Copper complexes bearing 2-aminobenzothiazole derivatives as potential antioxidant: Synthesis, characterization

Abstract

Novel copper complexes of Schiff base ligands of 2-aminobenzothiazole derivatives were synthesized by the condensation of Knoevenagel condensate of acetoacetanilide (obtained from substituted benzaldehydes and acetoacetanilide) and 2-aminobenzothiazole. They were characterized by elemental analysis, IR, 1H NMR, UV–Vis., molar conductance, magnetic susceptibility measurements and electrochemical studies. Based on the magnetic moment and electronic spectral data, square planar geometry has been suggested for all the complexes. Antibacterial and antifungal screening of the ligands and their complexes reveal that all the complexes show higher activities than the ligands. The binding behaviour of the complexes with calf thymus DNA has been investigated by electronic absorption spectra, viscosity measurements and cyclic voltammetry. The DNA binding constants reveal that all these complexes interact with DNA through intercalation binding mode. Superoxide dismutase and antioxidant activities of the copper complexes have also been studied. The antioxidant activities of the complexes showed higher activities. Thermal denaturation studies suggested the nature binding affinity of copper complexes with CT-DNA. All complexes exhibit suitable Cu(II)/Cu(I) redox potential to act as antioxidant enzymes mimic. Further, the copper complexes also showed catalase activity. It is hope that copper complexes were capable of decrease ROS levels or reduce oxidative stress in Alzheimer's patients.