title: Singlet oxygen generation in the superoxide reaction.
abstract: ESR spin trapping was utilized to study the singlet oxygen (1O2) generation in the reaction of superoxide (O2) with H2O2. The spin trap used was 2,2,6,6-tetramethyl-4-piperdone. Incubation of xanthine, xanthine oxidase and H2O2 generated 1O2 spin adduct signal. Omission of xanthine, xanthine oxidase or H2O2 caused a sharp decrease in 1O2 generation. 1O2 scavenger, sodium azide, inhibited 1O2 generation while .OH scavenger, ethanol, only slightly decreased the signal intensity. Potassium superoxide (KO2) decomposition generated 1O2. Catalase and sodium azide inhibited 1O2 generation and H2O2 enhanced it. The results demonstrate that O2 is capable of generating 1O2 upon reaction with H2O2.
authors.affiliation: Laboratory of Experimental Pathology, National Cancer Institute, NIH, Bethesda, MD 20892, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Mao
authors.forename: L
authors.initials: L
authors.lastname: Zang
authors.forename: X
authors.initials: X
authors.lastname: Shi
mesh_terms: D001386:Azides / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D026082:Singlet Oxygen; D019810:Sodium Azide; D013113:Spin Labels; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism*; D019820:Xanthine; D014969:Xanthine Oxidase / Q000378:metabolism; D014970:Xanthines / Q000378:metabolism
chemical_list: D001386:Azides; D005609:Free Radicals; D013113:Spin Labels; D014970:Xanthines; D013481:Superoxides; D026082:Singlet Oxygen; D019820:Xanthine; D017665:Hydroxyl Radical; D019810:Sodium Azide; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; D010100:Oxygen