Tannins and Related Compounds. LXXV. : Isolation and Characterization of Novel Diastereoisomeric Ellagitannins, Nupharins A and B, and Their Homologues from Nuphar japonicum DC.

Abstract

The diastereoisomeric ellagitannins, nupharins A (1) and B (11), and related compounds (8, 10, and 15), have been isolated from the rhizomes of Nuphar japonicum DC. (Nymphaeaceae). One the basis of physicochemical evidence, their structures were characterized as 1, 2, 4-tri-O-galloyl-(1) and 1, 2-di-O-galloyl-3, 6-(S)-hexahydroxydiphenoyl-α-D-glucopyranoses (8), 2-O-galloyl-3, 6-(S)-hexahydroxydiphenoyl-D-glucose (10), and 1, 2, 4-tri-O-galloyl- (11) and 1, 2-di-O-galloyl-(R)-hexahydroxydiphenoyl-α-D-glucopyranoses (15).