Novel copper superoxide dismutase mimics and damage mediated by O2.-.

Metabolites of oxygen such as superoxide anions (O2.-), hydrogen peroxide (H2O2), and hydroxyl radicals (OH.) are potentially damaging to biological systems. Univalent reduction of oxygen produces O2.-, which may be converted to H2O2 and OH(.). The biological damage mediated by O2.- can be attenuated by a cytosolic copper- and zinc-containing enzyme known as superoxide dismutase (SOD). Certain transition metal complexes having properties similar to SOD may be useful in suppressing such damage. However, known complexes have either been ineffective in vivo or may have toxic side effects. We prepared mixed-ligand copper complexes of polyamine using biomolecules such as pyridine or imidazoles as secondary ligands. The choice of polyamines and biomolecules was made with the aim of producing products with low toxicity. Our studies suggest that these copper complexes act as mimics of SOD in a variety of O2.(-)-generating systems and may be effective SOD mimics for their usage to abrogate such an injury in biological systems. This manuscript provides a brief state-of-the-art review on SOD mimics including our own studies.