Design, preparation, physicochemical characterization, structural conformational, biological evaluation, and DNA interaction for some new benzimidazole complexes

Abstract

New Cu (II), VO (II), Ag(I), and Pd (II)‐[BIP = 4,6‐dimethyl‐N‐(octahydro‐2H‐benzimidazol‐2‐ylidene)pyrimidin‐2‐amine] chelates have been synthesized by the reaction of BIP ligand resulting from the condensation of benzimidazole guanidine as well as acetylacetone with tested metal salts. The suggested structures of prepared compounds have been investigated spectroscopically through (FT‐IR, NMR, Mass spectra, and UV–Vis spectra), CHN analyses, conductivity, pH stability as well asmagnetic moment measurements. TGA studies have been also studied to govern the thermal behavior, stability, and decomposition of the metal chelates. Structural study of the tested chelates exposed their chemical transformation of ligand by chelation with the studied metals. The studies predicted a hexa‐coordinated geometry for the Cu and VO chelates, whereas tetra‐coordinated for the Ag and Pd chelates. DFT/B3LYP theoretical method was applied to obtain optimized geometry, molecular electrostatic potential (MEP) surface, and HOMO‐LUMO analysis for tested compounds. For estimation in the in vitro study, all the tested compounds have been screened for their biochemical features, including antioxidant, antimicrobial performances, and cytotoxicity. The antioxidant performance of prepared molecules has been studied by DPPH study and all the tested chelates displayed close antioxidant performance against the standard drugs. The cytotoxic analysis of tested compounds has been estimated against various cancer cell lines: (Hep‐G2, HCT‐116, and MCF‐7) using MTT analysis as well as calculated the cell viability for the corresponding human cell. The DNA binding capability for the tested compounds has been evaluated through absorption spectroscopic, viscosity estimation, as well as gel electrophoresis. The outcomes displayed a good binding tendency through the binding constant from 1.01 × 104 to 1.99 × 104 M−1 in the order BIPCu> BIPVO > BIPPd > BIPAg, respectively. Finally, docking simulation results indicated that the complexes were located in the intercalation site of DNA and confirmed experimental findings.