Efficient water-soluble copper(II) complexes with SOD/CO-like activities and the relationship between their structure and activity

Abstract

Superoxide dismutase is a significant member of the body’s natural antioxidant defense system. It can effectively eliminate superoxide anion free radicals from the body. Based on the functionalized ligand-isonicotinic acid, three copper complexes were successfully developed. The metal centers of complexes 1–3 were highly similar to the active sites of natural superoxide dismutase. It was found that complexes 1–3 exhibited both excellent superoxide dismutase (SOD)-like and catecholase (CO)-like activities at the same time. A model of oxidative stress, induced by hydrogen peroxide, was constructed based on the cytotoxicity test. In this model, the mimetic complex proved to have effective intracellular antioxidant capacity. Combined with the experimental data and DFT, the results showed that the electron acceptance ability and the coordination configuration of the active center of copper ions had important effects on the activity of SOD.