Cholestane Glycosides and Trihydroxy Fatty Acids from the Rhizomes of Dioscorea septemloba

Two new steroidal glycosides, named dioseptemlosides I (1) and J (2), along with two known trihydroxy fatty acids, (12Z,15Z)-9,10,11-trihydroxy-12,15-octadecadienoic acid (3) and (12Z)-9,10,11-trihydroxy-12-octadecenoic acid (4), were isolated from the rhizomes of Dioscorea septemloba. Their structures were determined by HRESIMS, 1D and 2D NMR experiments, physical data, and chemical methods. The antitumor activity of compounds 1-4 was evaluated against three tumor cell lines and all of them were inactive at a concentration of 10 mu M.