title: Fast nitroxyl trapping by ferric porphyrins.
abstract: Iron(II) porphyrin nitrosyl complexes are obtained in high yields from the reaction of iron(III) porphyrins with the nitroxyl donors sodium trioxodinitrate and toluensulfohydroxamic acid. The reaction was found to proceed both in organic solvents and in aqueous media from iron(III) (meso-tetraphenyl) porphyrinate ([FeIII(TPP)]+) and iron(III) meso-tetrakis (4-sulfonatophenyl) porphyrinate ([FeIII(TPPS)]3-) or iron(III) protoporphyrin IX, respectively. The kinetic rate constant for the reaction of ([FeIII(TPPS)]3-) with sodium trioxodinitrate (kon) was estimated to be 1.00 +/- 0.04 x 107 M-1 s-1. As well as resulting in a versatile method for obtaining ferrous nitrosyl porphyrins, the reaction points at ferric porphyrins as efficient nitroxyl traps and provides a tool to model nitroxyl reactivity toward hemeproteins.
authors.affiliation: Departamento de Química Inorgánica, Analítica y Química Física/INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, Piso 3, Buenos Aires (C1428EHA), Argentina.
authors.forename: Sara E
authors.initials: SE
authors.lastname: Bari
authors.forename: Marcelo A
authors.initials: MA
authors.lastname: Martí
authors.forename: Valentín T
authors.initials: VT
authors.lastname: Amorebieta
authors.forename: Darío A
authors.initials: DA
authors.lastname: Estrin
authors.forename: Fabio
authors.initials: F
authors.lastname: Doctorovich
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008665:Metalloporphyrins / Q000737:chemistry*; D009589:Nitrogen Oxides / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D005290:Ferric Compounds; D005609:Free Radicals; D008665:Metalloporphyrins; D009589:Nitrogen Oxides; C039900:nitroxyl