Tannins and related compounds. X. Rhubarb (2): Isolation and structures of a glycerol gallate, gallic acid glucoside gallates, galloylglucoses and isolindleyin.

Abstract

Six tannin-related compounds (I-VI) have been isolated from commercial rhubarb, and their structures have been established on the basis of chemical and spectroscopic data to be 1-O-galloylglycerol (I), gallic acid 3-O-β-D-(6'-O-galloyl)-glucopyranoside (II), gallic acid 4-O-β-D-(6'-O-galloyl)-glucopyranoside (III), 1, 6-di-O-galloyl-β-D-glucose (IV), 6-O-galloylglucose (V) and 4-(4'-hydroxyphenyl)-2-butanone 4'-O-β-D-(2"-O-galloyl)-glucopyranoside (VI, named isolindleyin).