Synthesis, characterization, DNA/BSA binding and cytotoxicity studies of Mononuclear Cu(II) and V(IV) complexes of Mannich bases derived from Lawsone

A series of new mononuclear copper complexes (1-5) and a vanadium complex (6) were synthesized using bidentate Mannich base ligands derived from bioactive molecule Lawsone. The structure of these new molecules/complexes (1-6) were characterized by various spectroscopic techniques such as UV-Vis, FT-IR, EPR, and ESI-MS. The structure of complex 1 was also confirmed by single crystal X-ray diffraction analysis, which revealed that complexes containing copper atom has slightly distorted square planar geometry. Computational studies were carried out for the synthesized compounds (1-6) using the DFT method with B3LYP/6-311 G (d, p) and LanL2DZ basis sets to assess the bond length, bond angle, HOMO, and LUMO energy gap (Delta E). The CT-DNA and BSA binding (protein binding affinity) studies revealed that complex 4 exhibited the highest DNA binding affinity and complexes 5 and 6 exhibited the highest protein binding affinity. The cytotoxic activity of complexes 3-6 was evaluated using MTT assay along with the apoptosis assessment (AO/EB staining) against HepG2 (human liver carcinoma cell line). Furthermore, the data revealed that all the complexes 3-6 displayed very good anticancer activity with IC50 values in the range of 5.46-2.71 mu M which is comparable with that of standard anticancer drug. (C) 2021 Elsevier B.V. All rights reserved.