Photolabile N-hydroxypyrid-2(1H)-one derivatives of guanine nucleosides: a new method for independent guanine radical generation

Org Biomol Chem. 2009 Dec 7;7(23):4965-72. doi: 10.1039/b909138f. Epub 2009 Oct 1.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Free Radicals / chemical synthesis
  • Free Radicals / chemistry
  • Guanine Nucleotides / chemical synthesis*
  • Guanine Nucleotides / chemistry
  • Molecular Structure
  • Photolysis
  • Pyridones / chemistry*
  • Stereoisomerism

Substances

  • Free Radicals
  • Guanine Nucleotides
  • Pyridones