title: Substitution of p- and o-hydroxyphenyl radicals at the 8 position of purine nucleosides by reaction with mutagenic p- and o-diazoquinones.
abstract: Incubation of 2'-deoxyadenosine (dAdo), 2'-deoxyguanosine (dGuo), adenosine, guanosine (Guo), thymidine, deoxycytidine with p- and o-diazoquinones, mutagens produced by the reaction of phenol and nitrite, at pH 7 and 37 degrees C resulted in a decrease of each nucleoside depending upon the concentration of the diazoquinones. pD-dAdo, pD-dGuo and pD-Guo were isolated from the reaction mixtures of dAdo, dGuo and Guo, respectively, with p-diazoquinone at pH 9.5, and oD-dGuo was from the mixture of dGuo and o-diazoquinone at pH 9.5. The products were identified as 8-(p-hydroxyphenyl)- and 8-(o-hydroxyphenyl)-purine nucleosides by 1H- and 13C-nuclear magnetic resonance spectra, secondary ion mass spectrum, ultraviolet absorption spectrum and elemental analysis. p- and o-Diazoquinones may be converted into p- and o-hydroxyphenyl radicals, respectively, which in turn attack the 8 position of the purine nucleosides. The mutagenicity of these diazoquinones may be partly due to the radical reactions.
authors.affiliation: Tokyo College of Pharmacy, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kikugawa
authors.forename: T
authors.initials: T
authors.lastname: Kato
authors.forename: K
authors.initials: K
authors.lastname: Kojima
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives*; D002851:Chromatography, High Pressure Liquid; D006151:Guanosine / Q000031:analogs & derivatives*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D009153:Mutagens / Q000737:chemistry* / Q000494:pharmacology; D011684:Purine Nucleosides / Q000737:chemistry*; D011809:Quinones / Q000737:chemistry* / Q000494:pharmacology; D013696:Temperature
chemical_list: D009153:Mutagens; D011684:Purine Nucleosides; D011809:Quinones; D006151:Guanosine; C055898:2-diazoquinone; C055897:4-diazoquinone; D000241:Adenosine