title: The metal-mediated formation of hydroxyl radical by aqueous extracts of cigarette tar.
abstract: Aqueous extracts of cigarette tar produce hydroxyl radicals that are spin trapped by 5,5-dimethyl-1-pyrroline-N-oxide. The addition of catalase almost completely inhibits and superoxide dismutase partially inhibits spin adduct formation. The addition of ethylenediamine tetraacetic acid greatly increases the amount of hydroxyl radical adduct observed; in contrast, diethylenetriamine pentaacetic acid causes complete inhibition of spin adduct formation. We suggest that the hydroxyl radical arises from the metal-mediated decomposition of hydrogen peroxide, and that hydrogen peroxide is formed from the reduction of dioxygen by the semiquinones present in the cigarette tar.
mesh_terms: D002374:Catalase / Q000378:metabolism; D055598:Chemical Phenomena; D002621:Chemistry; D004492:Edetic Acid; D004578:Electron Spin Resonance Spectroscopy; D000431:Ethanol; D006878:Hydroxides; D017665:Hydroxyl Radical; D010947:Plants, Toxic; D011137:Polystyrenes; D011145:Polyvinyls; D012907:Smoking; D013482:Superoxide Dismutase / Q000378:metabolism; D013638:Tars; D014026:Nicotiana
chemical_list: D006878:Hydroxides; D011137:Polystyrenes; D011145:Polyvinyls; D013638:Tars; D017665:Hydroxyl Radical; D000431:Ethanol; C006960:chelex; D004492:Edetic Acid; D002374:Catalase; D013482:Superoxide Dismutase