The triterpenes of Emmenospermum pancherianum

Abstract

The free triterpenes identified as constituents of Emmenospermum pancherianum Baill. are ceanothic acid (wood), betulic acid (bark), and the new triterpene, 18α,24-dihydroxy-A(1)-norlupa-2,20(29)-diene-27,28- dioic acid 28-methyl ester 27,18α-lactone (1a) (bark); the structure of the last has been determined by spectroscopic analysis. Both wood and bark contained saponin which in each case on acid hydrolysis gave ebelin lactone, and two new sapogenins, 24,25-dihydroebelin lactone (9a)and the tetracarbocyclic triterpenoid (10a) possessing an aromatic ring D; all three sapogenins are secondary sapogenins. The primary sapogenins jujubogenin (11a) and dihydrojujubogenin (12a)have been obtained by degradation of the wood saponin, and dihydrojujubogenin has been shown to be the precursor of (9a) and (10a).