Mechanistic and cytotoxicity studies of group IV β-diketonate complexes.

Group IV metal complexes have previously shown promise as novel anticancer agents. Here, we discuss the mechanistic and cytotoxic nature of a series of group IV b-diketonate coordina- tion complexes. Clear evidence that the ligands are exchangea- ble on the metal centre and that the b-diketonate ligands can act as potential drug delivery vehicles of the group IV metal ions was obtained. When evaluated for the cytotoxicity against human colon adenocarcinoma (HT-29) and human breast ade- nocarcinoma (MCF-7) cell lines, a general trend of decreasing potency down the group IV metals was observed. The most promising results obtained were for the hafnium complexes, with the tris diphenyl b-diketonate hafnium complex exhibit- ing IC50 values of 4.9