Role of carboxamido nitrogen in mononuclear manganese complex: Superoxide scavenging activity and nuclease activity

Three new ligands Pyimpy (2-((2-phenyl-2-(pyridin-2-yl)hydazono)methyl)pyridine), Me-Pyimpy (1-phenyl-1-(pyridin-2-yl)-2-(1-(Pyridin-2-yl)ethylidene)hydrazine) and PampH (N'-phenyl-N'-(pyridin-2-yl)picolinohydrazide) were synthesized. Hexa-coordinated mononuclear complexes [Mn(Pamp)(2)](ClO(4)) CH(3)OH, (3 CH(3)OH) (1), [Mn(Me-Pyimpy)(2)](ClO(4))(2) (2), and [Mn(Pamp)(2)](ClO(4)) CH(3)OH, (3 CH(3)OH) were synthesized and characterized The molecular structure of [Mn(Pamp)(2)](ClO(4)) CH(3)OH, (3 CH(3)OH) was determined by single crystal X-ray diffraction, which afforded distorted octahedral coordination sphere having meridionally spanning ligands The redox properties were exploited to examine superoxide dismutase (SOD) activity using Mn(II)/Mn(III) couple The complex 3 having ligands containing carboxamido nitrogen (N(am)) donor. has been revealed to catalyze more effectively the dismutation of superoxide (O(2)(-)) ions in xanthine-xanthine oxidase-nitro blue tetrazolium assay as compared to 1 and 2 Among the three complexes, complex 3 was found to be most effective in nuclease activity in the presence of H(2)O(2). (C) 2010 Elsevier B V All rights reserved