Steroidal and pregnane glycosides from Ypsilandra thibetica

The whole plants of Ypsilandra thibetica have been analyzed as part of a systematic study on saponin constituents of medicinal plants. This has resulted in the isolation of two new bisdesmosidic furostanol saponins, named ypsilandroside P (1) and ypsilandroside Q (2), and one new pregnane glycoside, named ypsilandroside R (3), together with nine known steroidal glycosides. Their structures were elucidated on the basis of extensive spectroscopic analysis, including that of 2D NMR data, and the results of acidic hydrolysis. Ypsilandroside P (1) was cytotoxicity against two human tumor cell lines.