Polygonumosides A–D, Stilbene Derivatives from Processed Roots of Polygonum multiflorum

Four new stilbene derivatives, polygonumosides A–D (1–4), were isolated from the processed roots of Polygonum multiflorum. Their structures were elucidated by spectroscopic analysis, including 1D and 2D NMR and ECD. Polygonumosides A (1) and B (2), possessing an unprecedented tetracyclic skeleton, were assigned as 2S- and 2R-2-(4-hydroxyphenyl)-9,10,11-trihydroxy-2H-benzo[c]furo[2,3-f]chromen-7(3H)-one-4-O-β-d-glucopyranosides, respectively, while polygonumosides C (3) and D (4) were assigned as a pair of diastereomeric stilbene glucoside dimers.