Two New Cytotoxic C-21 Steroidal Glycosides from the Root of Cynanchum auriculatum

Guided by in vitro antineoplastic tests, two new cytotoxic C-21 steroidal glycosides, auriculosides A (1) and B (2), were isolated from the root of Cynanchum auriculatum. Their structures were determined on the basis of chemical evidence and extensive spectroscopic methods including one-dimensional and two-dimensional NMR. These compounds showed cytotoxic activities against PC3, Hce-8693, Hela, and PAA cell lines.