title: A new mononuclear manganese(III) complex of an unsymmetrical hexadentate N3O3 ligand exhibiting superoxide dismutase and catalase-like activity: synthesis, characterization, properties and kinetics studies.
abstract: A mononuclear Mn(III) complex MnL·4H2O (H3L=1-[N-(2-pyridylmethyl),N-(2-hydroxybenzyl)amino]-3-[N'-(2-hydroxybenzyl),N'-(4-methylbenzyl)amino]propan-2-ol) has been prepared and characterized. This complex catalyzes the dismutation of superoxide efficiently, with catalytic rate constant kcat=1.7×10(6)M(-1)s(-1) and IC50 1.26μM, obtained through the nitro blue tetrazolium photoreduction inhibition superoxide dismutase assay, in aqueous solution of pH7.8. MnL is also able to disproportionate more than 300 equivalents of H2O2 in CH3CN, with initial rate of H2O2 decomposition given by ri=kcat [MnL](2) [H2O2] and kcat=1.32(2)mM(-2)min(-1). The accessibility of the Mn(IV) state (E(p)=0.53V vs. saturated calomel electrode), suggests MnL employs a high-valent catalytic cycle to decompose O2(-) and H2O2.
authors.affiliation: IQUIR (Instituto de Química Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, (S2002LRK), Rosario, Argentina.
authors.forename: Gabriela N
authors.initials: GN
authors.lastname: Ledesma
authors.affiliation: Laboratoire de Chimie de Coordination, UPR CNRS 8241, 205 Route de Narbonne, 31077 Toulouse Cedex 04, France; Université de Toulouse; UPS, INPT, LCC, F-31077 Toulouse, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Eury
authors.affiliation: Laboratoire d'Electrochimie Moléculaire UMR CNRS-P7 7591 Université Paris Diderot-Paris, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Anxolabéhère-Mallart
authors.affiliation: Laboratoire de Chimie de Coordination, UPR CNRS 8241, 205 Route de Narbonne, 31077 Toulouse Cedex 04, France; Université de Toulouse; UPS, INPT, LCC, F-31077 Toulouse, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Hureau
authors.affiliation: IQUIR (Instituto de Química Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, (S2002LRK), Rosario, Argentina. Electronic address: signorella@iquir-conicet.gov.ar.
authors.forename: Sandra R
authors.initials: SR
authors.lastname: Signorella
mesh_terms: D002374:Catalase / Q000737:chemistry; D002384:Catalysis; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007700:Kinetics; D008024:Ligands; D017895:Manganese Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010084:Oxidation-Reduction; D011412:Propanolamines / Q000138:chemical synthesis* / Q000737:chemistry; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry; D013482:Superoxide Dismutase / Q000737:chemistry
chemical_list: D056831:Coordination Complexes; D008024:Ligands; D017895:Manganese Compounds; D009942:Organometallic Compounds; D011412:Propanolamines; D011725:Pyridines; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase
keywords: Kinetics; Mn complex; Mn-based ROS scavenger; SOD/catalase activity