Four new C-glycosidic ellagitannins, castacrenins D - G, from Japanese chestnut wood (Castanea crenata Sieb. et Zucc.)

Abstract

In the course of studies on polyphenol metabolism in wood, four new C- glycosidic ellagitannins named castacrenins DG were isolated from the wood of the Japanese chestnut tree (Castanea crenata). Castacrenins D and F are related to vescalagin and have a gallic acid and an ellagic acid moiety, respectively. Castacrenins E and G are oxidative metabolites of castacrenins D and F, respectively, in which a pyrogallol ring of each C- glycosidic ellagitannin unit is replaced by a cyclopentenone ring.