title: Formation of compound I by photo-oxidation of compound II.
abstract: [reaction: see text] Compound I is the heme-iron(IV)-oxo porphyrin radical cation formed in peroxidase and catalase enzymes by reaction with hydrogen peroxide. As an alternative to chemical oxidations of porphyrin-iron(III) species, various compound I species were produced by 355 nm laser flash photolysis photooxidation of the corresponding compound II species, porphyrin-iron(IV)-oxo derivatives. The method is demonstrated by production and kinetic studies of the compound I species from 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin-iron, from horseradish peroxidase, and from wild-type horse skeletal myoglobin.
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607, USA.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: R Esala P
authors.initials: RE
authors.lastname: Chandrasena
authors.forename: Enrique
authors.initials: E
authors.lastname: Martinez
authors.forename: John H
authors.initials: JH
authors.lastname: Horner
authors.forename: Martin
authors.initials: M
authors.lastname: Newcomb
mesh_terms: D000818:Animals; D006735:Horseradish Peroxidase / Q000378:metabolism; D006736:Horses; D007501:Iron / Q000737:chemistry*; D007697:Kinesics; D008665:Metalloporphyrins / Q000138:chemical synthesis* / Q000737:chemistry*; D009211:Myoglobin / Q000737:chemistry; D010084:Oxidation-Reduction; D010777:Photochemistry / Q000379:methods
chemical_list: D008665:Metalloporphyrins; D009211:Myoglobin; C066317:ferryl iron; D007501:Iron; D006735:Horseradish Peroxidase