The New Pentacyclic Saponine Ecdysantherin [3/9-Hydroxy-20-methylpregn-5,14- dien- 16-one-(18-20 )-lactone ] from Ecdysanthera rosea Hook. et Am. (Apocynaceae)of Vietnam 

 -  Acta Crystallographica Sect. C, 52(6), p.1574-1576, 1996 .
<br/><br/> Ecdysantherin, 3/3-hydroxy-20-methylpregn-5,14-dien- 16-one-(18-20)-lactone, C21H2604, a new pentacyclic sapŠnine, was isolated from the powder of Ecdysanthera rosea Hook. et Am. (Apocynaceae)of Vietnam, and its structure was elucidated. It was found that ecdysantherin is a pentacyclic sapŠnine molecule with three sixmembered and two five-membered rings. An intermolecular OH.-.O hydrogen bond generates infinite chains of molecules in the z direction.