Pyridoxal derivatized copper(II) complexes: Evaluation of antioxidant, catecholase, and DNA cleavage activity

Abstract

This manuscript describes the synthesis, characterization and structural analysis of copper(II) complexes with pyridoxal-type bidentate ligands, obtained from the condensation between pyridoxal and ortho-halogenated substituted anilines (C1–C5). The complexes C1, C2 and C5 were measured by X-ray single crystal analysis which showed classic and trifurcated hydrogen bonds and interaction as a sigma-hole between the oxygen atoms of the iodine ligand derivative in the complex C5. All compounds were tested as mimetics of superoxide dismutase (SOD), through NBT photoreduction method in aqueous solution of pH 7.8, but the complex C5 showed an expressive IC50 of 0.4 μM.In addition, catecholase-like activity of C1–C5 in the presence of the substrate 3,5-di-tert-butylcatechol and cleavage of plasmid DNA were also evaluated. Again, the best results were associated with the complex C5 containing iodine in the ortho position.