title: Direct comparison of the reactivity of model complexes for Compounds 0, I, and II in oxygenation, hydrogen-abstraction, and hydride-transfer processes.
abstract: The iron(III) meso-tetramesitylporphyrin complex is a good biomimetic to study the catalytic reactions of cytochrome P450. All of the three most discussed reactive intermediates concerning P450 catalysis (namely, Cpd 0, Cpd I, and Cpd II) can be selectively produced, identified, and stabilized for many minutes in solution at low temperature by choosing appropriate reaction conditions. In this way, their reactivity against various substrates was determined by utilizing low-temperature rapid-scan UV/Vis spectroscopy. Since all reactive intermediates are derived from a single model complex, the results of these kinetic measurements provide for the first time a full comparability of the determined rate constants for the three intermediates. The rate constants reveal a significant dependence of the reactivity on the type of reaction (e.g., oxygenation, hydrogen abstraction, or hydride transfer), which closely correlates with the chemical nature of Cpds 0, I, and II. The detailed knowledge of the reactivity of these intermediates provides a valuable tool to evaluate their particular role in biological systems.
authors.affiliation: Inorganic Chemistry, Department of Chemistry and Pharmacy, University of Erlangen-Nuremberg, Egerlandstrasse 1, 91058 Erlangen, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Fertinger
authors.forename: Natalya
authors.initials: N
authors.lastname: Hessenauer-Ilicheva
authors.forename: Alicja
authors.initials: A
authors.lastname: Franke
authors.forename: Rudi
authors.initials: R
authors.lastname: van Eldik
mesh_terms: D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D008665:Metalloporphyrins / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013379:Substrate Specificity
chemical_list: D008665:Metalloporphyrins; C547334:iron(III) meso-tetramesitylporphyrin; D006859:Hydrogen; D003577:Cytochrome P-450 Enzyme System; D007501:Iron