Reactivity of wine polyphenols under oxidation conditions: Hemisynthesis of adducts between grape catechins or oak ellagitannins and odoriferous thiols

TETRAHEDRON

卷:75

Article

Petit, Emilie¹  Jacquet, Remi¹  Pouysegu, Laurent¹  Deffieux, Denis¹  Quideau, Stephane¹ 

[1] Univ Bordeaux, CNRS, ISM, UMR 5255, 351 Cours Liberat, F-33905 Talence, France

关键词: Wine;    Odoriferous thiols;    Grape catechins;    Oak ellagitannins;    Oxidation;   

DOI  :  10.1016/j.tet.2018.11.071

来源: Elsevier

【 摘 要 】

The reasons for the loss of characteristic odoriferous thiols during the aging of wine in oak-made barrels and subsequent storage in bottles have been in part attributed to covalent capture of these thiols by polyphenolic wine components that are dehydrogenated into electrophilic ortho-quinones upon wine oxygenation. Herein, FeCl3 was used as oxidant in oxygen-deprived aqueous solutions to dehydrogenate grape (epi)catechins and oak ellagitannins in the presence of two typical odoriferous thiols, 2-furanmethanethiol (2FMT) and 3-sulfanylhexan-1-ol (3SH). The preparative-scale conditions used enabled the isolation of six novel 2FMT-bearing (epi)catechin derivatives, three known 3SH-bearing catechin derivatives (the structures of two of those were revised to be strictly derived from 1,6-conjugate addition), three novel 2FMT-bearing castalagin derivatives, and one novel 3SH-bearing castalagin derivative. The structures of these castalagin-based thio-adducts revealed that the capture of thiols by the different dehydrogenated pyrogallol rings of castalagin starts at ring IV, then ring III, and finally ring V. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

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