Immunomodulating Steroidal Glycosides from the Roots of <i>Stephanotis mucronata</i>

Abstract

Abstract Guided by in vitro immunological tests, three immunomodulating steroidal glycosides, stemucronatosides A ( 1 ), B ( 2 ), and C ( 3 ), were isolated from the roots of Stephanotis mucronata. On the basis of chemical evidence and extensive spectroscopic methods including 1D and 2D NMR, their structures were determined as 12‐ O ‐deacetylmetaplexigenin 3‐[ O ‐6‐deoxy‐3‐ O ‐methyl‐ β ‐ D ‐allopyranosyl‐(1→4)‐ O ‐ β ‐ D ‐cymaropyranosyl‐(1→4)‐ β ‐ D ‐cymaropyranoside], 12‐ O ‐deacetylmetaplexigenin 3‐[ O ‐ β ‐ D ‐thevetopyranosyl‐(1→4)‐ O ‐ β ‐ D ‐cymaropyranosyl‐(1→4)‐ β ‐ D ‐cymaropyranoside], and metaplexigenin 3‐[ O ‐ β ‐ D ‐glucopyranosyl‐(1→4)‐ O ‐6‐deoxy‐3‐ O ‐methyl‐ β ‐ D ‐allopyranosyl‐(1→4)‐ O ‐ β ‐ D ‐cymaropyranosyl‐(1→4)‐ β ‐ D ‐cymaropyranoside], respectively. These compounds showed immunomodulating activities in vitro.