Diospyros melanoxylon Leaves: A Rich Source of Pentacyclic Triterpenes

Abstract

In a program designed to search for alternative uses of Diospyros melanoxylon leaves (bidi wrapper leaves), extensive chemical screening resulted in the isolation of nine pentacyclic triterpenes and ß -sitosterol. Out of the nine pentacyclic triterpenes, two are hitherto unreported (2 and 4), four are taxonomically significant (7-10), and the remaining three (1, 5 and 6) are known. Significantly, the ursane structures, viz., a -amyrin (0.7%) and ursolic acid (0.56%) and corsolic acid (0.14%), were obtained in fairly large quantities. In view of the excellent surface active properties and interesting biological activities attributed to some of these skeletons, their present isolation is of relevance.