Synthesis, structure, and cytotoxicity of platinum(iv) complexes bearing aminoxyl and dichloroacetate ligands

New platinum(iv)-aminoxyl complexes (PACs) 2a,b, bearing an aminoxyl radical with antioxidant properties in the equatorial position and axial dichloroacetate ligands capable of inhibiting the energy production in tumor cells through aerobic glycolysis were synthesized. Complexes 2a,b are characterized by moderate lipophilicity (log P-ow & SIM;2) and differ in the redox properties of aminoxyls. The cytotoxicity of complexes 2a,b was studied on tumor (HeLa, HepG2, MCF-7) and non-cancer cells Vero in comparison with cisplatin (CP), satraplatin (JM216), and previously described PNCs 3a,b bearing axial acetate ligands. The cytotoxicity of 2a,b for tumor cells (IC50 19-171 & mu;mol L-1) is 2-11 times higher than that of complexes 3a,b and comparable to IC50 values for CP and JM216 (10-187 & mu;mol L-1). For non-cancer cells Vero, the cytotoxicity of 2a,b (62-124 & mu;mol L-1) is significantly lower as compared to CP and JM216 (17.6-33 & mu;mol L-1).