Synthesis and characterization of two new trans palladium (II) complexes containing benzylamine ligand: DNA/BSA interactions, molecular docking and in vitro cytotoxic activity

Two new trans Pd (II) complexes with formulas Pd(PhCH2NH2)(2)Cl-2 (1) and [ Pd(PhCH2NH2)(2)(L)(2)](NO3)(2) (2) (L = Letrozole drug; 4,4'-((1H-1,2,4-triazol-1-yl) methylene) dibenzonitrile) have been synthesized and characterized by elemental analysis, FT-IR and NMR spectroscopy. Single crystal X-ray diffractometry has been used to determine the crystal structure of 1. UV-Vis spectroscopy, emission titration, circular dichroism and helix melting methods have been used to study the binding interaction of Pd (II) complexes with Calf Thymus deoxyribonucleic acid (CT-DNA). The analysis results show that 1 can interact with DNA via groove binding and 2 binds to DNA through partial intercalation mode. It was found that the binding constants (K-b) of the complexes toward BSA were (1.4 x 10(4) M-1) and (1.68 x 10(4) M-1) for 1 and 2, respectively. Competitive binding using Warfarin, Ibuprofen and Digoxin site markers with definite binding sites demonstrated that the complexes bind to more than one site on BSA. In the presence of Ibuprofen, the binding constant was surprisingly not fixed, while a smaller influence was observed in the presence of Warfarin and Digoxin on 1. The results indicated that the binding site for 1 was mainly located within site II of BSA. The result of the competitive titration of 2 was different. In the presence of Warfarin, the Kb value decreased, showing a competition between 2 and Warfarin. In addition, molecular docking studies have been conducted to determine the binding site of the DNA and BSA with 1. Finally, In vitro cytotoxicity of 1, 2 and cisplatin were carried out against leukemia cancer (Raji), lung cancer (A549) and breast cancer (MCF7) cell lines. According to the IC50 values, the cytotoxicity of 2 was more than 1. (C) 2017 Elsevier B.V. All rights reserved.