Structural Features of Copigmentation of Oenin with Different Polyphenol Copigments

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Natercia Teixeira (Author) Other; Luis Cruz (Author) FCUP; Natercia F Bras (Author) FCUP; Nuno Mateus (Author) FCUP; Maria Joao Ramos (Author) FCUP; Victor de Freitas (Author) FCUP

Journal

Title: Journal of Agricultural and Food Chemistry

Vol. 61

Pages: 6942-6948

ISSN: 0021-8561

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 59 Citations

Scopus - 69 Citations

Scientific classification

FOS: Agrarian Sciences > Other Agrarian Sciences

Other information

Authenticus ID: P-006-957

DOI: 10.1021/jf401174b

Abstract (EN): The copigmentation binding constants (K) for the interaction of different copigments with oenin (major red wine anthocyanin) were determined. All tests were performed in a 1296 ethanol citrate buffer solution (0.2 M) at pH 3.5, with an ionic strength adjusted to 0.5 M by the addition of sodium chloride. Over the past years, several copigmentation studies were made and many copigments were tested, but none of them included prodelphinidin B3 or a dimeric-type adduct like oenin-(O)-catechin, probably due to the difficulty in obtaining them. The data yielded from this study allowed concluding that (a) the presence of a pyrogallol group in the B ring of the flavan-3-ol structure slightly increases the copimentation potential and (b) within all copigments tested oenin-(O)-catechin was revealed to be the best. According to computational studies performed on epicatechin/oenin, epigallocatechin/oenin, procyanidin B3/oenin, and oenin-(O)-catechin/oenin complexes, the Delta G(binding) energy of the oenin-(O)-catechin/oenin complex is the most negative compared to the other copigmentation complexes, hence being more stable and thermodynamically favored. All structural data show that oenin-(0)-catechin and epigallocatechin are closer to the pigment molecule, which is in accordance with these two copigments having the highest experimental copigmentation binding constants for oenin.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7