Synthesis, cytotoxicity and DNA-binding levels of amminecyclohexy/ aminecarboxy/platinum(II) complexes

Six new amminecyclohexy/aminecarboxy/platinum(II) complexes with carboxylates (a~f) have been synthesized and characterized by elemental analysis, conductivity, IR, UV, and ¹H NMR spectra techniques. The cytotoxicity of the complexes was tested by MTT assay. The cell cycle analysis and the levels of total platinum bound to DNA were measured by flow cytometry and ICP-MS. The results show that complexes (c), (d), (e) and (f) have excellent cytotoxicity against EJ and HL-60 and complexes (c), (d) and (e) demonstrate cytotoxicity superior to that of the clinically established cisplatin. Complexes (a~f) have poor cytotoxicity against HCT-8, MCF-7 and BGC-823 than that of cisplatin. The complexes (a~f) induce a concentration-dependent accumulation of HL-60 and EJ cells in the G₂/M phase of the cell cycle as cisplatin. The levels of total platinum bound to DNA in HL-60 and EJ cells decrease in the sequence: c > d > e > cisplatin > f > a > b under the same experimental conditions.