Synthesis, molecular docking, antioxidant and anticanceractivitiesof tetraaza macrocyclic copper (Ii) complexes

Abstract

Three novel copper (II) complexes were synthesized from macrocyclic Schiff base ligand, which was derived from malonanilic acid hydrazone and thiosemicarbazide hydrochloride in 1:1 molar ratio. Schiff base ligand and all copper complexes were characterized by various physico-chemical and spectroscopic techniques like melting point, elemental analysis, molar conductance, UV-Vis, FT-IR, XRD, and thermo-gravimetric analysis (TGA). Spectroscopic studies confirm the distorted octahedral geometry of all the copper complexes. The biological activities of all compounds were evaluated like in-vitro antioxidant activity or percentage free radical scavenging effect via DPPH method against standard ascorbic acid and in vitro anticancer activity via MTT assay against MCF-7 breast cancer cell lines. Furthermore, for identification of binding modes of copper (II) complexes in the active pocket of target enzyme Topoisomerase IIα, molecular docking studies were also performed. Results of the biological activities showed that complex 1 exhibited the highest anti-cancer activity against MCF-7 cell line i.e. 7.21 ± 0.1 µg/ml among other copper complexes whereas compound 3 showed best antioxidant activity against ascorbic acid i.e. 86.04 µg/ml. Molecular docking study indicated here that all copper complexes were fitted into the active site of target enzyme and Copper complex 3 showed the maximum binding affinity (-20.4 kcal/mol) comparable to the other complexes.