Der Pharma Chemica
Journal for Medicinal Chemistry, Pharmaceutical Chemistry, Pharmaceutical Sciences and Computational Chemistry

Abstract

Molecular design, synthesis, spectral characterization and biological studies of copper complexes derived from Knoevenagel condensates

Author(s): J. Joseph, A. Suman

Benzimidazole (BZ) and 2-aminobenzimidazole (ABZ) are important pharmacophore for pharmacological activities. In the present study, a novel series of Cu(II) complexes with Knoevenagel condensate of b-diketimine Schiff base ligands have been synthesized. The characterization of the ligands and their complexes were carried out using FTIR, 1H-NMR, UV–Vis., elemental analysis, mass and EPR techniques. Absorption titration, electrochemical analyses and viscosity measurements were also carried out to determine the mode of binding with DNA (DNA binding interaction with copper complexes). The shift in DEp, E1/2 and Ipc values were explored the interaction of CT DNA with copper complexes. Variations in the absorbance due to their interaction with DNA were also investigated with copper complexes and different concentrations of DNA. Antimicrobial studies showed an effective antimicrobial activity of the copper ions after coordination with the ligands (chelation concept). In the electrochemical investigation, the interaction of complexes with DNA, the quasi-reversible redox couple of copper complexes slightly improve its reversibility with considerable decrease in current intensity. All the experimental results indicate that the Knoevenagel condensate of copper(II) complexes intercalate more effectively into the DNA base pairs than their ligands alone. The antioxidant properties of the Schiff base ligands and their complexes were evaluated in vitro by using SOD and H2O2 free radical scavengers. We hope that the synthesized copper complexes may be mimic enzymes and behave as better antioxidant.