The design of synthetic superoxide dismutase mimetics: seven-coordinate water soluble manganese(ii) and iron(ii) complexes and their superoxide dismutase-like activity studies

Abstract

Bio-inspired manganese [Mn(N₅Py)(H₂O)(CH₃OH)](ClO₄)₂ (1) and iron [Fe(N₅Py)(H₂O)(ClO₄)]ClO₄ (2) complexes derived from a pentadentate ligand (N₅Py = 2,6-bis((E)-1-phenyl-2-(pyridin-2-ylmethylene)hydrazinyl)pyridine) framework containing a N₅ binding motif were synthesized and characterized using different spectroscopic methods. The molecular structures of complexes 1 and 2 were determined by X-ray crystallography. These complexes were found to be stable under physiological conditions and exhibited an excellent superoxide dismutase (SOD) activity. The SOD activity was determined by a xanthine–xanthine oxidase–nitro blue tetrazolium assay and the IC₅₀ values were determined to be 1.53 and 2.09 μM, respectively.