Vinylcatechin dimers are much better copigments for anthocyanins than catechin dimer procyanidin b3.
The binding constants (K) for the interaction of three copigments (CP), two epimeric vinylcatechin dimers (CP1 and CP2), and catechin dimer B3 (CP3) with two pigments, malvidin-3-glucoside (oenin) and malvidin-3,5-diglucoside (malvin), were determined. The K values clearly show that both vinylcatechin dimers have much higher affinity for oenin and malvin than dimer B3: K(CP2) > K(CP1) >> K(CP3). Quantum mechanics and molecular dynamics calculations were also performed to interpret the binding data and specify the relative arrangement of the pigment and copigment molecules within the complexes.
Centro de Investigacao em Quimica, Departamento de Quimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal.
Luís
L
Cruz
Natércia F
NF
Brás
Natércia
N
Teixeira
Nuno
N
Mateus
Maria João
MJ
Ramos
Olivier
O
Dangles
Victor
V
De Freitas
D044946:Biflavonoids / Q000737:chemistry*; D002392:Catechin / Q000737:chemistry*; D019281:Dimerization; D056004:Molecular Dynamics Simulation; D010860:Pigments, Biological / Q000737:chemistry*; D044945:Proanthocyanidins / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
D044946:Biflavonoids; D010860:Pigments, Biological; D044945:Proanthocyanidins; C479581:procyanidin B3; D002392:Catechin