Triterpenoids from Cassine xylocarpa and Celastrus vulcanicola (Celastraceae)

Abstract Two new pentacyclic triterpenoids, xyloketal ( 1 ), a 3,25-epoxy-olean-12-ene, and 3β,21α-dihydroxyglut-5-ene ( 2 ) along with seven known triterpene compounds ( 3 – 9 ) were isolated from the root barks of Cassine xylocarpa and Celastrus vulcanicola . Their structures were characterized by spectroscopic methods, mainly NMR ( 1 H, 13 C, HSQC, HMBC and ROESY) and EIMS, and comparison with data reported in the literature. Also molecular mechanic calculations were used to calculate the minimum energy conformer of compound 1 and its epimer.