The new pentacyclic saponine ecdysantherin [3β-hydroxy-20-methylpregn-5,14-dien-16-one-(18-20)-lactone] from Ecdysanthera rosea Hook. et Arn. (Apocynaceae) of Vietnam

Abstract

Ecdysantherin, 3β-hydroxy-20-methylpregn-5,14-dien-16-one-(18-20)-lactone, C21H26O4, a new pentacyclic saponine, was isolated from the powder of Ecdysanthera rosea Hook. et Arn. (Apocynaceae) of Vietnam, and its structure was elucidated. It was found that ecdysantherin is a pentacyclic saponine molecule with three six-membered and two five-membered rings. An intermolecular OH⋯O hydrogen bond generates infinite chains of molecules in the z direction.