Two new triterpenoids from the resin ofStyrax tonkinensis

Two new triterpenoids, 3β,6β-dihydroxy-12-oxo-13Hα-olean-28,19β-olide (1) and 3-oxo-olean-11,13(18)-dien-28,19β-olide (2) were isolated from the resin of Styrax tonkinensis (Pier.) Craib. The structures of both triterpenoids were determined by physicochemical and spectroscopic methods. Compound 1 is the second triterpene found with cis-fused C/D ring from the resin, which is rarely observed in oleanane-type triterpenes.