Superoxide dismutase mimetic complex of Mn(II)/N,N-bis(2-pyridylmethyl)-(S)-histidine

A novel dinuclear Mn(II) complex, [Mn(L)(H2O)](2)(ClO4)(2) (1) where L is N , N-bis(2-pyridylmethyl)-(S)-histidinate, was synthesized. X-ray structure analysis of 1 revealed that each Mn(II) ion is a doubly carboxylate-bridged sevencoordinate structure. Cyclic voltammmetry indicated that electrode re action of 1 was dependent on pH, The reactivity toward superoxide was evalu ated by in vitro xanthine-xanthine oxidase-cytochrome c assay. The IC50 val ue of 1 is equal to 0.29 mu M (1 M = 1 mol dm(-3)), which is one of the hig hest values in Mn(II) SOD mimetic complexes.