Abstract

Three C₂₁ steroidal glycosides, stephanoside E (compound 1) together with two new others (compound 2 and 3) were isolated from the metabolites of stemucronatoside K, an immunosuppressive C₂₁ steroidal glycosides from Stephanotis mucronata. On the basis of chemical evidence and extensive spectroscopic methods including one-dimensional and two-dimensional nuclear magnetic resonance (NMR), structures of 2 and 3 were determined to be 12-O-acetyl- 20-O-(N-methyl) anthraniloylsarcostin 3-O-{b-D-6-deoxy-3-O-methyl-b-D- allopyranosyl-(1→4)- b-D- cymaropyranosyl-(1→4)- b-D-cymaropyranoside} (2) and 12-O-acetyl-20-O-(N-methyl) anthraniloylsarcostin 3-O-{6-deoxy-b-D- allopyranosyl-(1→4)- b-D-cymaropyranosyl-(1→4)- b-D-cymaropyranoside} (compound 3), respectively.

Key words: Stemucronatoside K, metabolites, steroidal glycosides.