title: Identification of products formed by reaction of 3',5'-di-O-acetyl-2'-deoxyguanosine with hypochlorous acid or a myeloperoxidase-H2O2-Cl- system.
abstract: Hypochlorous acid (HOCl), generated by myeloperoxidase from H(2)O(2) and Cl(-), plays an important role in host defense and inflammatory tissue injury. We have studied the reaction of 3',5'-di-O-acetyl-2'-deoxyguanosine with reagent HOCl and with a human myeloperoxidase-H(2)O(2)-Cl(-) system in order to characterize polar reaction products. When 100 microM 3',5'-di-O-acetyl-2'-deoxyguanosine was reacted with 100 microM HOCl at pH 7.4 and 37 degrees C and the reaction was terminated by N-acetylcysteine, 3',5'-di-O-acetyl derivatives of previously reported products, such as diastereomers of spiroiminodihydantoin nucleoside, a diimino-imidazole nucleoside, an amino-imidazolone nucleoside, and 8-chloro-2'-deoxyguanosine were formed. In addition, we report the formation of 3',5'-di-O-acetyl derivatives of a guanidinohydantoin nucleoside, an iminoallantoin nucleoside, and a diamino-oxazolone nucleoside in this system. The identification of the products was based on their identical ESI-MS and UV spectra and HPLC retention times with authentic compounds synthesized with other oxidation systems. All of these products were also formed in the reaction of 3',5'-di-O-acetyl-2'-deoxyguanosine with the myeloperoxidase-H(2)O(2)-Cl(-) system under mildly acidic conditions. The yields of the products were greatly affected by the pH of the reaction mixture. The total yields of these products formed by HOCl at pH 7.4 and by the myeloperoxidase-H(2)O(2)-Cl(-) system at pH 4.5 were 72 and 43% of the consumed 3',5'-di-O-acetyl-2'-deoxyguanosine, respectively, indicating that nearly half of the consumption of 3',5'-di-O-acetyl-2'-deoxyguanosine by HOCl and the myeloperoxidase-H(2)O(2)-Cl(-) system can be accounted for by the formation of these products.
authors.affiliation: Unit of Endogenous Cancer Risk Factors and Unit of Nutrition and Cancer, International Agency for Research on Cancer, 150 Cours Albert Thomas, 69372 Lyon, Cedex 08, France.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Suzuki
authors.forename: Marlin D
authors.initials: MD
authors.lastname: Friesen
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohshima
mesh_terms: D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000737:chemistry* / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006997:Hypochlorous Acid / Q000378:metabolism*; D007093:Imidazoles / Q000737:chemistry / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D009538:Nicotine / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism*; D012965:Sodium Chloride / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
chemical_list: D007093:Imidazoles; D012965:Sodium Chloride; D009538:Nicotine; D006997:Hypochlorous Acid; D008715:Methionine; D006861:Hydrogen Peroxide; D009195:Peroxidase; D003849:Deoxyguanosine