Search results for "Metabolite"
showing 10 items of 551 documents
Real time monitoring of the metabolic capacity of ex-vivo rat olfactory mucosa by on-line PTR-MS
2016
Real time monitoring of the metabolic capacity of ex-vivo rat olfactory mucosa by on-line PTR-MS. Congrès français de Spectrométrie de Masse et d'Analyse Protéomique (SMAP 2015)
Does the lingual film intervene in the perception of taste?
2017
International audience; The biological film at the surface of the tongue, composed of saliva and microorganims, is an important interface between exogenous taste molecules and receptors involved in taste perception. However, the relationships between the composition of the lingual film and the perception of taste are not fully described. Thus, the aim of the present work was to study the differences in the biochemical (protein concentration, metabolite profiles) and microbiological compositions of the tongue films from 20 adult subjects, and to explore the possible relationships between composition and taste sensitivity assessed by means of a rapid at-home test. Preliminary results showed t…
Regulation of the synthesis of aryl metabolites by phospholipid sources in the white-rot fungus Bjerkandera adusta
1999
The white-rot basidiomycete Bjerkandera adusta was cultivated in a liquid medium enriched with l-phenylalanine and various phospholipid sources (lecithin, egg yolk and asolectin). Three aromatic metabolites (benzaldehyde, benzyl alcohol and benzoic acid) were produced under these culture conditions. High concentrations of benzaldehyde (404 mg l–1) were obtained when the cultures were supplemented with 10 g lecithin l–1. Benzyl alcohol production was promoted when the strain was grown with 5 or 10 g lecithin l–1. In the absence of or with a low concentration of lecithin (2.5 g l–1), benzoic acid was the major aryl metabolite synthesized. The results presented here indicate that aryl alcohol …
Metabolic Profiling of Glucose-Fed Metabolically Active Resting Zymomonas mobilis Strains
2020
Zymomonas mobilis is the most efficient bacterial ethanol producer and its physiology is potentially applicable to industrial-scale bioethanol production. However, compared to other industrially important microorganisms, the Z. mobilis metabolome and adaptation to various nutritional and genetic perturbations have been poorly characterized. For rational metabolic engineering, it is essential to understand how central metabolism and intracellular redox balance are maintained in Z. mobilis under various conditions. In this study, we applied quantitative mass spectrometry-based metabolomics to explore how glucose-fed non-growing Z. mobilis Zm6 cells metabolically adapt to change of oxygen avai…
Bioconcentration and metabolism of 3,4-dichloroaniline in different life stages of guppy and zebrafish
1993
Abstract Bioconcentration factors (BCF) and metabolism of 3,4-dichloroaniline in different life stages of guppy (Poecilia reticulata Peters ) and zebrafish (Brachydanio rerio Hamilton-Buchanan ) were investigated. The results prove that embryos of zebrafish, four-day-old yolk sac larvae, 17-day-old larvae and adult zebrafish are able to transform the chemical to 3,4-dichloroacetanilide. Bioconcentration factors in these life stages are between 30 and 42, exept yolk sac larvae showing a BCF of 86. 3,4-Dichloroacetanilide was also detected in extracts of newborn and adult guppies, but they are able to form an additional, yet unknown metabolite. The BCF varies from 34 in six-month-old guppies …
Field-Grown and In Vitro Propagated Round-Leaved Sundew (Drosera rotundifolia L.) Show Differences in Metabolic Profiles and Biological Activities
2021
Drosera rotundifolia L. is a carnivorous plant used in traditional medicine for its therapeutic properties. Because of its small size, its collection in nature is laborious and different cultivation methods have been studied to ensure availability. However, only a few studies exist where the lab-grown sundew tissue and field-grown sundew would have been compared in their functionality or metabolic profiles. In this study, the antioxidant and antiviral activities of lab-grown and field-grown sundew extracts and their metabolic profiles are examined. The effect of drying methods on the chromatographic profile of the extracts is also shown. Antioxidant activity was significantly higher (5–6 ti…
Promoter Activation in Dhfq Mutants as an Efficient Tool for Specialized Metabolite Production Enabling Direct Bioactivity Testing
2019
Abstract Natural products (NPs) from microorganisms have been important sources for discovering new therapeutic and chemical entities. While their corresponding biosynthetic gene clusters (BGCs) can be easily identified by gene‐sequence‐similarity‐based bioinformatics strategies, the actual access to these NPs for structure elucidation and bioactivity testing remains difficult. Deletion of the gene encoding the RNA chaperone, Hfq, results in strains losing the production of most NPs. By exchanging the native promoter of a desired BGC against an inducible promoter in Δhfq mutants, almost exclusive production of the corresponding NP from the targeted BGC in Photorhabdus, Xenorhabdus and Pseud…
Deoxycholic Acid Methyl Ester — a Novel Bacterial Metabolite of Cholic Acid
1985
Summary Methyl deoxycholate was identified as a novel bacterial metabolite of cholate, produced anaerobically by strains of most saccharolytic Bacteroides species ( B. distasonis, B. eggerthii, B. fragilis, B. incommunis, B. thetaiotaomicron, B. uniformis, B. variabilis, B. vulgatus , and unnamed species). It was also detected with a few strains of Eubacterium and Lactobacillus species. Among 2476 freshly isolated human fecal cultures the frequency of carboxyl group esterification was comparable with that of 7α-dehydroxylation (92 versus 102 cultures). Both activities were, however, lost for unknown reasons after serial transfers. Two of ten mixed fecal cultures tested esterified 3α,7α- or …
Phenobarbital Induction of UDP-glucosyltransferase Activity in Drosophila melanogaster Meigen
2000
The inducibility of UDP-glucosyltransferase activities towards the exogenous substrates 1-naphthol and 2-naphthol and the endogenous metabolite xanthurenic acid was demonstrated in Drosophila melanogaster Meigen larvae and adults using phenobarbital as an inducer. In adults, a 3.5-fold increase of glucosyltransferase activity toward xanthurenic acid and a 2.0-fold increase of the activity toward exogenous substrates (1-naphthol and 2-naphthol) was found. In larvae, maximum induction of all three UDP-glucosyltransferase activities (2.5-fold and 1.5-fold increase of the activity toward the exogenous and endogenous substrates, respectively) was achieved when insects, reared on solid medium, we…
Release of Inflammatory Mediators (PGE2, IL-6) by Fenofibric Acid-Photosensitized Human Keratinocytes and Fibroblasts
1998
Ultraviolet-A radiation has weak effects on the release of inflammatory mediators by skin cells due to the poor overlap between UVA wavelengths and the absorption spectra of the relevant chromophores of key biomole-cules. However, this situation could be very different in the presence of a photosensitizing drug. To investigate this issue, we have irradiated human skin cells (keratinocytes and fibroblasts) in the presence of fenofibric acid (the active phototoxic metabolite of fenofibrate). The results of this research show a dual effect on the production/release of inflammatory mediators: the synthesis of the proinflammatory cytokine interleukin-6 becomes strongly inhibited at photosensitiz…