Constituents of Asclepiadaceae Plants. XXXIII. Component of Marsdenia tomentosa DECNE. Structure of Tomentosin

Abstract

A new polyoxypregnane derivative, tomentosin (12β-O-tigloyl-20-O-acetyl-tomentogenin) was isolated from the stem of Marsdenia tomentosa. Tomentosin is the first example of the diester possessing a tomentogenin skeleton to be isolated from the Asclepiadaceae plant, and it did not undergo any internal acyl migration which occurrs on mild alkaline hydrolysis of C-12β, 20-diester of sarcostin and other polyoxypregnane derivatives.