Abstract: Two novel C-21 steroidal aglycones named marsglogenin-A(Ⅱ) and marsglogenin-B(Ⅲ) as well as six known compounds sarcostin (Ⅰ), gymnemarsgenin (Ⅳ), 20-O-cinnamoylsarcostin (Ⅴ), penupogenin (Ⅵ), gagaminin (Ⅶ) and isolineolcn (Ⅷ) were isolated from the acid hydrolysate of the crude glycoside extracted with ethanol from the stem of Marsdenia globitera (Asclepiadaceae). The structures of marsglogenin-A and marsglogenin-B were deduced as 20-O-benzoylsarcostin and 12-O-benzoylsarcostin on the bases of chemical and spectral evidences respectively.

Key words: Marsdenia globifera, marsglogenin-A, marsglogenin-B