondary metabolites have antibiotic properties; others are potent toxins that are dangerous w...

  3. Antileishmanial Metabolites from Geosmithia langdonii

    PubMed Central

    2015-01-01

    Antileishmanial bioassay guided fractionation of Geosmithia langdonii has resulted in the isolation and identification of two new compounds (1 and 2) together with 10 known compounds (3–12). The structures of the isolated metabolites were elucidated based on comprehensive 1D and 2D NMR spectroscopic data as well as mass spectrometry. The absolute configuration at C4, C5, and C6 of 2 was determined as R using a modified Mosher esterification method and NOESY correlations. The extracts and the isolated metabolites were evaluated for their antileishmanial activities. Compounds 3, 9, 11, and 12 were found to be active against Leishmania donovani with IC50 values of 6.9, 3.3, 8.5, and 9.2 μM, respectively, while compounds 1, 5, and 10 showed lower activities against L. donovani with IC50 values of 13.0, 47.3, and 34.0 μM, respectively. PMID:25084548

  4. Formed and preformed metabolites: facts and comparisons.

    PubMed

    Pang, K Sandy; Morris, Marilyn E; Sun, Huadong

    2008-10-01

    The administration of metabolites arising from new drug entities is often employed in drug discovery to investigate their associated toxicity. It is expected that administration of metabolites can predict the exposure of metabolites originating from the administration of precursor drug. Whether exact and meaningful information can be obtained from this has been a topic of debate. This communication summarizes observations and theoretical relationships based on physiological modelling for the liver, kidney and intestine, three major eliminating organs/tissues. Theoretical solutions based on physiological modelling of organs were solved, and the results suggest that deviations are expected. Here, examples of metabolite kinetics observed mostly in perfused organs that did not match predictions are provided. For the liver, discrepancies in fate between formed and preformed metabolites may be explained by the heterogeneity of enzymes, the presence of membrane barriers and whether transporters are involved. For the kidney, differences have been attributed to glomerular filtration of the preformed but not the formed metabolite. For the intestine, the complexity of segregated flows to the enterocyte and serosal layers and differences in metabolism due to the route of administration are addressed. Administration of the metabolite may or may not directly reflect the toxicity associated with drug use. However, kinetic data on the preformed metabolite will be extremely useful to develop a sound model for modelling and simulations; in-vitro evidence on metabolite handling at the target organ is also paramount. Subsequent modelling and simulation of metabolite data arising from a combined model based on both drug and preformed metabolite data are needed to improve predictions on the behaviours of formed metabolites. PMID:18812018

  5. Aspirin metabolites are GPR35 agonists.

    PubMed

    Deng, Huayun; Fang, Ye

    2012-07-01

    Aspirin is widely used as an anti-inflammatory, anti-platelet, anti-pyretic, and cancer-preventive agent; however, the molecular mode of action is unlikely due entirely to the inhibition of cyclooxygenases. Here, we report the agonist activity of several aspirin metabolites at GPR35, a poorly characterized orphan G protein-coupled receptor. 2,3,5-Trihydroxybenzoic acid, an aspirin catabolite, was found to be the most potent GPR35 agonist among aspirin metabolites. Salicyluric acid, the main metabolite of aspirin, was also active. These results suggest that the GPR35 agonist activity of certain aspirin metabolites may contribute to the clinical features of aspirin. PMID:22526472

  6. Complicating factors in safety testing of drug metabolites: Kinetic differences between generated and preformed metabolites

    SciTech Connect

    Prueksaritanont, Thomayant . E-mail: thomayant_prueksaritanont@merck.com; Lin, Jiunn H.; Baillie, Thomas A.

    2006-12-01

    This paper aims to provide a scientifically based perspective on issues surrounding the proposed toxicology testing of synthetic drug metabolites as a means of ensuring adequate nonclinical safety evaluation of drug candidates that generate metabolites considered either to be unique to humans or are present at much higher levels in humans than in preclinical species. We put forward a number of theoretical considerations and present several specific examples where the kinetic behavior of a preformed metabolite given to animals or humans differs from that of the corresponding metabolite generated endogenously from its parent. The potential ramifications of this phenomenon are that the results of toxicity testing of the preformed metabolite may be misleading and fail to characterize the true toxicological contribution of the metabolite when formed from the parent. It is anticipated that such complications would be evident in situations where (a) differences exist in the accumulation of the preformed versus generated metabolites in specific tissues, and (b) the metabolite undergoes sequential metabolism to a downstream product that is toxic, leading to differences in tissue-specific toxicity. Owing to the complex nature of this subject, there is a need to treat drug metabolite issues in safety assessment on a case-by-case basis, in which a knowledge of metabolite kinetics is employed to validate experimental paradigms that entail administration of preformed metabolites to animal models.

  7. A New Paradigm for Known Metabolite Identification in Metabonomics/Metabolomics: Metabolite Identification Efficiency

    PubMed Central

    Everett, Jeremy R.

    2015-01-01

    A new paradigm is proposed for assessing confidence in the identification of known metabolites in metabonomics studies using NMR spectroscopy approaches. This new paradigm is based upon the analysis of the amount of metabolite identification information retrieved from NMR spectra relative to the molecular size of the metabolite. Several new indices are proposed including: metabolite identification efficiency (MIE) and metabolite identification carbon efficiency (MICE), both of which can be easily calculated. These indices, together with some guidelines, can be used to provide a better indication of known metabolite identification confidence in metabonomics studies than existing methods. Since known metabolite identification in untargeted metabonomics studies is one of the key bottlenecks facing the science currently, it is hoped that these concepts based on molecular spectroscopic informatics, will find utility in the field. PMID:25750701

  8. Urinary metabolites of diisodecyl phthalate in rats.

    PubMed

    Kato, Kayoko; Silva, Manori J; Wolf, Cynthia; Gray, L Earl; Needham, Larry L; Calafat, Antonia M

    2007-07-01

    Diisodecyl phthalate (DiDP) is an isomeric mixture of phthalates with predominantly 10-carbon branched-dialkyl chains, widely used as a plasticizer for polyvinyl chloride. The extent of human exposure to DiDP is unknown in part because adequate biomarkers of exposure to DiDP are not available. We identified several major metabolites of DiDP in urine of adult female Sprague-Dawley rats after a single oral administration of DiDP (300 mg/kg). These metabolites can potentially be used as biomarkers of exposure to DiDP. The metabolites extracted from urine were chromatographically resolved and identified by their chromatographic behavior and full scan negative ion electrospray ionization mass spectrum. The identity of metabolites with similar molecular weights was further examined in accurate mass mode. For some metabolites, unequivocal identification was done using authentic standards. Among these were the hydrolytic monoester of DiDP, monoisodecyl phthalate (MiDP), detected as a minor metabolite, and one omega oxidation product of MiDP, mono(carboxy-isononyl) phthalate (MCiNP), which was the most abundant urinary metabolite. We also tentatively identified other secondary metabolites of MiDP, mono(hydroxy-isodecyl) phthalate, mono(oxo-isodecyl) phthalate, mono(carboxy-isoheptyl) phthalate, mono(carboxy-isohexyl) phthalate, mono(carboxy-isopentyl) phthalate, mono(carboxy-isobutyl) phthalate, and mono(carboxy-ethyl) phthalate. Oxidative metabolites of diisoundecyl phthalate (DiUdP) and diisononyl phthalate (DiNP) were also detected suggesting the presence of DiUdP and DiNP in the DiDP formulation. The urinary concentrations of all these metabolites gradually decreased in the 4 days following the administration of DiDP. MCiNP and other DiDP secondary metabolites are more abundant in urine than MiDP, suggesting that these oxidative products are better biomarkers for DiDP exposure assessment than MiDP. Additional research on the toxicokinetics of these metabolites is needed

  9. 40 CFR 159.179 - Metabolites, degradates, contaminants, and impurities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... chemical properties of the metabolite or degradate. (B) Data regarding structurally analogous chemicals. (C) Data regarding chemical reactivity of the metabolite or degradate and structurally analogous...

  10. 40 CFR 159.179 - Metabolites, degradates, contaminants, and impurities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... chemical properties of the metabolite or degradate. (B) Data regarding structurally analogous chemicals. (C) Data regarding chemical reactivity of the metabolite or degradate and structurally analogous...

  11. 40 CFR 159.179 - Metabolites, degradates, contaminants, and impurities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... chemical properties of the metabolite or degradate. (B) Data regarding structurally analogous chemicals. (C) Data regarding chemical reactivity of the metabolite or degradate and structurally analogous...

  12. Application of mass spectrometry for metabolite identification.

    PubMed

    Ma, Shuguang; Chowdhury, Swapan K; Alton, Kevin B

    2006-06-01

    Metabolism studies play a pivotal role in drug discovery and development. Characterization of metabolic "hot-spots" as well as reactive and pharmacologically active metabolites is critical to designing new drug candidates with improved metabolic stability, toxicological profile and efficacy. Metabolite identification in the preclinical species used for safety evaluation is required in order to determine whether human metabolites have been adequately tested during non-clinical safety assessment. From an instrumental standpoint, high performance liquid chromatography (HPLC) coupled with mass spectrometry (MS) dominates all analytical tools used for metabolite identification. The general strategies employed for metabolite identification in both drug discovery and drug development settings together with sample preparation techniques are reviewed herein. These include a discussion of the various ionization methods, mass analyzers, and tandem mass spectrometry (MS/MS) techniques that are used for structural characterization in a modern drug metabolism laboratory. Mass spectrometry-based techniques, such as stable isotope labeling, on-line H/D exchange, accurate mass measurement to enhance metabolite identification and recent improvements in data acquisition and processing for accelerating metabolite identification are also described. Rounding out this review, we offer additional thoughts about the potential of alternative and less frequently used techniques such as LC-NMR/MS, CRIMS and ICPMS. PMID:16787159

  13. Familial resemblance for serum metabolite concentrations.

    PubMed

    Draisma, Harmen H M; Beekman, Marian; Pool, René; van Ommen, Gert-Jan B; Adamski, Jerzy; Prehn, Cornelia; Vaarhorst, Anika A M; de Craen, Anton J M; Willemsen, Gonneke; Slagboom, P Eline; Boomsma, Dorret I

    2013-10-01

    Metabolomics is the comprehensive study of metabolites, which are the substrates, intermediate, and end products of cellular metabolism. The heritability of the concentrations of circulating metabolites bears relevance for evaluating their suitability as biomarkers for disease. We report aspects of familial resemblance for the concentrations in human serum of more than 100 metabolites, measured using a targeted metabolomics platform. Age- and sex-corrected monozygotic twin correlations, midparent-offspring regression coefficients, and spouse correlations in subjects from two independent cohorts (Netherlands Twin Register and Leiden Longevity Study) were estimated for each metabolite. In the Netherlands Twin Register subjects, who were largely fasting, we found significant monozygotic twin correlations for 121 out of 123 metabolites. Heritability was confirmed by midparent-offspring regression. For most detected metabolites, the correlations between spouses were considerably lower than those between twins, indicating a contribution of genetic effects to familial resemblance. Remarkably high heritability was observed for free carnitine (monozygotic twin correlation 0.66), for the amino acids serine (monozygotic twin correlation 0.77) and threonine (monozygotic twin correlation 0.64), and for phosphatidylcholine acyl-alkyl C40:3 (monozygotic twin correlation 0.77). For octenoylcarnitine, a consistent point estimate of approximately 0.50 was found for the spouse correlations in the two cohorts as well as for the monozygotic twin correlation, suggesting that familiality for this metabolite is explained by shared environment. We conclude that for the majority of metabolites targeted by the used metabolomics platform, the familial resemblance of serum concentrations is largely genetic. Our results contribute to the knowledge of the heritability of fasting serum metabolite concentrations, which is relevant for biomarker research. PMID:23985338

  14. Metabolism and metabolites of polychlorinated biphenyls (PCBs)

    PubMed Central

    Grimm, FA; Hu, D; Kania-Korwel, I; Lehmler, HJ; Ludewig, G; Hornbuckle, KC; Duffel, MW; Bergman, A; Robertson, LW

    2015-01-01

    The metabolism of polychlorinated biphenyls (PCBs) is complex and has an impact on toxicity and thereby assessment of PCB risks. A large number of reactive and stable metabolites are formed in the processes of biotransformation in biota in general and in humans in particular. The aim of this document is to provide an overview of PCB metabolism and to identify metabolites of concern and their occurrence. Emphasis is given to mammalian metabolism of PCBs and their hydroxyl, methylsulfonyl, and sulfated metabolites, especially those that persist in human blood. Potential intracellular targets and health risks are also discussed. PMID:25629923

  15. A wood preservative metabolite in river water.

    PubMed

    Khoroshko, Larisa O; Petrova, Varvara N; Viktorovskii, Igor V; Lahtiperä, Mirja; Sinkkonen, Seija; Paasivirta, Jaakko

    2005-01-01

    A previously unknown pollutant in river water was identified to be 2-mercaptobenzothiazole (2-MBT) by interpretation and simulation of its GC/LRMS spectrum. Further GC/HRMS measurement of the isotope composition of the molecular ion verified this structure. 2-MBT is a well-known agent for corrosion inhibition and a stable metabolite of several other benzothiazoles. The present 2-MBT trace was most probably a metabolite of the wood preservative TCMTB which leaked from an upstream sawmill. The metabolite had been detected earlier in urine of the sawmill workers, but now was identified in the recipient water environment for the first time. PMID:15768735

  16. Secondary metabolites from Rubiaceae species.

    PubMed

    Martins, Daiane; Nunez, Cecilia Veronica

    2015-01-01

    This study describes some characteristics of the Rubiaceae family pertaining to the occurrence and distribution of secondary metabolites in the main genera of this family. It reports the review of phytochemical studies addressing all species of Rubiaceae, published between 1990 and 2014. Iridoids, anthraquinones, triterpenes, indole alkaloids as well as other varying alkaloid subclasses, have shown to be the most common. These compounds have been mostly isolated from the genera Uncaria, Psychotria, Hedyotis, Ophiorrhiza and Morinda. The occurrence and distribution of iridoids, alkaloids and anthraquinones point out their chemotaxonomic correlation among tribes and subfamilies. From an evolutionary point of view, Rubioideae is the most ancient subfamily, followed by Ixoroideae and finally Cinchonoideae. The chemical biosynthetic pathway, which is not so specific in Rubioideae, can explain this and large amounts of both iridoids and indole alkaloids are produced. In Ixoroideae, the most active biosysthetic pathway is the one that produces iridoids; while in Cinchonoideae, it produces indole alkaloids together with other alkaloids. The chemical biosynthetic pathway now supports this botanical conclusion. PMID:26205062

  17. Coping with shrub secondary metabolites by ruminants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangelands throughout the world contain varying but often substantial proportions of shrubs. Shrubs are generally heavily chemically defended, and herbivores must either contend with their plant secondary metabolites (PSM) or avoid a significant component of the available forage. Browsing ruminants ...

  18. The Significance of Lichens and Their Metabolites

    NASA Astrophysics Data System (ADS)

    Huneck, S.

    Lichens, symbiontic organisms of fungi and algae, synthesize numerous metabolites, the "lichen substances," which comprise aliphatic, cycloaliphatic, aromatic, and terpenic compounds. Lichens and their metabolites have a manifold biological activity: antiviral, antibiotic, antitumor, allergenic, plant growth inhibitory, antiherbivore, and enzyme inhibitory. Usnic acid, a very active lichen substance is used in pharmaceutical preparations. Large amounts of Pseudevernia furfuracea and Evernia prunastri are processed in the perfume industry, and some lichens are sensitive reagents for the evaluation of air pollution.

  19. Cellular toxicity of nicotinamide metabolites.

    PubMed

    Rutkowski, Bolesław; Rutkowski, Przemysław; Słomińska, Ewa; Smolenski, Ryszard T; Swierczyński, Julian

    2012-01-01

    There are almost 100 different substances called uremic toxins. Nicotinamide derivatives are known as new family of uremic toxins. These uremic compounds play a role in an increased oxidative stress and disturbances in cellular repair processes by inhibiting poly (ADP-ribose) polymerase activity. New members of this family were discovered and described. Their toxic properties were a subject of recent studies. This study evaluated the concentration of 4-pyridone-3-carboxamid-1-β-ribonucleoside-triphosphate (4PYTP) and 4-pyridone-3-carboxamid-1-β-ribonucleoside-monophosphate (4PYMP) in erythrocytes of patients with chronic renal failure. Serum and red blood cells were collected from chronic renal failure patients on conservative treatment, those treated with hemodialysis, and at different times from those who underwent kidney transplantation. Healthy volunteers served as a control group. Nicotinamide metabolites were determined using liquid chromatography with mass spectrometry based on originally discovered and described method. Three novel compounds were described: 4-pyridone-3-carboxamid-1-β-ribonucleoside (4PYR), 4PYMP, and 4PYTP. 4PYR concentration was elevated in the serum, whereas 4PYMP and 4PYTP concentrations were augmented in erythrocytes of dialysis patients. Interestingly, concentrations of these compounds were less elevated during the treatment with erythropoietin-stimulating agents (ESAs). After successful kidney transplantation, concentrations of 4PYR and 4PYMP normalized according to the graft function, whereas that of 4PYTP was still elevated. During the incubation of erythrocytes in the presence of 4PYR, concentration of 4PYMP rose very rapidly while that of 4PYTP increased slowly. Therefore, we hypothesized that 4PYR, as a toxic compound, was actively absorbed by erythrocytes and metabolized to the 4PYMP and 4PYTP, which may interfere with function and life span of these cells. PMID:22200423

  20. Metabolites of cannabidiol identified in human urine.

    PubMed

    Harvey, D J; Mechoulam, R

    1990-03-01

    1. Urine from a dystonic patient treated with cannabidiol (CBD) was examined by g.l.c.-mass spectrometry for CBD metabolites. Metabolites were identified as their trimethylsilyl (TMS), [2H9]TMS, and methyl ester/TMS derivatives and as the TMS derivatives of the product of lithium aluminium deuteride reduction. 2. Thirty-three metabolites were identified in addition to unmetabolized CBD, and a further four metabolites were partially characterized. 3. The major metabolic route was hydroxylation and oxidation at C-7 followed by further hydroxylation in the pentyl and propenyl groups to give 1"-, 2"-, 3"-, 4"- and 10-hydroxy derivatives of CBD-7-oic acid. Other metabolites, mainly acids, were formed by beta-oxidation and related biotransformations from the pentyl side-chain and these were also hydroxylated at C-6 or C-7. The major oxidized metabolite was CBD-7-oic acid containing a hydroxyethyl side-chain. 4. Two 8,9-dihydroxy compounds, presumably derived from the corresponding epoxide were identified. 5. Also present were several cyclized cannabinoids including delta-6- and delta-1-tetrahydrocannabinol and cannabinol. 6. This is the first metabolic study of CBD in humans; most observed metabolic routes were typical of those found for CBD and related cannabinoids in other species. PMID:2336840

  1. Transplacental transport of netobimin metabolites in ewes.

    PubMed

    Cristofol, C; Carretero, A; Fernandez, M; Navarro, M; Sautet, J; Ruberte, J; Arboix, M

    1995-01-01

    Neither netobimin (NTB) nor its metabolite albendazole (ABZ) were found in plasma after an oral administration of 20 mg/kg of NTB to pregnant ewes during the last third of gestation. ABZ metabolites, albendazole sulphoxide (ABZSO) and albendazole sulphone (ABZSO2) were found in plasma 30 min and 2 h, respectively, after administration. The maximal plasma concentration (Cmax) of ABZSO was detected at 11.6 +/- 1.0 h and for ABZSO2 at 16.5 +/- 2.3 h. The plasma levels of the latter remained constant for 36 h, and decreased as ABZSO was removed from the blood. Jugular plasma levels of both metabolites did not differ significantly from those observed in the ovarian vein, suggesting that there were no exchanges between foetal and placental tissues. Both metabolite concentrations were similar in the umbilical vein and artery and in the amniotic and allantoic fluids, their values were half the maternal plasma concentration, leading to the conclusion that there was transplacental movement of metabolites. Both metabolites reached the foetus and could be responsible for the teratogenicity of NTB in sheep. PMID:8751036

  2. [Secondary Metabolites from Marine Microorganisms. I. Secondary Metabolites from Marine Actinomycetes].

    PubMed

    Orlova, T I; Bulgakova, V G; Polin, A N

    2015-01-01

    Review represents data on new active metabolites isolated from marine actinomycetes published in 2007 to 2014. Marine actinomycetes are an unlimited source of novel secondary metabolites with various biological activities. Among them there are antibiotics, anticancer compounds, inhibitors of biochemical processes. PMID:26863742

  3. Secondary metabolites in fungus-plant interactions

    PubMed Central

    Pusztahelyi, Tünde; Holb, Imre J.; Pócsi, István

    2015-01-01

    Fungi and plants are rich sources of thousands of secondary metabolites. The genetically coded possibilities for secondary metabolite production, the stimuli of the production, and the special phytotoxins basically determine the microscopic fungi-host plant interactions and the pathogenic lifestyle of fungi. The review introduces plant secondary metabolites usually with antifungal effect as well as the importance of signaling molecules in induced systemic resistance and systemic acquired resistance processes. The review also concerns the mimicking of plant effector molecules like auxins, gibberellins and abscisic acid by fungal secondary metabolites that modulate plant growth or even can subvert the plant defense responses such as programmed cell death to gain nutrients for fungal growth and colonization. It also looks through the special secondary metabolite production and host selective toxins of some significant fungal pathogens and the plant response in form of phytoalexin production. New results coming from genome and transcriptional analyses in context of selected fungal pathogens and their hosts are also discussed. PMID:26300892

  4. Metabolite profiles during oral glucose challenge.

    PubMed

    Ho, Jennifer E; Larson, Martin G; Vasan, Ramachandran S; Ghorbani, Anahita; Cheng, Susan; Rhee, Eugene P; Florez, Jose C; Clish, Clary B; Gerszten, Robert E; Wang, Thomas J

    2013-08-01

    To identify distinct biological pathways of glucose metabolism, we conducted a systematic evaluation of biochemical changes after an oral glucose tolerance test (OGTT) in a community-based population. Metabolic profiling was performed on 377 nondiabetic Framingham Offspring cohort participants (mean age 57 years, 42% women, BMI 30 kg/m(2)) before and after OGTT. Changes in metabolite levels were evaluated with paired Student t tests, cluster-based analyses, and multivariable linear regression to examine differences associated with insulin resistance. Of 110 metabolites tested, 91 significantly changed with OGTT (P ≤ 0.0005 for all). Amino acids, β-hydroxybutyrate, and tricarboxylic acid cycle intermediates decreased after OGTT, and glycolysis products increased, consistent with physiological insulin actions. Other pathways affected by OGTT included decreases in serotonin derivatives, urea cycle metabolites, and B vitamins. We also observed an increase in conjugated, and a decrease in unconjugated, bile acids. Changes in β-hydroxybutyrate, isoleucine, lactate, and pyridoxate were blunted in those with insulin resistance. Our findings demonstrate changes in 91 metabolites representing distinct biological pathways that are perturbed in response to an OGTT. We also identify metabolite responses that distinguish individuals with and without insulin resistance. These findings suggest that unique metabolic phenotypes can be unmasked by OGTT in the prediabetic state. PMID:23382451

  5. Streptomyces metabolites in divergent microbial interactions.

    PubMed

    Takano, Hideaki; Nishiyama, Tatsuya; Amano, Sho-ichi; Beppu, Teruhiko; Kobayashi, Michihiko; Ueda, Kenji

    2016-03-01

    Streptomyces and related bacteria produce a wide variety of secondary metabolites. Of these, many compounds have industrial applications, but the question of why this group of microorganism produces such various kinds of biologically active substances has not yet been clearly answered. Here, we overview the results from our studies on the novel function and role of Streptomyces metabolites. The diverged action of negative and positive influences onto the physiology of various microorganisms infers the occurrence of complex microbial interactions due to the effect of small molecules produced by Streptomyces. The interactions may serve as a basis for the constitution of biological community. PMID:26408311

  6. [Autism and Autism-associated Metabolites].

    PubMed

    Watanabe, Kunitomo

    2016-06-01

    Gene-microbiota interactions are now proposed to be a special case of gene-environmental interaction. Preclinical and clinical data summarized in this article reveal that a specific serum metabolite, associated with alterations in gut microbiome composition, might have an emerging role in the onset and pathogenesis of autism. Altered level of this specified metabolite may induce perturbations in the epigenome and modulate the expression of key disease susceptible genes in neurons and their associated cells during critical periods of neurodevelopment. The gut microbiota itself is now regarded as a reservoir for environmental epigenetic factors. PMID:27279160

  7. Transporter and its engineering for secondary metabolites.

    PubMed

    Lv, Huajun; Li, Jianhua; Wu, Yingying; Garyali, Sanjog; Wang, Yong

    2016-07-01

    Secondary metabolites possess a lot of biological activities, and to achieve their functions, transmembrane transportation is crucial. Elucidation of their transport mechanisms in the cell is critical for discovering ways to improve the production. Here, we have summarized the recent progresses for representative secondary metabolite transporters and also the strategies for uncovering the transporter systems in plants and microbes. We have also discussed the transporter engineering strategies being utilized for improving the heterologous natural product production, which exhibits promising future under the guide of synthetic biology. PMID:27209041

  8. Serum albumin complexation of acetylsalicylic acid metabolites.

    PubMed

    Jurkowski, Wiktor; Porebski, Grzegorz; Obtułowicz, Krystyna; Roterman, Irena

    2009-06-01

    One possible origin of the type I hypersensitivity reaction is reaction of drugs such as acetylsalicylic acid and its metabolites being complexed with human serum albumin. Albumin, being transporting molecule abundant in blood plasma is able to bind large array of ligands varying from small single carbon particles to long hydrophobic tailed lipidic acids (e.g. myristic acid). This non specificity is possible because of multi domain scaffold and large flexibility of inter-domain loops, which results in serious reorientation of domains. Hypothesis that acetylsalicylic acid metabolites may play indirect role in activation of allergic reaction has been tested. Binding of acetylsalicylic acid metabolites in intra-domain space causes significant increase of liability of domains IIIA and IIIB. One of metabolites, salicyluric acid, once is bound causes distortion and partial unfolding of helices in domains IA, IIB and IIIB. Changed are both directions and amplitude of relative motions as well as intra-domain distances. In result albumin is able to cross-link of adjacent IgE receptors which subsequently starts allergic reaction. PMID:19689242

  9. Aspirin-triggered metabolites of EFAs.

    PubMed

    Makriyannis, Alexandros; Nikas, Spyros P

    2011-10-28

    Aspirin triggers the biosynthesis of oxygenated metabolites from arachidonic, eicosapentaenoic, and docosahexaenoic (DHA) acids. In a preceding issue, Serhan et al. (2011) describe a novel aspirin-triggered DHA pathway for the biosynthesis of a potent anti-inflammatory and proresolving molecule. PMID:22035788

  10. Eleven microbial metabolites of 6-hydroxyflavanone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    6-Hydroxyflavanone (1) when fermented with fungal culture Cunninghamella blakesleeana (ATCC 8688a) yielded flavanone 6-O-ß-D-glucopyranoside (2), flavanone 6-sulfate (3), and 6-hydroxyflavanone 7-sulfate (4). Aspergillus alliaceus (ATCC 10060) also transformed 1 to metabolite 3 as well as 4'-hydrox...

  11. Microbial metabolism part 13 metabolites of hesperetin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungal culture, Mucor ramannianus (ATCC 2628) transformed hesperitin to four metabolites: 4'-methoxy -5, 7, 8, 3'-tetrahydroxyflavanone (8-hydroxyhesperetin), 5, 7, 3', 4'-tetrahydroxyflavanone (eriodictyol), 4'-methoxy-5, 3'-dihydroxyflavanone 7-sulfate (hesperetin 7-sulfate) and 5, 7, 3'-tri...

  12. METLIN: MS/MS metabolite data from the MAGGIE Project

    DOE Data Explorer

    METLIN is a metabolite database for metabolomics containing over 50,000 structures, it also represents a data management system designed to assist in a broad array of metabolite research and metabolite identification by providing public access to its repository of current and comprehensive MS/MS metabolite data. An annotated list of known metabolites and their mass, chemical formula, and structure are available on the METLIN website. Each metabolite is conveniently linked to outside resources such as the the Kyoto Encyclopedia of Genes and Genomes (KEGG) for further reference and inquiry. MS/MS data is also available on many of the metabolites. The list is expanding continuously as more metabolite information is being deposited and discovered. [from http://metlin.scripps.edu/] Metlin is a component of the MAGGIE Project. MAGGIE is funded by the DOE Genomics: GTL and is an acronym for "Molecular Assemblies, Genes, and Genomics Integrated Efficiently."

  13. Discovering the secondary metabolite potential encoded within Entomopathogenic Fungi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article discusses the secondary metabolite potential of the insect pathogens Metarhizium and Beauveria, including a bioinformatics analysis of secondary metabolite genes for which no products are yet identified....

  14. ALGAL METABOLITE INFLUENCE ON BLOOM SEQUENCE IN EUTROPHIED FRESHWATER PONDS

    EPA Science Inventory

    The extracellular metabolites of planktonic bloom dominant algae play a most significant role in the determination of bloom sequence in a eutrophied freshwater pond. Certain extracellular metabolites of planktonic blue-green algae substantially inhibit the growth of planktonic di...

  15. Novel bioactive metabolites of dipyrone (metamizol).

    PubMed

    Rogosch, Tobias; Sinning, Christian; Podlewski, Agnes; Watzer, Bernhard; Schlosburg, Joel; Lichtman, Aron H; Cascio, Maria G; Bisogno, Tiziana; Di Marzo, Vincenzo; Nüsing, Rolf; Imming, Peter

    2012-01-01

    Dipyrone is a common antipyretic drug and the most popular non-opioid analgesic in many countries. In spite of its long and widespread use, molecular details of its fate in the body are not fully known. We administered dipyrone orally to mice. Two unknown metabolites were found, viz. the arachidonoyl amides of the known major dipyrone metabolites, 4-methylaminoantipyrine (2) and 4-aminoantipyrine (3). They were identified by ESI-LC-MS/MS after extraction from the CNS, and comparison with reference substances prepared synthetically. The arachidonoyl amides were positively tested for cannabis receptor binding (CB(1) and CB(2)) and cyclooxygenase inhibition (COX-1 and COX-2 in tissues and as isolated enzymes), suggesting that the endogenous cannabinoid system may play a role in the effects of dipyrone against pain. PMID:22172309

  16. Pryogalloloestrogens -- a new group of oestrogen metabolites.

    PubMed

    Stubenrauch, G; Gelbke, H P; Knuppen, R

    1976-01-01

    After incubation of radioactive catecholoestrogen monomethyl ethers with rat liver slices the following well known metabolic pathways were observed: 1) demethylation, 2) 16alpha-hydroxylation, 3) oxidoreduction at C-atom 17, and 4) conjugation with glutathione, sulphuric acid and glucuronic acid. In addition, for the first time a further aromatic ortho-hydroxylation, leading to pyrogalloloestrogen derivatives, was detected. Thus, the incubation of 2-methoxyoestrone yielded 2,4-dihydroxyoestrone 2-methyl ether as the main metabolite of the lipophile fraction. Under the same conditions, 4-methoxyoestrone was converted to 2,4-dihydroxyoestrone 4-methyl ether and 2,4-dihydroxyoestradiol-17beta 4-methyl ether; these compounds were the quantitatively most important metabolites not only in the lipophile but also in the sulphate and glucuronide fractions. The identity of these new metabolic products was established by chromatography, microchemical reactions and recrystallisation to constant specific radioactivity. PMID:1248801

  17. Biologically Active Metabolites Synthesized by Microalgae

    PubMed Central

    de Morais, Michele Greque; Vaz, Bruna da Silva; de Morais, Etiele Greque; Costa, Jorge Alberto Vieira

    2015-01-01

    Microalgae are microorganisms that have different morphological, physiological, and genetic traits that confer the ability to produce different biologically active metabolites. Microalgal biotechnology has become a subject of study for various fields, due to the varied bioproducts that can be obtained from these microorganisms. When microalgal cultivation processes are better understood, microalgae can become an environmentally friendly and economically viable source of compounds of interest, because production can be optimized in a controlled culture. The bioactive compounds derived from microalgae have anti-inflammatory, antimicrobial, and antioxidant activities, among others. Furthermore, these microorganisms have the ability to promote health and reduce the risk of the development of degenerative diseases. In this context, the aim of this review is to discuss bioactive metabolites produced by microalgae for possible applications in the life sciences. PMID:26339647

  18. Metabolite specific proton magnetic resonance imaging

    SciTech Connect

    Hurd, R.E.; Freeman, D.M.

    1989-06-01

    An imaging method is described that makes use of proton double quantum nuclear magnetic resonance (NMR) to construct images based on selected metabolites such as lactic acid. The optimization of the method is illustrated in vitro, followed by in vivo determination of lactic acid distribution in a solid tumor model. Water suppression and editing of lipid signals are such that two-dimensional spectra of lactic acid may be obtained from a radiation-induced fibrosarcoma (RIF-1) tumor in under 1 min and lactic acid images from the same tumor in under 1 hr at 2.0 T. This technique provides a fast and reproducible method at moderate magnetic field strength for mapping biologically relevant metabolites.

  19. Gut microbiota, metabolites and host immunity.

    PubMed

    Rooks, Michelle G; Garrett, Wendy S

    2016-05-27

    The microbiota - the collection of microorganisms that live within and on all mammals - provides crucial signals for the development and function of the immune system. Increased availability of technologies that profile microbial communities is facilitating the entry of many immunologists into the evolving field of host-microbiota studies. The microbial communities, their metabolites and components are not only necessary for immune homeostasis, they also influence the susceptibility of the host to many immune-mediated diseases and disorders. In this Review, we discuss technological and computational approaches for investigating the microbiome, as well as recent advances in our understanding of host immunity and microbial mutualism with a focus on specific microbial metabolites, bacterial components and the immune system. PMID:27231050

  20. Metabolites of a blocked chloramphenicol producer.

    PubMed

    Lewis, Elizabeth A; Adamek, Tamara L; Vining, Leo C; White, Robert L

    2003-01-01

    Addition of p-aminophenylalanine (4), an advanced biosynthetic precursor of the antibiotic chloramphenicol (5), to a Streptomyces venezuelae pabAB mutant (VS629) restored chloramphenicol production and led to formation of the non-chlorinated analogue corynecin II (6) and four acetanilide derivatives: p-(acetylamino)phenylalanine (7), p-(acetylamino)benzyl alcohol (13), p-(acetylamino)benzoic acid (14), and p-(acetylamino)phenol (acetaminophen, 16). Metabolite structures were deduced from NMR and MS-MS data and established by chromatographic and spectroscopic comparisons with authentic samples. Reference compound 13 was synthesized by reducing the acid chloride of 14. Shunt pathways are proposed to account for the formation of the metabolites from p-aminophenylalanine. PMID:12542347

  1. Emerging role of thyroid hormone metabolites.

    PubMed

    Gnocchi, D; Steffensen, K R; Bruscalupi, G; Parini, P

    2016-07-01

    Thyroid hormones (THs) are essential for the regulation of development and metabolism in key organs. THs produce biological effects both by directly affecting gene expression through the interaction with nuclear receptors (genomic effects) and by activating protein kinases and/or ion channels (short-term effects). Such activations can be either direct, in the case of ion channels, or mediated by membrane or cytoplasmic receptors. Short-term-activated signalling pathways often play a role in the regulation of genomic effects. Several TH intermediate metabolites, which were previously considered without biological activity, have now been associated with a broad range of actions, mostly attributable to short-term effects. Here, we give an overview of the physiological roles and mechanisms of action of THs, focusing on the emerging position that TH metabolites are acquiring as important regulators of physiology and metabolism. PMID:26748938

  2. Preparative Microfluidic Electrosynthesis of Drug Metabolites

    PubMed Central

    2013-01-01

    In vivo, a drug molecule undergoes its first chemical transformation within the liver via CYP450-catalyzed oxidation. The chemical outcome of the first pass hepatic oxidation is key information to any drug development process. Electrochemistry can be used to simulate CYP450 oxidation, yet it is often confined to the analytical scale, hampering product isolation and full characterization. In an effort to replicate hepatic oxidations, while retaining high throughput at the preparative scale, microfluidic technology and electrochemistry are combined in this study by using a microfluidic electrochemical cell. Several commercial drugs were subjected to continuous-flow electrolysis. They were chosen for their various chemical reactivity: their metabolites in vivo are generated via aromatic hydroxylation, alkyl oxidation, glutathione conjugation, or sulfoxidation. It is demonstrated that such metabolites can be synthesized by flow electrolysis at the 10 to 100 mg scale, and the purified products are fully characterized. PMID:24900614

  3. [Basidiomycetes: A new source of secondary metabolites.].

    PubMed

    Brizuela, M A; García, L; Pérez, L; Mansur, M

    1998-06-01

    The area of natural products research is the most rapidly growing field of organic chemistry, due to the great technical developments in the isolation and identification techniques. Today, near to one million natural products -isolated from the most diverse living things- are known. Microorganisms are among the least-studied of these. Nevertheless, they offer large possibilities for the discovery of new structures and biological activities. Among the microorganisms, the Basidiomycetes present a production capacity and a range of biologically active metabolites, which have scarcely been investigated. The wide spectrum of natural products with biological activity produced by Basidiomycetes includes antimicrobial agents, antifungal, antiviral and cytotoxic activities, enzymes, plant growth regulators and flavors. These metabolites are generally grouped by their chemical origin, and the relationship between chemical structure and the different biological activities reported. The main objective of this review is to bring an updated revision of the numerous and interesting biosynthetic pathways from basidiomycetes. PMID:17655412

  4. Heterogeneous distribution of metabolites across plant species

    NASA Astrophysics Data System (ADS)

    Takemoto, Kazuhiro; Arita, Masanori

    2009-07-01

    We investigate the distribution of flavonoids, a major category of plant secondary metabolites, across species. Flavonoids are known to show high species specificity, and were once considered as chemical markers for understanding adaptive evolution and characterization of living organisms. We investigate the distribution among species using bipartite networks, and find that two heterogeneous distributions are conserved among several families: the power-law distributions of the number of flavonoids in a species and the number of shared species of a particular flavonoid. In order to explain the possible origin of the heterogeneity, we propose a simple model with, essentially, a single parameter. As a result, we show that two respective power-law statistics emerge from simple evolutionary mechanisms based on a multiplicative process. These findings provide insights into the evolution of metabolite diversity and characterization of living organisms that defy genome sequence analysis for different reasons.

  5. Metabolic regulation and overproduction of primary metabolites

    PubMed Central

    Sanchez, Sergio; Demain, Arnold L.

    2008-01-01

    Summary Overproduction of microbial metabolites is related to developmental phases of microorganisms. Inducers, effectors, inhibitors and various signal molecules play a role in different types of overproduction. Biosynthesis of enzymes catalysing metabolic reactions in microbial cells is controlled by well‐known positive and negative mechanisms, e.g. induction, nutritional regulation (carbon or nitrogen source regulation), feedback regulation, etc. The microbial production of primary metabolites contributes significantly to the quality of life. Fermentative production of these compounds is still an important goal of modern biotechnology. Through fermentation, microorganisms growing on inexpensive carbon and nitrogen sources produce valuable products such as amino acids, nucleotides, organic acids and vitamins which can be added to food to enhance its flavour, or increase its nutritive values. The contribution of microorganisms goes well beyond the food and health industries with the renewed interest in solvent fermentations. Microorganisms have the potential to provide many petroleum‐derived products as well as the ethanol necessary for liquid fuel. Additional applications of primary metabolites lie in their impact as precursors of many pharmaceutical compounds. The roles of primary metabolites and the microbes which produce them will certainly increase in importance as time goes on. In the early years of fermentation processes, development of producing strains initially depended on classical strain breeding involving repeated random mutations, each followed by screening or selection. More recently, methods of molecular genetics have been used for the overproduction of primary metabolic products. The development of modern tools of molecular biology enabled more rational approaches for strain improvement. Techniques of transcriptome, proteome and metabolome analysis, as well as metabolic flux analysis. have recently been introduced in order to identify new and

  6. Three new metabolites from Botrytis cinerea.

    PubMed

    Wang, Tian-Shan; Zhou, Jin-Yan; Tan, Hong

    2008-01-01

    Three new metabolites, gamma-abscisolactone (1), botrytisic acids A (3) and B (4) were isolated from the fermentation broth of Botrytis cinerea TB-3-H8. Their structures were elucidated on the basis of MS, IR, UV, and NMR spectroscopic data. Compound 2 was isolated from natural resource for the first time. The structure of 1 was further confirmed by single-crystal X-ray diffraction (CCDC-265897). PMID:19003608

  7. Phthalate Metabolites, Consumer Habits and Health Effects.

    PubMed

    Wallner, Peter; Kundi, Michael; Hohenblum, Philipp; Scharf, Sigrid; Hutter, Hans-Peter

    2016-01-01

    Phthalates are multifunctional chemicals used in a wide variety of consumer products. The aim of this study was to investigate whether levels of urinary phthalate metabolites in urine samples of Austrian mothers and their children were associated with consumer habits and health indicators. Within an Austrian biomonitoring survey, urine samples from 50 mother-child pairs of five communities (two-stage random stratified sampling) were analysed. The concentrations of 14 phthalate metabolites were determined, and a questionnaire was administered. Monoethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP), monobenzyl phthalate (MBzP), mono-(2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (5OH-MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (5oxo-MEHP), mono-(5-carboxy-2-ethylpentyl) phthalate (5cx-MEPP), and 3-carboxy-mono-propyl phthalate (3cx-MPP) could be quantified in the majority of samples. Significant correlations were found between the use of hair mousse, hair dye, makeup, chewing gum, polyethylene terephthalate (PET) bottles and the diethyl phthalate (DEP) metabolite MEP. With regard to health effects, significant associations of MEP in urine with headache, repeated coughing, diarrhoea, and hormonal problems were observed. MBzP was associated with repeated coughing and MEHP was associated with itching. PMID:27428989

  8. Phthalate Metabolites, Consumer Habits and Health Effects

    PubMed Central

    Wallner, Peter; Kundi, Michael; Hohenblum, Philipp; Scharf, Sigrid; Hutter, Hans-Peter

    2016-01-01

    Phthalates are multifunctional chemicals used in a wide variety of consumer products. The aim of this study was to investigate whether levels of urinary phthalate metabolites in urine samples of Austrian mothers and their children were associated with consumer habits and health indicators. Within an Austrian biomonitoring survey, urine samples from 50 mother-child pairs of five communities (two-stage random stratified sampling) were analysed. The concentrations of 14 phthalate metabolites were determined, and a questionnaire was administered. Monoethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP), monobenzyl phthalate (MBzP), mono-(2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (5OH-MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (5oxo-MEHP), mono-(5-carboxy-2-ethylpentyl) phthalate (5cx-MEPP), and 3-carboxy-mono-propyl phthalate (3cx-MPP) could be quantified in the majority of samples. Significant correlations were found between the use of hair mousse, hair dye, makeup, chewing gum, polyethylene terephthalate (PET) bottles and the diethyl phthalate (DEP) metabolite MEP. With regard to health effects, significant associations of MEP in urine with headache, repeated coughing, diarrhoea, and hormonal problems were observed. MBzP was associated with repeated coughing and MEHP was associated with itching. PMID:27428989

  9. The WEIZMASS spectral library for high-confidence metabolite identification.

    PubMed

    Shahaf, Nir; Rogachev, Ilana; Heinig, Uwe; Meir, Sagit; Malitsky, Sergey; Battat, Maor; Wyner, Hilary; Zheng, Shuning; Wehrens, Ron; Aharoni, Asaph

    2016-01-01

    Annotation of metabolites is an essential, yet problematic, aspect of mass spectrometry (MS)-based metabolomics assays. The current repertoire of definitive annotations of metabolite spectra in public MS databases is limited and suffers from lack of chemical and taxonomic diversity. Furthermore, the heterogeneity of the data prevents the development of universally applicable metabolite annotation tools. Here we present a combined experimental and computational platform to advance this key issue in metabolomics. WEIZMASS is a unique reference metabolite spectral library developed from high-resolution MS data acquired from a structurally diverse set of 3,540 plant metabolites. We also present MatchWeiz, a multi-module strategy using a probabilistic approach to match library and experimental data. This strategy allows efficient and high-confidence identification of dozens of metabolites in model and exotic plants, including metabolites not previously reported in plants or found in few plant species to date. PMID:27571918

  10. Detection and characterization of clostebol sulfate metabolites in Caucasian population.

    PubMed

    Balcells, Georgina; Pozo, Oscar J; Garrostas, Lorena; Esquivel, Argitxu; Matabosch, Xavier; Kotronoulas, Aristotelis; Joglar, Jesús; Ventura, Rosa

    2016-06-01

    Anabolic androgenic steroids (AAS) are synthetic testosterone derivatives which undergo extensive metabolism in man. Differences in the excretion of phase II metabolites are strongly associated with inter-individual and inter-ethnic variations. Sulfate metabolites have been described as long-term metabolites for some AAS. Clostebol is the 4-chloro derivative of testosterone and the aim of the present study was the evaluation of clostebol sulfate metabolites in Caucasian population by LC-MS/MS technology. Clostebol was orally administered to four healthy Caucasian male volunteers, and excretion study urines were collected up to 31 days. Several analytical strategies (neutral loss scan, precursor ion scan and selected reaction monitoring acquisitions modes) were applied to detect sulfate metabolites in post-administration samples. Sixteen sulfate metabolites were detected, five of them having detectability times above 10 days (S1a, S2a, S3b, S3g and S4b). Interestingly, metabolite S1a could be detected up to the last collected sample of all excretion studies and it was characterized by LC-MS/MS and GC-MS as 4ξ-chloro-5α-androst-3β-ol-17-one 3β-sulfate. Thus, monitoring of S1a improves the detection time of clostebol misuse with respect to the commonly monitored metabolites, excreted in the glucuronide fraction. Importantly, this new metabolite can be incorporated into recently developed LC-MS/MS screening methods base on the direct detection of phase II metabolites. PMID:27085012

  11. Maternal and Infant Urinary Phthalate Metabolite Concentrations: Are They Related?

    PubMed Central

    Sathyanarayana, S; Calafat, Antonia Maria; Liu, Fan; Swan, Shanna Helen

    2008-01-01

    Background Phthalates are synthetic chemicals that are ubiquitous in our society and may have adverse health effects in humans. Detectable concentrations of phthalate metabolites have been found in adults and children, but no studies have examined the relationship between maternal and infant phthalate metabolite concentrations. Objective We investigated the relationship between maternal and infant urinary phthalate metabolite concentrations. Methods We measured nine phthalate metabolites in urine samples from 210 mother/infant pairs collected on the same study visit day (1999–2005) and obtained demographic history from questionnaires. Using multivariate linear regression analyses, we examined the degree to which maternal urine phthalate metabolite concentration predicted infant phthalate metabolite concentration. All analyses were adjusted for infant age, creatinine concentration, and race. Results Correlation coefficients between phthalate metabolite concentrations in the urine of mothers and their infants were generally low but increased with decreasing age of infant. In multivariate analyses, mother’s phthalate metabolite concentrations were significantly associated with infants’ concentrations for six phthalate metabolites: monobenzyl phthalate, monoethyl phthalate, monoisobutyl phthalate, and three metabolites of di(2-ethylhexyl) phthalate: mono(2-ethylhexyl) phthalate, mono(2-ethyl-5-hydroxy-hexyl) phthalate and mono(2-ethyl-5-oxo-hexyl) phthalate (p-values for all coefficients <0.05). Discussion Mother’s urine phthalate metabolite concentration is significantly associated with infant urine phthalate metabolite concentration for six phthalate metabolites. It is plausible that shared exposures to phthalates in the immediate surrounding environment accounted for these relationships, but other unidentified sources may also contribute to infants’ phthalate exposures. This study indicates the importance of further identifying infant phthalate exposures

  12. Endogenous cross-talk of fungal metabolites

    PubMed Central

    Sheridan, Kevin J.; Dolan, Stephen K.; Doyle, Sean

    2015-01-01

    Non-ribosomal peptide (NRP) synthesis in fungi requires a ready supply of proteogenic and non-proteogenic amino acids which are subsequently incorporated into the nascent NRP via a thiotemplate mechanism catalyzed by NRP synthetases. Substrate amino acids can be modified prior to or during incorporation into the NRP, or following incorporation into an early stage amino acid-containing biosynthetic intermediate. These post-incorporation modifications involve a range of additional enzymatic activities including but not exclusively, monooxygenases, methyltransferases, epimerases, oxidoreductases, and glutathione S-transferases which are essential to effect biosynthesis of the final NRP. Likewise, polyketide biosynthesis is directly by polyketide synthase megaenzymes and cluster-encoded ancillary decorating enzymes. Additionally, a suite of additional primary metabolites, for example: coenzyme A (CoA), acetyl CoA, S-adenosylmethionine, glutathione (GSH), NADPH, malonyl CoA, and molecular oxygen, amongst others are required for NRP and polyketide synthesis (PKS). Clearly these processes must involve exquisite orchestration to facilitate the simultaneous biosynthesis of different types of NRPs, polyketides, and related metabolites requiring identical or similar biosynthetic precursors or co-factors. Moreover, the near identical structures of many natural products within a given family (e.g., ergot alkaloids), along with localization to similar regions within fungi (e.g., conidia) suggests that cross-talk may exist, in terms of biosynthesis and functionality. Finally, we speculate if certain biosynthetic steps involved in NRP and PKS play a role in cellular protection or environmental adaptation, and wonder if these enzymatic reactions are of equivalent importance to the actual biosynthesis of the final metabolite. PMID:25601857

  13. Cytochrome c adducts with PCB quinoid metabolites.

    PubMed

    Li, Miao; Teesch, Lynn M; Murry, Daryl J; Pope, R Marshal; Li, Yalan; Robertson, Larry W; Ludewig, Gabriele

    2016-02-01

    Polychlorinated biphenyls (PCBs) are a group of 209 individual congeners widely used as industrial chemicals. PCBs are found as by-products in dye and paint manufacture and are legacy, ubiquitous, and persistent as human and environmental contaminants. PCBs with fewer chlorine atoms may be metabolized to hydroxy- and dihydroxy-metabolites and further oxidized to quinoid metabolites both in vitro and in vivo. Specifically, quinoid metabolites may form adducts on nucleophilic sites within cells. We hypothesized that the PCB-quinones covalently bind to cytochrome c and, thereby, cause defects in the function of cytochrome c. In this study, synthetic PCB quinones, 2-(4'-chlorophenyl)-1,4-benzoquinone (PCB3-pQ), 4-4'-chlorophenyl)-1,2-benzoquinone (PCB3-oQ), 2-(3', 5'-dichlorophenyl)-1,4-benzoquinone, 2-(3',4', 5'-trichlorophenyl)-1,4-benzoquinone, and 2-(4'-chlorophenyl)-3,6-dichloro-1,4-benzoquinone, were incubated with cytochrome c, and adducts were detected by liquid chromatography-mass spectrometry (LC-MS) and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI TOF). Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was employed to separate the adducted proteins, while trypsin digestion and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were applied to identify the amino acid binding sites on cytochrome c. Conformation change of cytochrome c after binding with PCB3-pQ was investigated by SYBYL-X simulation and cytochrome c function was examined. We found that more than one molecule of PCB-quinone may bind to one molecule of cytochrome c. Lysine and glutamic acid were identified as the predominant binding sites. Software simulation showed conformation changes of adducted cytochrome c. Additionally, cross-linking of cytochrome c was observed on the SDS-PAGE gel. Cytochrome c was found to lose its function as electron acceptor after incubation with PCB quinones. These data provide evidence that the covalent

  14. MASS SPECTROMETRY IMAGING FOR DRUGS AND METABOLITES

    PubMed Central

    Greer, Tyler; Sturm, Robert; Li, Lingjun

    2011-01-01

    Mass spectrometric imaging (MSI) is a powerful analytical technique that provides two- and three-dimensional spatial maps of multiple compounds in a single experiment. This technique has been routinely applied to protein, peptide, and lipid molecules with much less research reporting small molecule distributions, especially pharmaceutical drugs. This review’s main focus is to provide readers with an up-to-date description of the substrates and compounds that have been analyzed for drug and metabolite composition using MSI technology. Additionally, ionization techniques, sample preparation, and instrumentation developments are discussed. PMID:21515430

  15. Antimycobacterial activity of lichen metabolites in vitro.

    PubMed

    Ingólfsdóttir, K; Chung, G A; Skúlason, V G; Gissurarson, S R; Vilhelmsdóttir, M

    1998-04-01

    Several compounds, whose structures represent the most common chemical classes of lichen metabolites, were screened for in vitro activity against Mycobacterium aurum, a non-pathogenic organism with a similar sensitivity profile to M. tuberculosis. Of the compounds tested, usnic acid from Cladonia arbuscula exhibited the highest activity with an MIC value of 32 microg/ml. Atranorin and lobaric acid, both isolated from Stereocaulon alpinum, salazinic acid from Parmelia saxatilis and protolichesterinic acid from Cetraria islandica all showed MIC values >/=125 microg/ml. PMID:9795033

  16. Herbicide Metabolites in Surface Water and Groundwater: Introduction and Overview

    USGS Publications Warehouse

    Thurman, E.M.; Meyer, M.T.

    1996-01-01

    Several future research topics for herbicide metabolites in surface and ground water are outlined in this chapter. They are herbicide usage, chemical analysis of metabolites, and fate and transport of metabolites in surface and ground water. These three ideas follow the themes in this book, which are the summary of a symposium of the American Chemical Society on herbicide metabolites in surface and ground water. First, geographic information systems allow the spatial distribution of herbicide-use data to be combined with geochemical information on fate and transport of herbicides. Next these two types of information are useful in predicting the kinds of metabolites present and their probable distribution in surface and ground water. Finally, methods development efforts may be focused on these specific target analytes. This chapter discusses these three concepts and provides an introduction to this book on the analysis, chemistry, and fate and transport of herbicide metabolites in surface and ground water.

  17. Novel sulfur-containing microbial metabolite of primaquine.

    PubMed

    Hufford, C D; Baker, J K; McChesney, J D; Clark, A M

    1986-08-01

    Microbial metabolism studies of the antimalarial drug primaquine, using Streptomyces roseochromogenus (ATCC 13400) have produced an N-acetylated metabolite and a methylene-linked dimeric product, both of which have been previously reported, and a novel sulfur-containing microbial metabolite. The structure of the metabolite as a sulfur-linked dimer was proposed on the basis of spectral and chemical data. The molecular formula C34H44N6O4S was established from field-desorption mass spectroscopy and analytical data. The 1H- and 13C-nuclear magnetic resonance spectral data firmly established that the novel metabolite was a symmetrically substituted dimer of primaquine N-acetate with a sulfur atom linking the two units at C-5. The metabolite has been shown to be a mixture of stereoisomers which can equilibrate in solution. This observation was confirmed by microbial synthesis of the metabolite from optically active primaquine. PMID:3767340

  18. Using Hairy Roots for Production of Valuable Plant Secondary Metabolites.

    PubMed

    Tian, Li

    2015-01-01

    Plants synthesize a wide variety of natural products, which are traditionally termed secondary metabolites and, more recently, coined specialized metabolites. While these chemical compounds are employed by plants for interactions with their environment, humans have long since explored and exploited plant secondary metabolites for medicinal and practical uses. Due to the tissue-specific and low-abundance accumulation of these metabolites, alternative means of production in systems other than intact plants are sought after. To this end, hairy root culture presents an excellent platform for producing valuable secondary metabolites. This chapter will focus on several major groups of secondary metabolites that are manufactured by hairy roots established from different plant species. Additionally, the methods for preservations of hairy roots will also be reviewed. PMID:25583225

  19. Cyanobacteria as Cell Factories to Produce Plant Secondary Metabolites

    PubMed Central

    Xue, Yong; He, Qingfang

    2015-01-01

    Cyanobacteria represent a promising platform for the production of plant secondary metabolites. Their capacity to express plant P450 proteins, which have essential functions in the biosynthesis of many plant secondary metabolites, makes cyanobacteria ideal for this purpose, and their photosynthetic capability allows cyanobacteria to grow with simple nutrient inputs. This review summarizes the advantages of using cyanobacteria to transgenically produce plant secondary metabolites. Some techniques to improve heterologous gene expression in cyanobacteria are discussed. PMID:25973419

  20. Metabolite profiling of wheat (Triticum aestivum L.) phloem exudate

    PubMed Central

    2014-01-01

    Background Biofortification of staple crops with essential micronutrients relies on the efficient, long distance transport of nutrients to the developing seed. The main route of this transport in common wheat (Triticum aestivum) is via the phloem, but due to the reactive nature of some essential micronutrients (specifically Fe and Zn), they need to form ligands with metabolites for transport within the phloem. Current methods available in collecting phloem exudate allows for small volumes (μL or nL) to be collected which limits the breadth of metabolite analysis. We present a technical advance in the measurement of 79 metabolites in as little as 19.5 nL of phloem exudate. This was achieved by using mass spectrometry based, metabolomic techniques. Results Using gas chromatography–mass spectrometry (GC-MS), 79 metabolites were detected in wheat phloem. Of these, 53 were identified with respect to their chemistry and 26 were classified as unknowns. Using the ratio of ion area for each metabolite to the total ion area for all metabolites, 39 showed significant changes in metabolite profile with a change in wheat reproductive maturity, from 8–12 to 17–21 days after anthesis. Of these, 21 were shown to increase and 18 decreased as the plant matured. An amine group derivitisation method coupled with liquid chromatography MS (LC-MS) based metabolomics was able to quantify 26 metabolites and semi-quantitative data was available for a further 3 metabolites. Conclusions This study demonstrates that it is possible to determine metabolite profiles from extremely small volumes of phloem exudate and that this method can be used to determine variability within the metabolite profile of phloem that has occurred with changes in maturity. This is also believed to be the first report of the presence of the important metal complexing metabolite, nicotianamine in the phloem of wheat. PMID:25143779

  1. Structure elucidation of metabolites of swertiamarin produced by Aspergillus niger

    NASA Astrophysics Data System (ADS)

    Jun, Chang; Xue-Ming, Zhao; Chang-Xiao, Liu; Tie-Jun, Zhang

    2008-04-01

    The in vitro metabolism of swertiamarin was carried out in preparative scale using the fungus Aspergillus niger and the metabolites were isolated by semi-preparative HPLC combined with liquid-liquid extraction. Two metabolites, erythrocentaurin and one new compound were obtained and identified by 1H, 13C and 2D NMR and high resolution MS. The anti-inflammatory activity of the novel metabolite was tested and compared with that of swertiamarin in a mice model.

  2. Buckwheat phenolic metabolites in health and disease.

    PubMed

    Kreft, Marko

    2016-06-01

    Buckwheat (Fagopyrum esculentum Moench, F. tataricum Gaertner) groats and flour have been established globally as nutritional foods because of their high levels of proteins, polyphenols and minerals. In some regions, buckwheat herb is used as a functional food. In the present study, reports of in vitro studies, preclinical and clinical trials dealing with the effect of buckwheat and its metabolites were reviewed. There are numerous reports of potential health benefits of consuming buckwheat, which may be in the form of food, dietary supplements, home remedies or possibly pharmaceutical drugs; however, adverse effects, including those resulting from contamination, must be considered. There are reports of antioxidative activity of buckwheat, which contains high levels of rutin and quercetin. On the other hand, both cytotoxic and antigenotoxic effects have been shown. Reduction of hyperlipidaemia, reduction of blood pressure and improved weight regulation have been suggested. Consuming buckwheat may have a beneficial effect on diabetes, since lower postprandial blood glucose and insulin response have been reported. In addition, buckwheat metabolites, such as rutin, may have intrinsic protective effects in preserving insulin signalling. Rutin has also been suggested to have potential therapeutic applications for the treatment of Alzheimer's disease. The literature indicates that buckwheat is safe to consume and may have various beneficial effects on human health. PMID:27046048

  3. Metabolite production by different Ulocladium species.

    PubMed

    Andersen, Birgitte; Hollensted, Morten

    2008-08-15

    Ulocladium, which is phylogenetically related to Alternaria, contains species that are food spoilers and plant pathogens, but also species that have potential as enzyme producers and bio-control agents. Ulocladium spp. are often found on dead vegetation, in soil, air and dust, but also on food and feedstuffs and on water-damaged building materials. The aim was to study the morphological and chemical diversity within the genus Ulocladium. Cultures of 52 Ulocladium strains were identified morphologically, and then extracted and analyzed using automated Chemical Image Analysis. Production of individual metabolites was correlated to species identity and source of isolation (substratum). Chemical analyses corroborated the morphological identifications and showed the existence of several species species-specific metabolites, of which most were known compounds. The production of curvularins was specific to Ulocladium atrum, while most species produced infectopyrones and derivatives of altertoxin I. None of the 52 Ulocladium strains produced alternariols, tenuazonic acid, altersolanols or macrosporin, which are common in species of Alternaria. PMID:18599140

  4. Antiinflammatory and Immunomodulating Properties of Fungal Metabolites

    PubMed Central

    Lull, Cristina; Wichers, Harry J.; Savelkoul, Huub F. J.

    2005-01-01

    We discuss current information on the ability of extracts and isolated metabolites from mushrooms to modulate immune responses. This can result in a more enhanced innate and acquired disease resistance. The major immunomodulating effects of these active substances derived from mushrooms include mitogenicity and activation of immune effector cells, such as lymphocytes, macrophages, and natural killer cells, resulting in the production of cytokines, including interleukins (ILs), tumor necrosis factor alpha (TNF)-α, and interferon gamma (INF)-γ. In particular, the ability of selective mushroom extracts to modulate the differentiation capacity of CD4+ T cells to mature into TH1 and/or TH2 subsets will be discussed. As a consequence these extracts will have profound effects in particular diseases, like chronic autoimmune TH1-mediated or allergic TH2-mediated diseases. Immunosuppressive effects by mushroom components have also been observed. The therapeutic effects of mushrooms, such as anticancer activity, suppression of autoimmune diseases, and allergy have been associated with their immunomodulating effects. However, further studies are needed to determine the molecular mechanisms of the immunomodulating effects of mushrooms metabolites both individually and in complex mixtures, for example, extracts. PMID:16030389

  5. Multiple tyrosine metabolites are GPR35 agonists

    PubMed Central

    Deng, Huayun; Hu, Haibei; Fang, Ye

    2012-01-01

    Both kynurenic acid and 2-acyl lysophosphatidic acid have been postulated to be the endogenous agonists of GPR35. However, controversy remains whether alternative endogenous agonists exist. The molecular targets accounted for many nongenomic actions of thyroid hormones are mostly unknown. Here we report the agonist activity of multiple tyrosine metabolites at the GPR35. Tyrosine metabolism intermediates that contain carboxylic acid and/or catechol functional groups were first selected. Whole cell dynamic mass redistribution (DMR) assays enabled by label-free optical biosensor were then used to characterize their agonist activity in native HT-29. Molecular assays including β-arrestin translocation, ERK phosphorylation and receptor internalization confirmed that GPR35 functions as a receptor for 5,6-dihydroxyindole-2-carboxylic acid, 3,3′,5′-triiodothyronine, 3,3′,5-triiodothyronine, gentisate, rosmarinate, and 3-nitrotyrosine. These results suggest that multiple tyrosine metabolites are alternative endogenous ligands of GPR35, and GPR35 may represent a druggable target for treating certain diseases associated with abnormality of tyrosine metabolism. PMID:22523636

  6. Hormonal and Metabolite Regulation of Hepatic Glucokinase.

    PubMed

    Agius, Loranne

    2016-07-17

    Liver glucose metabolism is dependent on glucokinase activity. Glucokinase expression is transcriptionally regulated by hormones and metabolites of glucose, and glucokinase activity is dependent on reversible binding of glucokinase to a specific inhibitor protein, glucokinase regulatory protein (GKRP), and to other binding proteins such as 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase (PFK2/FBP2), which functions as an activator. Glucokinase is inhibited in the postabsorptive state by sequestration in the nucleus bound to GKRP, and it is activated postprandially by portal hyperglycemia and fructose through dissociation from GKRP, translocation to the cytoplasm, and binding to PFK2/FBP2. Glucagon dissociates this interaction, promoting translocation back to the nucleus. In humans, changes in glucokinase expression and activity are associated with poorly controlled type 2 diabetes and with nonalcoholic fatty liver disease, and a common variant of GKRP with altered binding affinity for glucokinase is associated with increased blood and liver lipids and other metabolic traits that implicate a role for GKRP in maintaining intrahepatic metabolite homeostasis. PMID:27146014

  7. Cholesterol metabolites exported from human brain.

    PubMed

    Iuliano, Luigi; Crick, Peter J; Zerbinati, Chiara; Tritapepe, Luigi; Abdel-Khalik, Jonas; Poirot, Marc; Wang, Yuqin; Griffiths, William J

    2015-07-01

    The human brain contains approximately 25% of the body's cholesterol. The brain is separated from the circulation by the blood brain barrier. While cholesterol will not passes this barrier, oxygenated forms of cholesterol can cross the barrier. Here by measuring the difference in the oxysterol content of blood plasma in the jugular vein and in a forearm vein by mass spectrometry (MS) we were able to determine the flux of more than 20 cholesterol metabolites between brain and the circulation. We confirm that 24S-hydroxycholesterol is exported from brain at a rate of about 2-3mg/24h. Gas chromatography (GC)-MS data shows that the cholesterol metabolites 5α-hydroxy-6-oxocholesterol (3β,5α-dihydroxycholestan-6-one), 7β-hydroxycholesterol and 7-oxocholesterol, generally considered to be formed through reactive oxygen species, are similarly exported from brain at rates of about 0.1, 2 and 2mg/24h, respectively. Although not to statistical significance both GC-MS and liquid chromatography (LC)-MS methods indicate that (25R)26-hydroxycholesterol is imported to brain, while LC-MS indicates that 7α-hydroxy-3-oxocholest-4-enoic acid is exported from brain. PMID:25668615

  8. Regulation of Vascular and Renal Function by Metabolite Receptors.

    PubMed

    Peti-Peterdi, János; Kishore, Bellamkonda K; Pluznick, Jennifer L

    2016-01-01

    To maintain metabolic homeostasis, the body must be able to monitor the concentration of a large number of substances, including metabolites, in real time and to use that information to regulate the activities of different metabolic pathways. Such regulation is achieved by the presence of sensors, termed metabolite receptors, in various tissues and cells of the body, which in turn convey the information to appropriate regulatory or positive or negative feedback systems. In this review, we cover the unique roles of metabolite receptors in renal and vascular function. These receptors play a wide variety of important roles in maintaining various aspects of homeostasis-from salt and water balance to metabolism-by sensing metabolites from a wide variety of sources. We discuss the role of metabolite sensors in sensing metabolites generated locally, metabolites generated at distant tissues or organs, or even metabolites generated by resident microbes. Metabolite receptors are also involved in various pathophysiological conditions and are being recognized as potential targets for new drugs. By highlighting three receptor families-(a) citric acid cycle intermediate receptors, (b) purinergic receptors, and PMID:26667077

  9. Blood styrene and urinary metabolites in styrene polymerisation.

    PubMed Central

    Wolff, M S; Lorimer, W V; Lilis, R; Selikoff, I J

    1978-01-01

    The results of the analysis of blood and urine samples for styrene and its metabolites in 491 workers in a styrene polymerisation plant in the United States are reported. The levels of exposure to styrene were estimated to be less than 10 ppm, but nevertheless styrene and metabolites were detectable in more than 50% of workers in polymerisation jobs, within 4 h of exposure. Workers involved in the manufacture and purification of styrene from ethyl benzene also had detectable blood styrene and urinary metabolites in 83% of recently exposed subjects. The relationship between styrene in blood and in subcutaneous fat and urinary metabolites as pharmacokinetic variables is discussed. PMID:737139

  10. Reactive Metabolites: Current and Emerging Risk and Hazard Assessments.

    PubMed

    Thompson, Richard A; Isin, Emre M; Ogese, Monday O; Mettetal, Jerome T; Williams, Dominic P

    2016-04-18

    Although idiosyncratic adverse drug reactions are rare, they are still a major concern to patient safety. Reactive metabolites are widely accepted as playing a pivotal role in the pathogenesis of idiosyncratic adverse drug reactions. While there are today well established strategies for the risk assessment of stable metabolites within the pharmaceutical industry, there is still no consensus on reactive metabolite risk assessment strategies. This is due to the complexity of the mechanisms of these toxicities as well as the difficulty in identifying and quantifying short-lived reactive intermediates such as reactive metabolites. In this review, reactive metabolite risk and hazard assessment approaches are discussed, and their pros and cons highlighted. We also discuss the nature of idiosyncratic adverse drug reactions, using acetaminophen and nefazodone to exemplify the complexity of the underlying mechanisms of reactive metabolite mediated hepatotoxicity. One of the key gaps moving forward is our understanding of and ability to predict the contribution of immune activation in idiosyncratic adverse drug reactions. Sections are included on the clinical phenotypes of immune mediated idiosyncratic adverse drug reactions and on the present understanding of immune activation by reactive metabolites. The advances being made in microphysiological systems have a great potential to transform our ability to risk assess reactive metabolites, and an overview of the key components of these systems is presented. Finally, the potential impact of systems pharmacology approaches in reactive metabolite risk assessments is highlighted. PMID:26735163

  11. Genetic Influences on Metabolite Levels: A Comparison across Metabolomic Platforms

    PubMed Central

    Yet, Idil; Menni, Cristina; Shin, So-Youn; Mangino, Massimo; Soranzo, Nicole; Adamski, Jerzy; Suhre, Karsten; Spector, Tim D.

    2016-01-01

    Metabolomic profiling is a powerful approach to characterize human metabolism and help understand common disease risk. Although multiple high-throughput technologies have been developed to assay the human metabolome, no technique is capable of capturing the entire human metabolism. Large-scale metabolomics data are being generated in multiple cohorts, but the datasets are typically profiled using different metabolomics platforms. Here, we compared analyses across two of the most frequently used metabolomic platforms, Biocrates and Metabolon, with the aim of assessing how complimentary metabolite profiles are across platforms. We profiled serum samples from 1,001 twins using both targeted (Biocrates, n = 160 metabolites) and non-targeted (Metabolon, n = 488 metabolites) mass spectrometry platforms. We compared metabolite distributions and performed genome-wide association analyses to identify shared genetic influences on metabolites across platforms. Comparison of 43 metabolites named for the same compound on both platforms indicated strong positive correlations, with few exceptions. Genome-wide association scans with high-throughput metabolic profiles were performed for each dataset and identified genetic variants at 7 loci associated with 16 unique metabolites on both platforms. The 16 metabolites showed consistent genetic associations and appear to be robustly measured across platforms. These included both metabolites named for the same compound across platforms as well as unique metabolites, of which 2 (nonanoylcarnitine (C9) [Biocrates]/Unknown metabolite X-13431 [Metabolon] and PC aa C28:1 [Biocrates]/1-stearoylglycerol [Metabolon]) are likely to represent the same or related biochemical entities. The results demonstrate the complementary nature of both platforms, and can be informative for future studies of comparative and integrative metabolomics analyses in samples profiled on different platforms. PMID:27073872

  12. Genetic Influences on Metabolite Levels: A Comparison across Metabolomic Platforms.

    PubMed

    Yet, Idil; Menni, Cristina; Shin, So-Youn; Mangino, Massimo; Soranzo, Nicole; Adamski, Jerzy; Suhre, Karsten; Spector, Tim D; Kastenmüller, Gabi; Bell, Jordana T

    2016-01-01

    Metabolomic profiling is a powerful approach to characterize human metabolism and help understand common disease risk. Although multiple high-throughput technologies have been developed to assay the human metabolome, no technique is capable of capturing the entire human metabolism. Large-scale metabolomics data are being generated in multiple cohorts, but the datasets are typically profiled using different metabolomics platforms. Here, we compared analyses across two of the most frequently used metabolomic platforms, Biocrates and Metabolon, with the aim of assessing how complimentary metabolite profiles are across platforms. We profiled serum samples from 1,001 twins using both targeted (Biocrates, n = 160 metabolites) and non-targeted (Metabolon, n = 488 metabolites) mass spectrometry platforms. We compared metabolite distributions and performed genome-wide association analyses to identify shared genetic influences on metabolites across platforms. Comparison of 43 metabolites named for the same compound on both platforms indicated strong positive correlations, with few exceptions. Genome-wide association scans with high-throughput metabolic profiles were performed for each dataset and identified genetic variants at 7 loci associated with 16 unique metabolites on both platforms. The 16 metabolites showed consistent genetic associations and appear to be robustly measured across platforms. These included both metabolites named for the same compound across platforms as well as unique metabolites, of which 2 (nonanoylcarnitine (C9) [Biocrates]/Unknown metabolite X-13431 [Metabolon] and PC aa C28:1 [Biocrates]/1-stearoylglycerol [Metabolon]) are likely to represent the same or related biochemical entities. The results demonstrate the complementary nature of both platforms, and can be informative for future studies of comparative and integrative metabolomics analyses in samples profiled on different platforms. PMID:27073872

  13. Characterization of Urinary Phthalate Metabolites Among Custodians.

    PubMed

    Cavallari, Jennifer M; Simcox, Nancy J; Wakai, Sara; Lu, Chensheng; Garza, Jennifer L; Cherniack, Martin

    2015-10-01

    Phthalates, a ubiquitous class of chemicals found in consumer, personal care, and cleaning products, have been linked to adverse health effects. Our goal was to characterize urinary phthalate metabolite concentrations and to identify work and nonwork sources among custodians using traditional cleaning chemicals and 'green' or environmentally preferable products (EPP). Sixty-eight custodians provided four urine samples on a workday (first void, before shift, end of shift, and before bedtime) and trained observers recorded cleaning tasks and types of products used (traditional, EPP, or disinfectant) hourly over the work shifts. Questionnaires were used to assess personal care product use. Four different phthalate metabolites [monoethyl phthalate (MEP), monomethyl phthalate (MMP), mono (2-ethylhexyl) phthalate (MEHP), and monobenzyl phthalate (MBzP)] were quantified using liquid chromatography mass spectrometry. Geometric means (GM) and 95% confidence intervals (95% CI) were calculated for creatinine-adjusted urinary phthalate concentrations. Mixed effects univariate and multivariate modeling, using a random intercept for each individual, was performed to identify predictors of phthalate metabolites including demographics, workplace factors, and personal care product use. Creatinine-adjusted urinary concentrations [GM (95% CI)] of MEP, MMP, MEHP, and MBzP were 107 (91.0-126), 2.69 (2.18-3.30), 6.93 (6.00-7.99), 8.79 (7.84-9.86) µg g(-1), respectively. An increasing trend in phthalate concentrations from before to after shift was not observed. Creatinine-adjusted urinary MEP was significantly associated with frequency of traditional cleaning chemical intensity in the multivariate model after adjusting for potential confounding by demographics, workplace factors, and personal care product use. While numerous demographics, workplace factors, and personal care products were statistically significant univariate predictors of MMP, MEHP, and MBzP, few associations persisted

  14. From the Lab Bench: Plant secondary metabolites: The good and the bad.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A column was written to discuss the negatives and positives of plant secondary metabolites. Primary metabolites are those metabolites that are required for survival, such as protein, carbohydrates, and lipids. Plant secondary metabolites are produced from primary metabolites and are not required f...

  15. Encapsulates for Food Bioconversions and Metabolite Production

    NASA Astrophysics Data System (ADS)

    Breguet, Véronique; Vojinovic, Vojislav; Marison, Ian W.

    The control of production costs in the food industry must be very strict as a result of the relatively low added value of food products. Since a wide variety of enzymes and/or cells are employed in the food industry for starch processing, cheese making, food preservation, lipid hydrolysis and other applications, immobilization of the cells and/or enzymes has been recognized as an attractive approach to improving food processes while minimizing costs. This is due to the fact that biocatalyst immobilization allows for easier separation/purification of the product and reutilization of the biocatalyst. The advantages of the use of immobilized systems are many, and they have a special relevance in the area of food technology, especially because industrial processes using immobilized biosystems are usually characterized by lower capital/energy costs and better logistics. The main applications of immobilization, related to the major processes of food bioconversions and metabolite production, will be described and discussed in this chapter.

  16. Unique metabolites protect earthworms against plant polyphenols

    PubMed Central

    Liebeke, Manuel; Strittmatter, Nicole; Fearn, Sarah; Morgan, A. John; Kille, Peter; Fuchser, Jens; Wallis, David; Palchykov, Vitalii; Robertson, Jeremy; Lahive, Elma; Spurgeon, David J.; McPhail, David; Takáts, Zoltán; Bundy, Jacob G.

    2015-01-01

    All higher plants produce polyphenols, for defence against above-ground herbivory. These polyphenols also influence the soil micro- and macro-fauna that break down plant leaf litter. Polyphenols therefore indirectly affect the fluxes of soil nutrients and, ultimately, carbon turnover and ecosystem functioning in soils. It is unknown how earthworms, the major component of animal biomass in many soils, cope with high-polyphenol diets. Here, we show that earthworms possess a class of unique surface-active metabolites in their gut, which we term ‘drilodefensins'. These compounds counteract the inhibitory effects of polyphenols on earthworm gut enzymes, and high-polyphenol diets increase drilodefensin concentrations in both laboratory and field populations. This shows that drilodefensins protect earthworms from the harmful effects of ingested polyphenols. We have identified the key mechanism for adaptation to a dietary challenge in an animal group that has a major role in organic matter recycling in soils worldwide. PMID:26241769

  17. Unique metabolites protect earthworms against plant polyphenols.

    PubMed

    Liebeke, Manuel; Strittmatter, Nicole; Fearn, Sarah; Morgan, A John; Kille, Peter; Fuchser, Jens; Wallis, David; Palchykov, Vitalii; Robertson, Jeremy; Lahive, Elma; Spurgeon, David J; McPhail, David; Takáts, Zoltán; Bundy, Jacob G

    2015-01-01

    All higher plants produce polyphenols, for defence against above-ground herbivory. These polyphenols also influence the soil micro- and macro-fauna that break down plant leaf litter. Polyphenols therefore indirectly affect the fluxes of soil nutrients and, ultimately, carbon turnover and ecosystem functioning in soils. It is unknown how earthworms, the major component of animal biomass in many soils, cope with high-polyphenol diets. Here, we show that earthworms possess a class of unique surface-active metabolites in their gut, which we term 'drilodefensins'. These compounds counteract the inhibitory effects of polyphenols on earthworm gut enzymes, and high-polyphenol diets increase drilodefensin concentrations in both laboratory and field populations. This shows that drilodefensins protect earthworms from the harmful effects of ingested polyphenols. We have identified the key mechanism for adaptation to a dietary challenge in an animal group that has a major role in organic matter recycling in soils worldwide. PMID:26241769

  18. Spatial distribution of metabolites in the human lens.

    PubMed

    Tamara, Semen O; Yanshole, Lyudmila V; Yanshole, Vadim V; Fursova, Anjella Zh; Stepakov, Denis A; Novoselov, Vladimir P; Tsentalovich, Yuri P

    2016-02-01

    Spatial distribution of 34 metabolites along the optical and equatorial axes of the human lens has been determined. For the majority of metabolites, the homogeneous distribution has been observed. That suggests that the rate of the metabolite transformation in the lens is low due to the general metabolic passivity of the lens fiber cells. However, the redox processes are active in the lens; as a result, some metabolites, including antioxidants, demonstrate the "nucleus-depleted" type of distribution, whereas secondary UV filters show the "nucleus-enriched" type. The metabolite concentrations at the lens poles and equator are similar for all metabolites under study. The concentric pattern of the "nucleus-depleted" and "nucleus-enriched" distributions testifies that the metabolite distribution inside the lens is mostly governed by a passive diffusion, relatively free along the fiber cells and retarded in the radial direction across the cells. No significant difference in the metabolite distribution between the normal and cataractous human lenses was found. PMID:26500196

  19. Synthesis of an Albendazole Metabolite: Characterization and HPLC Determination

    ERIC Educational Resources Information Center

    Mahler, Graciela; Davyt, Danilo; Gordon, Sandra; Incerti, Marcelo; Nunez, Ivana; Pezaroglo, Horacio; Scarone, Laura; Serra, Gloria; Silvera, Mauricio; Manta, Eduardo

    2008-01-01

    In this laboratory activity, students are introduced to the synthesis of an albendazole metabolite obtained by a sulfide oxidation reaction. Albendazole as well as its metabolite, albendazole sulfoxide, are used as anthelmintic drugs. The oxidation reagent is H[subscript 2]O[subscript 2] in acetic acid. The reaction is environmental friendly,…

  20. Determination of Tamoxifen and its Major Metabolites in Exposed Fish

    EPA Science Inventory

    Tamoxifen (TAM), (Z)-1-(p-dimethylaminoethoxyphenyl)-1, 2-diphenyl-1-butene, is a nonsteroidal agent that has been used in breast cancer treatment for decades. Its major metabolites are 4-hydroxytamoxifen (4-OHT), N-desmethyltamoxifen (DMT), and endoxifen. While TAM and metabolit...

  1. Profiling Reactive Metabolites via Chemical Trapping and Targeted Mass Spectrometry.

    PubMed

    Chang, Jae Won; Lee, Gihoon; Coukos, John S; Moellering, Raymond E

    2016-07-01

    Metabolomic profiling studies aim to provide a comprehensive, quantitative, and dynamic portrait of the endogenous metabolites in a biological system. While contemporary technologies permit routine profiling of many metabolites, intrinsically labile metabolites are often improperly measured or omitted from studies due to unwanted chemical transformations that occur during sample preparation or mass spectrometric analysis. The primary glycolytic metabolite 1,3-bisphosphoglyceric acid (1,3-BPG) typifies this class of metabolites, and, despite its central position in metabolism, has largely eluded analysis in profiling studies. Here we take advantage of the reactive acylphosphate group in 1,3-BPG to chemically trap the metabolite with hydroxylamine during metabolite isolation, enabling quantitative analysis by targeted LC-MS/MS. This approach is compatible with complex cellular metabolome, permits specific detection of the reactive (1,3-) instead of nonreactive (2,3-) BPG isomer, and has enabled direct analysis of dynamic 1,3-BPG levels resulting from perturbations to glucose processing. These studies confirmed that standard metabolomic methods misrepresent cellular 1,3-BPG levels in response to altered glucose metabolism and underscore the potential for chemical trapping to be used for other classes of reactive metabolites. PMID:27314642

  2. Influence of abiotic stress signals on secondary metabolites in plants

    PubMed Central

    Ramakrishna, Akula; Ravishankar, Gokare Aswathanarayana

    2011-01-01

    Plant secondary metabolites are unique sources for pharmaceuticals, food additives, flavors, and industrially important biochemicals. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Secondary metabolites play a major role in the adaptation of plants to the environment and in overcoming stress conditions. Environmental factors viz. temperature, humidity, light intensity, the supply of water, minerals, and CO2 influence the growth of a plant and secondary metabolite production. Drought, high salinity, and freezing temperatures are environmental conditions that cause adverse effects on the growth of plants and the productivity of crops. Plant cell culture technologies have been effective tools for both studying and producing plant secondary metabolites under in vitro conditions and for plant improvement. This brief review summarizes the influence of different abiotic factors include salt, drought, light, heavy metals, frost etc. on secondary metabolites in plants. The focus of the present review is the influence of abiotic factors on secondary metabolite production and some of important plant pharmaceuticals. Also, we describe the results of in vitro cultures and production of some important secondary metabolites obtained in our laboratory. PMID:22041989

  3. Screening botanical extracts for quinoid metabolites.

    PubMed

    Johnson, B M; Bolton, J L; van Breemen, R B

    2001-11-01

    Botanical dietary supplements represent a significant share of the growing market for alternative medicine in the USA, where current regulations do not require assessment of their safety. To help ensure the safety of such products, an in vitro assay using pulsed ultrafiltration and LC-MS-MS has been developed to screen botanical extracts for the formation of electrophilic and potentially toxic quinoid species upon bioactivation by hepatic cytochromes P450. Rat liver microsomes were trapped in a flow-through chamber by an ultrafiltration membrane, and samples containing botanical extracts, GSH and NADP(H), were flow-injected into the chamber. Botanical compounds that were metabolized to reactive intermediates formed stable GSH adducts mimicking a common in vivo detoxification pathway. If present in the ultrafiltrate, GSH conjugates were detected using LC-MS-MS with precursor ion scanning followed by additional characterization using product ion scanning and comparison to standard compounds. As expected, no GSH adducts of reactive metabolites were found in extracts of Trifolium pratense L. (red clover), which are under investigation as botanical dietary supplements for the management of menopause. However, extracts of Sassafras albidum (Nutt.) Nees (sassafras), Symphytum officinale L. (comfrey), and Rosmarinus officinalis L. (rosemary), all of which are known to contain compounds that are either carcinogenic or toxic to mammals, produced GSH adducts during this screening assay. Several compounds that formed GSH conjugates including novel metabolites of rosmarinic acid were identified using database searching and additional LC-MS-MS studies. This assay should be useful as a preliminary toxicity screen during the development of botanical dietary supplements. A positive test suggests that additional toxicological studies are warranted before human consumption of a botanical product. PMID:11712913

  4. Metabolite Proofreading in Carnosine and Homocarnosine Synthesis

    PubMed Central

    Veiga-da-Cunha, Maria; Chevalier, Nathalie; Stroobant, Vincent; Vertommen, Didier; Van Schaftingen, Emile

    2014-01-01

    Carnosine synthase is the ATP-dependent ligase responsible for carnosine (β-alanyl-histidine) and homocarnosine (γ-aminobutyryl-histidine) synthesis in skeletal muscle and brain, respectively. This enzyme uses, also at substantial rates, lysine, ornithine, and arginine instead of histidine, yet the resulting dipeptides are virtually absent from muscle or brain, suggesting that they are removed by a “metabolite repair” enzyme. Using a radiolabeled substrate, we found that rat skeletal muscle, heart, and brain contained a cytosolic β-alanyl-lysine dipeptidase activity. This enzyme, which has the characteristics of a metalloenzyme, was purified ≈200-fold from rat skeletal muscle. Mass spectrometry analysis of the fractions obtained at different purification stages indicated parallel enrichment of PM20D2, a peptidase of unknown function belonging to the metallopeptidase 20 family. Western blotting showed coelution of PM20D2 with β-alanyl-lysine dipeptidase activity. Recombinant mouse PM20D2 hydrolyzed β-alanyl-lysine, β-alanyl-ornithine, γ-aminobutyryl-lysine, and γ-aminobutyryl-ornithine as its best substrates. It also acted at lower rates on β-alanyl-arginine and γ-aminobutyryl-arginine but virtually not on carnosine or homocarnosine. Although acting preferentially on basic dipeptides derived from β-alanine or γ-aminobutyrate, PM20D2 also acted at lower rates on some “classic dipeptides” like α-alanyl-lysine and α-lysyl-lysine. The same activity profile was observed with human PM20D2, yet this enzyme was ∼100–200-fold less active on all substrates tested than the mouse enzyme. Cotransfection in HEK293T cells of mouse or human PM20D2 together with carnosine synthase prevented the accumulation of abnormal dipeptides (β-alanyl-lysine, β-alanyl-ornithine, γ-aminobutyryl-lysine), thus favoring the synthesis of carnosine and homocarnosine and confirming the metabolite repair role of PM20D2. PMID:24891507

  5. Software-assisted serum metabolite quantification using NMR.

    PubMed

    Jung, Young-Sang; Hyeon, Jin-Seong; Hwang, Geum-Sook

    2016-08-31

    The goal of metabolomics is to analyze a whole metabolome under a given set of conditions, and accurate and reliable quantitation of metabolites is crucial. Absolute concentration is more valuable than relative concentration; however, the most commonly used method in NMR-based serum metabolic profiling, bin-based and full data point peak quantification, provides relative concentration levels of metabolites and are not reliable when metabolite peaks overlap in a spectrum. In this study, we present the software-assisted serum metabolite quantification (SASMeQ) method, which allows us to identify and quantify metabolites in NMR spectra using Chenomx software. This software uses the ERETIC2 utility from TopSpin to add a digitally synthesized peak to a spectrum. The SASMeQ method will advance NMR-based serum metabolic profiling by providing an accurate and reliable method for absolute quantification that is superior to bin-based quantification. PMID:27506360

  6. Urinary pesticide metabolites in school students from northern Thailand.

    PubMed

    Panuwet, Parinya; Prapamontol, Tippawan; Chantara, Somporn; Barr, Dana B

    2009-05-01

    We evaluated exposure to pesticides among secondary school students aged 12-13 years old in Chiang Mai Province, Thailand. Pesticide-specific urinary metabolites were used as biomarkers of exposure for a variety of pesticides, including organophosphorus insecticides, synthetic pyrethroid insecticides and selected herbicides. We employed a simple solid-phase extraction with analysis using isotope dilution high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). A total of 207 urine samples from Thai students were analyzed for 18 specific pesticide metabolites. We found 14 metabolites in the urine samples tested; seven of them were detected with a frequency > or=17%. The most frequently detected metabolites were 2-[(dimethoxyphosphorothioyl) sulfanyl] succinic acid (malathion dicarboxylic acid), para-nitrophenol (PNP), 3,5,6-trichloro-2-pyridinol (TPCY; metabolite of chlorpyrifos), 2,4-dichlorophenoxyacetic acid (2,4-D), cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acids (c-DCCA and t-DCCA; metabolite of permethrin) and 3-phenoxybenzoic acid (3-PBA; metabolite of pyrethroids). The students were classified into 4 groups according to their parental occupations: farmers (N=60), merchants and traders (N=39), government and company employees (N=52), and laborers (N=56). Children of farmers had significantly higher urinary concentrations of pyrethroid insecticide metabolites than did other children (p<0.05). Similarly, children of agricultural families had significantly higher pyrethroid metabolite concentrations. Males had significantly higher values of PNP (Mann-Whitney test, p=0.009); however, no other sex-related differences were observed. Because parental occupation and agricultural activities seemed to have little influence on pesticide levels, dietary sources were the likely contributors to the metabolite levels observed. PMID:18760967

  7. Steady-State Metabolite Concentrations Reflect a Balance between Maximizing Enzyme Efficiency and Minimizing Total Metabolite Load

    PubMed Central

    Amador-Noguez, Daniel; Haraldsdóttir, Hulda S.; Milo, Ron; Rabinowitz, Josh; Liebermeister, Wolfram; Shlomi, Tomer

    2013-01-01

    Steady-state metabolite concentrations in a microorganism typically span several orders of magnitude. The underlying principles governing these concentrations remain poorly understood. Here, we hypothesize that observed variation can be explained in terms of a compromise between factors that favor minimizing metabolite pool sizes (e.g. limited solvent capacity) and the need to effectively utilize existing enzymes. The latter requires adequate thermodynamic driving force in metabolic reactions so that forward flux substantially exceeds reverse flux. To test this hypothesis, we developed a method, metabolic tug-of-war (mTOW), which computes steady-state metabolite concentrations in microorganisms on a genome-scale. mTOW is shown to explain up to 55% of the observed variation in measured metabolite concentrations in E. coli and C. acetobutylicum across various growth media. Our approach, based strictly on first thermodynamic principles, is the first method that successfully predicts high-throughput metabolite concentration data in bacteria across conditions. PMID:24086517

  8. Detection and quantification of boscalid and its metabolites in honeybees.

    PubMed

    Jabot, Claire; Daniele, Gaëlle; Giroud, Barbara; Tchamitchian, Sylvie; Belzunces, Luc P; Casabianca, Hervé; Vulliet, Emmanuelle

    2016-08-01

    Boscalid is a new-generation fungicide that has been detected in several bee matrices. The objective of this work was to characterize boscalid metabolites in honeybees based on in vivo experimentation, and next to verify the presence of theses metabolites into honeybees from colonies presenting troubles. A methodology based on complementary mass spectrometric tools, namely ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-QToF) or triple quadrupole mass spectrometry (UHPLC-QqQ) was implemented. Honeybees were sprayed with boscalid, at field rate (to induce the metabolization process) and the parent compound with its generated metabolites were then extracted using modified EU-QuEChERS method. The mass characteristics including exact mass, isotopic profile and mass fragments allowed assuming the structure of several metabolites. Some of them were unambiguously identified by comparison with synthesized analytical standards. The metabolites were resulted from hydroxylation and dechlorination of the parent compound as well as the substitution of a chlorine atom with an hydroxyl group. The metabolites were then quantified in bee samples collected from various beehives located in France. Boscalid and three of its metabolites were present in some samples at a level ranged between 0.2 and 36.3 ng/g. PMID:27179242

  9. Using Molecular Networking for Microbial Secondary Metabolite Bioprospecting

    PubMed Central

    Purves, Kevin; Macintyre, Lynsey; Brennan, Debra; Hreggviðsson, Guðmundur Ó.; Kuttner, Eva; Ásgeirsdóttir, Margrét E.; Young, Louise C.; Green, David H.; Edrada-Ebel, Ruangelie; Duncan, Katherine R.

    2016-01-01

    The oceans represent an understudied resource for the isolation of bacteria with the potential to produce novel secondary metabolites. In particular, actinomyces are well known to produce chemically diverse metabolites with a wide range of biological activities. This study characterised spore-forming bacteria from both Scottish and Antarctic sediments to assess the influence of isolation location on secondary metabolite production. Due to the selective isolation method used, all 85 isolates belonged to the phyla Firmicutes and Actinobacteria, with the majority of isolates belonging to the genera Bacillus and Streptomyces. Based on morphology, thirty-eight isolates were chosen for chemical investigation. Molecular networking based on chemical profiles (HR-MS/MS) of fermentation extracts was used to compare complex metabolite extracts. The results revealed 40% and 42% of parent ions were produced by Antarctic and Scottish isolated bacteria, respectively, and only 8% of networked metabolites were shared between these locations, implying a high degree of biogeographic influence upon secondary metabolite production. The resulting molecular network contained over 3500 parent ions with a mass range of m/z 149–2558 illustrating the wealth of metabolites produced. Furthermore, seven fermentation extracts showed bioactivity against epithelial colon adenocarcinoma cells, demonstrating the potential for the discovery of novel bioactive compounds from these understudied locations. PMID:26761036

  10. Secondary Metabolites from Higher Fungi: Discovery, Bioactivity, and Bioproduction

    NASA Astrophysics Data System (ADS)

    Zhong, Jian-Jiang; Xiao, Jian-Hui

    Medicinal higher fungi such as Cordyceps sinensis and Ganoderma lucidum have been used as an alternative medicine remedy to promote health and longevity for people in China and other regions of the world since ancient times. Nowadays there is an increasing public interest in the secondary metabolites of those higher fungi for discovering new drugs or lead compounds. Current research in drug discovery from medicinal higher fungi involves a multifaceted approach combining mycological, biochemical, pharmacological, metabolic, biosynthetic and molecular techniques. In recent years, many new secondary metabolites from higher fungi have been isolated and are more likely to provide lead compounds for new drug discovery, which may include chemopreventive agents possessing the bioactivity of immunomodulatory, anticancer, etc. However, numerous challenges of secondary metabolites from higher fungi are encountered including bioseparation, identification, biosynthetic metabolism, and screening model issues, etc. Commercial production of secondary metabolites from medicinal mushrooms is still limited mainly due to less information about secondary metabolism and its regulation. Strategies for enhancing secondary metabolite production by medicinal mushroom fermentation include two-stage cultivation combining liquid fermentation and static culture, two-stage dissolved oxygen control, etc. Purification of bioactive secondary metabolites, such as ganoderic acids from G. lucidum, is also very important to pharmacological study and future pharmaceutical application. This review outlines typical examples of the discovery, bioactivity, and bioproduction of secondary metabolites of higher fungi origin.

  11. Accumulation in murine amniotic fluid of halothane and its metabolites.

    PubMed

    Danielsson, B R; Ghantous, H; Dencker, L

    1984-11-01

    The distribution of radioactivity in pregnant mice was registered at 0, 4, and 24 hrs after a 10 min. period of inhalation of 14C-halothane. Autoradiographic methods were used to allow to distinguish between the distribution of volatile (non-metabolize) halothane, water-soluble metabolites, and firmly tissue-bound metabolites. While volatile radioactivity was seen predominantly at short survival intervals, e.g. in body fat, blood, brain and liver, metabolites accumulated with time. Peak values occurred at 4 hrs in most organs (measured with liquid scintillation as well). The most remarkable findings were the high concentrations of radioactivity in amniotic fluid (and the ocular fluids of adults) with peak values at 4 hrs and rather high concentrations still prevailing at 24 hrs after inhalation. It is assumed that this activity represents only partly volaile halothane and mostly non-volatile metabolites. High activity of metabolites was seen in the neuroepithelium of the embryo in early gestation. Firmly tissue-bound metabolites, still remaining after washing the tissues with trichloroacetic acid and organic solvents, were found in the nasal mucosa, trachea and bronchial tree and in (presumably centrilobular) zones of the liver of adults after inhalation and 5-day old mice after intraperitoneal injection, indicating the formation of reactive metabolites in these organs. Firmly tissue-bound activity was not observed in the corresponding foetal organs. PMID:6528811

  12. A reassessment of the nomenclature of polychlorinated biphenyl (PCB) metabolites.

    PubMed Central

    Maervoet, Johan; Covaci, Adrian; Schepens, Paul; Sandau, Courtney D; Letcher, Robert J

    2004-01-01

    Polychlorinated biphenyls (PCBs) are a widespread class of persistent organic chemicals that accumulate in the environment and humans and are associated with a broad spectrum of health effects. PCB biotransformation has been shown to lead to two classes of PCB metabolites that are present as contaminant residues in the tissues of selected biota: hydroxylated (HO) and methyl sulfone (MeSO2) PCBs. Although these two types of metabolites are related structures, different rules for abbreviation of both classes have emerged. It is important that a standardized nomenclature for the notation of PCB metabolites be universally agreed upon. We suggest that the full chemical name of the PCB metabolite and a shorthand notation should be adopted using the International Union of Pure and Applied Chemistry's chemical name/original Ballschmiter and Zell number of the parent congener, followed by the assignment of the phenyl ring position number of the MeSO2- or HO-substituent. This nomenclature provides a clear, unequivocal set of rules in naming and abbreviating the PCB metabolite structure. Furthermore, this unified PCB metabolite nomenclature approach can be extended to the naming and abbreviation of potential metabolites of structurally analogous contaminants such as HO-polybrominated biphenyls and HO-polybrominated diphenyl ethers. PMID:14998742

  13. Physiochemical property space distribution among human metabolites, drugs and toxins

    PubMed Central

    2009-01-01

    Background The current approach to screen for drug-like molecules is to sieve for molecules with biochemical properties suitable for desirable pharmacokinetics and reduced toxicity, using predominantly biophysical properties of chemical compounds, based on empirical rules such as Lipinski's "rule of five" (Ro5). For over a decade, Ro5 has been applied to combinatorial compounds, drugs and ligands, in the search for suitable lead compounds. Unfortunately, till date, a clear distinction between drugs and non-drugs has not been achieved. The current trend is to seek out drugs which show metabolite-likeness. In identifying similar physicochemical characteristics, compounds have usually been clustered based on some characteristic, to reduce the search space presented by large molecular datasets. This paper examines the similarity of current drug molecules with human metabolites and toxins, using a range of computed molecular descriptors as well as the effect of comparison to clustered data compared to searches against complete datasets. Results We have carried out statistical and substructure functional group analyses of three datasets, namely human metabolites, drugs and toxin molecules. The distributions of various molecular descriptors were investigated. Our analyses show that, although the three groups are distinct, present-day drugs are closer to toxin molecules than to metabolites. Furthermore, these distributions are quite similar for both clustered data as well as complete or unclustered datasets. Conclusion The property space occupied by metabolites is dissimilar to that of drugs or toxin molecules, with current drugs showing greater similarity to toxins than to metabolites. Additionally, empirical rules like Ro5 can be refined to identify drugs or drug-like molecules that are clearly distinct from toxic compounds and more metabolite-like. The inclusion of human metabolites in this study provides a deeper insight into metabolite/drug/toxin-like properties and

  14. NeeMDB: Convenient Database for Neem Secondary Metabolites

    PubMed Central

    Hatti, Kaushik S; Muralitharan, Lakshmi; Hegde, Rajendra; Kush, Anil

    2014-01-01

    Indian Neem tree is known for its pesticidal and medicinal properties for centuries. Structure elucidation of large number of secondary metabolites responsible for its diverse properties has been achieved. However, this data is spread over various books, scientific reports and publications and difficult to access. We have compiled and stored structural details of neem metabolites in NeeMDB, a database which can be easily accessed, queried and downloaded. NeeMDB would be central in dissipating structural information of neem secondary metabolites world over. PMID:24966540

  15. Cerebrospinal fluid monoamine metabolites and suicide.

    PubMed

    Jokinen, Jussi; Nordström, Anna-Lena; Nordström, Peter

    2009-01-01

    Prospective studies of the serotonergic system and suicide report that low 5-hydroxyindolacetic acid (5-HIAA) in the cerebrospinal fluid (CSF) and a history of attempted suicide predict suicide risk. Low CSF homovanillic acid (HVA) is reported to be associated with past and future lethality of suicide attempts but not with suicide. The interrelationships between monoamine metabolites, violent method, suicide intent and lethality of suicidal behaviour are complex. We hypothesized that CSF 5-HIAA and HVA levels are related to suicide intent, violence and lethality of suicidal behaviour. Fifteen male suicide attempters admitted to a psychiatric ward at the Karolinska University Hospital and eight healthy male volunteers were submitted to lumbar puncture and CSF 5-HIAA and HVA were assayed. Suicide intent with the Beck Suicide Intent Scale (SIS), lethality and violence of suicidal behaviour were assessed. All patients were followed up for causes of death. Six suicides and one fatal accident were identified with death certificates. Mean CSF 5-HIAA but not CSF HVA differed between suicides and survivors. Violent suicides had higher suicide intent and CSF 5-HIAA than non-violent suicides. In violent suicides, CSF 5-HIAA levels were negatively correlated with SIS. Greater suicide intent may be associated with greater aggressive intent and predicts a violent suicide method. PMID:19034712

  16. Protein acetylation in metabolism - metabolites and cofactors.

    PubMed

    Menzies, Keir J; Zhang, Hongbo; Katsyuba, Elena; Auwerx, Johan

    2016-01-01

    Reversible acetylation was initially described as an epigenetic mechanism regulating DNA accessibility. Since then, this process has emerged as a controller of histone and nonhistone acetylation that integrates key physiological processes such as metabolism, circadian rhythm and cell cycle, along with gene regulation in various organisms. The widespread and reversible nature of acetylation also revitalized interest in the mechanisms that regulate lysine acetyltransferases (KATs) and deacetylases (KDACs) in health and disease. Changes in protein or histone acetylation are especially relevant for many common diseases including obesity, diabetes mellitus, neurodegenerative diseases and cancer, as well as for some rare diseases such as mitochondrial diseases and lipodystrophies. In this Review, we examine the role of reversible acetylation in metabolic control and how changes in levels of metabolites or cofactors, including nicotinamide adenine dinucleotide, nicotinamide, coenzyme A, acetyl coenzyme A, zinc and butyrate and/or β-hydroxybutyrate, directly alter KAT or KDAC activity to link energy status to adaptive cellular and organismal homeostasis. PMID:26503676

  17. Stability of cocaine and its metabolites in municipal wastewater--the case for using metabolite consolidation to monitor cocaine utilization.

    PubMed

    Bisceglia, Kevin J; Lippa, Katrice A

    2014-03-01

    Transformations of cocaine and eleven of its metabolites were investigated in untreated municipal sewage at pH ≈ 7 and 9, 23, and 31 °C. Results indicated that hydrolysis-possibly bacterially mediated-was the principal transformation pathway. Residues possessing alkyl esters were particularly susceptible to hydrolysis, with pseudo-first-order rate constants varying from 0.54 to 1.7 day(-1) at 23 °C. Metabolites lacking esters or possessing only a benzoyl ester appeared stable. Residues lacking alkyl esters did accumulate through hydrolysis of precursors, however. As noted previously, this may positively bias cocaine utilization estimates based on benzoylecgonine alone. Reported variability in metabolic excretion was used in conjunction with transformation data to evaluate different approaches for estimating cocaine loading. Results indicate that estimates derived from measurands that capture all major cocaine metabolites, such as COCtot (the sum of all measurable metabolites) and EChyd (the sum of all metabolites that can be hydrolyzed to ecgonine), may reduce uncertainty arising from variability in metabolite transformation and excretion, possibly to ≈ 10 % RSD. This is more than a two-fold reduction relative to estimates derived from benzoylecgonine (>26 % RSD), and roughly equivalent to reported uncertainties from sources that are not metabolite-specific (e.g., sampling frequency, flow variability). They and other composite measurands merit consideration from the sewage epidemiology community, beginning with efforts to evaluate the stability of the total cocaine load under realistic sewer conditions. PMID:24337995

  18. Identification of metabolites of hexazinone by mass spectrometry.

    PubMed

    Reiser, R W; Belasco, I J; Rhodes, R C

    1983-11-01

    The metabolites of hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione ] obtained in the rat and in plants were identified by mass spectrometry. Rat urine metabolites were identified from direct probe spectra obtained on metabolites separated by thin-layer chromatography. Sugarcane metabolites were identified by gas chromatography mass spectrometry of the trimethylsilyl derivatives. The major metabolic routes were found to be hydroxylation of the cyclohexyl group and demethylation. All identifications were confirmed by synthesis and direct comparison of chromatographic data and mass spectra. Hexazinone is metabolized quickly and extensively in the biological systems studied, and is relatively nonpersistent in the environment. PMID:6661503

  19. IN VITRO CYTOTOXICITY OF BTEX METABOLITES IN HELA CELL LINES

    EPA Science Inventory

    Fuel leakage from underground storage tanks is a major source of groundwater contamination. Although the toxicity of regulated compounds such as benzene, toluene, ethylbenzene, and xylene (BTEX) are well recognized, the cytotoxicity of their metabolites has not been studied exte...

  20. ANALYSIS OF ARACHIDONIC ACID METABOLITE AND PLATELET ACTIVATING FACTOR PRODUCTION

    EPA Science Inventory

    Metabolites of arachidonic acid ("eicosanoids") and platelet activating factor are important bioactive lipids that may be involved in the pathobiological alterations in animals induced by pollutant exposure. nalysis of these substances in biological tissue and fluids is important...

  1. Metabolites: messengers between the microbiota and the immune system.

    PubMed

    Levy, Maayan; Thaiss, Christoph A; Elinav, Eran

    2016-07-15

    The mammalian intestine harbors one of the largest microbial densities on Earth, necessitating the implementation of control mechanisms by which the host evaluates the state of microbial colonization and reacts to deviations from homeostasis. While microbial recognition by the innate immune system has been firmly established as an efficient means by which the host evaluates microbial presence, recent work has uncovered a central role for bacterial metabolites in the orchestration of the host immune response. In this review, we highlight examples of how microbiota-modulated metabolites control the development, differentiation, and activity of the immune system and classify them into functional categories that illustrate the spectrum of ways by which microbial metabolites influence host physiology. A comprehensive understanding of how microbiota-derived metabolites shape the human immune system is critical for the rational design of therapies for microbiota-driven diseases. PMID:27474437

  2. Exposure to benzene metabolites causes oxidative damage in Saccharomyces cerevisiae.

    PubMed

    Raj, Abhishek; Nachiappan, Vasanthi

    2016-06-01

    Hydroquinone (HQ) and benzoquinone (BQ) are known benzene metabolites that form reactive intermediates such as reactive oxygen species (ROS). This study attempts to understand the effect of benzene metabolites (HQ and BQ) on the antioxidant status, cell morphology, ROS levels and lipid alterations in the yeast Saccharomyces cerevisiae. There was a reduction in the growth pattern of wild-type cells exposed to HQ/BQ. Exposure of yeast cells to benzene metabolites increased the activity of the anti-oxidant enzymes catalase, superoxide dismutase and glutathione peroxidase but lead to a decrease in ascorbic acid and reduced glutathione. Increased triglyceride level and decreased phospholipid levels were observed with exposure to HQ and BQ. These results suggest that the enzymatic antioxidants were increased and are involved in the protection against macromolecular damage during oxidative stress; presumptively, these enzymes are essential for scavenging the pro-oxidant effects of benzene metabolites. PMID:27016252

  3. Metabolite Signatures of Metabolic Risk Factors and their Longitudinal Changes.

    PubMed

    Yin, Xiaoyan; Subramanian, Subha; Willinger, Christine M; Chen, George; Juhasz, Peter; Courchesne, Paul; Chen, Brian H; Li, Xiaohang; Hwang, Shih-Jen; Fox, Caroline S; O'Donnell, Christopher J; Muntendam, Pieter; Fuster, Valentin; Bobeldijk-Pastorova, Ivana; Sookoian, Silvia C; Pirola, Carlos J; Gordon, Neal; Adourian, Aram; Larson, Martin G; Levy, Daniel

    2016-04-01

    This study tested metabolite associations with risk factors cross-sectionally and with risk factor changes over time to uncover mechanistic links between metabolomics dysregulation and metabolic risk. PMID:26908103

  4. Metabolites and DNA adduct formation from flavoenzyme-activated porfiromycin.

    PubMed

    Pan, S S; Iracki, T

    1988-08-01

    Porfiromycin was reductively metabolized by NADPH cytochrome P-450 reductase and xanthine oxidase under anaerobic conditions. The production of metabolites varied with the pH and the contents of the reaction buffer. In Tris buffer, two major metabolites were produced at pH 7.5 and above, whereas one major metabolite was produced at pH 6.5. The three major metabolites were separated and isolated by HPLC. Identification by californium-252 plasma desorption mass spectrometry showed that the two major metabolites from pH 7.5 were (trans) and (cis)-forms of 7-amino-1-hydroxyl-2-methylaminomitosene and the major metabolite from pH 6.5 was 7-amino-2-methylaminomitosene. All three major metabolites showed substitutions at the C-1 position. DNA was alkylated readily by enzyme-activated porfiromycin. Digestion of porfiromycin-alkylated DNA by DNase, snake venom phosphodiesterase, and alkaline phosphatase resulted in an insoluble nuclease-resistant fraction and a soluble fraction. The nuclease-resistant fraction reflected a high content of cross-linked adducts. Upon HPLC analysis, the solubilized fraction contained two monofunctionally linked porfiromycin adducts and a possibly cross-linked dinucleotide. The major adduct was isolated by HPLC and identified by NMR, as N2-(2'-deoxyguanosyl)-7-amino-2-methylaminomitosene. The N2 position of deoxyguanosine appeared as the major monofunctional alkylating site for DNA alkylation by porfiromycin. Thus, mitomycin C and porfiromycin (which differs from mitomycin C only by the addition of a methyl group to the aziridine nitrogen) share the same enzymatic activating mechanism that leads to the formation of the same types of metabolites and the same specificity of DNA alkylation. PMID:3412325

  5. Metabolite profiling in plant biology: platforms and destinations

    PubMed Central

    Kopka, Joachim; Fernie, Alisdair; Weckwerth, Wolfram; Gibon, Yves; Stitt, Mark

    2004-01-01

    Optimal use of genome sequences and gene-expression resources requires powerful phenotyping platforms, including those for systematic analysis of metabolite composition. The most used technologies for metabolite profiling, including mass spectral, nuclear magnetic resonance and enzyme-based approaches, have various advantages and disadvantages, and problems can arise with reliability and the interpretation of the huge datasets produced. These techniques will be useful for answering important biological questions in the future. PMID:15186482

  6. Gram scale synthesis of the glucuronide metabolite of ABT-724.

    PubMed

    Engstrom, Kenneth M; Daanen, Jerome F; Wagaw, Seble; Stewart, Andrew O

    2006-10-27

    A gram scale synthesis of the glucuronide metabolite of ABT-724 is reported. Glycosidic coupling between a trichloroacetimidate glucuronyl donor and a Cbz-protected hydroxypyridylpiperazine glycosyl acceptor is the key step in the synthesis, since attempts to directly glucuronidate the aglycon, aglycon derivatives, and other truncated glycosyl acceptors were unsuccessful. The route was used to produce 2.1 g of metabolite in eight steps from 2-chloro-5-hydroxypyridine in 21% overall yield. PMID:17064008

  7. Fusarial toxins: secondary metabolites of Fusarium fungi.

    PubMed

    Nesic, Ksenija; Ivanovic, Snezana; Nesic, Vladimir

    2014-01-01

    Exposure to mycotoxins occurs worldwide, even though there are geographic and climatic differences in the amounts produced and occurrence of these substances.Mycotoxins are secondary chemical metabolites of different fungi. They are natural contaminants of cereals, so their presence is often inevitable. Among many genera that produce mycotoxins, Fusarium fungi are the most widespread in cereal-growing areas of the planet. Fusarium fungi produce a diversity of mycotoxin types, whose distributions are also diverse. What is produced and where it is produced is influenced primarily by environmental conditions, and crop production and storage methods. The amount of toxin produced depends on physical (viz., moisture, relative humidity, temperature, and mechanical damage), chemical (viz., carbon dioxide,oxygen, composition of substrate, insecticides and fungicides), and biological factors (viz., plant variety, stress, insects, spore load, etc.). Moisture and temperature have a major influence on mold growth rate and mycotoxin production.Among the most toxic and prevalent fusaria) toxins are the following: zearalenone,fumonisins, moniliformin and trichothecenes (T-2/HT-2 toxin, deoxynivalenol,diacetoxyscirpenol, nivalenol). Zearalenone (ZEA; ZON, F-2 toxin) isaphy to estrogenic compound, primarily a field contaminant, which exhibits estrogenic activity and has been implicated in numerous mycotoxicoses of farm animals,especially pigs. Recently, evidence suggests that ZEA has potential to stimulate the growth of human breast cancer cells. Fumonisins are also cancer-promoting metabolites,of which Fumonisin 8 I (FBI) is the most important. Moniliformin (MON) isalso highly toxic to both animals and humans. Trichothecenes are classified as gastrointestinal toxins, dermatotoxins, immunotoxins, hematotoxins, and gene toxins.T-2 and HT-2 toxin, and diacetoxyscirpenol (DAS, anguidine) are the most toxic mycotoxins among the trichothecene group. Deoxynivalenol (DON, vomitoxin) and

  8. DNA adduct formation by alachlor metabolites

    SciTech Connect

    Brown, M.A.; Kimmel, E.C.; Casida, J.E.

    1988-01-01

    The extent of DNA adduct formation by alachlor (ArN(CH/sub 2/OCH/sub 3/)C(O)CH/sub 2/Cl wherein Ar is 2,6-diethylphenyl) and its metabolites is used as a guide to deduce the causal agent(s) in the carcinogenicity of this major herbicide. (/sup 14/C-phenyl)Alachlor is compared to its two metabolic cleavage products, (/sup 14/C-phenyl) 2-chloro-N-(2,6-diethylphenyl)acetamide (CDEPA) (ArNHC(O)CH/sub 2/Cl) and (/sup 14/C-phenyl)2,6-diethylaniline (DEA) (ArNH/sub 2/), and to (/sup 14/C-methoxy)alachlor in various in vitro and in vivo systems. Horseradish peroxidase and hydrogen peroxide activate DEA, but not CEDPA or alachlor, for formation of adducts with calf thymus DNA, which probably involves 2,6-diethylnitrosobenzene (ArNO) as an intermediate. Mouse liver microsomes and NADPH are both required to enhance the binding from each labeled preparation to calf thymus DNA; 4-fold higher labeling is observed from (/sup 14/C-methoxy)- than from (/sup 14/C-phenyl)alachlor. This 4-fold preferential DNA labeling from the /sup 14/C-methoxy compound is likewise found in the liver of mice treated intraperitoneally. Mouse liver protein and hemoglobin are also labeled, in vivo, with (/sup 14/C-phenyl)alachlor, -CDEPA and -DEA, and, as with the DNA, the labeling of these proteins is 1.5- to 2-fold higher with (/sup 14/C-methoxy)alachlor.

  9. Acrolein metabolites, diabetes and insulin resistance.

    PubMed

    Feroe, Aliya G; Attanasio, Roberta; Scinicariello, Franco

    2016-07-01

    Acrolein is a dietary and environmental pollutant that has been associated in vitro to dysregulate glucose transport. We investigated the association of urinary acrolein metabolites N-acetyl-S-(3-hydroxypropyl)-l-cysteine (3-HPMA) and N-acetyl-S-(carboxyethyl)-l-cysteine (CEMA) and their molar sum (∑acrolein) with diabetes using data from investigated 2027 adults who participated in the 2005-2006 National Health and Nutrition Examination Survey (NHANES). After excluding participants taking insulin or other diabetes medication we, further, investigated the association of the compounds with insulin resistance (n=850), as a categorical outcome expressed by the homeostatic model assessment (HOMA-IR>2.6). As secondary analyses, we investigated the association of the compounds with HOMA-IR, HOMA-β, fasting insulin and fasting plasma glucose. The analyses were performed using urinary creatinine as independent variable in the models, and, as sensitivity analyses, the compounds were used as creatinine corrected variables. Diabetes as well as insulin resistance (defined as HOMA-IR>2.6) were positively associated with the 3-HPMA, CEMA and ∑Acrolein with evidence of a dose-response relationship (p<0.05). The highest 3rd and 4th quartiles of CEMA compared to the lowest quartile were significantly associated with higher HOMA-IR, HOMA-β and fasting insulin with a dose-response relationship. The highest 3rd quartile of 3-HPMA and ∑Acrolein were positively and significantly associated with HOMA-IR, HOMA-β and fasting insulin. These results suggest a need of further studies to fully understand the implications of acrolein with type 2 diabetes and insulin. PMID:26991531

  10. Volatile Metabolites of Pathogens: A Systematic Review

    PubMed Central

    Bos, Lieuwe D. J.; Sterk, Peter J.; Schultz, Marcus J.

    2013-01-01

    Ideally, invading bacteria are detected as early as possible in critically ill patients: the strain of morbific pathogens is identified rapidly, and antimicrobial sensitivity is known well before the start of new antimicrobial therapy. Bacteria have a distinct metabolism, part of which results in the production of bacteria-specific volatile organic compounds (VOCs), which might be used for diagnostic purposes. Volatile metabolites can be investigated directly in exhaled air, allowing for noninvasive monitoring. The aim of this review is to provide an overview of VOCs produced by the six most abundant and pathogenic bacteria in sepsis, including Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli. Such VOCs could be used as biological markers in the diagnostic approach of critically ill patients. A systematic review of existing literature revealed 31 articles. All six bacteria of interest produce isopentanol, formaldehyde, methyl mercaptan, and trimethylamine. Since humans do not produce these VOCs, they could serve as biological markers for presence of these pathogens. The following volatile biomarkers were found for identification of specific strains: isovaleric acid and 2-methyl-butanal for Staphylococcus aureus; 1-undecene, 2,4-dimethyl-1-heptane, 2-butanone, 4-methyl-quinazoline, hydrogen cyanide, and methyl thiocyanide for Pseudomonas aeruginosa; and methanol, pentanol, ethyl acetate, and indole for Escherichia coli. Notably, several factors that may effect VOC production were not controlled for, including used culture media, bacterial growth phase, and genomic variation within bacterial strains. In conclusion, VOCs produced by bacteria may serve as biological markers for their presence. Goal-targeted studies should be performed to identify potential sets of volatile biological markers and evaluate the diagnostic accuracy of these markers in critically ill patients. PMID

  11. Metabolic Enzymes of Cocaine Metabolite Benzoylecgonine.

    PubMed

    Chen, Xiabin; Zheng, Xirong; Zhan, Max; Zhou, Ziyuan; Zhan, Chang-Guo; Zheng, Fang

    2016-08-19

    Cocaine is one of the most addictive drugs without a U.S. Food and Drug Administration (FDA)-approved medication. Enzyme therapy using an efficient cocaine-metabolizing enzyme is recognized as the most promising approach to cocaine overdose treatment. The actual enzyme, known as RBP-8000, under current clinical development for cocaine overdose treatment is our previously designed T172R/G173Q mutant of bacterial cocaine esterase (CocE). The T172R/G173Q mutant is effective in hydrolyzing cocaine but inactive against benzoylecgonine (a major, biologically active metabolite of cocaine). Unlike cocaine itself, benzoylecgonine has an unusually stable zwitterion structure resistant to further hydrolysis in the body and environment. In fact, benzoylecgonine can last in the body for a very long time (a few days) and, thus, is responsible for the long-term toxicity of cocaine and a commonly used marker for drug addiction diagnosis in pre-employment drug tests. Because CocE and its mutants are all active against cocaine and inactive against benzoylecgonine, one might simply assume that other enzymes that are active against cocaine are also inactive against benzoylecgonine. Here, through combined computational modeling and experimental studies, we demonstrate for the first time that human butyrylcholinesterase (BChE) is actually active against benzoylecgonine, and that a rationally designed BChE mutant can not only more efficiently accelerate cocaine hydrolysis but also significantly hydrolyze benzoylecgonine in vitro and in vivo. This sets the stage for advanced studies to design more efficient mutant enzymes valuable for the development of an ideal cocaine overdose enzyme therapy and for benzoylecgonine detoxification in the environment. PMID:27224254

  12. Profile of urinary arsenic metabolites during pregnancy.

    PubMed Central

    Hopenhayn, Claudia; Huang, Bin; Christian, Jay; Peralta, Cecilia; Ferreccio, Catterina; Atallah, Raja; Kalman, David

    2003-01-01

    Chronic exposure to inorganic arsenic (In-As) from drinking water is associated with different health effects, including skin, lung, bladder, and kidney cancer as well as vascular and possibly reproductive effects. In-As is metabolized through the process of methylation, resulting in the production and excretion of methylated species, mainly monomethylarsenate (MMA) and dimethylarsenate (DMA). Because a large percentage of the dose is excreted in urine, the distribution of urinary In-As, MMA, and DMA is considered a useful indicator of methylation patterns in human populations. Several factors affect these patterns, including sex and exposure level. In this study, we investigated the profile of urinary In-As, MMA, and DMA of pregnant women. Periodic urine samples were collected from early to late pregnancy among 29 pregnant women living in Antofagasta, Chile, who drank tap water containing 40 micro g/L In-As. The total urinary arsenic across four sampling periods increased with increasing weeks of gestation, from an initial mean value of 36.1 to a final value of 54.3 micro g/L. This increase was mainly due to an increase in DMA, resulting in lower percentages of In-As and MMA and a higher percentage of DMA. Our findings indicate that among women exposed to moderate arsenic from drinking water during pregnancy, changes occur in the pattern of urinary arsenic excretion and metabolite distribution. The toxicologic significance of this is not clear, given recent evidence suggesting that intermediate methylated species may be highly toxic. Nevertheless, this study suggests that arsenic metabolism changes throughout the course of pregnancy, which in turn may have toxicologic effects on the developing fetus. Key words: arsenic, arsenic metabolism, arsenic methylation, Chile, pregnancy, urinary arsenic. PMID:14644662

  13. DHEA metabolites activate estrogen receptors alpha and beta

    PubMed Central

    Michael Miller, Kristy K.; Al-Rayyan, Numan; Ivanova, Margarita M.; Mattingly, Kathleen A.; Ripp, Sharon L.; Klinge, Carolyn M.; Prough, Russell A.

    2012-01-01

    Dehydroepiandrosterone (DHEA) levels were reported to associate with increased breast cancer risk in postmenopausal women, but some carcinogen-induced rat mammary tumor studies question this claim. The purpose of this study was to determine how DHEA and its metabolites affect estrogen receptors α or β (ERα or ERβ) -regulated gene transcription and cell proliferation. In transiently transfected HEK-293 cells, androstenediol, DHEA, and DHEA-S activated ERα. In ERβ transfected HepG2 cells, androstenedione, DHEA, androstenediol, and 7-oxo DHEA stimulated reporter activity. ER antagonists ICI 182,780 (fulvestrant) and 4-hydroxytamoxifen, general P450 inhibitor miconazole, and aromatase inhibitor exemestane inhibited activation by DHEA or metabolites in transfected cells. ERβ-selective antagonist R,R-THC (R,R-cis-diethyl tetrahydrochrysene) inhibited DHEA and DHEA metabolite transcriptional activity in ERβ-transfected cells. Expression of endogenous estrogen-regulated genes: pS2, progesterone receptor, cathepsin D1, and nuclear respiratory factor-1 was increased by DHEA and its metabolites in an ER-subtype, gene, and cell-specific manner. DHEA metabolites, but not DHEA, competed with 17β-estradiol for ERα and ERβ binding and stimulated MCF-7 cell proliferation, demonstrating that DHEA metabolites interact directly with ERα and ERβ in vitro, modulating estrogen target genes in vivo. PMID:23123738

  14. Modulation of antimicrobial metabolites production by the fungus Aspergillus parasiticus

    PubMed Central

    Bracarense, Adriana A.P.; Takahashi, Jacqueline A.

    2014-01-01

    Biosynthesis of active secondary metabolites by fungi occurs as a specific response to the different growing environments. Changes in this environment alter the chemical and biological profiles leading to metabolites diversification and consequently to novel pharmacological applications. In this work, it was studied the influence of three parameters (fermentation length, medium composition and aeration) in the biosyntheses of antimicrobial metabolites by the fungus Aspergillus parasiticus in 10 distinct fermentation periods. Metabolism modulation in two culturing media, CYA and YES was evaluated by a 22 full factorial planning (ANOVA) and on a 23 factorial planning, role of aeration, medium composition and carbohydrate concentration were also evaluated. In overall, 120 different extracts were prepared, their HPLC profiles were obtained and the antimicrobial activity against A. flavus, C. albicans, E. coli and S. aureus of all extracts was evaluated by microdilution bioassay. Yield of kojic acid, a fine chemical produced by the fungus A. parasiticus was determined in all extracts. Statistical analyses pointed thirteen conditions able to modulate the production of bioactive metabolites by A. parasiticus. Effect of carbon source in metabolites diversification was significant as shown by the changes in the HPLC profiles of the extracts. Most of the extracts presented inhibition rates higher than that of kojic acid as for the extract obtained after 6 days of fermentation in YES medium under stirring. Kojic acid was not the only metabolite responsible for the activity since some highly active extracts showed to possess low amounts of this compound, as determined by HPLC. PMID:24948950

  15. A toxic metabolite of Nigrospora oryzae (Berk and Br.) petch.

    PubMed

    Wilson, M E; Davis, N D; Diener, U L

    1986-09-01

    Nigrospora oryzae was isolated from dallisgrass (Paspalum dilatatum Poir.) collected in Auburn and from hay shipped under refrigeration to Florida. Some of these samples were eaten by cattle and horses that subsequently developed lameness. Metabolites of N. oryzae were separated by thin layer chromatography and tested for toxicity. Only one metabolite was toxic. Metabolite A showed toxicity to brine shrimp with an LD50 = 500 micrograms/ml in 8 h. It also had an antibiotic effect on Bacillus megaterium ATCC 14581 with a minimum inhibitory level of 10.1 micrograms/disc. As little as 435 micrograms of a crude methanolic extract of N. oryzae showed mild toxicity to chick embryos. The metabolite was not toxic to mice nor rats at the levels tested. Quantitative procedures developed for the determination of metabolite A showed that the maximum production occurred in yeast extract-sucrose liquid medium with an initial pH of 5-6, when incubated as a stationary culture for 28 days at 25 degrees C. It was concluded that metabolite A is a weak antibiotic rather than a mycotoxin, and was probably not associated with the symptoms of lameness observed in cattle and horses. The antibiotic is not one previously reported for N. oryzae. PMID:3095644

  16. Discovering Regulated Metabolite Families in Untargeted Metabolomics Studies.

    PubMed

    Treutler, Hendrik; Tsugawa, Hiroshi; Porzel, Andrea; Gorzolka, Karin; Tissier, Alain; Neumann, Steffen; Balcke, Gerd Ulrich

    2016-08-16

    The identification of metabolites by mass spectrometry constitutes a major bottleneck which considerably limits the throughput of metabolomics studies in biomedical or plant research. Here, we present a novel approach to analyze metabolomics data from untargeted, data-independent LC-MS/MS measurements. By integrated analysis of MS(1) abundances and MS/MS spectra, the identification of regulated metabolite families is achieved. This approach offers a global view on metabolic regulation in comparative metabolomics. We implemented our approach in the web application "MetFamily", which is freely available at http://msbi.ipb-halle.de/MetFamily/ . MetFamily provides a dynamic link between the patterns based on MS(1)-signal intensity and the corresponding structural similarity at the MS/MS level. Structurally related metabolites are annotated as metabolite families based on a hierarchical cluster analysis of measured MS/MS spectra. Joint examination with principal component analysis of MS(1) patterns, where this annotation is preserved in the loadings, facilitates the interpretation of comparative metabolomics data at the level of metabolite families. As a proof of concept, we identified two trichome-specific metabolite families from wild-type tomato Solanum habrochaites LA1777 in a fully unsupervised manner and validated our findings based on earlier publications and with NMR. PMID:27452369

  17. Global metabolite analysis of yeast: evaluation of sample preparation methods.

    PubMed

    Villas-Bôas, Silas G; Højer-Pedersen, Jesper; Akesson, Mats; Smedsgaard, Jørn; Nielsen, Jens

    2005-10-30

    Sample preparation is considered one of the limiting steps in microbial metabolome analysis. Eukaryotes and prokaryotes behave very differently during the several steps of classical sample preparation methods for analysis of metabolites. Even within the eukaryote kingdom there is a vast diversity of cell structures that make it imprudent to blindly adopt protocols that were designed for a specific group of microorganisms. We have therefore reviewed and evaluated the whole sample preparation procedures for analysis of yeast metabolites. Our focus has been on the current needs in metabolome analysis, which is the analysis of a large number of metabolites with very diverse chemical and physical properties. This work reports the leakage of intracellular metabolites observed during quenching yeast cells with cold methanol solution, the efficacy of six different methods for the extraction of intracellular metabolites, and the losses noticed during sample concentration by lyophilization and solvent evaporation. A more reliable procedure is suggested for quenching yeast cells with cold methanol solution, followed by extraction of intracellular metabolites by pure methanol. The method can be combined with reduced pressure solvent evaporation and therefore represents an attractive sample preparation procedure for high-throughput metabolome analysis of yeasts. PMID:16240456

  18. Metabolite identification through multiple kernel learning on fragmentation trees

    PubMed Central

    Shen, Huibin; Dührkop, Kai; Böcker, Sebastian; Rousu, Juho

    2014-01-01

    Motivation: Metabolite identification from tandem mass spectrometric data is a key task in metabolomics. Various computational methods have been proposed for the identification of metabolites from tandem mass spectra. Fragmentation tree methods explore the space of possible ways in which the metabolite can fragment, and base the metabolite identification on scoring of these fragmentation trees. Machine learning methods have been used to map mass spectra to molecular fingerprints; predicted fingerprints, in turn, can be used to score candidate molecular structures. Results: Here, we combine fragmentation tree computations with kernel-based machine learning to predict molecular fingerprints and identify molecular structures. We introduce a family of kernels capturing the similarity of fragmentation trees, and combine these kernels using recently proposed multiple kernel learning approaches. Experiments on two large reference datasets show that the new methods significantly improve molecular fingerprint prediction accuracy. These improvements result in better metabolite identification, doubling the number of metabolites ranked at the top position of the candidates list. Contact: huibin.shen@aalto.fi Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24931979

  19. Modulation of mast cell and basophil functions by benzene metabolites.

    PubMed

    Triggiani, Massimo; Loffredo, Stefania; Granata, Francescopaolo; Staiano, Rosaria I; Marone, Gianni

    2011-11-01

    Benzene is a carcinogenic compound used in industrial manufacturing and a common environmental pollutant mostly derived from vehicle emissions and cigarette smoke. Benzene exposure is associated with a variety of clinical conditions ranging from hematologic diseases to chronic lung disorders. Beside its direct toxicity, benzene exerts multiple effects after being converted to reactive metabolites such as hydroquinone and benzoquinone. Mast cells and basophils are primary effector cells involved in the development of respiratory allergies such as rhinitis and bronchial asthma and they play an important role in innate immunity. Benzene and its metabolites can influence mast cell and basophil responses either directly or by interfering with other cells, such as T cells, macrophages and monocytes, which are functionally connected to mast cells and basophils. Hydroquinone and benzoquinone inhibit the release of preformed mediators, leukotriene synthesis and cytokine production in human basophils stimulated by IgE- and non IgE-mediated agonists. Furthermore, these metabolites reduce IgE-mediated degranulation of mast cells and the development of allergic lung inflammation in rats. Both in vitro and in vivo studies indicate that benzene metabolites alter biochemical and functional activities of other immunocompetent cells and may impair immune responses in the lung. These inhibitory effects of benzene metabolites are primarily mediated by interference with early transduction signals such as PI3 kinase. Together, currently available studies indicate that benzene metabolites interfere by multiple mechanisms with the role of basophils and mast cells in innate immunity and in chronic inflammation in the lung. PMID:22103854

  20. Reactive ring-opened aldehyde metabolites in benzene hematotoxicity

    SciTech Connect

    Witz, G.; Zhang, Zhihua; Goldstein, B.D.

    1996-12-01

    The hematotoxicity of benzene is mediated by reactive benzene metabolites and possibly by other intermediates including reactive oxygen species. We previously hypothesized that ring-opened metabolites may significantly contribute to benzene hematotoxicity. Consistent with this hypothesis, our studies initially demonstrated that benzene is metabolized in vitro to trans-trans-muconaldehyde (MUC), a reactive six-carbon diene dialdehyde, and that MUC is toxic to the bone marrow in a manner similar to benzene. Benzene toxicity most likely involves interactions among several metabolites that operate by different mechanisms to produce more than one biological effect. Our studies indicate that MUC coadministered with hydroquinone is a particularly potent metabolite combination that causes bone marrow damage, suggesting that the involvement of ring-opened metabolites in benzene toxicity may be related to their biological effects in combination with other benzene metabolites. Studies in our laboratory and by others indicate that MUC is metabolized to a variety of compounds by oxidation or reduction of the aldehyde groups. 37 refs., 2 figs., 1 tab.

  1. Identification of intra- and inter-individual metabolite variation in plasma metabolite profiles of cats and dogs.

    PubMed

    Colyer, Alison; Gilham, Matthew S; Kamlage, Beate; Rein, Dietrich; Allaway, David

    2011-10-01

    The purpose of the present study was first to identify drivers of variance in plasma metabolite profiles of cats and dogs that may affect the interpretation of nutritional metabolomic studies. A total of fourteen cats and fourteen dogs housed in environmentally enriched accommodation were fed a single batch of diet to maintain body weight. Fasting blood samples were taken on days 14, 16 and 18 of the study. Gas chromatography-mass spectrometry (GC-MS), liquid chromatography (LC)-MS/MS and solid-phase extraction-LC-MS/MS analyses were used for metabolite profiling. Principal component (PC) analysis that indicated 31 and 27 % of the variance was explained in PC1 and PC2 for cats and dogs, respectively, with most individuals occupying a unique space. As the individual was a major driver of variance in the plasma metabolome, the second objective was to identify metabolites associated with the individual variation observed. The proportion of intra- and inter-individual variance was calculated for 109 cat and 101 dog metabolites with a low intra-individual variance (SD < 0.05). Of these, fifteen cat and six dog metabolites had inter-individual variance accounting for at least 90 % of the total variance. There were four metabolites common to both species (campesterol, DHA, a cholestenol and a sphingosine moiety). Many of the metabolites with >75 % inter-individual variance were common to both species and to similar areas of metabolism. In summary, the individual is an important driver of variance in the fasted plasma metabolome, and specific metabolites and areas of metabolism may be differentially regulated by individuals in two companion animal species. PMID:22005413

  2. Severe drought stress is affecting selected primary metabolites, polyphenols, and volatile metabolites in grapevine leaves (Vitis vinifera cv. Pinot noir).

    PubMed

    Griesser, Michaela; Weingart, Georg; Schoedl-Hummel, Katharina; Neumann, Nora; Becker, Manuel; Varmuza, Kurt; Liebner, Falk; Schuhmacher, Rainer; Forneck, Astrid

    2015-03-01

    Extreme weather conditions with prolonged dry periods and high temperatures as well as heavy rain events can severely influence grapevine physiology and grape quality. The present study evaluates the effects of severe drought stress on selected primary metabolites, polyphenols and volatile metabolites in grapevine leaves. Among the 11 primary metabolites, 13 polyphenols and 95 volatiles which were analyzed, a significant discrimination between control and stressed plants of 7 primary metabolites, 11 polyphenols and 46 volatile metabolites was observed. As single parameters are usually not specific enough for the discrimination of control and stressed plants, an unsupervised (PCA) and a supervised (PLS-DA) multivariate approach were applied to combine results from different metabolic groups. In a first step a selection of five metabolites, namely citric acid, glyceric acid, ribose, phenylacetaldehyde and 2-methylbutanal were used to establish a calibration model using PLS regression to predict the leaf water potential. The model was strong enough to assign a high number of plants correctly with a correlation of 0.83. The PLS-DA provides an interesting approach to combine data sets and to provide tools for the specific evaluation of physiological plant stresses. PMID:25602440

  3. NMR identification of endogenous metabolites interacting with fatted and non-fatted human serum albumin in blood plasma: Fatty acids influence the HSA-metabolite interaction

    NASA Astrophysics Data System (ADS)

    Jupin, Marc; Michiels, Paul J.; Girard, Frederic C.; Spraul, Manfred; Wijmenga, Sybren S.

    2013-03-01

    Metabolites and their concentrations are direct reporters on body biochemistry. Thanks to technical developments metabolic profiling of body fluids, such as blood plasma, by for instance NMR has in the past decade become increasingly accurate enabling successful clinical diagnostics. Human Serum Albumin (HSA) is the main plasma protein (˜60% of all plasma protein) and responsible for the transport of endogenous (e.g. fatty acids) and exogenous metabolites, which it achieves thanks to its multiple binding sites and its flexibility. HSA has been extensively studied with regard to its binding of drugs (exogenous metabolites), but only to a lesser extent with regard to its binding of endogenous (non-fatty acid) metabolites. To obtain correct NMR measured metabolic profiles of blood plasma and/or potentially extract information on HSA and fatty acids content, it is necessary to characterize these endogenous metabolite/plasma protein interactions. Here, we investigate these metabolite-HSA interactions in blood plasma and blood plasma mimics. The latter contain the roughly twenty metabolites routinely detected by NMR (also most abundant) in normal relative concentrations with fatted or non-fatted HSA added or not. First, we find that chemical shift changes are small and seen only for a few of the metabolites. In contrast, a significant number of the metabolites display reduced resonance integrals and reduced free concentrations in the presence of HSA or fatted HSA. For slow-exchange (or strong) interactions, NMR resonance integrals report the free metabolite concentration, while for fast exchange (weak binding) the chemical shift reports on the binding. Hence, these metabolites bind strongly to HSA and/or fatted HSA, but to a limited degree because for most metabolites their concentration is smaller than the HSA concentration. Most interestingly, fatty acids decrease the metabolite-HSA binding quite significantly for most of the interacting metabolites. We further find

  4. The metabolite profiling of coastal coccolithophorid species Pleurochrysis carterae (Haptophyta)

    NASA Astrophysics Data System (ADS)

    Zhou, Chengxu; Luo, Jie; Ye, Yangfang; Yan, Xiaojun; Liu, Baoning; Wen, Xin

    2015-11-01

    Pleurochrysis carterae is a calcified coccolithophorid species that usually blooms in the coastal area and causes aquaculture losses. The cellular calcification, blooming and many other critical species specific eco-physiological processes are closely related to various metabolic pathways. The purpose of this study is to apply the unbiased and non-destructive method of nuclear magnetic resonance (NMR) to detect the unknown holistic metabolite of P. carterae. The results show that NMR spectroscopic method is practical in the analysis of metabolites of phytoplankton. The metabolome of P. carterae was dominated by 26 metabolites involved in a number of different primary and secondary metabolic pathways. Organic acids and their derivatives, amino acids, sugars, nucleic aides were mainly detected. The abundant metabolites are that closely related to the process of cellular osmotic adjustment, which possibly reflect the active ability of P. carterae to adapt to the versatile coastal niche. DMSP (dimethylsulphoniopropionate) was the most dominant metabolite in P. carterae, up to 2.065±0.278 mg/g lyophilized cells, followed by glutamate and lactose, the contents were 0.349±0.035 and 0.301±0.073 mg/g lyophilized cells respectively. Other metabolites that had the content ranged between 0.1-0.2 mg/g lyophilized cells were alanine, isethionate and arabinose. Amino acid (valine, phenylalanine, isoleucine, tyrosine), organic acid salts (lactate, succinate), scyllitol and uracil had content ranged from 0.01 to below 0.1 mg/g lyophilized cells. Trigonelline, fumarate and formate were detected in very low content (only thousandths of 1 mg per gram of lyophilized cells or below). Our results of the holistic metabolites of P. carterae are the basic references for the further studies when multiple problems will be addressed to this notorious blooming calcifying species.

  5. Methodological considerations for measuring glucocorticoid metabolites in feathers

    PubMed Central

    Berk, Sara A.; McGettrick, Julie R.; Hansen, Warren K.; Breuner, Creagh W.

    2016-01-01

    In recent years, researchers have begun to use corticosteroid metabolites in feathers (fCORT) as a metric of stress physiology in birds. However, there remain substantial questions about how to measure fCORT most accurately. Notably, small samples contain artificially high amounts of fCORT per millimetre of feather (the small sample artefact). Furthermore, it appears that fCORT is correlated with circulating plasma corticosterone only when levels are artificially elevated by the use of corticosterone implants. Here, we used several approaches to address current methodological issues with the measurement of fCORT. First, we verified that the small sample artefact exists across species and feather types. Second, we attempted to correct for this effect by increasing the amount of methanol relative to the amount of feather during extraction. We consistently detected more fCORT per millimetre or per milligram of feather in small samples than in large samples even when we adjusted methanol:feather concentrations. We also used high-performance liquid chromatography to identify hormone metabolites present in feathers and measured the reactivity of these metabolites against the most commonly used antibody for measuring fCORT. We verified that our antibody is mainly identifying corticosterone (CORT) in feathers, but other metabolites have significant cross-reactivity. Lastly, we measured faecal glucocorticoid metabolites in house sparrows and correlated these measurements with corticosteroid metabolites deposited in concurrently grown feathers; we found no correlation between faecal glucocorticoid metabolites and fCORT. We suggest that researchers should be cautious in their interpretation of fCORT in wild birds and should seek alternative validation methods to examine species-specific relationships between environmental challenges and fCORT. PMID:27335650

  6. The pharmacokinetics of anthocyanins and their metabolites in humans

    PubMed Central

    de Ferrars, R M; Czank, C; Zhang, Q; Botting, N P; Kroon, P A; Cassidy, A; Kay, C D

    2014-01-01

    BACKGROUND AND PURPOSE Anthocyanins are phytochemicals with reported vasoactive bioactivity. However, given their instability at neutral pH, they are presumed to undergo significant degradation and subsequent biotransformation. The aim of the present study was to establish the pharmacokinetics of the metabolites of cyanidin-3-glucoside (C3G), a widely consumed dietary phytochemical with potential cardioprotective properties. EXPERIMENTAL APPROACH A 500 mg oral bolus dose of 6,8,10,3′,5′-13C5-C3G was fed to eight healthy male participants, followed by a 48 h collection (0, 0.5, 1, 2, 4, 6, 24, 48 h) of blood, urine and faecal samples. Samples were analysed by HPLC-ESI-MS/MS with elimination kinetics established using non-compartmental pharmacokinetic modelling. KEY RESULTS Seventeen 13C-labelled compounds were identified in the serum, including 13C5-C3G, its degradation products, protocatechuic acid (PCA) and phloroglucinaldehyde (PGA), 13 metabolites of PCA and 1 metabolite derived from PGA. The maximal concentrations of the phenolic metabolites (Cmax) ranged from 10 to 2000 nM, between 2 and 30 h (tmax) post-consumption, with half-lives of elimination observed between 0.5 and 96 h. The major phenolic metabolites identified were hippuric acid and ferulic acid, which peaked in the serum at approximately 16 and 8 h respectively. CONCLUSIONS AND IMPLICATIONS Anthocyanins are metabolized to a structurally diverse range of metabolites that exhibit dynamic kinetic profiles. Understanding the elimination kinetics of these metabolites is key to the design of future studies examining their utility in dietary interventions or as therapeutics for disease risk reduction. PMID:24602005

  7. Methodological considerations for measuring glucocorticoid metabolites in feathers.

    PubMed

    Berk, Sara A; McGettrick, Julie R; Hansen, Warren K; Breuner, Creagh W

    2016-01-01

    In recent years, researchers have begun to use corticosteroid metabolites in feathers (fCORT) as a metric of stress physiology in birds. However, there remain substantial questions about how to measure fCORT most accurately. Notably, small samples contain artificially high amounts of fCORT per millimetre of feather (the small sample artefact). Furthermore, it appears that fCORT is correlated with circulating plasma corticosterone only when levels are artificially elevated by the use of corticosterone implants. Here, we used several approaches to address current methodological issues with the measurement of fCORT. First, we verified that the small sample artefact exists across species and feather types. Second, we attempted to correct for this effect by increasing the amount of methanol relative to the amount of feather during extraction. We consistently detected more fCORT per millimetre or per milligram of feather in small samples than in large samples even when we adjusted methanol:feather concentrations. We also used high-performance liquid chromatography to identify hormone metabolites present in feathers and measured the reactivity of these metabolites against the most commonly used antibody for measuring fCORT. We verified that our antibody is mainly identifying corticosterone (CORT) in feathers, but other metabolites have significant cross-reactivity. Lastly, we measured faecal glucocorticoid metabolites in house sparrows and correlated these measurements with corticosteroid metabolites deposited in concurrently grown feathers; we found no correlation between faecal glucocorticoid metabolites and fCORT. We suggest that researchers should be cautious in their interpretation of fCORT in wild birds and should seek alternative validation methods to examine species-specific relationships between environmental challenges and fCORT. PMID:27335650

  8. Urine Metabolite Profiles Predictive of Human Kidney Allograft Status.

    PubMed

    Suhre, Karsten; Schwartz, Joseph E; Sharma, Vijay K; Chen, Qiuying; Lee, John R; Muthukumar, Thangamani; Dadhania, Darshana M; Ding, Ruchuang; Ikle, David N; Bridges, Nancy D; Williams, Nikki M; Kastenmüller, Gabi; Karoly, Edward D; Mohney, Robert P; Abecassis, Michael; Friedewald, John; Knechtle, Stuart J; Becker, Yolanda T; Samstein, Benjamin; Shaked, Abraham; Gross, Steven S; Suthanthiran, Manikkam

    2016-02-01

    Noninvasive diagnosis and prognostication of acute cellular rejection in the kidney allograft may help realize the full benefits of kidney transplantation. To investigate whether urine metabolites predict kidney allograft status, we determined levels of 749 metabolites in 1516 urine samples from 241 kidney graft recipients enrolled in the prospective multicenter Clinical Trials in Organ Transplantation-04 study. A metabolite signature of the ratio of 3-sialyllactose to xanthosine in biopsy specimen-matched urine supernatants best discriminated acute cellular rejection biopsy specimens from specimens without rejection. For clinical application, we developed a high-throughput mass spectrometry-based assay that enabled absolute and rapid quantification of the 3-sialyllactose-to-xanthosine ratio in urine samples. A composite signature of ratios of 3-sialyllactose to xanthosine and quinolinate to X-16397 and our previously reported urinary cell mRNA signature of 18S ribosomal RNA, CD3ε mRNA, and interferon-inducible protein-10 mRNA outperformed the metabolite signatures and the mRNA signature. The area under the receiver operating characteristics curve for the composite metabolite-mRNA signature was 0.93, and the signature was diagnostic of acute cellular rejection with a specificity of 84% and a sensitivity of 90%. The composite signature, developed using solely biopsy specimen-matched urine samples, predicted future acute cellular rejection when applied to pristine samples taken days to weeks before biopsy. We conclude that metabolite profiling of urine offers a noninvasive means of diagnosing and prognosticating acute cellular rejection in the human kidney allograft, and that the combined metabolite and mRNA signature is diagnostic and prognostic of acute cellular rejection with very high accuracy. PMID:26047788

  9. The metabolite profiling of coastal coccolithophorid species Pleurochrysis carterae (Haptophyta)

    NASA Astrophysics Data System (ADS)

    Zhou, Chengxu; Luo, Jie; Ye, Yangfang; Yan, Xiaojun; Liu, Baoning; Wen, Xin

    2016-07-01

    Pleurochrysis carterae is a calcified coccolithophorid species that usually blooms in the coastal area and causes aquaculture losses. The cellular calcification, blooming and many other critical species specific eco-physiological processes are closely related to various metabolic pathways. The purpose of this study is to apply the unbiased and non-destructive method of nuclear magnetic resonance (NMR) to detect the unknown holistic metabolite of P. carterae. The results show that NMR spectroscopic method is practical in the analysis of metabolites of phytoplankton. The metabolome of P. carterae was dominated by 26 metabolites involved in a number of different primary and secondary metabolic pathways. Organic acids and their derivatives, amino acids, sugars, nucleic aides were mainly detected. The abundant metabolites are that closely related to the process of cellular osmotic adjustment, which possibly reflect the active ability of P. carterae to adapt to the versatile coastal niche. DMSP (dimethylsulphoniopropionate) was the most dominant metabolite in P. carterae, up to 2.065±0.278 mg/g lyophilized cells, followed by glutamate and lactose, the contents were 0.349±0.035 and 0.301±0.073 mg/g lyophilized cells respectively. Other metabolites that had the content ranged between 0.1-0.2 mg/g lyophilized cells were alanine, isethionate and arabinose. Amino acid (valine, phenylalanine, isoleucine, tyrosine), organic acid salts (lactate, succinate), scyllitol and uracil had content ranged from 0.01 to below 0.1 mg/g lyophilized cells. Trigonelline, fumarate and formate were detected in very low content (only thousandths of 1 mg per gram of lyophilized cells or below). Our results of the holistic metabolites of P. carterae are the basic references for the further studies when multiple problems will be addressed to this notorious blooming calcifying species.

  10. Targeted serum metabolite profiling and sequential metabolite ratio analysis for colorectal cancer progression monitoring.

    PubMed

    Zhu, Jiangjiang; Djukovic, Danijel; Deng, Lingli; Gu, Haiwei; Himmati, Farhan; Abu Zaid, Mohammad; Chiorean, Elena Gabriela; Raftery, Daniel

    2015-10-01

    Colorectal cancer (CRC) is one of the most prevalent cancers worldwide and a major cause of human morbidity and mortality. In addition to early detection, close monitoring of disease progression in CRC can be critical for patient prognosis and treatment decisions. Efforts have been made to develop new methods for improved early detection and patient monitoring; however, research focused on CRC surveillance for treatment response and disease recurrence using metabolomics has yet to be reported. In this proof of concept study, we applied a targeted liquid chromatography tandem mass spectrometry (LC-MS/MS) metabolic profiling approach focused on sequential metabolite ratio analysis of serial serum samples to monitor disease progression from 20 CRC patients. The use of serial samples reduces patient to patient metabolic variability. A partial least squares-discriminant analysis (PLS-DA) model using a panel of five metabolites (succinate, N2, N2-dimethylguanosine, adenine, citraconic acid, and 1-methylguanosine) was established, and excellent model performance (sensitivity = 0.83, specificity = 0.94, area under the receiver operator characteristic curve (AUROC) = 0.91 was obtained, which is superior to the traditional CRC monitoring marker carcinoembryonic antigen (sensitivity = 0.75, specificity = 0.76, AUROC = 0.80). Monte Carlo cross validation was applied, and the robustness of our model was clearly observed by the separation of true classification models from the random permutation models. Our results suggest the potential utility of metabolic profiling for CRC disease monitoring. PMID:26342311

  11. Reactive ring-opened aldehyde metabolites in benzene hematotoxicity.

    PubMed Central

    Witz, G; Zhang, Z; Goldstein, B D

    1996-01-01

    The hematotoxicity of benzene is mediated by reactive benzene metabolites and possibly by other intermediates including reactive oxygen species. We previously hypothesized that ring-opened metabolites may significantly contribute to benzene hematotoxicity. Consistent with this hypothesis, our studies initially demonstrated that benzene is metabolized in vitro to trans-trans-muconaldehyde (MUC), a reactive six-carbon diene dialdehyde, and that MUC is toxic to the bone marrow in a manner similar to benzene. Benzene toxicity most likely involves interactions among several metabolites that operate by different mechanisms to produce more than one biological effect. Our studies indicate that MUC coadministered with hydroquinone is a particularly potent metabolite combination that causes bone marrow damage, suggesting that the involvement of ring-opened metabolites in benzene toxicity may be related to their biological effects in combination with other benzene metabolites. Studies in our laboratory and by others indicate that MUC is metabolized to a variety of compounds by oxidation or reduction of the aldehyde groups. The aldehydic MUC metabolite 6-hydroxy-trans-trans-2,4-hexadienal (CHO-M-OH), similar to MUC but to a lesser extent, is reactive toward glutathione, mutagenic in V79 cells, and hematotoxic in mice. It is formed by monoreduction of MUC, a process that is reversible and could be of biological significance in benzene bone marrow toxicity. The MUC metabolite 6-hydroxy-trans-trans-2,4-hexadienoic (COOH-M-OH) is an end product of MUC metabolism in vitro. Our studies indicate that COOH-M-OH is a urinary metabolite of benzene in mice, a finding that provides further indirect evidence for the in vivo formation of MUC from benzene. Mechanistic studies showed the formation of cis-trans-muconaldehyde in addition to MUC from benzene incubated in a hydroxyl radical-generating Fenton system. These results suggest that the benzene ring is initially opened to cis

  12. Current approaches toward production of secondary plant metabolites

    PubMed Central

    Hussain, Md. Sarfaraj; Fareed, Sheeba; Ansari, Saba; Rahman, Md. Akhlaquer; Ahmad, Iffat Zareen; Saeed, Mohd.

    2012-01-01

    Plants are the tremendous source for the discovery of new products with medicinal importance in drug development. Today several distinct chemicals derived from plants are important drugs, which are currently used in one or more countries in the world. Secondary metabolites are economically important as drugs, flavor and fragrances, dye and pigments, pesticides, and food additives. Many of the drugs sold today are simple synthetic modifications or copies of the naturally obtained substances. The evolving commercial importance of secondary metabolites has in recent years resulted in a great interest in secondary metabolism, particularly in the possibility of altering the production of bioactive plant metabolites by means of tissue culture technology. Plant cell and tissue culture technologies can be established routinely under sterile conditions from explants, such as plant leaves, stems, roots, and meristems for both the ways for multiplication and extraction of secondary metabolites. In vitro production of secondary metabolite in plant cell suspension cultures has been reported from various medicinal plants, and bioreactors are the key step for their commercial production. Based on this lime light, the present review is aimed to cover phytotherapeutic application and recent advancement for the production of some important plant pharmaceuticals. PMID:22368394

  13. Concurrent quantification of tryptophan and its major metabolites

    PubMed Central

    Lesniak, Wojciech G.; Jyoti, Amar; Mishra, Manoj K.; Louissaint, Nicolette; Romero, Roberto; Chugani, Diane C.; Kannan, Sujatha; Kannan, Rangaramanujam M.

    2014-01-01

    An imbalance in tryptophan (TRP) metabolites is associated with several neurological and inflammatory disorders. Therefore, analytical methods allowing for simultaneous quantification of TRP and its major metabolites would be highly desirable, and may be valuable as potential biomarkers. We have developed a HPLC method for concurrent quantitative determination of tryptophan, serotonin, 5-hydroxyindoleacetic acid, kynurenine, and kynurenic acid in tissue and fluids. The method utilizes the intrinsic spectroscopic properties of TRP and its metabolites that enable UV absorbance and fluorescence detection by HPLC, without additional labeling. The origin of the peaks related to analytes of interest was confirmed by UV–Vis spectral patterns using a PDA detector and mass spectrometry. The developed methods were validated in rabbit fetal brain and amniotic fluid at gestational day 29. Results are in excellent agreement with those reported in the literature for the same regions. This method allows for rapid quantification of tryptophan and four of its major metabolites concurrently. A change in the relative ratios of these metabolites can provide important insights in predicting the presence and progression of neuroinflammation in disorders such as cerebral palsy, autism, multiple sclerosis, Alzheimer disease, and schizophrenia. PMID:24036037

  14. Secondary metabolites in floral nectar reduce parasite infections in bumblebees

    PubMed Central

    Richardson, Leif L.; Adler, Lynn S.; Leonard, Anne S.; Andicoechea, Jonathan; Regan, Karly H.; Anthony, Winston E.; Manson, Jessamyn S.; Irwin, Rebecca E.

    2015-01-01

    The synthesis of secondary metabolites is a hallmark of plant defence against herbivores. These compounds may be detrimental to consumers, but can also protect herbivores against parasites. Floral nectar commonly contains secondary metabolites, but little is known about the impacts of nectar chemistry on pollinators, including bees. We hypothesized that nectar secondary metabolites could reduce bee parasite infection. We inoculated individual bumblebees with Crithidia bombi, an intestinal parasite, and tested effects of eight naturally occurring nectar chemicals on parasite population growth. Secondary metabolites strongly reduced parasite load, with significant effects of alkaloids, terpenoids and iridoid glycosides ranging from 61 to 81%. Using microcolonies, we also investigated costs and benefits of consuming anabasine, the compound with the strongest effect on parasites, in infected and uninfected bees. Anabasine increased time to egg laying, and Crithidia reduced bee survival. However, anabasine consumption did not mitigate the negative effects of Crithidia, and Crithidia infection did not alter anabasine consumption. Our novel results highlight that although secondary metabolites may not rescue survival in infected bees, they may play a vital role in mediating Crithidia transmission within and between colonies by reducing Crithidia infection intensities. PMID:25694627

  15. Detection of Volatile Metabolites of Garlic in Human Breast Milk

    PubMed Central

    Scheffler, Laura; Sauermann, Yvonne; Zeh, Gina; Hauf, Katharina; Heinlein, Anja; Sharapa, Constanze; Buettner, Andrea

    2016-01-01

    The odor of human breast milk after ingestion of raw garlic at food-relevant concentrations by breastfeeding mothers was investigated for the first time chemo-analytically using gas chromatography−mass spectrometry/olfactometry (GC-MS/O), as well as sensorially using a trained human sensory panel. Sensory evaluation revealed a clear garlic/cabbage-like odor that appeared in breast milk about 2.5 h after consumption of garlic. GC-MS/O analyses confirmed the occurrence of garlic-derived metabolites in breast milk, namely allyl methyl sulfide (AMS), allyl methyl sulfoxide (AMSO) and allyl methyl sulfone (AMSO2). Of these, only AMS had a garlic-like odor whereas the other two metabolites were odorless. This demonstrates that the odor change in human milk is not related to a direct transfer of garlic odorants, as is currently believed, but rather derives from a single metabolite. The formation of these metabolites is not fully understood, but AMSO and AMSO2 are most likely formed by the oxidation of AMS in the human body. The excretion rates of these metabolites into breast milk were strongly time-dependent with large inter-individual differences. PMID:27275838

  16. Metabolite essentiality elucidates robustness of Escherichia coli metabolism

    PubMed Central

    Kim, Pan-Jun; Lee, Dong-Yup; Kim, Tae Yong; Lee, Kwang Ho; Jeong, Hawoong; Lee, Sang Yup; Park, Sunwon

    2007-01-01

    Complex biological systems are very robust to genetic and environmental changes at all levels of organization. Many biological functions of Escherichia coli metabolism can be sustained against single-gene or even multiple-gene mutations by using redundant or alternative pathways. Thus, only a limited number of genes have been identified to be lethal to the cell. In this regard, the reaction-centric gene deletion study has a limitation in understanding the metabolic robustness. Here, we report the use of flux-sum, which is the summation of all incoming or outgoing fluxes around a particular metabolite under pseudo-steady state conditions, as a good conserved property for elucidating such robustness of E. coli from the metabolite point of view. The functional behavior, as well as the structural and evolutionary properties of metabolites essential to the cell survival, was investigated by means of a constraints-based flux analysis under perturbed conditions. The essential metabolites are capable of maintaining a steady flux-sum even against severe perturbation by actively redistributing the relevant fluxes. Disrupting the flux-sum maintenance was found to suppress cell growth. This approach of analyzing metabolite essentiality provides insight into cellular robustness and concomitant fragility, which can be used for several applications, including the development of new drugs for treating pathogens. PMID:17698812

  17. Secondary metabolites in floral nectar reduce parasite infections in bumblebees.

    PubMed

    Richardson, Leif L; Adler, Lynn S; Leonard, Anne S; Andicoechea, Jonathan; Regan, Karly H; Anthony, Winston E; Manson, Jessamyn S; Irwin, Rebecca E

    2015-03-22

    The synthesis of secondary metabolites is a hallmark of plant defence against herbivores. These compounds may be detrimental to consumers, but can also protect herbivores against parasites. Floral nectar commonly contains secondary metabolites, but little is known about the impacts of nectar chemistry on pollinators, including bees. We hypothesized that nectar secondary metabolites could reduce bee parasite infection. We inoculated individual bumblebees with Crithidia bombi, an intestinal parasite, and tested effects of eight naturally occurring nectar chemicals on parasite population growth. Secondary metabolites strongly reduced parasite load, with significant effects of alkaloids, terpenoids and iridoid glycosides ranging from 61 to 81%. Using microcolonies, we also investigated costs and benefits of consuming anabasine, the compound with the strongest effect on parasites, in infected and uninfected bees. Anabasine increased time to egg laying, and Crithidia reduced bee survival. However, anabasine consumption did not mitigate the negative effects of Crithidia, and Crithidia infection did not alter anabasine consumption. Our novel results highlight that although secondary metabolites may not rescue survival in infected bees, they may play a vital role in mediating Crithidia transmission within and between colonies by reducing Crithidia infection intensities. PMID:25694627

  18. Signaling by small metabolites in systemic acquired resistance.

    PubMed

    Shah, Jyoti; Chaturvedi, Ratnesh; Chowdhury, Zulkarnain; Venables, Barney; Petros, Robby A

    2014-08-01

    Plants can retain the memory of a prior encounter with a pest. This memory confers upon a plant the ability to subsequently activate defenses more robustly when challenged by a pest. In plants that have retained the memory of a prior, localized, foliar infection by a pathogen, the pathogen-free distal organs develop immunity against subsequent infections by a broad-spectrum of pathogens. The long-term immunity conferred by this mechanism, which is termed systemic acquired resistance (SAR), is inheritable over a few generations. Signaling mediated by the phenolic metabolite salicylic acid (SA) is critical for the manifestation of SAR. Recent studies have described the involvement of additional small metabolites in SAR signaling, including methyl salicylate, the abietane diterpenoid dehydroabietinal, the lysine catabolite pipecolic acid, a glycerol-3-phosphate-dependent factor and the dicarboxylic acid azelaic acid. Many of these metabolites can be systemically transported through the plant and probably facilitate communication by the primary infected tissue with the distal tissues, which is essential for the activation of SAR. Some of these metabolites have been implicated in the SAR-associated rapid activation of defenses in response to subsequent exposure to the pathogen, a mechanism termed priming. Here, we summarize the role of these signaling metabolites in SAR, and the relationship between them and SA signaling in SAR. PMID:24506415

  19. A modular modulation method for achieving increases in metabolite production.

    PubMed

    Acerenza, Luis; Monzon, Pablo; Ortega, Fernando

    2015-01-01

    Increasing the production of overproducing strains represents a great challenge. Here, we develop a modular modulation method to determine the key steps for genetic manipulation to increase metabolite production. The method consists of three steps: (i) modularization of the metabolic network into two modules connected by linking metabolites, (ii) change in the activity of the modules using auxiliary rates producing or consuming the linking metabolites in appropriate proportions and (iii) determination of the key modules and steps to increase production. The mathematical formulation of the method in matrix form shows that it may be applied to metabolic networks of any structure and size, with reactions showing any kind of rate laws. The results are valid for any type of conservation relationships in the metabolite concentrations or interactions between modules. The activity of the module may, in principle, be changed by any large factor. The method may be applied recursively or combined with other methods devised to perform fine searches in smaller regions. In practice, it is implemented by integrating to the producer strain heterologous reactions or synthetic pathways producing or consuming the linking metabolites. The new procedure may contribute to develop metabolic engineering into a more systematic practice. PMID:25683235

  20. STUDIES OF METABOLITE-PROTEIN INTERACTIONS: A REVIEW

    PubMed Central

    Matsuda, Ryan; Bi, Cong; Anguizola, Jeanethe; Sobansky, Matthew; Rodriquez, Elliot; Badilla, John Vargas; Zheng, Xiwei; Hage, Benjamin; Hage, David S.

    2014-01-01

    The study of metabolomics can provide valuable information about biochemical pathways and processes at the molecular level. There have been many reports that have examined the structure, identity and concentrations of metabolites in biological systems. However, the binding of metabolites with proteins is also of growing interest. This review examines past reports that have looked at the binding of various types of metabolites with proteins. An overview of the techniques that have been used to characterize and study metabolite-protein binding is first provided. This is followed by examples of studies that have investigated the binding of hormones, fatty acids, drugs or other xenobiotics, and their metabolites with transport proteins and receptors. These examples include reports that have considered the structure of the resulting solute-protein complexes, the nature of the binding sites, the strength of these interactions, the variations in these interactions with solute structure, and the kinetics of these reactions. The possible effects of metabolic diseases on these processes, including the impact of alterations in the structure and function of proteins, are also considered. PMID:24321277

  1. Secondary Metabolites from Three Florida Sponges with Antidepressant Activity

    PubMed Central

    Kochanowska, Anna J.; Rao, Karumanchi V.; Childress, Suzanne; El-Alfy, Abir; Matsumoto, Rae R.; Kelly, Michelle; Stewart, Gina S.; Sufka, Kenneth J.; Hamann, Mark T.

    2016-01-01

    Brominated indole alkaloids are a common class of metabolites reported from sponges of the order Verongida. Herein we report the isolation, structure determination, and activity of metabolites from three Florida sponges, namely, Verongula rigida (order Verongida, family Aplysinidae), Smenospongia aurea, and S. cerebriformis (order Dictyoceratida, family Thorectidae). All three species were investigated chemically, revealing similarities in secondary metabolites. Brominated compounds, as well as sesquiterpene quinones and hydroquinones, were identified from both V. rigida and S. aurea despite their apparent taxonomic differences at the ordinal level. Similar metabolites found in these distinct sponge species of two different genera provide evidence for a microbial origin of the metabolites. Isolated compounds were evaluated in the Porsolt forced swim test (FST) and the chick anxiety–depression continuum model. Among the isolated compounds, 5,6-dibromo-N,N-dimethyltryptamine (1) exhibited significant antidepressant-like action in the rodent FST model, while 5-bromo-N,N-dimethyltryptamine (2) caused significant reduction of locomotor activity indicative of a potential sedative action. The current study provides ample evidence that marine natural products with the diversity of brominated marine alkaloids will provide potential leads for antidepressant and anxiolytic drugs. PMID:18217716

  2. Growth promoting effects of some lichen metabolites on probiotic bacteria.

    PubMed

    Gaikwad, Subhash; Verma, Neeraj; Sharma, B O; Behera, B C

    2014-10-01

    In the present study, the extract of four natural lichen species Canoparmelia eruptens, Everniastrum cirrhatum, Parmotrema austrosinense and Rimelia cetrata were studied for the source of natural antioxidant and their purified secondary metabolites were evaluated for growth promoting effects on probiotic bacteria Lactobacillus casei. The methanolic fraction of lichen species showed moderate to high antioxidant activity in the order P. austrosinense > E. cirrhatum > C. eruptens > R. cetrata. The lichen metabolites showed antioxidant activity with an IC50 values (μg/ml); lecanoric acid 79-95, salazinic 88-108, atranorin 100-116 and consalazinic acid 119-125. As far as the growth promoting effects of lichen metabolites on L. casei is concerned, lecanoric acid at 100 μg/ml conc. showed high growth stimulating activity in terms of increased dry matter of biomass (56.08 mg) of L. casei. Other lichen metabolites; salazinic acid, atranorin and consalazinic acid produced relatively less dry biomass 43.98 mg, 41.1 mg, 40.68 mg, respectively. However, standard antioxidants butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and Trolox after 36 h produced 39.04-47.81 mg dry biomass. At lower pH the growth promoting activity of lichen metabolites was found stable. PMID:25328204

  3. Pyrazolones metabolites are relevant for identifying selective anaphylaxis to metamizole.

    PubMed

    Ariza, Adriana; García-Martín, Elena; Salas, María; Montañez, María I; Mayorga, Cristobalina; Blanca-Lopez, Natalia; Andreu, Inmaculada; Perkins, James; Blanca, Miguel; Agúndez, José A G; Torres, María J

    2016-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) are the most common cause of hypersensitivity reactions, with pyrazolones the most frequent drugs inducing selective reactions. Immediate selective hypersensitivity to pyrazolones is thought to be mediated by specific-IgE. Sensitivity of in vitro diagnostic tests is low and this may be due to the incomplete characterization of the structures involved. Here we investigated whether main metabolites of metamizole (dipyrone) in human could be involved in the immune response using the basophil activation test (BAT). We studied subjects with confirmed selective immediate hypersensitivity to metamizole and performed BAT with metamizole and its metabolites: 4-methylamino-antipyrine (MAA), 4-aminoantipyrine (AA), 4-acetylamino-antipyrine (AAA) and 4-formylamino-antipyrine (FAA). BAT results showed an increase of positive results from 37.5% to 62.5% using metamizole plus metabolites as compared with the BAT carried out only with the parent drug, demonstrating that metamizole metabolites have a role in the reaction and can induce specific basophil activation in patients with immediate hypersensitivity to this drug. Our findings indicate that pyrazolone metabolites are useful for improving the in vitro diagnosis of allergic reactions to metamizole. PMID:27030298

  4. Pyrazolones metabolites are relevant for identifying selective anaphylaxis to metamizole

    PubMed Central

    Ariza, Adriana; García-Martín, Elena; Salas, María; Montañez, María I.; Mayorga, Cristobalina; Blanca-Lopez, Natalia; Andreu, Inmaculada; Perkins, James; Blanca, Miguel; Agúndez, José A. G.; Torres, María J.

    2016-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) are the most common cause of hypersensitivity reactions, with pyrazolones the most frequent drugs inducing selective reactions. Immediate selective hypersensitivity to pyrazolones is thought to be mediated by specific-IgE. Sensitivity of in vitro diagnostic tests is low and this may be due to the incomplete characterization of the structures involved. Here we investigated whether main metabolites of metamizole (dipyrone) in human could be involved in the immune response using the basophil activation test (BAT). We studied subjects with confirmed selective immediate hypersensitivity to metamizole and performed BAT with metamizole and its metabolites: 4-methylamino-antipyrine (MAA), 4-aminoantipyrine (AA), 4-acetylamino-antipyrine (AAA) and 4-formylamino-antipyrine (FAA). BAT results showed an increase of positive results from 37.5% to 62.5% using metamizole plus metabolites as compared with the BAT carried out only with the parent drug, demonstrating that metamizole metabolites have a role in the reaction and can induce specific basophil activation in patients with immediate hypersensitivity to this drug. Our findings indicate that pyrazolone metabolites are useful for improving the in vitro diagnosis of allergic reactions to metamizole. PMID:27030298

  5. Detection of Volatile Metabolites of Garlic in Human Breast Milk.

    PubMed

    Scheffler, Laura; Sauermann, Yvonne; Zeh, Gina; Hauf, Katharina; Heinlein, Anja; Sharapa, Constanze; Buettner, Andrea

    2016-01-01

    The odor of human breast milk after ingestion of raw garlic at food-relevant concentrations by breastfeeding mothers was investigated for the first time chemo-analytically using gas chromatography-mass spectrometry/olfactometry (GC-MS/O), as well as sensorially using a trained human sensory panel. Sensory evaluation revealed a clear garlic/cabbage-like odor that appeared in breast milk about 2.5 h after consumption of garlic. GC-MS/O analyses confirmed the occurrence of garlic-derived metabolites in breast milk, namely allyl methyl sulfide (AMS), allyl methyl sulfoxide (AMSO) and allyl methyl sulfone (AMSO₂). Of these, only AMS had a garlic-like odor whereas the other two metabolites were odorless. This demonstrates that the odor change in human milk is not related to a direct transfer of garlic odorants, as is currently believed, but rather derives from a single metabolite. The formation of these metabolites is not fully understood, but AMSO and AMSO₂ are most likely formed by the oxidation of AMS in the human body. The excretion rates of these metabolites into breast milk were strongly time-dependent with large inter-individual differences. PMID:27275838

  6. Ginseng Metabolites on Cancer Chemoprevention: An Angiogenesis Link?

    PubMed Central

    Wang, Chong-Zhi; Cai, Yi; Anderson, Samantha; Yuan, Chun-Su

    2015-01-01

    Cancer is a leading cause of death in the United States. Angiogenesis inhibitors have been introduced for the treatment of cancer. Based on the fact that many anticancer agents have been developed from botanical sources, there is a significant untapped resource to be found in natural products. American ginseng is a commonly used herbal medicine in the U.S., which possess antioxidant properties. After oral ingestion, natural ginseng saponins are biotransformed to their metabolites by the enteric microbiome before being absorbed. The major metabolites, ginsenoside Rg3 and compound K, showed significant potent anticancer activity compared to that of their parent ginsenosides Rb1, Rc and Rd. In this review, the molecular mechanisms of ginseng metabolites on cancer chemoprevention, especially apoptosis and angiogenic inhibition, are discussed. Ginseng gut microbiome metabolites showed significant anti-angiogenic effects on pulmonary, gastric and ovarian cancers. This review suggests that in addition to the chemopreventive effects of ginseng compounds, as angiogenic inhibitors, ginsenoside metabolites could be used in combination with other cancer chemotherapeutic agents in cancer management. PMID:26941993

  7. Endocidal Regulation of Secondary Metabolites in the Producing Organisms.

    PubMed

    Li, Shiyou; Wang, Ping; Yuan, Wei; Su, Zushang; Bullard, Steven H

    2016-01-01

    Secondary metabolites are defined as organic compounds that are not directly involved in the normal growth, development, and reproduction of an organism. They are widely believed to be responsible for interactions between the producing organism and its environment, with the producer avoiding their toxicities. In our experiments, however, none of the randomly selected 44 species representing different groups of plants and insects can avoid autotoxicity by its endogenous metabolites once made available. We coined the term endocides (endogenous biocides) to describe such metabolites that can poison or inhibit the parent via induced biosynthesis or external applications. Dosage-dependent endocides can selectively induce morphological mutations in the parent organism (e.g., shrubbiness/dwarfism, pleiocotyly, abnormal leaf morphogenesis, disturbed phyllotaxis, fasciated stems, and variegation in plants), inhibit its growth, development, and reproduction and cause death than non-closely related species. The propagule, as well as the organism itself contains or produces adequate endocides to kill itself. PMID:27389069

  8. Plant chemical defenses: are all constitutive antimicrobial metabolites phytoanticipins?

    PubMed

    Pedras, M Soledade C; Yaya, Estifanos E

    2015-01-01

    A critical perspective on phytoanticipins, constitutive plant secondary metabolites with defensive roles against microbes is presented. This mini-review focuses on the chemical groups and structural types of defensive plant metabolites thus far not reviewed from the phytoanticipin perspective: i) fatty acid derivatives and polyketides, ii) terpenoids, iii) shikimates, phenylpropanoids and derivatives, and iv) benzylisoquinoline and pyrrolizidine alkaloids. The more traditional groups of phytoanticipins are briefly summarized, with particular focus on the latest results: i) benzoxazinoids, ii) cyanogenic glycosides, iii) glucosinolates and their metabolic products, and iv) saponins. Current evidence suggests that a better understanding of the functions of plant metabolites will drive their application to protect crops against microbial diseases. PMID:25920246

  9. Cell Factories of Higher Fungi for Useful Metabolite Production.

    PubMed

    Qin, Hao; Xu, Jun-Wei; Xiao, Jian-Hui; Tang, Ya-Jie; Xiao, Han; Zhong, Jian-Jiang

    2016-01-01

    Higher fungi or called as macro-fungi, consisting of the divisions ascomycetes, basidiomycetes, and imperfect fungi, are receiving great interest around the world, because studies of higher fungi help us not only to find new edible and officinal resources but also to understand their complicated biology. In recent decades, a large number of useful substances from higher fungi have been isolated, identified, and characterized, which have important biological functions, such as reducing blood pressure, enhancing immunity, and possessing anti-cancer and anti-HIV and other pharmacological activities. This chapter will review the genetic manipulation tools for higher fungi, omics analysis of higher-fungus cell factories, and production of useful metabolites by higher fungi, including those of terpenoids, heterocyclics, polysaccharides, and polyketides. Trends in future development of cell factories of higher fungi for useful metabolite production will also be analyzed. Graphical Abstract Strategies for improving cell factories of higher fungi for useful metabolite production. PMID:26475464

  10. Endocidal Regulation of Secondary Metabolites in the Producing Organisms

    PubMed Central

    Li, Shiyou; Wang, Ping; Yuan, Wei; Su, Zushang; Bullard, Steven H.

    2016-01-01

    Secondary metabolites are defined as organic compounds that are not directly involved in the normal growth, development, and reproduction of an organism. They are widely believed to be responsible for interactions between the producing organism and its environment, with the producer avoiding their toxicities. In our experiments, however, none of the randomly selected 44 species representing different groups of plants and insects can avoid autotoxicity by its endogenous metabolites once made available. We coined the term endocides (endogenous biocides) to describe such metabolites that can poison or inhibit the parent via induced biosynthesis or external applications. Dosage-dependent endocides can selectively induce morphological mutations in the parent organism (e.g., shrubbiness/dwarfism, pleiocotyly, abnormal leaf morphogenesis, disturbed phyllotaxis, fasciated stems, and variegation in plants), inhibit its growth, development, and reproduction and cause death than non-closely related species. The propagule, as well as the organism itself contains or produces adequate endocides to kill itself. PMID:27389069

  11. The role of nicotinic acid metabolites in flushing and hepatotoxicity.

    PubMed

    Stern, Ralph H

    2007-07-01

    Flushing and hepatotoxicity are important adverse effects of nicotinic acid. This article reviews the role of metabolism of nicotinic acid in the production of these side effects. The suggestion that nicotinic acid (NUA) formation produces flushing is traced to a correlation of flushing with NUA C(max) (maximal concentration) and the observation that aspirin inhibits NUA formation and flushing. The former does not establish causation and the latter can be explained by inhibition of prostaglandin formation. Recent characterization of the GPR109A receptor that mediates prostaglandin release by Langerhans cells to produce flushing has shown nicotinic acid, not NUA, is responsible. The suggestion that nicotinamide metabolites produce hepatotoxicity is not supported by any data. The mechanism of hepatotoxicity is unknown and a toxic metabolite of nicotinic acid has not been identified. Different nicotinic acid formulations produce different metabolite patterns due to nonlinear pharmacokinetics, but there is no evidence that these differences have any clinical importance. PMID:21291680

  12. Understanding Boswellia papyrifera tree secondary metabolites through bark spectral analysis

    NASA Astrophysics Data System (ADS)

    Girma, Atkilt; Skidmore, Andrew K.; de Bie, C. A. J. M.; Bongers, Frans

    2015-07-01

    Decision makers are concerned whether to tap or rest Boswellia Papyrifera trees. Tapping for the production of frankincense is known to deplete carbon reserves from the tree leading to production of less viable seeds, tree carbon starvation and ultimately tree mortality. Decision makers use traditional experience without considering the amount of metabolites stored or depleted from the stem-bark of the tree. This research was designed to come up with a non-destructive B. papyrifera tree metabolite estimation technique relevant for management using spectroscopy. The concentration of biochemicals (metabolites) found in the tree bark was estimated through spectral analysis. Initially, a random sample of 33 trees was selected, the spectra of bark measured with an Analytical Spectral Device (ASD) spectrometer. Bark samples were air dried and ground. Then, 10 g of sample was soaked in Petroleum ether to extract crude metabolites. Further chemical analysis was conducted to quantify and isolate pure metabolite compounds such as incensole acetate and boswellic acid. The crude metabolites, which relate to frankincense produce, were compared to plant properties (such as diameter and crown area) and reflectance spectra of the bark. Moreover, the extract was compared to the ASD spectra using partial least square regression technique (PLSR) and continuum removed spectral analysis. The continuum removed spectral analysis were performed, on two wavelength regions (1275-1663 and 1836-2217) identified through PLSR, using absorption features such as band depth, area, position, asymmetry and the width to characterize and find relationship with the bark extracts. The results show that tree properties such as diameter at breast height (DBH) and the crown area of untapped and healthy trees were strongly correlated to the amount of stored crude metabolites. In addition, the PLSR technique applied to the first derivative transformation of the reflectance spectrum was found to estimate the

  13. Plants and endophytes: equal partners in secondary metabolite production?

    PubMed

    Ludwig-Müller, Jutta

    2015-07-01

    Well known plant production systems should be re-evaluated due to findings that the interesting metabolite might actually be produced by microbes intimately associated with the plant, so-called endophytes. Endophytes can be bacteria or fungi and they are characterized usually by the feature that they do not cause any harm to the host. Indeed, in some cases, such as mycorrhizal fungi or other growth promoting endophytes, they can be beneficial for the plant. Here some examples are reviewed where the host plant and/or endophyte metabolism can be induced by the other partner. Also, partial or complete biosynthesis pathways for plant secondary metabolites can be attributed to such endophytes. In other cases the host plant is able to metabolize substances from fungal origin. The question of the natural role of such metabolic changes for the endophyte will be briefly touched. Finally, the consequences for the use of plant cultures for secondary metabolite production is discussed. PMID:25792513

  14. Reevaluating the hype: four bacterial metabolites under scrutiny

    PubMed Central

    Mayerhofer, R.; Holzer, P.

    2015-01-01

    With microbiome research being a fiercely contested playground in science, new data are being published at tremendous pace. The review at hand serves to critically revise four microbial metabolites widely applied in research: butyric acid, flagellin, lipoteichoic acid, and propionic acid. All four metabolites are physiologically present in healthy humans. Nevertheless, all four are likewise involved in pathologies ranging from cancer to mental retardation. Their inflammatory potential is equally friend and foe. The authors systematically analyze positive and negative attributes of the aforementioned substances, indicating chances and dangers with the use of pre- and probiotic therapeutics. Furthermore, the widespread actions of microbial metabolites on distinct organs and diseases are reconciled. Moreover, the review serves as critical discourse on scientific methods commonly employed in microbiome research and comparability as well as reproducibility issues arising thereof. PMID:25883790

  15. Metabolites of isocorynoxeine in rats after its oral administration.

    PubMed

    Chen, Ya-Ping; Lu, Min-Nan; Hao, Jing-Chao; Li, Mei-Hong; Hattori, Masao; Wang, Wei

    2015-01-01

    This work presents the metabolites of isocorynoxeine (ICOR), which is one of four bioactive tetracyclic oxindole alkaloids isolated from Uncaria hooks used commonly in the traditional Chinese medicines and Kampo medicines. After oral administration of 40 mg kg(-1) ICOR to rats, bile was drained and analyzed by LC-MS. Two phase I metabolites, namely 11-hydroxyisocorynoxeine (M1) and 10-hydroxyisocorynoxeine (M2), and two phase II metabolites, namely 11-hydroxyisocorynoxeine 11-O-β-D-glucuronide (M3) and 10-hydroxyisocorynoxeine 10-O-β-D-glucuronide (M4), were isolated from rat excreta and bile, respectively, whose structures were elucidated on the basis of CD, NMR, and MS. PMID:25633191

  16. How astrocyte networks may contribute to cerebral metabolite clearance

    PubMed Central

    Asgari, Mahdi; de Zélicourt, Diane; Kurtcuoglu, Vartan

    2015-01-01

    The brain possesses an intricate network of interconnected fluid pathways that are vital to the maintenance of its homeostasis. With diffusion being the main mode of solute transport in cerebral tissue, it is not clear how bulk flow through these pathways is involved in the removal of metabolites. In this computational study, we show that networks of astrocytes may contribute to the passage of solutes between tissue and paravascular spaces (PVS) by serving as low resistance pathways to bulk water flow. The astrocyte networks are connected through aquaporin-4 (AQP4) water channels with a parallel, extracellular route carrying metabolites. Inhibition of the intracellular route by deletion of AQP4 causes a reduction of bulk flow between tissue and PVS, leading to reduced metabolite clearance into the venous PVS or, as observed in animal studies, a reduction of tracer influx from arterial PVS into the brain tissue. PMID:26463008

  17. How astrocyte networks may contribute to cerebral metabolite clearance.

    PubMed

    Asgari, Mahdi; de Zélicourt, Diane; Kurtcuoglu, Vartan

    2015-01-01

    The brain possesses an intricate network of interconnected fluid pathways that are vital to the maintenance of its homeostasis. With diffusion being the main mode of solute transport in cerebral tissue, it is not clear how bulk flow through these pathways is involved in the removal of metabolites. In this computational study, we show that networks of astrocytes may contribute to the passage of solutes between tissue and paravascular spaces (PVS) by serving as low resistance pathways to bulk water flow. The astrocyte networks are connected through aquaporin-4 (AQP4) water channels with a parallel, extracellular route carrying metabolites. Inhibition of the intracellular route by deletion of AQP4 causes a reduction of bulk flow between tissue and PVS, leading to reduced metabolite clearance into the venous PVS or, as observed in animal studies, a reduction of tracer influx from arterial PVS into the brain tissue. PMID:26463008

  18. Autonomous Metabolomics for Rapid Metabolite Identification in Global Profiling

    PubMed Central

    2015-01-01

    An autonomous metabolomic workflow combining mass spectrometry analysis with tandem mass spectrometry data acquisition was designed to allow for simultaneous data processing and metabolite characterization. Although previously tandem mass spectrometry data have been generated on the fly, the experiments described herein combine this technology with the bioinformatic resources of XCMS and METLIN. As a result of this unique integration, we can analyze large profiling datasets and simultaneously obtain structural identifications. Validation of the workflow on bacterial samples allowed the profiling on the order of a thousand metabolite features with simultaneous tandem mass spectra data acquisition. The tandem mass spectrometry data acquisition enabled automatic search and matching against the METLIN tandem mass spectrometry database, shortening the current workflow from days to hours. Overall, the autonomous approach to untargeted metabolomics provides an efficient means of metabolomic profiling, and will ultimately allow the more rapid integration of comparative analyses, metabolite identification, and data analysis at a systems biology level. PMID:25496351

  19. Autonomous metabolomics for rapid metabolite identification in global profiling.

    PubMed

    Benton, H Paul; Ivanisevic, Julijana; Mahieu, Nathaniel G; Kurczy, Michael E; Johnson, Caroline H; Franco, Lauren; Rinehart, Duane; Valentine, Elizabeth; Gowda, Harsha; Ubhi, Baljit K; Tautenhahn, Ralf; Gieschen, Andrew; Fields, Matthew W; Patti, Gary J; Siuzdak, Gary

    2015-01-20

    An autonomous metabolomic workflow combining mass spectrometry analysis with tandem mass spectrometry data acquisition was designed to allow for simultaneous data processing and metabolite characterization. Although previously tandem mass spectrometry data have been generated on the fly, the experiments described herein combine this technology with the bioinformatic resources of XCMS and METLIN. As a result of this unique integration, we can analyze large profiling datasets and simultaneously obtain structural identifications. Validation of the workflow on bacterial samples allowed the profiling on the order of a thousand metabolite features with simultaneous tandem mass spectra data acquisition. The tandem mass spectrometry data acquisition enabled automatic search and matching against the METLIN tandem mass spectrometry database, shortening the current workflow from days to hours. Overall, the autonomous approach to untargeted metabolomics provides an efficient means of metabolomic profiling, and will ultimately allow the more rapid integration of comparative analyses, metabolite identification, and data analysis at a systems biology level. PMID:25496351

  20. [Occurrence of indole alkaloids among secondary metabolites of soil Aspergillus].

    PubMed

    Vinokurova, N G; Khmel'nitskaia, I I; Baskunov, B P; Arinbasarov, M U

    2003-01-01

    The occurrence of indole alkaloids among secondary fungal metabolites was studied in species of the genus Aspergillus, isolated from soils that were sampled in various regions of Russia (a total of 102 isolates of the species A. niger, A. phoenicis, A. fumigatus, A. flavus, A. versicolor, A. ustus, A. clavatus, and A. ochraceus). Clavine alkaloids were represented by fumigaclavine, which was formed by A. fumigatus. alpha-Cyclopiazonic acid was formed by isolates of A. fumigatus, A. flavus, A. versicolor, A. phoenicis, and A. clavatus. The occurrence of indole-containing diketopiperazine alkaloids was documented for isolates of A. flavus, A. fumigatus, A. clavatus, and A. ochraceus. No indole-containing metabolites were found among the metabolites of A. ustus or A. niger. PMID:12722658

  1. Secondary metabolites from Penicillium corylophilum isolated from damp buildings.

    PubMed

    McMullin, David R; Nsiama, Tienabe K; Miller, J David

    2014-01-01

    Indoor exposure to the spores and mycelial fragments of fungi that grow on damp building materials can result in increased non-atopic asthma and upper respiratory disease. The mechanism appears to involve exposure to low doses of fungal metabolites. Penicillium corylophilum is surprisingly common in damp buildings in USA, Canada and western Europe. We examined isolates of P. corylophilum geographically distributed across Canada in the first comprehensive study of secondary metabolites of this fungus. The sesquiterpene phomenone, the meroterpenoids citreohybridonol and andrastin A, koninginin A, E and G, three new alpha pyrones and four new isochromans were identified from extracts of culture filtrates. This is the first report of koninginins, meroterpenoids and alpha pyrones from P. corylophilum. These secondary metabolite data support the removal of P. corylophilum from Penicillium section Citrina and suggest that further taxonomic studies are required on this species. PMID:24891425

  2. Small‐molecule elicitation of microbial secondary metabolites

    PubMed Central

    Pettit, Robin K.

    2011-01-01

    Summary Microbial natural products continue to be an unparalleled resource for pharmaceutical lead discovery, but the rediscovery rate is high. Bacterial and fungal sequencing studies indicate that the biosynthetic potential of many strains is much greater than that observed by fermentation. Prodding the expression of such silent (cryptic) pathways will allow us to maximize the chemical diversity available from microorganisms. Cryptic metabolic pathways can be accessed in the laboratory using molecular or cultivation‐based approaches. A targeted approach related to cultivation‐based methods is the application of small‐molecule elicitors to specifically affect transcription of secondary metabolite gene clusters. With the isolation of the novel secondary metabolites lunalides A and B, oxylipins, cladochromes F and G, nygerone A, chaetoglobosin‐542, ‐540 and ‐510, sphaerolone, dihydrosphaerolone, mutolide and pestalone, and the enhanced production of known secondary metabolites like penicillin and bacitracin, chemical elicitation is proving to be an effective way to augment natural product libraries. PMID:21375710

  3. Exploring antagonistic metabolites of established biocontrol agent of marine origin.

    PubMed

    Rane, Makarand Ramesh; Sarode, Prashant Diwakar; Chaudhari, Bhushan Liladhar; Chincholkar, Sudhir Bhaskarrao

    2008-12-01

    Biocontrol ability of Pseudomonas aeruginosa ID 4365, a biocontrol agent of groundnut phytopathogens from marine origin, was previously attributed to the production of pyoverdin type of siderophores. However, pyoverdin-rich supernatants of this organism showed better antifungal activity compared to equivalent amount of purified pyoverdin indicating presence of undetected metabolite(s) in pyoverdin rich supernatants. On the basis of observation that antagonistic activity was iron-dependent and iron-independent, an attempt was made to detect the presence of additional metabolites. In addition to pyoverdin, strain produced additional siderophores, viz. pyochelin and salicylic acid. Two broad spectrum antifungal compounds, viz. pyocyanin and phenazine-1-carboxylic acid, were detected, characterized, and activity against phytopathogens was demonstrated. Iron- and phosphate-dependent co-production of siderophores and phenazines was confirmed. Strain showed additional features like production of hydrogen cyanide, indol-3-acetic acid, and phosphate solubilization. PMID:18626581

  4. Pesticides in ground water: Do atrazine metabolites matter?

    USGS Publications Warehouse

    Liu, S.; Yen, S.T.; Kolpin, D.W.

    1996-01-01

    Atrazine and atrazine-residue (atrazine + two metabolites - deethylatrazine and deisopropylatrazine) concentrations were examined to determine if consideration of these atrazine metabolites substantially adds to our understanding of the distribution of this pesticide in groundwater of the midcontinental United States. The mean of atrazine.residue concentrations was 53 percent greater than that of atrazine alone for those observations above the detection limit (> 0.05 μg/l). Furthermore, a censored regression analysis using atrazine-residue concentrations revealed significant factors not identified when only atrazine concentrations were used. Thus, knowledge of concentrations of these atrazine metabolites is required to obtain a true estimation of risk of using these aquifers as sources for drinking water, and such knowledge also provides information that ultimately may be important for future management policies designed to reduce atrazine concentrations in ground water.

  5. Use of mass spectrometry for imaging metabolites in plants

    SciTech Connect

    Lee, Young-Jin; Perdian, David; Song, Zhihong; Yeung, Edward; Nikolau, Basil

    2012-03-27

    We discuss and illustrate recent advances that have been made to image the distribution of metabolites among cells and tissues of plants using different mass spectrometry technologies. These technologies include matrix-assisted laser desorption ionization, desorption electrospray ionization, and secondary ion mass spectrometry. These are relatively new technological applications of mass spectrometry and they are providing highly spatially resolved data concerning the cellular distribution of metabolites. We discuss the advantages and limitations of each of these mass spectrometric methods, and provide a description of the technical barriers that are currently limiting the technology to the level of single-cell resolution. However, we anticipate that advances in the next few years will increase the resolving power of the technology to provide unprecedented data on the distribution of metabolites at the subcellular level, which will increase our ability to decipher new knowledge concerning the spatial organization of metabolic processes in plants.

  6. Use of Mass spectrometry for imaging metabolites in plants

    SciTech Connect

    Lee, Young Jin; Perdian, David C.; Song, Zhihong; Yeung, Edward S.; Nikolau, Basil

    2012-03-27

    We discuss and illustrate recent advances that have been made to image the distribution of metabolites among cells and tissues of plants using different mass spectrometry technologies. These technologies include matrix-assisted laser desorption ionization, desorption electrospray ionization, and secondary ion mass spectrometry. These are relatively new technological applications of mass spectrometry and they are providing highly spatially resolved data concerning the cellular distribution of metabolites. We discuss the advantages and limitations of each of these mass spectrometric methods, and provide a description of the technical barriers that are currently limiting the technology to the level of single-cell resolution. However, we anticipate that advances in the next few years will increase the resolving power of the technology to provide unprecedented data on the distribution of metabolites at the subcellular level, which will increase our ability to decipher new knowledge concerning the spatial organization of metabolic processes in plants.

  7. Mechanistic Modeling to Predict Midazolam Metabolite Exposure from In Vitro Data.

    PubMed

    Nguyen, Hoa Q; Kimoto, Emi; Callegari, Ernesto; Obach, R Scott

    2016-05-01

    Methods to predict the pharmacokinetics of drugs in humans from in vitro data have been established, but corresponding methods to predict exposure to circulating metabolites are unproven. The objective of this study was to use in vitro methods combined with static and dynamic physiologically based pharmacokinetic (PBPK) models to predict metabolite exposures, using midazolam and its major metabolites as a test system. Intrinsic clearances (CLint) of formation of individual metabolites were determined using human liver microsomes. Metabolic CLintof hydroxymidazolam metabolites via oxidation and glucuronidation were also determined. Passive diffusion intrinsic clearances of hydroxymidazolam metabolites were determined using sandwich cultured human hepatocytes and the combination of this term along with the metabolic CLint, and liver blood flow was used to estimate the fraction of the metabolite that can enter the systemic circulation after formation in the liver. The metabolite/parent drug area under the plasma concentration-time curve ratio (AUCm/AUCp) was predicted using a static model relating the fraction of midazolam clearance to each metabolite, the clearance rates of midazolam and hydroxymidazolam metabolites, and the availability of the metabolites. Additionally, the human disposition of midazolam metabolites was simulated using a SimCYP PBPK model. Both approaches yielded AUCm/AUCpratios that were in agreement with the in vivo ratios. This study shows that in vivo midazolam metabolite exposure can be predicted from in vitro data and PBPK modeling. This study emphasized the importance of metabolite systemic availability from its tissue of formation, which remains a challenge to quantitative prediction. PMID:26956641

  8. Tools and ingredients for the biocatalytic synthesis of metabolites.

    PubMed

    Wohlgemuth, Roland

    2009-09-01

    Metabolic networks have been an interesting starting point not only for the design of synthetic routes in a similar sequence of reactions, e.g., in biomimetic syntheses, but also for assembling a number of biocatalytic steps by preparing the required enzymes and auxiliary reagents. Retrosynthetic analysis involving multiple biocatalytic reactions steps therefore needs to consider the practically realized biocatalytic single steps. The opportunities for route selection are enlarged if novel synthetic reactions connecting easily available starting materials and products are found, and/or both biocatalytic and classical reactions of organic chemistry are utilized. Tools and ingredients for biocatalytic synthesis are of special interest for reactions difficult to achieve by classical organic synthesis. Densely and differentially functionalized small molecules do not allow much space for protecting or activating groups. Biocatalytic reactions have therefore performed well for a number of useful metabolites in enantiopure form to achieve full functionality. Although many well-known metabolites from classical biochemistry have only been prepared in racemic form, it is of fundamental interest to have these available in enantiomerically pure form. Biocatalytic reactions with nature's privileged chiral catalysts appear to be a promising synthetic strategy towards these metabolites, especially when sensitive or stable-isotope-labeled metabolites are to be prepared. The main applications for these metabolites are as references materials in metabolomics, as enzyme substrates for the characterization of metabolic enzyme activities and as potential pharmaceuticals in biomedical research. The use of stable-isotope-labeled metabolites can thereby simplify in vivo applications and metabolic flux analyses. PMID:19777483

  9. Bar Coding MS(2) Spectra for Metabolite Identification.

    PubMed

    Spalding, Jonathan L; Cho, Kevin; Mahieu, Nathaniel G; Nikolskiy, Igor; Llufrio, Elizabeth M; Johnson, Stephen L; Patti, Gary J

    2016-03-01

    Metabolite identifications are most frequently achieved in untargeted metabolomics by matching precursor mass and full, high-resolution MS(2) spectra to metabolite databases and standards. Here we considered an alternative approach for establishing metabolite identifications that does not rely on full, high-resolution MS(2) spectra. First, we select mass-to-charge regions containing the most informative metabolite fragments and designate them as bins. We then translate each metabolite fragmentation pattern into a binary code by assigning 1's to bins containing fragments and 0's to bins without fragments. With 20 bins, this binary-code system is capable of distinguishing 96% of the compounds in the METLIN MS(2) library. A major advantage of the approach is that it extends untargeted metabolomics to low-resolution triple quadrupole (QqQ) instruments, which are typically less expensive and more robust than other types of mass spectrometers. We demonstrate a method of acquiring MS(2) data in which the third quadrupole of a QqQ instrument cycles over 20 wide isolation windows (coinciding with the location and width of our bins) for each precursor mass selected by the first quadrupole. Operating the QqQ instrument in this mode yields diagnostic bar codes for each precursor mass that can be matched to the bar codes of metabolite standards. Furthermore, our data suggest that using low-resolution bar codes enables QqQ instruments to make MS(2)-based identifications in untargeted metabolomics with a specificity and sensitivity that is competitive to high-resolution time-of-flight technologies. PMID:26837423

  10. Quantitating Metabolites in Protein Precipitated Serum Using NMR Spectroscopy

    PubMed Central

    2015-01-01

    Quantitative NMR-based metabolite profiling is challenged by the deleterious effects of abundant proteins in the intact blood plasma/serum, which underscores the need for alternative approaches. Protein removal by ultrafiltration using low molecular weight cutoff filters thus represents an important step. However, protein precipitation, an alternative and simple approach for protein removal, lacks detailed quantitative assessment for use in NMR based metabolomics. In this study, we have comprehensively evaluated the performance of protein precipitation using methanol, acetonitrile, perchloric acid, and trichloroacetic acid and ultrafiltration approaches using 1D and 2D NMR, based on the identification and absolute quantitation of 44 human blood metabolites, including a few identified for the first time in the NMR spectra of human serum. We also investigated the use of a “smart isotope tag,” 15N-cholamine for further resolution enhancement, which resulted in the detection of a number of additional metabolites. 1H NMR of both protein precipitated and ultrafiltered serum detected all 44 metabolites with comparable reproducibility (average CV, 3.7% for precipitation; 3.6% for filtration). However, nearly half of the quantified metabolites in ultrafiltered serum exhibited 10–74% lower concentrations; specifically, tryptophan, benzoate, and 2-oxoisocaproate showed much lower concentrations compared to protein precipitated serum. These results indicate that protein precipitation using methanol offers a reliable approach for routine NMR-based metabolomics of human blood serum/plasma and should be considered as an alternative to ultrafiltration. Importantly, protein precipitation, which is commonly used by mass spectrometry (MS), promises avenues for direct comparison and correlation of metabolite data obtained from the two analytical platforms to exploit their combined strength in the metabolomics of blood. PMID:24796490

  11. Urinary metabolites of 14C-labeled thyroxine in man

    PubMed Central

    Pittman, Constance S.; Buck, Melvin W.; Chambers, Joseph B.

    1972-01-01

    Studies were carried out to determine the chemical structures of thyroxine metabolites after total deiodination. Normal subjects were given thyroxine labeled with 14C on the nonphenolic ring and the alanine side chain, 8-11 μg/day for 10 days. By paper chromatography of fresh urine, six or more 14C-labeled compounds were separated. The 14C-labeled metabolites were concentrated by passing the urine through a nonionic polymeric adsorbent. Two major thyroxine metabolites were identified. The identification was made by three different methods: (a) chromatography, (b) synthesis of derivatives, and (c) recrystallization to constant specific activity. One 14C-labeled metabolite was identified as thyroacetic acid or 4-phenoxy-(4′-hydroxy) phenyl-acetic acid. Another one was identified as thyronine. Of the total urinary 14C radioactivity, 43.7% was recovered as thyroacetic acid and 19.8% was recovered as thyronine. Approximately one-fifth of each of these metabolites was present in the urine in bound form which released the free metabolites during acid hydrolysis. The average daily excretion of thyroacetic acid was 13.7% of the renal disposal rate of thyroxine, or approximately 7.5 μg/day. The average daily excretion of thyronine was 6.5% of the renal disposal rate of thyroxine or approximately 3.9 μg/day while the urinary iodide made up 64.7% of the renal disposal rate of thyroxine. Our findings provide the needed proof that the major metabolic pathways of thyroxine remove the iodine atoms by substituting hydrogen for iodine and leave the diphenyl ether nucleus intact. PMID:5032524

  12. The diet-microbiota-metabolite axis regulates the host physiology.

    PubMed

    Yamada, Takahiro; Takahashi, Daisuke; Hase, Koji

    2016-07-01

    The intestinal microbiota has been implicated in a wide range of diseases, including inflammatory bowel disease, obesity and cancer. Food ingredients are considered a major determinant of gut microbial composition, as exemplified by high-fat diet-induced dysbiosis that can affect host physiology. Accumulating studies show that microbial metabolites are key regulators of the intestinal epithelial barrier and gut immunity. In particular, short-chain fatty acids produced by bacterial fermentation of indigestible polysaccharides have profound impacts on host physiology beyond the gut. In this review, we describe the influences of the diet-microbiota-metabolite axis on host physiology, and especially on the immune and metabolic systems. PMID:26970281

  13. Optical properties of drug metabolites in latent fingermarks

    NASA Astrophysics Data System (ADS)

    Shen, Yao; Ai, Qing

    2016-02-01

    Drug metabolites usually have structures of split-ring resonators (SRRs), which might lead to negative permittivity and permeability in electromagnetic field. As a result, in the UV-vis region, the latent fingermarks images of drug addicts and non drug users are inverse. The optical properties of latent fingermarks are quite different between drug addicts and non-drug users. This is a technic superiority for crime scene investigation to distinguish them. In this paper, we calculate the permittivity and permeability of drug metabolites using tight-binding model. The latent fingermarks of smokers and non-smokers are given as an example.

  14. Quenching methods for the analysis of intracellular metabolites.

    PubMed

    Wahrheit, Judith; Heinzle, Elmar

    2014-01-01

    Sampling and quenching methods for intracellular metabolite analysis in mammalian cells in adherent and suspension culture are described. Quenching of adherent cells is achieved by application of hot air after removal of the supernatant by suction. For suspension cultures, the addition of excess ice-cold saline results in a rapid inactivation of metabolism and significant dilution of extracellular metabolites. Medium carryover is prevented by rinsing the cells with washing solution. Separation of supernatant from suspension cells via centrifugation is incomplete due to required short centrifugation time. Thus, it is necessary to determine the reproducible cell recovery after quenching. PMID:24297418

  15. Toward Awakening Cryptic Secondary Metabolite Gene Clusters in Filamentous Fungi

    PubMed Central

    Lim, Fang Yun; Sanchez, James F.; Wang, Clay C.C.; Keller, Nancy P.

    2013-01-01

    Mining for novel natural compounds is of eminent importance owing to the continuous need for new pharmaceuticals. Filamentous fungi are historically known to harbor the genetic capacity for an arsenal of natural compounds, both beneficial and detrimental to humans. The majority of these metabolites are still cryptic or silent under standard laboratory culture conditions. Mining for these cryptic natural products can be an excellent source for identifying new compound classes. Capitalizing on the current knowledge on how secondary metabolite gene clusters are regulated has allowed the research community to unlock many hidden fungal treasures, as described in this chapter. PMID:23084945

  16. Lichen secondary metabolites as DNA-interacting agents.

    PubMed

    Plsíkova, J; Stepankova, J; Kasparkova, J; Brabec, V; Backor, M; Kozurkova, M

    2014-03-01

    A series of lichen secondary metabolites (parietin, atranorin, usnic and gyrophoric acid) and their interactions with calf thymus DNA were investigated using molecular biophysics and biochemical methods. The binding constants K were estimated to range from 4.3×10(5) to 2.4×10(7)M(-1) and the percentage of hypochromism was found to be 16-34% (from spectral titration). The results of spectral measurement indicate that the compounds act as effective DNA-interacting agents. Electrophoretic separation studies prove that from all the metabolites tested in this study, only gyrophoric acid exhibited an inhibitory effect on Topo I (25μM). PMID:24269500

  17. Optical properties of drug metabolites in latent fingermarks

    PubMed Central

    Shen, Yao; Ai, Qing

    2016-01-01

    Drug metabolites usually have structures of split-ring resonators (SRRs), which might lead to negative permittivity and permeability in electromagnetic field. As a result, in the UV-vis region, the latent fingermarks images of drug addicts and non drug users are inverse. The optical properties of latent fingermarks are quite different between drug addicts and non-drug users. This is a technic superiority for crime scene investigation to distinguish them. In this paper, we calculate the permittivity and permeability of drug metabolites using tight-binding model. The latent fingermarks of smokers and non-smokers are given as an example. PMID:26838730

  18. Efficient Syntheses of Vitamin K Chain-Shortened Acid Metabolites

    PubMed Central

    Teitelbaum, Aaron M.; Scian, Michele; Nelson, Wendel L.; Rettie, Allan E.

    2015-01-01

    Vitamin K sequentially undergoes ω-oxidation followed by successive rounds of β-oxidation to ultimately produce two chain-shortened carboxylic acid metabolites, vitamin K acid 1 and vitamin K acid 2. Two facile syntheses of these acid metabolites are described, each starting from commercially available menadione-cyclopentadiene adduct 3. Vitamin K acid 1 was synthesized in five steps via alkylation with a geranyl halide followed by subsequent oxidation reactions, while fully retaining the trans configuration of the side chain 2’,3’-double bond. Vitamin K acid 2 was synthesized in 5 steps from 3 via alkylation with dimethylallyl chloride and subsequent oxidation reactions. PMID:27003951

  19. Associations of cord blood metabolites with early childhood obesity risk

    PubMed Central

    Isganaitis, Elvira; Rifas-Shiman, Sheryl L.; Oken, Emily; Dreyfuss, Jonathan; Gall, Walt; Gillman, Matthew W.; Patti, Mary-Elizabeth

    2015-01-01

    Background/Objective Rapid postnatal weight gain is a potentially modifiable risk factor for obesity and metabolic syndrome. To identify markers of rapid infancy weight gain and childhood obesity, we analyzed the metabolome in cord blood from infants differing in their postnatal weight trajectories. Methods We performed a nested case-control study within Project Viva, a longitudinal cohort of mothers and children. We selected cases (n=26) based on top quartile of change in weight-for-age 0-6 mo and BMI >85th percentile in mid-childhood (median 7.7 years). Controls (n=26) were age- and sex-matched, had normal postnatal weight gain (2nd or 3rd quartile of change in weight-for-age 0-6 mo) and normal mid-childhood weight (BMI 25th-75th percentile). Cord blood metabolites were measured using untargeted LC/MS; individual metabolites and pathways differing between cases vs. controls were compared in categorical analyses. We adjusted metabolites for maternal age, maternal BMI, and breastfeeding duration (linear regression), and assessed whether metabolites improved the ability to predict case-control status (logistic regression). Results Of 415 detected metabolites, 16 were altered in cases vs. controls (T-test, nominal P<0.05). 3 metabolites were related to tryptophan: serotonin, tryptophan betaine, and tryptophyl leucine (46%, 48% and 26% lower in cases, respectively, P<0.05). Mean levels of 2 methyl donors, dimethylglycine and N-acetylmethionine, were also lower in cases (18% and 16% respectively, P=0.01). Moreover, the glutamine:glutamate ratio was reduced by 33% (P<0.05) in cases. Levels of serotonin, tryptophyl leucine, and N-acetylmethionine remained significantly different after adjustment for maternal BMI, age, and breastfeeding. Adding metabolite levels to logistic regression models including only clinical covariates improved the ability to predict case vs. control status. Conclusions Several cord blood metabolites are associated with rapid postnatal weight gain

  20. Specialized metabolites from the microbiome in health and disease

    PubMed Central

    Sharon, Gil; Garg, Neha; Debelius, Justine; Knight, Rob; Dorrestein, Pieter C.; Mazmanian, Sarkis K.

    2015-01-01

    The microbiota, and the genes that comprise its microbiome, play key roles in human health. Host-microbe interactions affect immunity, metabolism, development, and behavior, and dysbiosis of gut bacteria contributes to disease. Despite advances in correlating changes in the microbiota with various conditions, specific mechanisms of host-microbiota signaling remain largely elusive. We discuss the synthesis of microbial metabolites, their absorption, and potential physiological effects on the host. We propose that the effects of specialized metabolites may explain present knowledge gaps linking the gut microbiota to biological host mechanisms during initial colonization, and in health and disease. PMID:25440054

  1. METABOLISM OF VINCLOZOLIN AND ITS METABOLITES IN RATS

    EPA Science Inventory

    ETD-04-008

    METABOLISM OF VINCLOZOLIN AND ITS METABOLITES IN RAT. A Sierra-Santoyo1, R Harrison2, H A Barton2 and M F Hughes2. 1Toxicology Section, CINVESTAV-IPN, Mexico City, Mexico; 2USEPA, ORD, NHEERL, RTP, NC.

    Vinclozolin (V) is a fungicide used in agricultural...

  2. HPLC ANALYSIS OF VINCLOZOLIN AND ITS METABOLITES IN SERUM

    EPA Science Inventory


    HPLC ANALYSIS OF VINCLOZOLIN AND ITS METABOLITES IN SERUM. A Sierra-Santoyo1,2, H A Barton1 and M F Hughes1. 1US EPA, ORD, NHEERL, ETD, RTP, NC; 2Toxicology Section, CINVESTAV-IPN, Mexico City, Mexico.

    The fungicide vinclozolin (V) is used predominantly for treatment...

  3. Removal of cyanobacterial metabolites by nanofiltration from two treated waters.

    PubMed

    Dixon, Mike B; Falconet, Charlotte; Ho, Lionel; Chow, Christopher W K; O'Neill, Brian K; Newcombe, Gayle

    2011-04-15

    Cyanobacterial metabolites, both toxic and non-toxic, are a major problem for the water industry. Nanofiltration (NF) may be an effective treatment option for removing organic micropollutants, such as cyanobacterial metabolites, from drinking water due to its size exclusion properties. A rapid bench scale membrane test (RBSMT) unit was utilised to trial four NF membranes to remove the cyanobacterial metabolites, microcystin, cylindrospermopsin (CYN), 2-methylisoborneol (MIB) and geosmin (GSM) in two treated waters sourced from the Palmer and Myponga water treatment plants. Membrane fouling was observed for both treated waters; however, only minor differences were observed between feed waters of differing natural organic matter (NOM) concentration. Low molecular weight cut-off (MWCO), or 'tight' NF, membranes afforded average removals above 90% for CYN, while removal by higher MWCO, or 'loose' NF membranes was lower. MIB and GSM were removed effectively (above 75%) by tight NF but less effectively by loose NF. Microcystin variants (MCRR, MCYR, MCLR, MCLA) were removed to above 90% by tight NF membranes; however, removal using loose NF membranes depended on the hydrophobicity and charge of the variant. Different NOM concentration in the treated waters had no effect on the removal of cyanobacterial metabolites. PMID:21339048

  4. Reactive Arrays of Colorimetric Sensors for Metabolite and Steroid Identification.

    PubMed

    Batres, Gary; Jones, Talia; Johnke, Hannah; Wilson, Mark; Holmes, Andrea E; Sikich, Sharmin

    2014-12-31

    The work described herein examines a rapid mix-and-measure method called DETECHIP suitable for screening of steroids and metabolites. The addition of steroids and metabolites to reactive arrays of colorimetric sensors generated characteristic color "fingerprints" that were used to identify the analyte. A color analysis tool was used to identify the analyte pool that now includes biologically relevant analytes. The mix-and-measure arrays allowed the detection of disease metabolites, orotic acid and argininosuccinic acid; and the steroids androsterone, 1,4-androstadiene, testosterone, stanozolol, and estrone. The steroid 1,4-androstadiene was also detected by this method while dissolved in synthetic urine. Some of the steroids, such as androstadiene, stanozolol, and androsterone were co-dissolved with (2-hydroxypropyl)-β-cyclodextrin in order to increase solubility in aqueous buffered solutions. The colorimetric arrays do not intend to eliminate ELISA or mass spectroscopy based screening, but to possibly provide an alternative analytical detection method for steroids and metabolites. PMID:25019034

  5. Oxidative metabolites of lycopene and their biological functions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To gain a better understanding of the beneficial biological activities of lycopene on cancer prevention, a greater knowledge of the metabolism of lycopene is needed. In particular, the identification of lycopene metabolites and oxidation products in vivo; the importance of tissue specific lycopene c...

  6. 40 CFR 159.179 - Metabolites, degradates, contaminants, and impurities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Metabolites, degradates, contaminants, and impurities. 159.179 Section 159.179 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS STATEMENTS OF POLICIES AND INTERPRETATIONS Reporting Requirements for Risk/Benefit Information § 159.179...

  7. Three plasma metabolite signatures for diagnosing high altitude pulmonary edema

    NASA Astrophysics Data System (ADS)

    Guo, Li; Tan, Guangguo; Liu, Ping; Li, Huijie; Tang, Lulu; Huang, Lan; Ren, Qian

    2015-10-01

    High-altitude pulmonary edema (HAPE) is a potentially fatal condition, occurring at altitudes greater than 3,000 m and affecting rapidly ascending, non-acclimatized healthy individuals. However, the lack of biomarkers for this disease still constitutes a bottleneck in the clinical diagnosis. Here, ultra-high performance liquid chromatography coupled with Q-TOF mass spectrometry was applied to study plasma metabolite profiling from 57 HAPE and 57 control subjects. 14 differential plasma metabolites responsible for the discrimination between the two groups from discovery set (35 HAPE subjects and 35 healthy controls) were identified. Furthermore, 3 of the 14 metabolites (C8-ceramide, sphingosine and glutamine) were selected as candidate diagnostic biomarkers for HAPE using metabolic pathway impact analysis. The feasibility of using the combination of these three biomarkers for HAPE was evaluated, where the area under the receiver operating characteristic curve (AUC) was 0.981 and 0.942 in the discovery set and the validation set (22 HAPE subjects and 22 healthy controls), respectively. Taken together, these results suggested that this composite plasma metabolite signature may be used in HAPE diagnosis, especially after further investigation and verification with larger samples.

  8. Metabolomics for undergraduates: Identification and pathway assignment of mitochondrial metabolites.

    PubMed

    Marques, Ana Patrícia; Serralheiro, Maria Luisa; Ferreira, António E N; Freire, Ana Ponces; Cordeiro, Carlos; Silva, Marta Sousa

    2016-01-01

    Metabolomics is a key discipline in systems biology, together with genomics, transcriptomics, and proteomics. In this omics cascade, the metabolome represents the biochemical products that arise from cellular processes and is often regarded as the final response of a biological system to environmental or genetic changes. The overall screening approach to identify all the metabolites in a given biological system is called metabolic fingerprinting. Using high-resolution and high-mass accuracy mass spectrometry, large metabolome coverage, sensitivity, and specificity can be attained. Although the theoretical concepts of this methodology are usually provided in life-science programs, hands-on laboratory experiments are not usually accessible to undergraduate students. Even if the instruments are available, there are not simple laboratory protocols created specifically for teaching metabolomics. We designed a straightforward hands-on laboratory experiment to introduce students to this methodology, relating it to biochemical knowledge through metabolic pathway mapping of the identified metabolites. This study focuses on mitochondrial metabolomics since mitochondria have a well-known, medium-sized cellular sub-metabolome. These features facilitate both data processing and pathway mapping. In this experiment, students isolate mitochondria from potatoes, extract the metabolites, and analyze them by high-resolution mass spectrometry (using an FT-ICR mass spectrometer). The resulting mass list is submitted to an online program for metabolite identification, and compounds associated with mitochondrial pathways can be highlighted in a metabolic network map. PMID:26537432

  9. Genomic Analysis of Secondary Metabolite Production by Pseudomonas fluorescens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pseudomonas fluorescens is a diverse bacterial species known for its ubiquity in natural habitats and its production of secondary metabolites. The high degree of ecological and metabolic diversity represented in P. fluorescens is reflected in the genomic diversity displayed among strains. Certain st...

  10. Metabolite profiling in retinoblastoma identifies novel clinicopathological subgroups

    PubMed Central

    Kohe, Sarah; Brundler, Marie-Anne; Jenkinson, Helen; Parulekar, Manoj; Wilson, Martin; Peet, Andrew C; McConville, Carmel M

    2015-01-01

    Background: Tumour classification, based on histopathology or molecular pathology, is of value to predict tumour behaviour and to select appropriate treatment. In retinoblastoma, pathology information is not available at diagnosis and only exists for enucleated tumours. Alternative methods of tumour classification, using noninvasive techniques such as magnetic resonance spectroscopy, are urgently required to guide treatment decisions at the time of diagnosis. Methods: High-resolution magic-angle spinning magnetic resonance spectroscopy (HR-MAS MRS) was undertaken on enucleated retinoblastomas. Principal component analysis and cluster analysis of the HR-MAS MRS data was used to identify tumour subgroups. Individual metabolite concentrations were determined and were correlated with histopathological risk factors for each group. Results: Multivariate analysis identified three metabolic subgroups of retinoblastoma, with the most discriminatory metabolites being taurine, hypotaurine, total-choline and creatine. Metabolite concentrations correlated with specific histopathological features: taurine was correlated with differentiation, total-choline and phosphocholine with retrolaminar optic nerve invasion, and total lipids with necrosis. Conclusions: We have demonstrated that a metabolite-based classification of retinoblastoma can be obtained using ex vivo magnetic resonance spectroscopy, and that the subgroups identified correlate with histopathological features. This result justifies future studies to validate the clinical relevance of these subgroups and highlights the potential of in vivo MRS as a noninvasive diagnostic tool for retinoblastoma patient stratification. PMID:26348444

  11. Cytotoxic dibromotyrosine-derived metabolites from the sponge Aplysina gerardogreeni.

    PubMed

    Hernández-Guerrero, Claudia J; Zubía, Eva; Ortega, María J; Carballo, J Luis

    2007-08-01

    The chemical study of the sponge Aplysina gerardogreeni collected at the Gulf of California has led to the isolation of four new dibromotyrosine-derived metabolites, aplysinones A-D, whose structures were determined by spectroscopic analysis and chemical methods. The new compounds and four semisynthetic analogues prepared in this study have shown cytotoxic activity against human tumor cell lines. PMID:17512741

  12. INFLUENCE OF DIETARY ARSENIC ON URINARY ARSENIC METABOLITE EXCRETION

    EPA Science Inventory

    Influence of Dietary Arsenic on Urinary Arsenic Metabolite Excretion

    Cara L. Carty, M.S., Edward E. Hudgens, B.Sc., Rebecca L. Calderon, Ph.D., M.S.P.H., Richard Kwok, M.S.P.H., Epidemiology and Biomarkers Branch/HSD, NHEERL/US EPA; David J. Thomas, Ph.D., Pharmacokinetics...

  13. Genomics of Secondary Metabolite Production by Pseudomonas fluorescens Pf-5

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pseudomonas spp. are prolific producers of secondary metabolites, and the availability of genomic sequences now opens the door for discovery of novel natural products with potential roles in the ecology and plant growth promoting properties of these bacteria. The rhizosphere bacterium Pseudomonas f...

  14. Association between Metabolite Profiles, Metabolic Syndrome and Obesity Status

    PubMed Central

    Allam-Ndoul, Bénédicte; Guénard, Frédéric; Garneau, Véronique; Cormier, Hubert; Barbier, Olivier; Pérusse, Louis; Vohl, Marie-Claude

    2016-01-01

    Underlying mechanisms associated with the development of abnormal metabolic phenotypes among obese individuals are not yet clear. Our aim is to investigate differences in plasma metabolomics profiles between normal weight (NW) and overweight/obese (Ov/Ob) individuals, with or without metabolic syndrome (MetS). Mass spectrometry-based metabolite profiling was used to compare metabolite levels between each group. Three main principal components factors explaining a maximum of variance were retained. Factor 1’s (long chain glycerophospholipids) metabolite profile score was higher among Ov/Ob with MetS than among Ov/Ob and NW participants without MetS. This factor was positively correlated to plasma total cholesterol (total-C) and triglyceride levels in the three groups, to high density lipoprotein -cholesterol (HDL-C) among participants without MetS. Factor 2 (amino acids and short to long chain acylcarnitine) was positively correlated to HDL-C and negatively correlated with insulin levels among NW participants. Factor 3’s (medium chain acylcarnitines) metabolite profile scores were higher among NW participants than among Ov/Ob with or without MetS. Factor 3 was negatively associated with glucose levels among the Ov/Ob with MetS. Factor 1 seems to be associated with a deteriorated metabolic profile that corresponds to obesity, whereas Factors 2 and 3 seem to be rather associated with a healthy metabolic profile. PMID:27240400

  15. Metabolites identification of bioactive licorice compounds in rats.

    PubMed

    Wang, Qi; Qian, Yi; Wang, Qing; Yang, Yan-Fang; Ji, Shuai; Song, Wei; Qiao, Xue; Guo, De-An; Liang, Hong; Ye, Min

    2015-11-10

    Licorice (Glycyrrhiza uralensis Fisch.) is one of the most popular herbal medicines worldwide. This study aims to identify the metabolites of seven representative bioactive licorice compounds in rats. These compounds include 22β-acetoxyl glycyrrhizin (1), licoflavonol (2), licoricidin (3), licoisoflavanone (4), isoglycycoumarin (5), semilicoisoflavone B (6), and 3-methoxy-9-hydroxy-pterocarpan (7). After oral administration of 250mg/kg of 1 or 40mg/kg of 2-7 to rats, a total of 16, 43 and 31 metabolites were detected in the plasma, urine and fecal samples, respectively. The metabolites were characterized by HPLC/DAD/ESI-MS(n) and LC/IT-TOF-MS analyses. Particularly, two metabolites of 1 were unambiguously identified by comparing with reference standards, and 22β-acetoxyl glycyrrhizin-6″-methyl ester (1-M2) is a new compound. Compound 1 could be readily hydrolyzed to eliminate the glucuronic acid residue. The phenolic compounds (4-7) mainly undertook phase II metabolism (glucuronidation or sulfation). Most phenolic compounds with an isoprenyl group (chain or cyclized, 2-5) could also undertake hydroxylation reaction. This is the first study on in vivo metabolism of these licorice compounds. PMID:26311472

  16. Urinary concentrations of PAH and VOC metabolites in marijuana users

    PubMed Central

    Wei, Binnian; Alwis, K. Udeni; Li, Zheng; Wang, Lanqing; Valentin-Blasini, Liza; Sosnoff, Connie S.; Xia, Yang; Conway, Kevin P.; Blount, Benjamin C.

    2016-01-01

    Background Marijuana is seeing increased therapeutic use, and is the world’s third most-popular recreational drug following alcohol and tobacco. This widening use poses increased exposure to potentially toxic combustion by-products from marijuana smoke and the potential for public health concerns. Objectives To compare urinary metabolites of polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) among self-reported recent marijuana users and nonusers, while accounting for tobacco smoke exposure. Methods Measurements of PAH and VOC metabolites in urine samples were combined with questionnaire data collected from participants in the National Health and Nutrition Examination Surveys (NHANES) from 2005 to 2012 in order to categorize participants (≥18 years) into exclusive recent marijuana users and nonusers. Adjusted geometric means (GMs) of urinary concentrations were computed for these groups using multiple regression analyses to adjust for potential confounders. Results Adjusted GMs of many individual monohydroxy PAHs (OH-PAHs) were significantly higher in recent marijuana users than in nonusers (p < 0.05). Urinary thiocyanate (p < 0.001) and urinary concentrations of many VOC metabolites, including metabolites of acrylonitrile (p < 0.001) and acrylamide (p < 0.001), were significantly higher in recent marijuana users than in nonusers. Conclusions We found elevated levels of biomarkers for potentially harmful chemicals among self-identified, recent marijuana users compared with nonusers. These findings suggest that further studies are needed to evaluate the potential health risks to humans from the exposure to these agents when smoking marijuana. PMID:26690539

  17. Three plasma metabolite signatures for diagnosing high altitude pulmonary edema

    PubMed Central

    Guo, Li; Tan, Guangguo; Liu, Ping; Li, Huijie; Tang, Lulu; Huang, Lan; Ren, Qian

    2015-01-01

    High-altitude pulmonary edema (HAPE) is a potentially fatal condition, occurring at altitudes greater than 3,000 m and affecting rapidly ascending, non-acclimatized healthy individuals. However, the lack of biomarkers for this disease still constitutes a bottleneck in the clinical diagnosis. Here, ultra-high performance liquid chromatography coupled with Q-TOF mass spectrometry was applied to study plasma metabolite profiling from 57 HAPE and 57 control subjects. 14 differential plasma metabolites responsible for the discrimination between the two groups from discovery set (35 HAPE subjects and 35 healthy controls) were identified. Furthermore, 3 of the 14 metabolites (C8-ceramide, sphingosine and glutamine) were selected as candidate diagnostic biomarkers for HAPE using metabolic pathway impact analysis. The feasibility of using the combination of these three biomarkers for HAPE was evaluated, where the area under the receiver operating characteristic curve (AUC) was 0.981 and 0.942 in the discovery set and the validation set (22 HAPE subjects and 22 healthy controls), respectively. Taken together, these results suggested that this composite plasma metabolite signature may be used in HAPE diagnosis, especially after further investigation and verification with larger samples. PMID:26459926

  18. Synthesis of the alkylated active metabolite of tipidogrel.

    PubMed

    Zhi, Shuang; Xia, Guangping; Liu, Ying; Tao, Zunwei; Chen, Ligong; Liu, Dengke

    2015-04-15

    Tipidogrel (3), an effective anti-platelet drug candidate working by irreversibly inhibiting P2Y12 receptor, holds great promise in overcoming clopidogrel resistance and increasing bioavailability. As a prodrug like other thienopyridines, it metabolizes through thiophene ring opening to form active metabolites 3a and 3b, nevertheless they are easily to form disulfide bond. Derivatization of 3a and 3b via alkylation with MPBr can prevent disulfide conjugation and ensure reliable pharmacokinetic results. Thus, in order to support its pre-clinical studies on efficiencies in the formation of tipidogrel active metabolites, 13a and 13b were synthesized via seven steps of chemosynthesis and incubation with MPBr in rat plasma in vitro. The resulting crude productions were purified by semi-preparative HPLC to give Z configuration 13a and E configuration 13b. In LC-MS/MS spectra, they showed identical fragmentation pattern and retention time with M-13a and M-13b, the MPBr-derivatives of active metabolites of tipidogrel in rats. Thus, 13a and 13b were the anticipated alkylated active metabolite of tipidogrel. In addition, in the nucleophilic substitution of thioacetate with compound 11, besides the anticipated compounds 12a and 12b, their isomers compounds 12c and 12d were detected, whose structures were confirmed and the corresponding mechanism was presented. PMID:25801935

  19. Characterization of furanocoumarin metabolites in the parsnip webworm, Depressaria pastinacella

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although metabolites of furanocoumarins have been characterized in a wide range of organisms, to date they have been identified in only a single insect species, Papilio polyxenes. Depressaria pastinacella, the parsnip webworm, like P. polyxenes a specialist on Apiaceae, routinely consumes plant tis...

  20. Metabolism of a highly selective gelatinase inhibitor generates active metabolite.

    PubMed

    Lee, Mijoon; Villegas-Estrada, Adriel; Celenza, Giuseppe; Boggess, Bill; Toth, Marta; Kreitinger, Gloria; Forbes, Christopher; Fridman, Rafael; Mobashery, Shahriar; Chang, Mayland

    2007-11-01

    (4-Phenoxyphenylsulfonyl)methylthiirane (inhibitor 1) is a highly selective inhibitor of gelatinases (matrix metalloproteinases 2 and 9), which is showing considerable promise in animal models for cancer and stroke. Despite demonstrated potent, selective, and effective inhibition of gelatinases both in vitro and in vivo, the compound is rapidly metabolized, implying that the likely activity in vivo is due to a metabolite rather than the compound itself. To this end, metabolism of inhibitor 1 was investigated in in vitro systems. Four metabolites were identified by LC/MS-MS and the structures of three of them were further validated by comparison with authentic synthetic samples. One metabolite, 4-(4-thiiranylmethanesulfonylphenoxy)phenol (compound 21), was generated by hydroxylation of the terminal phenyl group of 1. This compound was investigated in kinetics of inhibition of several matrix metalloproteinases. This metabolite was a more potent slow-binding inhibitor of gelatinases (matrix metalloproteinase-2 and matrix metalloproteinase-9) than the parent compound 1, but it also served as a slow-binding inhibitor of matrix metalloproteinase-14, the upstream activator of matrix metalloproteinase-2. PMID:17927722

  1. Chemotyping the distribution of vitamin D metabolites in human serum

    NASA Astrophysics Data System (ADS)

    Müller, Miriam J.; Stokes, Caroline S.; Lammert, Frank; Volmer, Dietrich A.

    2016-02-01

    Most studies examining the relationships between vitamin D and disease or health focus on the main 25-hydroxyvitamin D3 (25(OH)D3) metabolite, thus potentially overlooking contributions and dynamic effects of other vitamin D metabolites, the crucial roles of several of which have been previously demonstrated. The ideal assay would determine all relevant high and low-abundant vitamin D species simultaneously. We describe a sensitive quantitative assay for determining the chemotypes of vitamin D metabolites from serum after derivatisation and ultra-high performance liquid chromatography-electrospray ionisation-tandem mass spectrometry (UHPLC-ESI-MS/MS). We performed a validation according to the ‘FDA Guidance for Industry Bioanalytical Method Validation’. The proof-of-concept of the method was then demonstrated by following the metabolite concentrations in patients with chronic liver diseases (CLD) during the course of a vitamin D supplementation study. The new quantitative profiling assay provided highly sensitive, precise and accurate chemotypes of the vitamin D metabolic process rather than the usually determined 25(OH)D3 concentrations.

  2. Childhood Psychosis and Monoamine Metabolites in Spinal Fluid.

    ERIC Educational Resources Information Center

    Gillberg, Christopher; And Others

    1983-01-01

    Analysis of cerebrospinal fluid of 22 psychotic children, 22 normal controls, and Ss with mental retardation, progressive encephalopathy, or meningitis revealed that psychotic Ss had raised levels of homovanillic acid. Thirteen Ss diagnosed as autistic showed isolated inrease of this metabolite. Increased concentration of mongamines was not…

  3. Effects of progesterone and its metabolites on human granulosa cells.

    PubMed

    Pietrowski, D; Gong, Y; Mairhofer, M; Gessele, R; Sator, M

    2014-02-01

    The corpus luteum (CL) is under control of gonadotrophic hormones and produces progesterone, which is necessary for endometrial receptivity. Recent studies have shown that progesterone and its metabolites are involved in cell proliferation and apoptosis of cancer cells. Here weanalyzed the role of progesterone and its meta-bolites on luteinized granulosa cells (LGC) by FACS analysis and quantitative Real-Time PCR. We detected the mRNA of the progesterone metabolizing genes SRD5A1, AKR1C1, and AKR1C2 in LGC. The stimulation of LGC with progesterone or progesterone metabolites did not show any effect on the mRNA expression of these genes. However, a downregulation of Fas expression was found to be accomplished by progesterone and human chorionic gonadotropin. Our findings do not support the concept of an effect of progesterone metabolites on LGCs. However, it suggests an antiapoptotic effect of hCG and progesterone during corpus luteum development by downregulation of Fas. PMID:24136781

  4. Another Reason to Thank Mom: Gestational Effects of Microbiota Metabolites.

    PubMed

    Rakoff-Nahoum, Seth

    2016-04-13

    Microbial colonization after birth profoundly affects development of the host. In a recent paper, Gomez de Agüero et al. (2016) reveal a new aspect of ontogeny influenced by the microbiota: the impact of gestational gut bacterial metabolites on early immune maturation of the neonatal intestine. PMID:27078061

  5. Electrophilicities and Protein Covalent Binding of Demethylation Metabolites of Colchicine.

    PubMed

    Guo, Xiucai; Lin, Dongju; Li, Weiwei; Wang, Kai; Peng, Ying; Zheng, Jiang

    2016-03-21

    Colchicine, an alkaloid existing in plants of Liliaceous colchicum, has been widely used in the treatment of gout and familial Mediterranean fever. The administration of colchicine was found to cause liver injury in humans. The mechanisms of colchicine-induced liver toxicity remain unknown. The objectives of this study were to determine the electrophilicities of demethylation metabolites of colchicine and investigate the protein adductions derived from the reactive metabolites of colchicine. Four demethylated colchicine (1-, 2-, 3-, and 10-DMCs), namely, M1-M4, were detected in colchicine-fortified microsomal incubations. Four N-acetyl cysteine (NAC) conjugates (M5-M8) derived from colchicine were detected in the microsomes in the presence of NAC. M5 and M6 were derived from 10-DMC. M7 resulted from the reaction of 2-DMC or 3-DMC with NAC, and M8 originated from 10-DMC. Microsomal protein covalent binding was observed after exposure to colchicine. Two cysteine adducts (CA-1 and CA-2) derived from 10-DMC were found in proteolytically digested microsomal protein samples after incubation with colchicine. The findings allow us to define the chemical property of demethylation metabolites of colchicine and the interaction between protein and the reactive metabolites of colchicine generated in situ. PMID:26845511

  6. DEVELOPMENTAL TOXICITY OF ATRAZINE METABOLITES IN FISCHER 344 RATS

    EPA Science Inventory

    Previously we have shown that atrazine, a commonly used herbicide, causes full-litter resorption (FLR) in Fischer 344 rats at 50 mg/kg. In this study, we tested four atrazine metabolites for their potential to cause FLR and developmental toxicity. Desethylatrazine (DEA), desis...

  7. The Metabolite Transporters of the Plastid Envelope: An Update

    PubMed Central

    Facchinelli, Fabio; Weber, Andreas P. M.

    2011-01-01

    The engulfment of a photoautotrophic cyanobacterium by a primitive mitochondria-bearing eukaryote traces back to more than 1.2 billion years ago. This single endosymbiotic event not only provided the early petroalgae with the metabolic capacity to perform oxygenic photosynthesis, but also introduced a plethora of other metabolic routes ranging from fatty acids and amino acids biosynthesis, nitrogen and sulfur assimilation to secondary compounds synthesis. This implicated the integration and coordination of the newly acquired metabolic entity with the host metabolism. The interface between the host cytosol and the plastidic stroma became of crucial importance in sorting precursors and products between the plastid and other cellular compartments. The plastid envelope membranes fulfill different tasks: they perform important metabolic functions, as they are involved in the synthesis of carotenoids, chlorophylls, and galactolipids. In addition, since most genes of cyanobacterial origin have been transferred to the nucleus, plastidial proteins encoded by nuclear genes are post-translationally transported across the envelopes through the TIC–TOC import machinery. Most importantly, chloroplasts supply the photoautotrophic cell with photosynthates in form of reduced carbon. The innermost bilayer of the plastidic envelope represents the permeability barrier for the metabolites involved in the carbon cycle and is literally stuffed with transporter proteins facilitating their transfer. The intracellular metabolite transporters consist of polytopic proteins containing membrane spans usually in the number of four or more α-helices. Phylogenetic analyses revealed that connecting the plastid with the host metabolism was mainly a process driven by the host cell. In Arabidopsis, 58% of the metabolite transporters are of host origin, whereas only 12% are attributable to the cyanobacterial endosymbiont. This review focuses on the metabolite transporters of the inner envelope

  8. Role of aniline metabolites in aniline-induced hemolytic anemia.

    PubMed

    Harrison, J H; Jollow, D J

    1986-09-01

    Hemolytic anemia after aniline and aniline-related drugs such as dapsone and primaquine is thought to be mediated by active/reactive metabolite(s) formed during the hepatic clearance of the parent compounds. To determine whether any of the known metabolites of aniline contribute to the hemolytic response seen in rats given aniline, rats were infused with isologous 51Cr-labeled erythrocytes 24 hr before administration of aniline or aniline metabolites. The time course of blood radioactivity was followed in individual rats by serial sampling from the orbital sinus and the time required for blood radioactivity to fall by 50% (T50Cr) was used as a measure of in vivo erythrocyte survival. Aniline HCl produced a dose-dependent reduction in the T50Cr. Acetanilide also reduced the T50Cr, but was less potent than aniline. Aminophenols (2-, 3- and 4-) in similar doses did not significantly alter the T50Cr. In contrast, phenylhydroxylamine produced a dose-dependent decrease in the T50Cr with approximately 10 times the potency of aniline. The T50Cr was also decreased in a concentration-dependent manner for labeled erythrocytes incubated in vitro with phenylhydroxylamine, then readministered to rats, indicating a direct toxic effect of phenylhydroxylamine on erythrocytes. In addition, the area under the blood time course curve for phenylhydroxylamine plus nitrosobenzene was equivalent in rats administered equitoxic doses of aniline or phenylhydroxylamine, indicating that sufficient phenylhydroxylamine is formed in vivo during aniline clearance to account for aniline's toxicity. These results suggest that phenylhydroxylamine is the active metabolite that mediates aniline-induced hemolytic anemia. PMID:3746658

  9. Cerebrospinal Fluid Levels of Monoamine Metabolites in the Epileptic Baboon

    PubMed Central

    Szabó, C. Ákos; Patel, Mayuri; Uteshev, Victor V.

    2016-01-01

    The baboon represents a natural model for genetic generalized epilepsy and sudden unexpected death in epilepsy (SUDEP). In this retrospective study, cerebrospinal fluid (CSF) monoamine metabolites and scalp electroencephalography (EEG) were evaluated in 263 baboons of a pedigreed colony. CSF monoamine abnormalities have been linked to reduced seizure thresholds, behavioral abnormalities and SUDEP in various animal models of epilepsy. The levels of 3-hydroxy-4-methoxyphenylglycol, 5-hydroxyindolacetic acid and homovanillic acid in CSF samples drawn from the cisterna magna were analyzed using high-performance liquid chromatography. These levels were compared between baboons with seizures (SZ), craniofacial trauma (CFT) and asymptomatic, control (CTL) baboons, between baboons with abnormal and normal EEG studies. We hypothesized that the CSF levels of major monoaminergic metabolites (i.e., dopamine, serotonin and norepinephrine) associate with the baboons’ electroclinical status and thus can be used as clinical biomarkers applicable to seizures/epilepsy. However, despite apparent differences in metabolite levels between the groups, usually lower in SZ and CFT baboons and in baboons with abnormal EEG studies, we did not find any statistically significant differences using a logistic regression analysis. Significant correlations between the metabolite levels, especially between 5-HIAA and HVA, were preserved in all electroclinical groups. While we were not able to demonstrate significant differences in monoamine metabolites in relation to seizures or EEG markers of epilepsy, we cannot exclude the monoaminergic system as a potential source of pathogenesis in epilepsy and SUDEP. A prospective study evaluating serial CSF monoamine levels in baboons with recently witnessed seizures, and evaluation of abnormal expression and function of monoaminergic receptors and transporters within epilepsy-related brain regions, may impact the electroclinical status. PMID:26924854

  10. A survey of phytotoxic microbial and plant metabolites as potential natural products for pest management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytotoxic microbial metabolites produced by certain phytopathogenic fungi and bacteria and a group of a phytotoxic plant metabolites including Amayllidaceae alkaloids and some derivatives of these compounds were evaluated for algicide, bactericide, insecticide, fungicide, and herbicide activities i...

  11. A Review of Cyanobacterial Odorous and Bioactive Metabolites: Impacts and Management Alternatives in Aquaculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An increased demand has pushed extensive aquaculture towards intensively operated production systems, commonly resulting in eutrophic conditions and cyanobacterial blooms. This review summarizes cyanobacterial secondary metabolites that can cause undesirable tastes and odors (odorous metabolites) o...

  12. Evaluation of aspirin metabolites as inhibitors of hypoxia-inducible factor hydroxylases.

    PubMed

    Lienard, Benoit M; Conejo-García, Ana; Stolze, Ineke; Loenarz, Christoph; Oldham, Neil J; Ratcliffe, Peter J; Schofield, Christopher J

    2008-12-21

    Known and potential aspirin metabolites were evaluated as inhibitors of oxygen-sensing hypoxia-inducible transcription factor (HIF) hydroxylases; some of the metabolites were found to stabilise HIF-alpha in cells. PMID:19048166

  13. Assessing the accuracy of software predictions of mammalian and microbial metabolites

    EPA Science Inventory

    New chemical development and hazard assessments benefit from accurate predictions of mammalian and microbial metabolites. Fourteen biotransformation libraries encoded in eight software packages that predict metabolite structures were assessed for their sensitivity (proportion of ...

  14. Novel rapid liquid chromatography tandem masspectrometry method for vemurafenib and metabolites in human plasma, including metabolite concentrations at steady state.

    PubMed

    Vikingsson, Svante; Strömqvist, Malin; Svedberg, Anna; Hansson, Johan; Höiom, Veronica; Gréen, Henrik

    2016-08-01

    A novel, rapid and sensitive liquid chromatography tandem-mass spectrometry method for quantification of vemurafenib in human plasma, that also for the first time allows for metabolite semi-quantification, was developed and validated to support clinical trials and therapeutic drug monitoring. Vemurafenib was analysed by precipitation with methanol followed by a 1.9 min isocratic liquid chromatography tandem masspectrometry analysis using an Acquity BEH C18 column with methanol and formic acid using isotope labelled internal standards. Analytes were detected in multireaction monitoring mode on a Xevo TQ. Semi-quantification of vemurafenib metabolites was performed using the same analytical system and sample preparation with gradient elution. The vemurafenib method was successfully validated in the range 0.5-100 μg/mL according to international guidelines. The metabolite method was partially validated owing to the lack of commercially available reference materials. For the first time concentration levels at steady state for melanoma patients treated with vemurafenib is presented. The low abundance of vemurafenib metabolites suggests that they lack clinical significance. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26683023

  15. High-resolution mass spectrometry elucidates metabonate (false metabolite) formation from alkylamine drugs during in vitro metabolite profiling.

    PubMed

    Barbara, Joanna E; Kazmi, Faraz; Muranjan, Seema; Toren, Paul C; Parkinson, Andrew

    2012-10-01

    In vitro metabolite profiling and characterization experiments are widely employed in early drug development to support safety studies. Samples from incubations of investigational drugs with liver microsomes or hepatocytes are commonly analyzed by liquid chromatography/mass spectrometry for detection and structural elucidation of metabolites. Advanced mass spectrometers with accurate mass capabilities are becoming increasingly popular for characterization of drugs and metabolites, spurring changes in the routine workflows applied. In the present study, using a generic full-scan high-resolution data acquisition approach with a time-of-flight mass spectrometer combined with postacquisition data mining, we detected and characterized metabonates (false metabolites) in microsomal incubations of several alkylamine drugs. If a targeted approach to mass spectrometric detection (without full-scan acquisition and appropriate data mining) were employed, the metabonates may not have been detected, hence their formation underappreciated. In the absence of accurate mass data, the metabonate formation would have been incorrectly characterized because the detected metabonates manifested as direct cyanide-trapped conjugates or as cyanide-trapped metabolites formed from the parent drugs by the addition of 14 Da, the mass shift commonly associated with oxidation to yield a carbonyl. This study demonstrates that high-resolution mass spectrometry and the associated workflow is very useful for the detection and characterization of unpredicted sample components and that accurate mass data were critical to assignment of the correct metabonate structures. In addition, for drugs containing an alkylamine moiety, the results suggest that multiple negative controls and chemical trapping agents may be necessary to correctly interpret the results of in vitro experiments. PMID:22798552

  16. Characterizing protein modifications by reactive metabolites using magnetic bead bioreactors and LC-MS/MS.

    PubMed

    Li, Dandan; Fu, You-Jun; Rusling, James F

    2015-03-18

    We report here label-free metabolite-protein adduct detection and identification employing magnetic beads coated with metabolic enzymes as bioreactors to generate metabolites and possible metabolite-protein adducts for analysis by liquid chromatography-tandem mass spectrometry. PMID:25693065

  17. Novel correlations between microbial taxa and amino acid metabolites in mouse cecal contents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gut microbes share a bi-directional relationship with thousands of metabolites in their environment. Many of these microbes and metabolites are associated with human diseases including obesity, cancer, and inflammatory diseases. Further understanding of how microbes affect metabolite concentration i...

  18. 10 CFR 26.133 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Cutoff levels for drugs and drug metabolites. 26.133... § 26.133 Cutoff levels for drugs and drug metabolites. Subject to the provisions of § 26.31(d)(3)(iii), licensees and other entities may specify more stringent cutoff levels for drugs and drug metabolites...

  19. 10 CFR 26.133 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Cutoff levels for drugs and drug metabolites. 26.133... § 26.133 Cutoff levels for drugs and drug metabolites. Subject to the provisions of § 26.31(d)(3)(iii), licensees and other entities may specify more stringent cutoff levels for drugs and drug metabolites...

  20. Characterizing Protein Modifications by Reactive Metabolites using Magnetic Bead Bioreactors and LC-MS/MS

    PubMed Central

    Li, Dandan; Fu, You-Jun; Rusling, James F.

    2015-01-01

    We report here label-free metabolite-protein adduct detection and identification employing magnetic beads coated with metabolic enzymes as bioreactors to generate metabolites and possible metabolite-protein adducts for analysis by liquid chromatography-tandem mass spectrometry. PMID:25693065

  1. 21 CFR 862.3250 - Cocaine and cocaine metabolite test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cocaine and cocaine metabolite test system. 862... Test Systems § 862.3250 Cocaine and cocaine metabolite test system. (a) Identification. A cocaine and cocaine metabolite test system is a device intended to measure cocaine and a cocaine...

  2. 21 CFR 862.3250 - Cocaine and cocaine metabolite test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cocaine and cocaine metabolite test system. 862... Test Systems § 862.3250 Cocaine and cocaine metabolite test system. (a) Identification. A cocaine and cocaine metabolite test system is a device intended to measure cocaine and a cocaine...

  3. 21 CFR 862.3250 - Cocaine and cocaine metabolite test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cocaine and cocaine metabolite test system. 862... Test Systems § 862.3250 Cocaine and cocaine metabolite test system. (a) Identification. A cocaine and cocaine metabolite test system is a device intended to measure cocaine and a cocaine...

  4. 21 CFR 862.3250 - Cocaine and cocaine metabolite test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cocaine and cocaine metabolite test system. 862... Test Systems § 862.3250 Cocaine and cocaine metabolite test system. (a) Identification. A cocaine and cocaine metabolite test system is a device intended to measure cocaine and a cocaine...

  5. 10 CFR 26.133 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Cutoff levels for drugs and drug metabolites. 26.133... § 26.133 Cutoff levels for drugs and drug metabolites. Subject to the provisions of § 26.31(d)(3)(iii), licensees and other entities may specify more stringent cutoff levels for drugs and drug metabolites...

  6. 10 CFR 26.133 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Cutoff levels for drugs and drug metabolites. 26.133... § 26.133 Cutoff levels for drugs and drug metabolites. Subject to the provisions of § 26.31(d)(3)(iii), licensees and other entities may specify more stringent cutoff levels for drugs and drug metabolites...

  7. 10 CFR 26.133 - Cutoff levels for drugs and drug metabolites.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Cutoff levels for drugs and drug metabolites. 26.133... § 26.133 Cutoff levels for drugs and drug metabolites. Subject to the provisions of § 26.31(d)(3)(iii), licensees and other entities may specify more stringent cutoff levels for drugs and drug metabolites...

  8. Absorption properties of micellar lipid metabolites into Caco2 cells.

    PubMed

    Tsuzuki, Wakako

    2007-07-01

    To elucidate the absorption characteristics of dietary lipids in the human intestine, we investigated the cellular uptake of lipid metabolites using a differential monolayer of the Caco2 cells. As lipid metabolites, several free fatty acids and 2-monoacylglycerols, were formed a mixed micelle by bile salts and lysophospholipids and they were supplied to the Caco2 cells. To estimate the effect of the mixed micelles on the permeability of cells' membranes during incubation with the mixed micelles, the transepitherial electrical resistance (TEER) value was monitored, and no pronounced changes of TEER was detected. This suggested that mixed micelles did not affect their cellular properties of the barrier measured by TEER. The lipid metabolites transferred from the mixed micelle into the Caco2 cells were determined quantitatively by an enzymatic colorimetric method and were done by thin layer chromatography (TLC) for a species of acylglycerols. These highly sensitive methods enabled us to monitor the transepithelial transports of various kinds of non-isotope-labeled various lipid metabolites. Newly re-synthesized triacylglycerols were accumulated in Caco2 cells after 30 min incubation with the mixed micelles, and their amounts increased gradually for 4 h. The secretion of re-esterified triacylglycerols into a basolateral medium from the Caco2 cells began at 2 h after the mixed micelles were added to the apical medium. The intake of external lipid metabolites by the Caco2 cells were evaluated by an initial 2-h incubation with the mixed micelles. For example, 2-monomyristin and 2-monopalmitin were more rapidly transferred into the Caco2 cells from the mixed micelles than 2-monocaprin was. On the other hand, the absorption rates of capric acid, lauric acid and myristic acid by the cells were larger than those of stearic acid and oleic acid. It revealed that the side-chain structure of these lipid metabolites affected their absorption by the Caco2 cells. The results of this

  9. Electrochemical generation of selegiline metabolites coupled to mass spectrometry.

    PubMed

    Mielczarek, Przemyslaw; Smoluch, Marek; Kotlinska, Jolanta H; Labuz, Krzysztof; Gotszalk, Teodor; Babij, Michal; Suder, Piotr; Silberring, Jerzy

    2015-04-10

    The metabolic pathways of selegiline (a drug used for the treatment of early-stage Parkinson's disease) were analyzed by electrochemical oxidation with application of the flow electrochemical cell consisting of three electrodes (ROXY™, Antec, the Netherlands). Two types of working electrodes were applied: glassy carbon (GC) and boron-doped diamond (BDD). The potential applied at working electrode and composition of the solvent were optimized for the best conditions for oxidation and identification processes. All products were directly analyzed on-line by mass spectrometry. For further characterization of electrochemical oxidation products, the novel approach involving reversed phase chromatography linked to mass spectrometry with dielectric barrier discharge ionization (DBDI-MS) was used. In this manuscript, we report a novel technique for simulation of drug metabolism by electrochemical system (EC) connected to liquid chromatography (LC) and dielectric barrier discharge ionization (DBDI) mass spectrometry (MS) for direct on-line detection of electrochemical oxidation products. Here, we linked LC/DBDI-MS system with an electrochemical flow cell in order to study metabolic pathways via identification of drug metabolites generated electrochemically. The DBDI source has never been used before for identification of psychoactive metabolites generated in an electrochemical flow cell. Our knowledge on the biological background of xenobiotics metabolism and its influence on human body is constantly increasing, but still many mechanisms are not explained. Nowadays, metabolism of pharmaceuticals is mainly studied using liver cells prepared from animals or humans. Cytochrome P450, present in microsomes, is primarily responsible for oxidative metabolism of xenobiotics. It was also shown, that breakdown of popular medicines may be successfully simulated by electrochemistry under appropriate conditions. The presented experiments allow for comparison of these two entirely

  10. Identification of catechol and hydroquinone metabolites of 4-monochlorobiphenyl.

    PubMed

    McLean, M R; Bauer, U; Amaro, A R; Robertson, L W

    1996-01-01

    Polychlorinated biphenyls (PCBs) may be metabolically activated to electrophiles, which bind to proteins and nucleic acids. One activation scheme involves the formation of reactive arene oxide intermediates during cytochrome P450-catalyzed hydroxylation. We propose a second activation pathway whereby PCB catechol and hydroquinone metabolites may be oxidized to reactive semiquinones and/or quinones. By employing 4-monochlorobiphenyl (4-MCB) as a model substrate and liver microsomes from rats treated with phenobarbital and 3-methyl-cholanthrene, five monol and three diol metabolites were identified. The major metabolite was 4-chloro-4'-monohydroxybiphenyl, followed by, in decreasing order, 4-chloro-3',4'-dihydroxybiphenyl, unknown B (a monol), 4-chloro-2',3'-dihydroxybiphenyl, 4-chloro-3'-hydroxybiphenyl, 4-chloro-2',5'-dihydroxybiphenyl, unknown A (a monol), and 4-chloro-2'-monohydroxybiphenyl. A trace of a dihydrodiol was detected by GC/MS. To elucidate the source of the diols, 4-MCB and the synthetic monol metabolites 4-chloro-2'-/-3'-/-4'-monohydroxybiphenyls were each employed as substrates in incubations with microsomes from rats treated with phenobarbital, 3-methylcholanthrene, or both inducers. The three diol metabolites were all produced from 4-MCB in incubations with microsomes from 3-methylcholanthrene-treated rats, but incubations with microsomes from phenobarbital-treated rats did not yield detectable amounts of 4-chloro-2',3'-dihydroxybiphenyl. 4-Chloro-2',3'-dihydroxybiphenyl was only found as a product of 4-chloro-2'-monohydroxybiphenyl. The 4-chloro-2',5'-dihydroxybiphenyl was found in extracts of incubations with 4-chloro-2'- and -3'-monohydroxybiphenyls, while the 4-chloro-3',4'-dihydroxybiphenyl was the only product found from 4-chloro-3'- and -4'-monohydroxybiphenyls. No other chlorinated diols were detected by GC/MS. These data suggest that the major route of biosynthesis of the diols was via a second hydroxylation step and not aromatization of