title: Antiradical properties of red wine portisins.
abstract: 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)(•-) 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.
authors.affiliation: Health and Environment Department, Environmental Resources and Technologies, AIT Austrian Institute of Technology GmbH, Konrad-Lorenz-Straße 24, 3430 Tulln, Austria.
authors.forename: Katharina F
authors.initials: KF
authors.lastname: Pirker
authors.forename: Joana
authors.initials: J
authors.lastname: Oliveira
authors.forename: Victor
authors.initials: V
authors.lastname: de Freitas
authors.forename: Bernard A
authors.initials: BA
authors.lastname: Goodman
authors.forename: Nuno
authors.initials: N
authors.lastname: Mateus
mesh_terms: D000872:Anthocyanins / Q000032:analysis*; D016166:Free Radical Scavengers / Q000032:analysis*; D005609:Free Radicals / Q000032:analysis; D014920:Wine / Q000032:analysis*
chemical_list: D000872:Anthocyanins; D016166:Free Radical Scavengers; D005609:Free Radicals