Photosensitized decomposition of S-nitrosothiols and 2-methyl-2-nitrosopropane Possible use for site-directed nitric oxide production

Ravinder Jit Singh, Neil Hogg, Joy Joseph, B. Kalyanaraman

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79 Scopus citations


Irradiation of S-nitrosoglutathione (GSNO) with light (λ = 550 nm) resulted in the homolytic decomposition of GSNO to generate glutathionyl radical (GS ·) and nitric oxide (·NO), which were monitored by ESR spectrometry. Inclusion of Rose Bengal (RB) resulted in a 9-fold increase in the quantum yield for ·NO production and also an increase in the rate of thiyl radical formation. The bimolecular rate constant for the interaction of triplet RB with GSNO has been estimated to be approximately 1.2 × 109 M-1s-1 by competition with oxygen. Hematoporphyrin (HP) also enhanced the rate of ·NO and tert-butyl radical. Aluminum 2-Methyl-2-nitrosopropane (MNP) decomposed on irradiation (λ = 660 nm) to form ·NO and tert-butyl radical. Aluminum phthalocyanine tetrasulphonate enhanced the rate of decomposition of MNP by 10-fold. These studies show that photosensitizers enhance the release of ·NO from donor compounds.

Original languageEnglish (US)
Pages (from-to)47-51
Number of pages5
JournalFEBS Letters
Issue number1
StatePublished - Feb 20 1995



  • 2-Methyl-2-nitrosopropane
  • Aluminum phthalocyanine tetrasulphonate
  • Hematoporphyrin
  • Nitric oxide
  • Rose Bengal
  • S-Nitrosoglutathione
  • Thiyl radical

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology

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