Linked Life Data

16467947

Source:http://linkedlifedata.com/resource/pubmed/id/16467947

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2006-2-9
pubmed:abstractText
Peroxynitric acid (O2NOOH) nitrates L-tyrosine and related compounds at pH 2-5. During reaction with O2(15)NOOH in the probe of a 15N NMR spectrometer, the NMR signals of the nitration products of L-tyrosine, N-acetyl-L-tyrosine, 4-fluorophenol and 4-methoxyphenylacetic acid appear in emission indicating a nitration via free radicals. Nuclear polarizations are built up in radical pairs [15NO2* , PhO*]F or [15NO2* , ArH*+]F formed by diffusive encounters of 15NO2 with phenoxyl-type radicals PhO or with aromatic radical cations ArH*+. Quantitative 15N CIDNP investigations with N-acetyl-L-tyrosine and 4-fluorophenol show that the radical-dependent nitration is the only reaction pathway. During the nitration reaction, the 15N NMR signal of 15NO3- also appears in emission. This is explained by singlet-triplet transitions in radical pairs [15NO2* , 15NO3*]S generated by electron transfer between O2(15)NOOH and H15NO2 formed as a reaction intermediate. During reaction of peroxynitric acid with ascorbic acid, 15N CIDNP is again observed in the 15N NMR signal of 15NO3- showing that ascorbic acid is oxidized by free radicals. In contrast to this, O2(15)NOOH reacts with glutathione and cysteine without the appearance of 15N CIDNP, indicating a direct oxidation without participation of free radicals.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1477-0520
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
721-9
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
15N CIDNP investigations of the peroxynitric acid nitration of L-tyrosine and of related compounds.
pubmed:affiliation
Organische Chemie, Universität Dortmund, Otto-Hahn-Strasse 6, D-44221 Dortmund, Germany. lehnig@chemie.uni-dortmund.de
pubmed:publicationType
Journal Article