Cytotoxic triterpenes from Crataegus pinnatifida

Bioassay-guided fractionation of Crataegus pinnatifida (Rosaceae) gave two cytotoxic ursane-type triterpenes which were identified as uvaol (1) and ur solic acid (2) by physicochemical and spectroscopic methods. 3-Oxo-ursolic acid (3) was synthesized from ursolic acid (2) by Jones method. The cytotox ic activities of these compounds were tested against murine L1210 and human cancer cell lines (A549, SK-OV-3, SK-MEL-2, XF498, and HCT15) in vitro. Co mpounds 1 and 2 showed moderate cytotoxicities against L1210, whereas they showed weak activities against human cancer cell lines. However, compound 3 exhibited potent cytotoxic activities both in murine and in human cancer c ell lines.