Mutagenicity and NO formation from UVA irradiated N-nitrosoproline, and characterization of photoproduct formed in UVA-irradiated mixture of N-nitrosoproline with 2-′deoxyguanosine in neutral solution

Sakae Arimoto, Masaki Machida, Kayoko Sano, Shuhei Aoyama, Chiharu Asahi, Noriko Tanaka, Keinosuke Okamoto, Tomoe Negishi, Sachiko Kimura, Toshinori Suzuki

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2 Citations (Scopus)


Earlier studies in our laboratory showed that UVA-irradiated N-nitrosoproline (NPRO) could produce mutagenic compounds and strand breaks in treated DNA with the release of nitric oxide and active oxygen species. In the present study, we investigated the phosphate-dependence of photomutagenicity and solvent effects on nitric oxide release from irradiated NPRO. We also investigated the UVA-driven reaction of NPRO with 2′-deoxyguanosine (dG) in neutral solution, and identified the chemical structure of the photoproduct. A mixture of NPRO and dG dissolved in neutral solution was irradiated with UVA at 320-400 nm for 6 h, and the solution was then subjected to HPLC analysis. The photoproduct isolated from the NPRO and dG mixture in neutral buffer was identified as 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG). We propose a photoreaction mechanism involving the absorption of UVA photons by NPRO followed by UVA-driven photolysis of NPRO, and subsequent production of active oxygen radicals that generate 8-oxodG.

Original languageEnglish
Pages (from-to)47-53
Number of pages7
JournalGenes and Environment
Issue number2
Publication statusPublished - 2014



  • 8-oxo-deoxyguanosine
  • DNA adduct
  • N-nitrosamine
  • NO radical
  • Photoreaction

ASJC Scopus subject areas

  • Genetics
  • Environmental Science (miscellaneous)
  • Social Psychology

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