Isolation and Structural Characterization of New Acylated Anthocyanin−Vinyl−Flavanol Pigments Occurring in Aging Red Wines

Abstract

Three newly formed pigments were detected and isolated from a 2-year-old Port wine through TSK Toyopearl HW-40(S) gel column chromatography and characterized by UV-visible spectrophotometry, NMR, and mass spectrometry (ESI/MS). (1)H NMR and (13)C NMR data for these pigments obtained using 1D and 2D NMR techniques (COSY, NOESY, gHSQC, and gHMBC) are reported for the first time. The structure of the pigments was found to correspond to the vinyl cycloadducts of malvidin 3-coumaroylglucoside bearing either a procyanidin dimer or a flavanol monomer ((+)-catechin or (-)-epicatechin). Additionally, conformational analysis was performed for one of these newly formed pigment using computer-assisted model building and molecular mechanics. A chemical nomenclature is proposed to unambiguously name this new family of anthocyanin-derived pigments.

Phenolic compounds and antioxidant activity of Macedonian red wines

“…Thus, compounds with molecular signals M + at m/z 517, 559 and 663 were identified as pyranomalvidin-3-glucoside (vitisin B), pyranomalvidin-3-acetylglucoside (acetyl-vitisin B) and pyranomalvidin-3-p-coumaroylglucoside (p-coumaroyl-vitisin B) all producing a fragment ion at m/z 355 by loss of glucoside (162 u), acetylgucoside (204 u) and p-coumaroylglucoside (308 u) groups, respectively. Two compounds with same molecular ions at m/z 805 were detected in the wines and tentatively identified as 10-flavanylpyranoanthocyanins (reaction products between anthocyanins and 8-vinylflavanols, released from the cleavage of previously formed ethyl bridged flavan-3-ol oligomers), namely 10-catechinpyranomalvidin-3-glucoside and 10-epicatechin-pyranomalvidin-3-glucoside (Mateus et al, 2003). The fragmentation of the molecular ion (m/z 805) produced fragment ions at m/z 643 and 491, the first one corresponding to elimination of a glucose moiety (162 u) and the second one to Retro Diels-Alder (RDA) fission of the B ring of the flavan-3-ol moiety, characterized by loss of 152 u.…”

Grape and wine phenolics: Observations and recent findings

“…the formation of the vitisin pyranoanthocyanins in wine has subsequently led to the identification of other reactive nucleophiles including hydroxycinnamic acids and ethanal-flavan-3-ol reaction products (He et al, 2006;Mateus et al, 2004Mateus et al, , 2003Benabdeljalil et al, 2000, Figure 7). in addition to ethanal mediated condensation reactions, recent work has shown that the oxidation of wine can result in the oxidation of glycerol to glyceraldehyde, another electrophilic species (laurie and Waterhouse, 2006a, b).…”

High Pressure Processing Technology on Bioactives in Fruits and Cereals

“…All these molecules have the same main fragment ion that corresponds to carboxy-pyrano- anthocyanin aglycone, released after loss of 162, 204, and 308 mass units (Table 20. 2;Fulcrand et al 1998;Mateus et al 2003). A series of pyranoanthocyanins formed by reactions of anthocyanins with acetaldehyde (pyrano-anthocyanins) have also been shown to be present in wines (Table 20.2).…”