title: Free radical scavenging activity of erdosteine metabolite I investigated by electron paramagnetic resonance spectroscopy.
abstract: The aim of this study was to explore the antiradical activity of Met I (an active metabolite of erdosteine) containing a pharmacologically active sulphydryl group, by means of electron paramagnetic resonance (EPR) spectroscopy which has not previously been used to characterize the antiradical activity of Met I. The effects of concentrations of 20, 10, 5, 2.5, 1.25 and 0.625 microg/ml of Met I were tested against: (a) the Fenton reaction model system with EPR detection of HO.; (b) the KO2-crown ether system with EPR detection of O2-.; (c) the EPR assay based on the reduction of the Tempol radical, and (d) the EPR assay based on the reduction of Fremy's salt radical. Our findings show that the intensity of 4 different free radicals was significantly reduced in the presence of Met I, thus indicating the presence of a termination reaction between the free radicals and Met I.
authors.affiliation: Department of Pharmacology, School of Medicine, University of Milan, Milan, Italy. piercarlo.braga@unimi.it
authors.forename: Pier Carlo
authors.initials: PC
authors.lastname: Braga
authors.forename: Maria
authors.initials: M
authors.lastname: Culici
authors.forename: Monica
authors.initials: M
authors.lastname: Dal Sasso
authors.forename: Mario
authors.initials: M
authors.lastname: Falchi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Spallino
mesh_terms: D000818:Animals; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006801:Humans; D006861:Hydrogen Peroxide; D017665:Hydroxyl Radical / Q000378:metabolism; D007501:Iron; D009603:Nitroso Compounds; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D013113:Spin Labels; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013864:Thioglycolates / Q000378:metabolism*; D013876:Thiophenes / Q000378:metabolism*
chemical_list: D003497:Cyclic N-Oxides; C045076:Fenton's reagent; D016166:Free Radical Scavengers; D009603:Nitroso Compounds; D017382:Reactive Oxygen Species; D013113:Spin Labels; D013438:Sulfhydryl Compounds; D013864:Thioglycolates; D013876:Thiophenes; C001259:Fremy's salt; D017665:Hydroxyl Radical; C048498:erdosteine; D006861:Hydrogen Peroxide; D007501:Iron; C001803:tempol