Identification of Anthocyanin-Flavanol Pigments in Red Wines by NMR and Mass Spectrometry

Abstract
Three newly formed Port wine pigments were isolated by Toyopearl HW-40(s) gel chromatography and semipreparative HPLC. Furthermore, the pigments were identified by mass spectrometry (LC/MS) and NMR techniques (1D and 2D). These anthocyanin-derived pigments showed UV−visible spectra different from those of the original grape anthocyanins. These pigments correspond to malvidin 3-glucoside linked through a vinyl bond to either (+)-catechin, (−)-epicatechin, or procyanidin dimer B3 [(+)-catechin-(+)-catechin]. NMR data of these pigments are reported for the first time. Keywords: Red wine; flavanol; aging; pigments; anthocyanins; NMR; mass spectrometry