Steroidal saponins from the rhizomes of Dioscorea bulbifera and their cytotoxic activity.

Two new steroidal saponins, diosbulbisides D (1) and E (2), along with five known saponins (3- 7) were isolated from the rhizomes of Dioscorea bulbifera L. Their structures were elucidated on the basis of spectral data. Compounds 6 and 7, two 3- O-trisaccharides of diosgenin spirostanes, showed moderate cytotoxic activity against human hepatocellular carcinoma cells, with IC₅₀ values of 3.89 µM and 7.47 µM on SMMC7721, and 10.87 µM and 19.10 µM on Bel-7402 cell lines, respectively. © Georg Thieme Verlag KG Stuttgart · New York.