Cu(II) complexes based on benzimidazole ligands: synthesis, characterization, DFT, molecular docking & bioactivity study

Abstract

Aim: The biggest cause of cancer deaths globally was lung cancer. New cancer fighting drugs are needed due to the rising number of cancer patients and cancer cells' treatment resistance.Results: Two Cu(II) complexes, synthesized from ligands based on 2-aminomethyl benzimidazole and salicylaldehyde derivatives, were designed and evaluated for their effectiveness against A549 lung cancer. The compounds were subjected to computational calculation using Density Functional Theory (DFT) to gather information on their reactivity. Furthermore, molecular docking are utilized to simulate the interaction between the compound and the MPP-9 protein. The synthesis of the ligands and their Cu(II) metal complexes are efficient and straightforward. The complexation between copper atom and the ligand are in 1:1 ratio. The MTT assay of the compounds against A549 lung carcinoma reveals that the both Cu(II) complexes good cytotoxicity activity, in comparison to their respective ligands. The low HOMO-LUMO band gap based on the DFT calculation predicts the high reactivity of the compounds. Furthermore, the low binding energy and the numbers of interactions of the Cu(II) complexes with MMP-9 protein binding site coincide with the antiproliferative activity tested in vitro.Conclusion: The cytotoxicity studies performed for Cu(L1Br) are promising, indicating a good candidate for a future drug.

Keywords: DFT; MTT assay; benzimidazole; copper complex; molecular docking; schiff base.