Study of the antiradical activity of wine polyphenols using UV--VIS and DFT methods

Abstract

This study investigates the antiradical activity of the wine polyphenols catechin (Cat) and quercetin (Que) in ethanol and wine-model solution, combining experimental DPPH• scavenging assays with Density Functional Theory (DFT) calculations. Quercetin exhibited similar activity in both media, one mol of polyphenol scavenging approximately 3.4 moles of DPPH•, whereas catechin showed enhanced performance in wine-model solution, neutralizing up to 4 moles of DPPH• compared to 2.8 moles in ethanol. Theoretical and experimental correlations indicate that catechin predominantly follows a SET-PT mechanism in wine-model solution, while quercetin likely undergoes alternative pathways, including possible dimerization.