title: Superoxide scavenging activity of spin-labeled nitrosourea and triazene derivatives.
abstract: Superoxide scavenging activities (SSA) of newly synthesized spin-labeled nitrosourea and triazene derivatives, and their precursor nitroxides were investigated by the ESR/spin-trapping method using the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and hypoxanthine/xanthine oxidase as the superoxide-generating system. The spin-labeled nitrosoureas, triazenes and their precursor nitroxides exhibited excellent SSA, whereas clinically used nitrosourea and triazene, which do not contain the nitroxide moiety, did not show any SSA. Furthermore, it was deduced that these nitroxides scavenge superoxide by redox cycling between nitroxide and corresponding hydroxylamine.
authors.affiliation: Department of Chemistry and Biochemistry, Medical University, Stara Zagora, Bulgaria.
authors.forename: V
authors.initials: V
authors.lastname: Gadzheva
authors.forename: K
authors.initials: K
authors.lastname: Ichimori
authors.forename: H
authors.initials: H
authors.lastname: Nakazawa
authors.forename: Z
authors.initials: Z
authors.lastname: Raikov
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000494:pharmacology*; D005609:Free Radicals; D015394:Molecular Structure; D009589:Nitrogen Oxides; D009607:Nitrosourea Compounds / Q000494:pharmacology*; D015203:Reproducibility of Results; D013113:Spin Labels; D013481:Superoxides / Q000378:metabolism*; D014226:Triazenes / Q000494:pharmacology*
chemical_list: D016166:Free Radical Scavengers; D005609:Free Radicals; D009589:Nitrogen Oxides; D009607:Nitrosourea Compounds; D013113:Spin Labels; D014226:Triazenes; D013481:Superoxides; C039900:nitroxyl