A Novel Glutathione-Hydroxycinnamic Acid Product Generated in Oxidative Wine Conditions
Quentin Bouzanquet, Célia Barril, Andrew C. Clark, Daniel A. Dias, Geoffrey R. Scollary
Journal of Agricultural and Food Chemistry
Abstract
This study characterizes a novel glutathione-substituted dihydroxyphenyl compound formed during the oxidation of white wine and model wine solutions, which may contribute to the synergistic role of glutathione and hydroxycinnamic acids in delaying oxidative coloration. The critical components for the formation of the compound were found to be hydroxycinnamic acids and glutathione, while ascorbic acid enabled the product to accumulate to higher concentrations. The presence of the wine components important in other wine oxidation mechanisms, (+)-catechin, ethanol and/or tartaric acid, was not essential for the formation of this new compound. Via LC-MS/MS, HR-MS and (1)H NMR (1D and 2D NMR) analyses, the major isomer of the compound formed from glutathione and caffeic acid was found to be 4-[(E)-2'-(S)-glutathionyl ethenyl]-catechol (GEC). Equivalent products were also confirmed via LC-MS/MS for other hydroxycinnamic acids (i.e., ferulic and coumaric acids). Only trace amounts of GEC were formed with the quinic ester of caffeic acid (i.e., chlorogenic acid), and no equivalent product was found for cinnamic acid. GEC was detected in a variety of white wines supplemented with glutathione and caffeic acid. A radical mechanism for the formation of the styrene-glutathione derivatives is proposed.
Extracted Claims
3 claims extracted from this paper into the knowledge graph
GEC detected in white wines
“GEC was detected in a variety of white wines supplemented with glutathione and caffeic acid.”
GEC formed from glutathione and caffeic acid
“Via LC-MS/MS, HR-MS and (1)H NMR (1D and 2D NMR) analyses, the major isomer of the compound formed from glutathione and caffeic acid was found to be 4-[(E)-2'-(S)-glutathionyl ethenyl]-catechol (GEC).”
glutathione and hydroxycinnamic acids form glutathione-substituted dihydroxyphenyl compound
“This study characterizes a novel glutathione-substituted dihydroxyphenyl compound formed during the oxidation of white wine and model wine solutions, which may contribute to the synergistic role of gl...”