Aromatic hydroxylation and nitration of phenylalanine and tyrosine by peroxynitrite. Evidence for hydroxyl radical production from peroxynitrite

Albert van der Vliet, Charles A. O'Neill, Barry Halliwell, Carroll E Cross, Harparkash Kaur

Research output: Contribution to journalArticle

341 Scopus citations


Peroxynitrite is a highly reactive species, generated from Superoxide and nitric oxide. Some effects of peroxynitrite are ascribed to the molecule itself, but decomposition products of the protonated form, peroxynitrous acid, may account for much of its reactivity in biological systems. Suggested products include highly-reactive hydroxyl radicals, but thermodynamic calculations have been used to claim that free hydroxyl radicals cannot be formed from peroxynitrite. We utilized aromatic hydroxylation of phenylalanine as a specific detector of hydroxyl radicals, and found that incubation of phenylalanine with peroxynitrite leads to a small amount of p-, m- and o-tyrosine, specific products of attack by this radical. Products of nitration of phenylalanine and tyrosine were also detected, as was dityrosine. Peroxynitrite decomposition generates several reactive species, including some that can nitrate aromatic rings. Formation of nitro-aromatic compounds may be a useful marker of peroxynitrite generation in biological systems.

Original languageEnglish (US)
Pages (from-to)89-92
Number of pages4
JournalFEBS Letters
Issue number1-2
StatePublished - Feb 14 1994



  • Dityrosine
  • Hydroxyl radical
  • Nitrotyrosine
  • Peroxynitrite
  • Phenylalanine
  • Tyrosine

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

Cite this