A new tannin-related compound from the rhizome of Polygonum bistorta L.

Abstract
A new tannin-related compound named bistortaside A (1) and a known compound have been isolated from the rhizome of Polygonum bistorta L. A new compound was elucidated as 3-methyl-gallic acid 4-O-β-d-(6′-O-3″-methyl-galloyl)-glucopyranoside and a known compound was quercetin-3′-O-β-d-glucopyranoside (2) on the basis of spectroscopic analysis.