Synthesis, structural characterization, biological evaluation and molecular docking studies of new platinum(II) complexes bearing isocyanides

Herein, new Pt(II) complexes [R′2Pt(CNR)2] (1a–c; R′ = Me and 2a–c; R′ = p-tolyl) were synthesized by the reaction of the precursor complexes cis,cis-[Me2Pt(μ-SMe2)2PtMe2], A, and cis-[(p-tolyl)2Pt(SMe2)2], B, with four and two equivalents of different types of isocyanide ligands (CNR; R = a; t-butyl, b; benzyl, and c; cyclohexyl isocyanide), respectively. All complexes were characterized by FTIR and NMR spectroscopies, and the structure of 2b was confirmed by single-crystal X-ray determination. The evaluation of the cytotoxicity of 1a–c and 2a–c against three human cancer cell lines, namely A549 (non-small cell lung cancer cell line), SKOV3 (human ovarian cancer cell line), and MCF-7 (human breast cancer cell line), revealed promising antitumor activities for 1b and 2a in comparison with that of the standard cisplatin. Moreover, 1b effectively rendered apoptosis-inducing activities to the MCF-7 cancer cell line. The electrophoresis mobility shift assays on plasmids as well as molecular docking studies on DNA structures effectively revealed the specific binding site, binding mode, and the best orientation of the complexes to DNA