Cytotoxic sesquiterpene lactones from Carpesium abrotanoides

Eight sesquiterpene lactones, 4 alpha,5 alpha-epoxy-10 alpha,14-dihydro-inuviscolide (1), 2,3-dihydroaromomaticin (2), carpesiolin (3), carabrone (4), carabrol (5), telekin (6), ivalin (7) and 11,13-didehydroivaxillin (8), were isolated from the aerial parts of Carpesium abrotanoides Linne (Compositae). In vitro cytotoxicity testing was carried out against L1210, A549, SK-OV-3, SK-MEL-2, XF-498 and HCT-15 tumor cell lines. Sesquiterpene lactone compounds 1 - 8 showed significant cytotoxic activity (ED50 values, < 20 microM) against all tumor call lines tested. Among these compounds, 4 alpha,5 alpha-epoxy-10 alpha,14-dihydro-inuviscolide (1), 2,3-dihydroaromomaticin (2), telekin (6) and ivalin (7) showed cytotoxic activity (ED50, < 10 microM) comparable to that of cisplatin.