Antiproliferative Prenylated Xanthones and Benzophenones from the Roots of Cudrania Tricuspidata in HSC-T6 Cells

Four new prenylated xanthones, cudracuspixanthones A-D (1-4), two new prenylated benzophenones, cudracuspiphenones A (5) and B (6), and 11 known xanthones (7-17) were isolated from the roots of Cudrania tricuspidata. The absolute configurations of compounds 2-4 were deduced by the comparison of the calculated optical rotation values with the measured data. Compounds 1, 5, and 6 showed moderate antiproliferative activity on HSC-T6 cells with IC50 values of 9.7, 3.3, and 7.1 μM, respectively. Compounds 2-4, 10, and 14-16 had weaker activity. Flow cytometric analysis suggested that compounds 1 and 5 inhibited HSC-T6 cell proliferation in part by inducing apoptosis.