title: Characterization of the activity of L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1-be nzopyran-6-yl-hydrogen phosphate] potassium salt in hydroxyl radical elimination.
abstract: The effect of L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H -1-benzopyran-6-yl-hydrogen phosphate] potassium salt (EPC-K1) on hydroxyl radical (*OH) elimination was studied using electron spin resonance (ESR) and spectrophotometric experiments. The addition of EPC-K, and *OH scavengers eliminated the *OH generated from Cu2+/H2O2, Fe2+/H2O2 and H2O2/UV-irradiation reaction systems. However, in competitive reactions using different concentrations of a spin-trap agent, the addition of the *OH scavenger altered the IC50 values, whereas the addition of EPC-K1 and a metal chelater did not change the value in the Cu2+/H2O2 and Fe2+/H2O2 reaction systems. The addition of EPC-K1 and metal chelater changed the ESR signal for free Cu2+. The spectrophotometric experiments confirmed that the addition of EPC-K1 and metal chelater altered the absorption spectra due to CuCl2 and FeSO4, whereas the *OH scavenger did not alter the spectra. Therefore, it was demonstrated that EPC-K, has the ability both to scavenge *OH directly and to inhibit the generation of *OH by the chelation of Cu2+ and Fe2+.
authors.affiliation: Department of Endodontics, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tomita
authors.forename: M
authors.initials: M
authors.lastname: Kashima
authors.forename: Y
authors.initials: Y
authors.lastname: Tsujimoto
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D001205:Ascorbic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000528:radiation effects; D017665:Hydroxyl Radical / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D014466:Ultraviolet Rays; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D014810:Vitamin E; D017665:Hydroxyl Radical; C066638:potassium ascorbyl tocopheryl phosphate; D003300:Copper; D006861:Hydrogen Peroxide; D007501:Iron; D001205:Ascorbic Acid