Anthraquinone intercalators as carrier molecules for second-generation platinum anticancer drugs

A series of complexes PtAm2L [where Am-2 = (NH3)(2), ethylenediamine(en), 1,2-diaminocyclohexane (DACH) or (NH3)(c-C6H11NH2) and where L is a bidentate 1,1-dicarboxylate ligand tethered to 1-aminoanthraquinone by various spacers] was prepared and screened in vitro against P388 leukemia cells. The free ligands displayed moderate activity and the corresponding platinum complexes were tenfold more active. The nature of the linker chain does not seem to affect the potency of the complexes. The potency depends on the nature of the inert amine ligand [NH3 > DACH > en]. The low aqueous solubility of these complexes prevented any in vivo studies and the preparation of water soluble analogs is currently under way.