title: Oxidation and radical intermediates associated with the glutathione conjugation of mucochloric acid.
abstract: The inactivation of the drinking water mutagen mucochloric acid (MCA) by reduced glutathione (GSH) was linked to the formation of an MCA-GSH conjugate, a nonmutagen in the Salmonella typhimurium (TA100) plate incorporation assay. Anaerobic formation of MCA-GSH is found now to be associated with oxidized glutathione (GSSG) and unconverted MCA. The anaerobic reaction of GSH with MCA in the presence of the radical trap 2-methyl-2-nitrosopropane (tNB; "tert-nitrosobutane") gives rise to an electron paramagnetic resonance (EPR) resulting from the overlapping spectra of two radical adducts. The first species exhibited hyperfine coupling constants of aN = 13.65 G and aH beta = 0.73 G. The second radical adduct exhibited a three-line signal of aN = 12.8 G. The first species is assigned to an adduct of the MCA radical because deuteration of MCA (5-deuterio-MCA) caused the beta-hydrogen hyperfine coupling to collapse. The second radical adduct is unaffected by the deuteration of MCA. Thus, the involvement of both GSSG and a carbon-centered MCA radical in the action of MCA on GSH is indicated.
authors.affiliation: Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse 13210-2786.
authors.forename: R T
authors.initials: RT
authors.lastname: LaLonde
authors.forename: S
authors.initials: S
authors.lastname: Xie
authors.forename: W
authors.initials: W
authors.lastname: Chamulitrat
authors.forename: R P
authors.initials: RP
authors.lastname: Mason
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004578:Electron Spin Resonance Spectroscopy; D005663:Furans / Q000737:chemistry*; D005978:Glutathione / Q000737:chemistry*; D009603:Nitroso Compounds / Q000737:chemistry; D010084:Oxidation-Reduction
chemical_list: D005663:Furans; D009603:Nitroso Compounds; C014117:mucochloric acid; D005978:Glutathione; C034526:tert-nitrosobutane