Modified mycotoxins have been gaining importance in recent years and present a certain challenge in LC-MS/MS analysis. Due to the previous lack of a labeled isotopologue of the modified mycotoxin deoxynivalenol-3-glucoside, in our study we synthesized the first (13)C-labeled internal standard. Therefore, we used the Königs-Knorr method to synthesize deoxynivalenol-3-β-d-[(13)C₆]-glucoside origi...

We have studied the inhibitory effect of five polyphenols namely, resveratrol, piceatannol, quercetin, quercetrin, and quercetin-3-beta-D glucoside on Escherichia coli ATP synthase. Recently published X-ray crystal structures of bovine mitochondrial ATP synthase inhibited by resveratrol, piceatannol, and quercetin, suggest that these compounds bind in a hydrophobic pocket between the gamma-subu...

Phenotypic characterization of the Arabidopsis thaliana transparent testa12 (tt12) mutant encoding a membrane protein of the multidrug and toxic efflux transporter family, suggested that TT12 is involved in the vacuolar accumulation of proanthocyanidin precursors in the seed. Metabolite analysis in tt12 seeds reveals an absence of flavan-3-ols and proanthocyanidins together with a reduction of ...

Two distinct mechanisms catalyzing glucoside uptake have been detected in E. coli K12. One of these has high stereospecificity for glucose and alkyl-aor alkyl-,3-glucosides,l and the second, for alkyl-jBand aryl-,3-glucosides.2' 3 Lin and his collaborators4 5 have concluded that aMG is not actively transported, but is trapped intracellularly as the result of a phosphorylation reaction catalyzed...

A new iridoid glucoside, urphoside A, and six known iridoid glucosides, pikuroside, aucubin, veronicoside, catalposide, amphicoside, and verminoside, were isolated from Veronica hederifolia together with a known megastigmane glucoside, 3-hydroxy-5,6-epoxy-beta-ionol-9-O-beta-D-glucopyranoside, and a hexitol, dulcitol. The structures of the isolated compounds were established by the extensive 1D...

Background and Aims: During ageing in oak barrels, wine undergoes changes because of the release of polyphenols and other molecules from wood. The aim of this study was to evaluate the influence of some oak wood-derived volatile compounds, ellagic acid and oak wood extracts on the levels of (+)-catechin, procyanidin B1 and malvidin-3-glucoside. Methods and Results: Phenolics and the oak wood de...

In the flowers of important ornamental Compositae plants, anthocyanins generally carry malonyl group(s) at their 3-glucosyl moiety. In this study, for the first time to our knowledge, we have identified a cDNA coding for this 3-glucoside-specific malonyltransferase for anthocyanins, i.e. malonyl-coenzyme A:anthocyanidin 3-O-glucoside-6"-O-malonyltransferase, from dahlia (Dahlia variabilis) flow...

BACKGROUND Quercetin and quercetin glycosides are widely consumed flavonoids found in many fruits and vegetables. These compounds have a wide range of potential health benefits, and understanding the bioavailability of flavonoids from foods is becoming increasingly important. METHODS This study combined an in vitro digestion, a lactase treatment and the Caco-2 cell model to examine quercetin ...

Repression of tryptophanase (tryptophan indole-lyase) by glucose and its non-metabolizable analogue methyl alpha-glucoside has been studied employing a series of isogenic strains of Escherichia coli lacking cyclic AMP phosphodiesterase and altered for two of the proteins of the phosphoenolpyruvate:sugar phosphotransferase system (PTS), Enzyme I and Enzyme IIAGlc. Basal activity of tryptophanase...