Synthesis, in vitro Cytotoxicity, and Interaction with DNA of Platinum(II) Complexes with N ‐Monocycloalkyl Derivatives of 1 R ,2 R ‐Diaminocyclohexane as Carrier Ligands

A series of platinum(II) complexes with N ‐monocyclopentyl/cyclohexyl derivatives of 1 R ,2 R ‐diaminocyclohexane as carrier ligands and dicarboxylate anions as leaving groups were synthesized and characterized. All complexes were characterized by elemental analysis, IR, 1 H NMR, and 13 C NMR spectroscopy, as well as ESIMS. The in vitro antiproliferative activities were tested by MTT assay against four human cancer cell lines; breast carcinoma (MCF‐7) and colon cancer (HCT‐116) cells were particularly sensitive, especially to complexes 1 f (IC 50 =9.81 and 1.49 μ M ) and 2 f (IC 50 =4.59 and 0.36 μ M ). Flow cytometry indicated that representative compounds exert cytotoxicity toward MCF‐7 and HCT‐116 cells through induction of apoptosis and blockage of cell‐cycle progression in the S phase, similar to cisplatin. The interaction between the platinum(II) complexes and pET22b plasmid DNA was observed by agarose gel electrophoresis, revealing that complex 2 f has the capacity to distort plasmid DNA in a manner distinct from that of oxaliplatin.