Antiradical Properties of Red Wine Portisins

The free radical chemistry of two polyphenolic pigments from red wine belonging to the family of portisins, has been investigated after reaction with O(2)(center dot-) radicals using electron paramagnetic resonance (EPR), spectroscopy Two portisins derived from malvidin-3-glucoside and cyanidin-3-glucoside were used for this study Stable free radicals were detected with both portisins and correspond to unpaired electrons localized on the B as well as F rings of the portisins Interpretations, were confirmed by comparison with the spectra of free radicals formed by oxidation of the model compounds cyanidin-3-glucoside, malvidin-3-glucoside, and catechin These results concur with previous work reporting the higher antiradical properties of these pigments compared to their anthocyanin precursors