Synthesis and Characterization of Metal Complexes [M(L)(Im)]NO₃, In Vitro DNA/BSA Binding Behavior and Cytotoxicity on HepG2 Cancer Cells

Abstract

A new ligand (HL) was prepared from heterocyclic 8‐Hydroxy‐2‐quinolinecarboxaldehyde and 2‐Aminobenzophenone in one pot synthesis. The metal complexes of the types [Zn(L)(Im)]NO3 (1), [Cu(L)(Im)]NO3 (2) and [Co(L)(Im)]NO3 (3) were prepared by adopting HL and Imidazole under refluxing conditions. The HL and complexes 1–3, were characterized by CHN elemental analysis and spectroscopic methods 1H NMR, 13C NMR, FT‐IR, ToF Mass. The spectroscopic studies suggest square pyramidal geometry in all complexes. The interaction of ligand and complexes with DNA and BSA was conducted by UV‐vis absorption and fluorescence spectroscopy. The Kb value of 2.17×104 M−1 for complex 2 is the highest depicting its greater binding propensity with DNA. Similarly, in BSA binding studies, complex 2 shows greater binding potential in the hydrophobic core probably near the Trp 212 in the subdomain IIA. Furthermore, the complex 2 shows excellent cytotoxicity on HepG2 cancer cells with IC50=74.05±0.69 μM. In the cell cycle analysis of HepG2 cells, it has been observed that complex 2 arrests the cell proliferation in the G1/S phase. Annexin V‐based flow cytometry analysis further indicated 6‐fold apoptotic cell death by complex 2 in the experiment along with non‐specific necrosis cell death.