Synthesis of 2-Substitutedbenzimidazolium Tetrachloroplatinate(II) Compounds and Their Cytotoxic Activities on Different Cell Lines

The aim of the study was the synthesis of novel platinum compounds having benzimidazole ligands and screening for their in vitro cytotoxic activity on human cervical carcinoma HeLa, human lung carcinoma A549, and human lung epithelial Beas-2B cell lines. 2-Substituted benzimidazole ligands were synthesized by using appropriate aldehydes and o-phenylenediamine. Subsequently, 2-substituted benzimidazole ligands and potassium tetrachloroplatinate(II) (K2PtCl4) were used to synthesize 2-isopropylbenzimidazole tetrachloroplatinate(II) (K1) and 2-(1-methylpropyl)benzimidazole tetrachloroplatinate(II) monohydrate (K2). HRMS, IR, elemental analysis, 1H-NMR, and melting point were used to characterize the synthesized compounds. Cytotoxic activities against HeLa, A549, and Beas-2B cells after 48 h and 72 h incubation of the platinum compounds were investigated via MTT assay. Cisplatin and carboplatin were used as reference drugs. The cytotoxic activity results showed that K2 platinum compound displayed 53.42%±2.21 (at 160 μM) on HeLa, 88.16%±0.22 (at 160 μM) on A549 and 92.09%±0.57 (at 160 μM) on Beas-2B after 48 h incubation, K2 displayed 27.42%±2.03 (at 160 μM) on HeLa, 93.95%±0.53 (at 160 μM) on A549 and 91.99±0.22 (at 160 μM) on Beas-2B after 72 h incubation. Both of the platinum compounds have higher cell inhibitory effects than reference drug carboplatin after 48 h incubation for tested cells.