Three New Triterpenoids from the Bark and Twigs of Schima crenata

Three new oleanane-type triterpenoids (1–3), along with two known analogues, A1-barrigenol (4) and 22α-O-angeloyl-A1-barrigenol (5), were isolated from the bark and twigs of Schima crenata. Their structures were elucidated by spectroscopic techniques and comparison with related compounds. All the isolates were evaluated for their cytotoxicities against HepG2, MDA-MB-231, MCF-7, and HeLa tumor cell lines. Compounds 1, 3, and 5 showed potent cytotoxic activities against those four human cancer lines with IC50 values ranging from 11.9 ± 2.11 to 45.0 ± 3.76 µM. Compound 2 exhibited selective cytotoxicity against HepG2 cells with IC50 value of 5.4 ± 0.95 µM.