Peroxynitrite reacts with biological nitrogen-containing cyclic molecules by a radical pathway, as demonstrated by ultraweak luminescence coupled with ESR technique.
Ultraweak luminescence (uwCL) was coupled with electron spin resonance to study the reactions of 3 heterocyclic compounds (tryptophan, serotonin and imidazole) with peroxynitrite at pH 8.7. Tryptophan and serotonin reacted with emission of a flash peak of light (5 s) followed by a long-living light emission of +/- 80 s. Addition of the spin trap 4-POBN at different intervals, after the beginning of reaction revealed that a short-living free radical was produced in the case of serotonin and imidazole, but that with tryptophan, the initial radical rearranged into a relatively long-living radical, which was still formed when 4-POBN was added after 55 s (decreasing phase of uwCL).
Mouithys-Mickalad
A
A
Centre for Oxygen Research and Development, Institut de Chimie, B6a, Sart-Tilman, Liège, Belgium. amouithys@ulg.ac.be
Kohnen
S
S
Deby
C
C
Noels
A F
AF
Lamy
M
M
Deby-Dupont
G
G
D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry; D007700:Kinetics; D008163:Luminescent Measurements; D015394:Molecular Structure; D009566:Nitrates / Q000737:chemistry*; D009589:Nitrogen Oxides / Q000737:chemistry; D011725:Pyridines; D012701:Serotonin / Q000737:chemistry; D013113:Spin Labels; D014364:Tryptophan / Q000737:chemistry
D005609:Free Radicals; D006571:Heterocyclic Compounds; D007093:Imidazoles; D009566:Nitrates; D009589:Nitrogen Oxides; D011725:Pyridines; D013113:Spin Labels; C043438:alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone; C039642:peroxynitric acid; D012701:Serotonin; C029899:imidazole; D014364:Tryptophan