Phytochemical Studies on Alstonia scholaris

Reinvestigation of the flowers of Alstonia scholaris of Pakistan origin have resulted in the isolation of three new triterpenoids, two of the ursane type, 3 beta-acetate-24-nor-urs-4,12-diene ester triterpene (1) and 3 beta-hydroxy-24-nor-urs-4,12,28-triene triterpene (2), and one of the oleanane type, 3,28-beta-diacetoxy-5-olea-triterpene (3), together with two known triterpenes, alpha-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.