Influence of a Flavan-3-ol Substituent on the Affinity of Anthocyanins (Pigments) toward Vinylcatechin Dimers and Proanthocyanidins (Copigments)

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Frederico Nave (Author) Other; Natercia F Bras (Author) FCUP; Luis Cruz (Author) FCUP; Natercia Teixeira (Author) Other; Nuno Mateus (Author) FCUP; Maria J Ramos (Author) FCUP; Florent Di Meo (Author) Other; Patrick Trouillas (Author) Other; Olivier Dangles (Author) Other; Victor De Freitas (Author) FCUP

Journal

Title: Journal of Physical Chemistry B

Vol. 116 No. 6

Pages: 14089-14099

ISSN: 1520-6106

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 28 Citations

Scopus - 30 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-002-2E0

DOI: 10.1021/jp307782y

Abstract (EN): The aim of this study is to investigate interactions possibly taking place in red wine between three flavanols (copigments, CP), i.e., two epimeric vinylcatechin dimers (CP1 and CP2) and catechin dimer B3 (CP3), and a specific pigment resulting from the condensation between the main grape anthocyanin malvidin 3-O-glucoside (oenin) and catechin, catechin-(4 -> 8)-oenin. By comparison with our previous work on oenin itself, the influence of the catechin moiety of the anthocyanin in the binding is established. The thermodynamic parameters show that both vinylcatechin dimers exhibit a higher affinity for catechin-(4 -> 8)-oenin, in comparison with proanthocyanidin B3, as previously observed with oenin. However, the corresponding binding constants are weaker, probably due to steric hindrance in the anthocyanin brought by the flavanol nucleus. Consequently, catechin-(4 -> 8)-oenin should be much less stabilized by copigmentation in hydroalcoholic solution than oenin. Quantum mechanics and molecular dynamics simulations are also performed to interpret the binding data, to specify the relative arrangement of the pigment and copigment molecules within the complexes, and to interpret their absorption properties in the visible range.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11