Chemical modification of manganese porphyrins with biomolecules for new functional antioxidants

Superoxide dismutase (SOD), which catalyzes the reduction of O2*- to H2O2, is the key enzyme for the protection of oxidative stress. Here we have chemically modified manganese (Mn) porphyrins with biomolecules for new functional antioxidants. The Mn-porphyrins were conjugated with the following biochemical functional molecules: (1) catalase, to catalyze reduction of H2O2 to H2O. The resulting conjugate showed dual functions of SOD and catalase; (2) a carbohydrate, to facilitate receptor binding and, hence, active targeting. The resulting conjugate showed both SOD activity and carbohydrate recognition. These results suggest that the antioxidants promise the application to biomedical fields.