Nine new steroidal glycosides from the roots of Cynanchum stauntonii.

Nine new steroidal glycosides, named as stauntosides C-K (2, 5, 7-10, 13, 14, and 16), along with seven known compounds (1, 3, 4, 6, 11, 12, and 15) were isolated from the 95% ethanol extract of the roots of Cynanchum stauntonii. The structures of these new compounds were elucidated on the basis of extensive spectroscopic analyses, mainly 1D and 2D NMR, and HRESI-MS, and qualitative chemical methods. Their significance in terms of the chemotaxonomy of C. stauntonii is discussed.