title: Photo-oxidation of duplex DNA with the stable trioxatriangulenium ion.
abstract: We show that 5'-Gs in 5'-GG-3' duplex DNA dinucleotide steps are preferentially oxidized by the trioxatriangulenium ion (TOTA( plus sign in circle )) upon photo-activation, an oxidation pattern characteristic of guanine radical cation formation. Some photo-oxidation of the 3'G in 5'GG3' steps and of isolated guanines is also observed but reactions carried out in D(2)O reveal only a minor increase in oxidation damage at these sites, indicating that electron transfer is the primary mechanism of guanine oxidation.
authors.affiliation: Division of Medicinal Chemistry, College of Pharmacy, and Institute for Cellular and Molecular Biology, The University of Texas at Austin, 78712, USA.
authors.forename: Arti
authors.initials: A
authors.lastname: Pothukuchy
authors.forename: Sampathkumar
authors.initials: S
authors.lastname: Ellapan
authors.forename: Karickal R
authors.initials: KR
authors.lastname: Gopidas
authors.forename: Miguel
authors.initials: M
authors.lastname: Salazar
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects*; D017666:Deuterium Oxide / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry; D006147:Guanine / Q000737:chemistry; D007477:Ions; D009692:Nucleic Acid Heteroduplexes / Q000737:chemistry* / Q000187:drug effects / Q000528:radiation effects*; D010084:Oxidation-Reduction; D010782:Photolysis; D011721:Pyrenes / Q000737:chemistry* / Q000494:pharmacology; D014867:Water / Q000737:chemistry
chemical_list: D005609:Free Radicals; D007477:Ions; D009692:Nucleic Acid Heteroduplexes; D011721:Pyrenes; C472757:trioxatriangulenium; D014867:Water; D006147:Guanine; D004247:DNA; D017666:Deuterium Oxide