Abstract 14479: Progress Towards A Peroxidase-free Catalase Mimic

Abstract

Manganese complexes that exhibit catalase activity (i.e., catalyze the disproportionation of H 2 O 2 into ½ O 2 and H 2 O) are intrinsically also able to exhibit peroxidase activity (i.e., catalyze the oxidation of other molecules with H 2 O 2 as terminal oxidant). Both reactivity modes can be harnessed for therapeutically beneficial outcomes. For example, Mn-porphyrin complexes can both ( a ) protect healthy cells during radiotherapy by preventing a shift in cellular redox state to more oxidized potentials as well as (b) trigger cancer cell apoptosis by impelling a shift to more oxidized potentials. However, it is difficult to predict in advance which reactivity mode will predominate in a given biological environment. Herein we present a ruthenium complex with catalase activity 11.9-fold higher, stability to H 2 O 2 120-fold higher, and catalase/peroxidase selectivity 89.2-fold higher than the best values achieved by the synthetic MnSOD mimics.