Two New C-21 Steroidal Glycosides from the Stems of Stephanotis mucronata

Two new C-21 steroidal glycosides, mucronatosides M(1) and N(2), were isolated from the stems of Stephanotis mucronata, together with one known compound stephanoside M(3). On the basis of chemical evidence and extensive spectroscopic methods, including one-dimensional and two-dimensional NMR, the structures of the two new compounds were identified as 12-O-tigloyl-20-O-N-methylanthraniloyl sarcostin 3-O-β-D-glucopyranosyl-(1→4)-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-(-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside (1), and 12-O- cinnamoyl-20-O-nicotinoyl(20S)-pregn-6-ene-3(,5(,8β,12β,14(,17β,20-heptanol 3-O-β-D-glucopyranosyl-(1→4)-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-(-D-cymaropyranoside (2).