Two new triterpenes fromAlstonia scholarisflowers

Abstract

In the context of our previous communication on phytochemical studies of the ethanolic extract of flowers of Alstonia scholaris of Pakistan origin, these have resulted in the isolation of two new triterpenoids. One is of the oleanane type, alstoprenyol, 3-β-hydroxy-28-β-acetoxy-5-olea triterpene (1), the other is of ursane type, alstoprenylene 3β-acetate-24-nor-urs-4,12,2'-triene ester triterpene (2) and together with four known triterpenes, α-amyrin acetate (3), α-amyrin (4), lupeol acetate (5) and 3β-hydroxy-24-nor-urs-4,12,28-triene triterpene (6) were isolated. The structures of 1-6 were elucidated with the aid of extensive NMR spectroscopic studies.

Isolation and structure determination of nematicidal iridoid sweroside from Alstonia scholaris

“…Keeping in view the pharmacological significance of the plant, phytochemical studies were undertaken on the constituents of the aerial parts of the plant in this laboratory two years earlier, which resulted in the isolation and characterization of various pentacyclic triterpenoids (Sultana and Muhammed, 2010;Sultana et al, 2012). In the present study, a bio-activity directed isolation of the ethanolic extract showing nematicidal activity was undertaken which resulted in the isolation of an active iridoid and triterpenoid compounds.…”