Abstract
Two mixed ligand complexes, viz., [Cu(Bz(OH))(Gly)]ClO4 1 and [Cu(Bz(OH))(Glu)]ClO4 2, where Bz(OH) = 1-benzimidazolylethanol, Gly = Glycine, and Glu = L-glutamic acid were synthesized Their structures and properties were characterized by elemental analysis, IR, Raman, UV-vis, and ESR spectroscopy. Electrochemical measurements, including cyclic voltammetry and electrical molar conductivity were also performed. Spectral features point to square-planar CuN2O2 coordination geometries for both complexes. Spectroscopic and electrochemical studies were performed in order to correlate structural features of the complexes with their catecholase and catalase-like activities. The electrochemical behavior for the oxidation of catechol was studied using cyclic voltammetry at a carbon paste electrode modified by complex 1. The increasing in both anodic and cathodic peak current is due the presence of the complex as a structural mimics of catecholase, which acts as a redox mediator or electron shuttle which catalyze the oxidation and reduction of catechol at the surface of carbon paste modified electrode. Complex 1 showed high catalase activity with IC50 = 2.0 mM. These studies showed that this complex was found to be promising candidates as durable electron-transfer catalyst being close to the efficiency of the mimicking enzymes displaying either catalase or tyrosinase activity to serve for complete reactive oxygen species (ROS) detoxification with respect to peroxides. The nuclease activity of complex 1 was also assessed by its ability to cleave bacterial plasmid DNA in the absence of any external additives