title: DEPMPO: an efficient tool for the coupled ESR-spin trapping of alkylperoxyl radicals in water.
abstract: Peroxidation is an important process both in chemistry and biology, and peroxyl radicals play a crucial role in various pathological situations involving lipid and protein peroxidation. A few secondary and tertiary peroxyl radicals can be detected directly by Electron Spin Resonance (ESR). However, primary and secondary alkylperoxyl radicals have extremely short lifetimes and their direct observation is impossible in biological samples. DMPO has been used to trap alkylperoxyl radicals generated in biological systems and the characterization of DMPO-alkylperoxyl spin adducts has been claimed by different authors. However, it was then clearly shown that all the assignments made previously to DMPO-OOR adducts were actually due to DMPO-OR adducts. We have investigated the potential of DEPMPO to characterize the formation of alkylperoxyl radicals in biological milieu. Various DEPMPO-OOR (R = Me, primary or secondary alkyl group) spin adducts were unambiguously characterized and the formation of DEPMPO-OOCH(3) was clearly established during the reaction of tert-butylhydroperoxide with chloroperoxidase and cytochrome c.
authors.affiliation: Universités d'Aix-Marseille I, II et III-CNRS UMR 6264, Laboratoire Chimie Provence, Equipe SREP, 13397 Marseille, Cedex 20, France. hakim.karoui@univ-provence.fr
authors.forename: Hakim
authors.initials: H
authors.lastname: Karoui
authors.forename: Florence
authors.initials: F
authors.lastname: Chalier
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Finet
authors.forename: Paul
authors.initials: P
authors.lastname: Tordo
mesh_terms: D000478:Alkylation; D000818:Animals; D045304:Cytochromes c / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000737:chemistry; D006736:Horses; D015394:Molecular Structure; D010545:Peroxides / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: C510912:(diethoxyphosphoryl)-5-methylpyrroline N-oxide; D005609:Free Radicals; D010545:Peroxides; D011758:Pyrroles; D014867:Water; C049375:perhydroxyl radical; D045304:Cytochromes c