Increased stability of S-nitrosothiol solutions via pH modulations

Istvn Hornyk, Krisztina Marosi, Levente Kiss, Pál Gróf, Zsombor Lacza

Research output: Contribution to journalArticle

9 Citations (Scopus)


S-nitrosothiol (RSNO) solutions represent a valuable source of nitric oxide and could be used as topical vasodilators, but their fast decomposition rate poses a serious obstacle to their potentially widespread therapeutic use. Our aim was to characterize and quantify the effect of pH on S-nitrosothiol formation and decomposition in simple aqueous solutions of S-nitrosoglutathione (GSNO), S-nitroso-N-acetylcysteine (SNAC) and S-nitroso-3-mercaptopropionic acid (SN3MPA). Furthermore, we investigated the effect of storage pH on the stability of GSNO incorporated in poly(ethylene glycol)/poly(vinyl alcohol) matrices. S-nitrosothiol concentrations were measured spectrophotometrically and laser Doppler scanning method was used to assess dermal blood flow. GSH and NAC solutions reached a complete transformation to nitrosothiols when synthesized using acidic NaNO 2 solution. The initial concentration of all investigated RSNOs decreased more slowly with pH adjusted to mildly basic values (8.4-8.8) for the storage period. Polymer gels of PVA/PEG compositions at mildly basic storage pH further reduced the decomposition rate succeeding to contain 46.8% of the initial GSNO concentration for 25 days. This amount of topically administered GSNO was still capable of increasing the dermal blood flow over 200% in human subjects.

Original languageEnglish
Pages (from-to)214-225
Number of pages12
JournalFree radical research
Issue number2
Publication statusPublished - Feb 1 2012



  • ESR spectroscopy
  • GSNO
  • PH
  • S-nitrosothiols
  • UV spectroscopy
  • decomposition
  • polymer matrices

ASJC Scopus subject areas

  • Biochemistry

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