Search results for "metabolite"
showing 10 items of 551 documents
Natural oxygenation of Champagne wine during ageing on lees: A metabolomics picture of hormesis
2016
International audience; The oxygenation of Champagne wine after 4 and 6 years of aging on lees in bottle was investigated by FTICR-MS and UPLC-Q-TOF-MS. Three levels of permeability were considered for the stoppers, ranging from 0.2 to 1.8 mg/L/year of oxygen transfer rate. Our results confirmed a good repeatability of ultrahigh resolution FTICR-MS, both in terms of m/z and coefficient of variation of peak intensities among biological replicates. Vintages appeared to be the most discriminated features, and metabolite annotations suggested that the oldest wines (2006) were characterized by a higher sensitivity towards oxygenation. Within each vintage, the oxygenation mechanisms appeared to b…
Phenolic metabolites from 5,000-year-old coprolites of Myotragus balearicus, an extinct insular bovid
2020
Abstract To date, the identification of polyphenols in the archaeological and palaeontological record has been limited. Here, we demonstrate for the first time the presence of flavonoid and phenolic metabolites from non-mineralised coprolites belonging to a non-human mammal species. Myotragus balearicus is the last species of a bovid lineage that became extinct during the Holocene in the western Mediterranean basin. In this work, we characterize the phenolic metabolites of M. balearicus coprolites for the first time. The chemical analysis of coprolites revealed the presence of flavonoids, such as flavones and flavonols. Moreover, the detection of conjugates of hydroxyphenylvaleric, hydroxyp…
Alpha-(13′-hydroxy)-6-hydroxychroman, the main product of alpha-tocopherol metabolism in human hepatocytes, regulates CYP4F2 and PPAR-γ expression
2017
The enzymatic metabolism of vitamin E in liver cells generates long chain metabolites (LCMs) with proposed regulatory activity on inflammatory and atherogenic genes. In this study the LCM formation kinetics was characterized in HepG2 and HepaRG human hepatic cells, supplemented with RRR-α-tocopherol (α-TOH). α-13’OH was the main product of α-TOH metabolism, while α-13’COOH metabolite and the short chain metabolite α-CEHC, were detected only in traces, thus demonstrating the poor efficiency of vitamin E catabolism in these cells. However, this metabolism was significantly simulated when the hepatic cells were challenged with (lipo)toxic agents, such as ethanol or palmitate. Under such condit…
SF002-96-1, a new drimane sesquiterpene lactone from an Aspergillus species, inhibits survivin expression
2013
Survivin, a member of the IAP (inhibitor of apoptosis) gene family, is overexpressed in virtually all human cancers and is functionally involved in the inhibition of apoptosis, regulation of cell proliferation, metastasis and resistance to therapy. Because of its upregulation in malignancy, survivin has currently attracting considerable interest as a new target for anticancer therapy. In a screening of approximately 200 strains of imperfect fungi for the production of inhibitors of survivin promoter activity, a new drimane sesquiterpene lactone, SF002-96-1, was isolated from fermentations of an Aspergillus species. The compound inhibited survivin promoter activity in transiently transfected…
Complex Metabolic Activation Pathways of Polycyclic Aromatic Hydrocarbons: 3-Hydroxy-trans-7,8-Dihydroxy-7,8-Dihydrobenzo[a]Pyrene as a Proximate Mut…
1988
3-Hydroxybenzo[a]pyrene (3-OH-BP) is a major metabolite of benzo[a]pyrene (BP) in various systems. Metabolites of 3-OH-BP, formed by liver enzymes, bind to DNA1,2 and are mutagenic3,4. However, the active species have not yet been identified. Administration of 3-OH-BP to rats results in the excretion of sulfate and glucuronic acid conjugates of 3-hydroxy-trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (3-OH-BP-7,8-diol) (Fig. 1) as major metabolites in the bile5. The hydroxyl groups of this triol are structurally superimposable to those of 9-hydroxy-trans-1,2-dihydroxy-1,2-dihydrochrysene (9-hydroxychrysene-1,2-diol, Fig. 1), which is a metabolite of chrysene6,7 and a potent promutagen8,9. 9-…
Reaktive Metabolite cancerogener polycyclischer Kohlenwasserstoffe: Synthese und Abfangreaktion von 9-Hydroxybenzo[a]pyren-4,5-oxid
1985
Le compose du titre est prepare a partir de l'acetate-9 de benzo [a] pyrene et piege par l'ethanethiol. Mecanismes
Double Diastereoselection in Aldol Reactions Mediated by Dicyclohexylchloroborane between Chiral Aldehydes and a Chiral Ethyl Ketone Derived from l-E…
2005
Both matched and mismatched diastereoselections have been observed in the aldol reactions of a range of chiral aldehydes with the dicyclohexylboron enolate of a chiral ethyl ketone related to l-erythrulose. As was previously observed in the corresponding aldol reactions with l-erythrulose derivatives, the Felkin−Anh model provides an adequate explanation for the stereochemical outcome of reactions with chiral α-methyl aldehydes. However, a satisfactory account of the results observed with α-oxygenated aldehydes was only possible with the Cornforth model. As a practical application of the methodology described herein, a C1−C9 fragment of the structure of the antifungal macrolide soraphen A1α…
Metabolomics approach to studying minimally processed peach (Prunus persica) fruit
2012
Fresh-cut fruit products for both retail and food service applications have increasingly appeared in the market place in recent years. Among different fruit types, peaches can be used and are highly appreciated as fresh-cut product although their commercial success is limited due to their short shelf-life and the quick onset of wounding-related physiological reactions. In this work we analyzed the technological and physiological changes induced by fresh-cut preparation in three different types of peach cultivars: 'Fayette' (melting), 'Wilhelmina' (non-melting) and 'Ghiaccio3' (stony hard). We performed a metabolite targeting profiling to focus on the changes in organic acid levels, importan…
Phenolic and acetylenic metabolites from Artemisia assoana
1987
Abstract Nine flavones, three coumarins, two flavone glycosides, p-hydroxyacetophenone and methyl caffeate have been isolated from the aerial parts of Artemisia assoana. Six diacetylenic spiroketal enol-ethers, a mixture of n-alkyl p-coumarates and a new phenylpropanoid metabolite, sinapyl alcohol diisovalerate, have been isolated from root extracts of the same plant. 1H and 13C NMR spectra of some of these compounds are given and taxonomic aspects are discussed.
Biosynthesis of xanthurenic acid 8-O-beta-D-glucoside in Drosophila. Characterization of the xanthurenic acid:UDP-glucosyltransferase activity.
1990
Xanthurenic acid 8-glucoside is a side metabolite of the tryptophan-xanthommatin pathway in Drosophila. From 3-hydroxykynurenine, two biosynthetic pathways can be envisaged, one via xanthurenic acid, and another via 3-O-glucoside of 3-hydroxykynurenine. In this report evidence is presented to show that the synthesis takes place via xanthurenic acid. (a) We have demonstrated that the Drosophila melanogaster vermilion purple mutant (unable to synthesize 3-hydroxykynurenine) synthesizes xanthurenic acid 8-glucoside when fed with xanthurenic acid; and (b) the activities required for its synthesis via xanthurenic acid have been found (3-hydroxykynurenine transaminase and xanthurenic acid:UDP-glu…