Cytotoxic terpenoids from Turraea pubescens

Three new triterpenoids, turrapubesols A-C (1-3), and one new sesquiterpenoid, 1 alpha,4 alpha-dihydroxyeudesman-11-ene (4), along with 12 known terpenoids were isolated from Turraea Pubescens. The structures of the terpenoids were established on the basis of extensive spectroscopic analyses and by a chemical transformation. The previous assignment of the NMR data for guaidiol (5) was corrected. Some of the triterpenoids exhibited cytotoxicity against the P-388 cell line.