Novel Benzimidazole Derived Imine-Based Ligand and its Co(III), Ni(II), Cu(II) and Pt(II) Complexes: Chemical Synthesis, Structure, Antimicrobial, DNA Interaction Studies and Nuclease Activity

Herein, we report the synthesis of a Schiff base ligand, 2-((E)-((1H-benzo[d]imidazol-2-yl)methylimino)methyl)-4,6-dichlorophenol (BMDC) and its Co(III), Ni(II), Cu(II) and Pt(II) coordinated compounds (henceforth named as M1, M2, M3, and M4, respectively). The synthesized compounds were subjected to various analytical and physical characterization techniques to confirm their molecular structures. Further, the DNA binding and cleavage propensity of the as-prepared metal complexes were evaluated using calf thymus DNA (CT-DNA) and supercoiled plasmid DNA (pBR322). The DNA interaction results revealed that the tested metal complexes bind with DNA through the covalent and non-covalent mode of interaction, which is investigated using absorption and fluorescence spectral studies followed by viscosity measurement. The scission of supercoiled plasmid DNA by the metal complexes suggested the potentiality of the molecules toward the cleavage of pBR322 DNA. Furthermore, the compounds were screened for in vitro antiproliferative activity, tested against the various cell lines such as A549, EAC, SIHA, and NIH3T3. Results revealed that compound M4 exhibited marked anti-proliferative activity against EAC cell line with a significant IC50 value of 10 µm compared to its parent ligand, BMDC, and other metal transition complexes under study. In addition, various hematological parameters (alkaline phosphate, creatinine, urea, RBC, and WBC) were studied, and significant results are obtained from the experiments.