Tannins and related compounds. XVI. Isolation and characterization of six methyl glucoside gallates and a gallic acid glucoside gallate from Sanguisorba officinalis L.

Six methyl glucoside gallates (I-VI) were isolated, together with gallic acid 3-O-β-D-(6'-O-galloyl)-glucopyranoside (VII), from the undeground part of Sanguisorba officinalis L. On the basis of chemical and spectroscopic evidence, the structures of these compounds were established to be 6-O-gallate (1), 6-O-digallate (2), 4, 6-di-O-gallate (3), 2, 3, 6-tri-O-gallate (4), 3, 4, 6-tri-O-gallate (5) and 2, 3, 4, 6-tetra-O-gallate (6) of methyl β-D-glucopyranoside.