Isolation and structural characterization of new acylated anthocyanin-vinyl-flavanol pigments occurring in aging red wines.
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.
Mateus
Nuno
N
Centro de Investigação em Química, Departamento de Química, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, Portugal. nbmateus@fc.up.pt
Carvalho
Elisabete
E
Carvalho
Alexandre R F
AR
Melo
André
A
González-Paramás
Ana M
AM
Santos-Buelga
Celestino
C
Silva
Artur M S
AM
De Freitas
Victor
V
D000215:Acylation; D000872:Anthocyanins / Q000737:chemistry / Q000302:isolation & purification*; D003198:Computer Simulation; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D010860:Pigments, Biological / Q000737:chemistry / Q000302:isolation & purification*; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet; D009626:Terminology as Topic; D013997:Time Factors; D014920:Wine / Q000032:analysis*
C471172:8-vinyl-epi-(4-8)-cat-(1V,2V-5O,4)-malvidin-3-coumaroylglucoside; C471173:8-vinylcat-(1V,2V-5O,4)-malvidin-3-coumaroylglucoside; D000872:Anthocyanins; D010860:Pigments, Biological