Phytochemical Studies on Alstonia scholaris

Abstract

Reinvestigation of the flowers of Alstonia scholaris of Pakistan origin have resulted in the isolation of three new triterpenoids, two of the ursane type, 3β -acetate-24-nor-urs-4,12-diene ester triterpene (1) and 3β -hydroxy-24-nor-urs-4,12,28-triene triterpene (2), and one of the oleanane type, 3,28-β - diacetoxy-5-olea-triterpene (3), together with two known triterpenes,α-amyrin acetate (4) and ursolic acid (5). This is the first report of the isolation of 4 and 5 from the flower part of this species. The structures of 1 - 5 were elucidated with the aid of extensive NMR-spectroscopic studies.