trans-Platinum(II) Thionate Complexes: Synthesis, Structural Characterization, and in†vitro Biological Assessment as Potent Anticancer Agents.

A series of Pt(II) complexes trans-[Pt(PPh2 allyl)2 (κ1 -S-SR)2 ], 1, PPh2 allyl=allyldiphenylphosphine, SR=pyridine-2-thiol (Spy, 1 a), 5-(trifluoromethyl)-pyridine-2-thiol (SpyCF3 -5, 1 b), pyrimidine-2-thiol (SpyN, 1 c), benzothiazole-2-thiol (Sbt, 1 d), benzimidazole-2-thiol (Sbi, 1 e), were synthesized. They were characterized by NMR, HR ESI-MS, and X-ray crystallography. Treatment of human cancer cell lines (A549, SKOV3, MCF-7) with these complexes resulted in promising antitumor effects in comparison with cisplatin. These compounds showed suitable selectivity between tumorigenic and non-tumorigenic (MCF-10 A) cell lines. Analyses of cell cycle progression and apoptosis were conducted for 1 a, the most cytotoxic compound, to screen dose/time response and to study the antiproliferative mechanism. An electrophoresis mobility shift assay was performed to assess the direct interaction of 1 a with DNA and the strong genotoxic ability was indicated through the comet assay method.