Document Detail

Generation of peroxynitrite from reaction of N-acetyl-N-nitrosotryptophan with hydrogen peroxide over a wide range of pH values.
MedLine Citation:
PMID:  15917893     Owner:  NLM     Status:  MEDLINE    
The novel reaction of N-acetyl-N-nitrosotryptophan (NANT) with hydrogen peroxide to yield peroxynitrite is demonstrated. Quantum chemical calculations performed at CBS-QB3 level of theory predicted that the reaction of N-nitrosoindole with both H(2)O(2) and its corresponding anion is thermodynamically feasible. At pH 13, the formation of peroxynitrite from the bimolecular reaction of NANT with H(2)O(2) is unequivocally demonstrated by (15)N NMR spectrometry. In order to prove the intermediacy of peroxynitrite from the NANT-H(2)O(2) system at neutral (7.4) and acidic pH (4.5), the characteristic pattern of CIDNP (chemically induced dynamic nuclear polarization) signals were recorded, i.e. enhanced absorption in the (15)N NMR signal of nitrate and emission in the (15)N NMR signal of nitrite. Most interestingly, the NANT-H(2)O(2) system nitrated N-acetyltyrosine at pH 4 via recombination of freely diffusing nitrogen dioxide and tyrosyl radicals, but nitration was negligible at pH 7.4. Since the combination between NANT and H(2)O(2) is slow, endogenous N-nitrosotryptophan residues cannot act as a "carrier" for peroxynitrite.
Michael Kirsch; Manfred Lehnig
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Publication Detail:
Type:  Journal Article     Date:  2005-04-29
Journal Detail:
Title:  Organic & biomolecular chemistry     Volume:  3     ISSN:  1477-0520     ISO Abbreviation:  Org. Biomol. Chem.     Publication Date:  2005 Jun 
Date Detail:
Created Date:  2005-05-26     Completed Date:  2006-07-05     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101154995     Medline TA:  Org Biomol Chem     Country:  England    
Other Details:
Languages:  eng     Pagination:  2085-90     Citation Subset:  IM    
Institut für Physiologische Chemie, Universitätsklinikum Essen, Hufelandstrasse 55, D-45122 Essen, Germany.
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MeSH Terms
Hydrogen Peroxide / chemistry*
Hydrogen-Ion Concentration*
Magnetic Resonance Spectroscopy
Nitrosamines / chemistry*
Peroxynitrous Acid / chemical synthesis*
Quantum Theory
Spectrophotometry, Ultraviolet
Tryptophan / analogs & derivatives*,  chemistry
Reg. No./Substance:
0/N-acetyl-N-nitrosotryptophan; 0/Nitrosamines; 14691-52-2/Peroxynitrous Acid; 73-22-3/Tryptophan; 7722-84-1/Hydrogen Peroxide

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