219 research outputs found
The hidden face of wine polyphenol polymerization highlighted by high resolution mass spectrometry
Polyphenols, including tannins and red anthocyanin pigments, are responsible for the color, taste, and beneficial health properties of plant-derived foods and beverages, especially in red wines. Known compounds represent only the emerged part of the "wine polyphenol iceberg". It is believed that the immersed part results from complex cascades of reactions involving grape polyphenols and yeast metabolites. We used a nontargeted strategy based on high-resolution mass spectrometry and Kendrick mass defect plots to explore this hypothesis. Reactions of acetaldehyde, epicatechin, and malvidin-3-O-glucoside, representing yeast metabolites, tannins, and anthocyanins, respectively, were selected for a proof-of-concept experiment. A series of compounds including expected and so-farunknown structures were detected. Random polymerization involving both the original substrates and intermediate products resulting from cascade reactions was demonstrated
Linking cocoa polyphenol composition to chocolate quality with Average-Mass-Spectra fingerprints
Linking cocoa polyphenol composition to chocolate quality with Average-Mass-Spectra fingerprints. CoCoTea 2019 (5. International Congress on Cocoa Coffee and Tea
Divergent effects of quercetin conjugates on angiogenesis
The present study reports the activities of quercetin and its main circulating conjugates in man (quercetin-3′-sulphate (Q3′S) and quercetin-3-glucuronide (Q3G)) on in vivo angiogenesis induced by vascular endothelial growth factor (VEGF) and examines the effects of these molecules on cultured endothelial cells. We found opposing effects of quercetin and its metabolites on angiogenesis. While quercetin and Q3G inhibited VEGF-induced endothelial cell functions and angiogenesis, Q3′S per se promoted endothelial cell proliferation and angiogenesis. The inhibitory effect elicited by Q3G was linked to inhibition of extracellular signal-regulated kinases 1/2 (ERK1/2) phosphorylation elicited by VEGF. The activation of endothelial cells by Q3′S was associated to stimulation of VEGF receptor-2 and to downstream signalling activation (phosphatidylinositol-3 kinase/Akt and nitric oxide synthase pathways), ultimately responsible for ERK1/2 phosphorylation. These data indicate that the effects of circulating quercetin conjugates on angiogenesis are different depending on the nature of the conjugate. Q3G andQ3′S are the two major conjugates in plasma, but their ratio is dependenton several factors, so thatinhibition or activation of angiogenesis could be subtly shifted as a result of metabolismin viv
Wine tannins and pigments
Wine tannins and pigments. 4. Annual Workshop INSA-UB: “Science and properties of cava and wine
Recent progress in tannin reactivity
Recent progress in tannin reactivity. 60. annual meeting of American Society of Enology and Viticultur
Les composés polyphénoliques : connaissances actuelles, rôle et incidences technologiques
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High resolution mass spectrometry approaches to characterize wine polyphenols
High resolution mass spectrometry approaches to characterize wine polyphenols. 254. National Meeting and Exposition of the American-Chemical-Society (ACS) on Chemistry's Impact on the Global Econom
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