Norditerpenic ester and pentacyclic triterpenoids from root bark of Calotropis procera (Ait) R. Br.

A new norditerpenyl ester, named Calotropterpenyl ester, and two unknown pentacyclic triterpenoids, namely calotropursenyl acetate and calotropfriedelenyl acetate have been isolated from the root bark of Calotropis procera. Their structures have been established as 6,10,14-trimethylpentadec-6-enyl-2',4',8',12',16'-pentamethyl nonadecane ester, urs-12,19(29)-diene-3 beta-yl acetate and friedelin-1-ene-3 beta-yl acetate, respectively, on the basis of spectral data analyses and chemical reactions.