Convenient syntheses of metabolically important quercetin glucuronides and sulfates

Abstract

Synthetic approaches to the major human plasma metabolites of quercetin, quercetin 3′-sulfate and the β- d -glucopyranosiduronic acid derivatives 3′-methylquercetin 3-glucuronide (isorhamnetin 3-glucuronide), quercetin 3-glucuronide and quercetin 3′-glucuronide are described. This is the first report of the chemical synthesis of quercetin 3′-glucuronide. All procedures start from the same precursor, 4′,7-di- O -benzylquercetin, and all are more convenient than existing methods.