Synthesis, cytotoxicity and DNA-binding levels of ammine/propylamine platinum(II) complexes with carboxylates

Seven new mixed ammine/propylamine platinum(II) complexes with carboxylates (a-g) have been synthesized and characterized by elemental analysis, conductivity, IR, UV, and (1)H NMR spectra techniques. The cytotoxicity of these complexes was tested by MTT assay. The levels of total platinum bound to DNA were measured by ICP-MS. The results indicate that the complexes (a-g) have better cytotoxicity against EJ and HL-60 than other carcinoma cell lines. The cytotoxicity increases in the sequence: g<f<e<d<b<c<a against tested carcinoma cell lines. The cytotoxicity of complexes (a-c) is equal to that of cisplatin against HL-60. The cytotoxicity of complex a is also equal to that of cisplatin against EJ. However, the complexes (a-g) are significantly less potent than cisplatin against BGC-823, HCT-8 and MCF-7. The total DNA-platination levels increase in the sequence: cisplatin<g<e<f<d<b<c<a under the same experimental conditions. It suggests that there is no correlation between total DNA-platination levels in HL-60 cells and cytotoxicity of ammine/propylamine platinum complexes. When leaving groups are aromatic carboxylates, the complexes have better cytotoxicity, and moreover, the substituent in benzene ring also influences cytotoxicity.