title: Photolabile N-hydroxypyrid-2(1H)-one derivatives of guanine nucleosides: a new method for independent guanine radical generation.
abstract: One-electron oxidized guanine is an important reactive intermediate in the formation of oxidatively generated damage in DNA and a variety of methods have been utilized for the abstraction of a single electron from the guanine moiety. In this study, an alternative approach for the site specific, independent generation of the guanine radical, utilizing N-hydroxypyrid-2(1H)-one as a photolabile modifier of guanine, is proposed. Novel photolabile 6-[(1-oxido-2-pyridinyl)oxo]-6-deoxy- and 2',6-dideoxy-guanosine derivatives capable of generating the neutral guanine radical (G(-H)*) upon photolysis were synthesized and characterized. The generation of G(-H)* proceeds through homolysis of the N-O bond and was confirmed through continuous photolysis product analysis and trapping studies, as well as laser flash photolysis experiments.
authors.affiliation: Organic Chemistry Laboratory, Department of Chemistry, University of Athens, Panepistimiopolis, 15771 Athens, Greece.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Kaloudis
authors.forename: Cecilia
authors.initials: C
authors.lastname: Paris
authors.forename: Despoina
authors.initials: D
authors.lastname: Vrantza
authors.forename: Susana
authors.initials: S
authors.lastname: Encinas
authors.forename: Raul
authors.initials: R
authors.lastname: Pérez-Ruiz
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Miranda
authors.forename: Thanasis
authors.initials: T
authors.lastname: Gimisis
mesh_terms: D005609:Free Radicals / Q000138:chemical synthesis / Q000737:chemistry; D006150:Guanine Nucleotides / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010782:Photolysis; D011728:Pyridones / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D005609:Free Radicals; D006150:Guanine Nucleotides; D011728:Pyridones