Polygonumnolides A1-B3, minor dianthrone derivatives from the roots of Polygonum multiflorum Thunb.

Seven new dianthrone glycosides, named polygonumnolides A1-B3 (1-7), were isolated from the 70 % EtOH extract of the dried roots of Polygonum multiflorum Thunb. using column chromatography and preparative high-performance liquid chromatography. Their structures were determined by 1D and 2D NMR and mass spectroscopy. The isolated compounds were evaluated for their cytotoxic effects against KB tumor cell lines and compounds 1-4 showed moderate cytotoxicity.