Abstract: From the stem of Marsdenia tenacissima(Roxb)Wight et Arn.,four new steroidal glycosides desgnated tenacissoside F(3),G(4),H(5) and I(6)possessing the same sugar chain:6-deoxy-3-O-methyl-β-D-allopyanosyl-(1→4)-β-D-oleandropyranosose,along with two known tenacissoside A(1),and B(2),were isolated and characterized by means of spectroscopic and chemical evidence.Furthermore ,diester groups at C-11 and C-12 of aglycone of these glycosides had been assigned by COLOC and 2D NMR techniques.

Key words: Asclepiadaceae, Marsdenia Tenacissima, C21 steroidal glycosides, Tenacissosides F, G, H and I