Pentacyclic triterpenoids from Rubus xanthocarpus

Eight pentacyclic triterpenoids have been isolated from the aerial parts of Rubus xanthocarpus and four of them are new compounds. Their structures we re elucidated on the basis of spectral data and chemical transformations as : 1 alpha,2 alpha,3 beta,19 alpha-tetrahydroxyurs-12-en-28-oic and, 2 alpha ,3 alpha,19 alpha,24-tetrahydroxyurs-12-en-28-oic acid-28-O-beta-D-glucopyr anusyl ester, 2 alpha,3 alpha,19 alpha-trihydroxyurs-12-en-24-formyl-28-oic acid-28-O-beta-D-glucopyranosyl eater and 2,3-O-isopropylidenyl-2 alpha,3 alpha,19 alpha-trihydroxyurs-12-en-28-oic acid. (C) 1998 Elsevier Science L td. All rights reserved.