Linked Life Data

2562426

Source:http://linkedlifedata.com/resource/pubmed/id/2562426

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1992-3-9
pubmed:abstractText
The oxidations of the carcinogen N-hydroxy-N-(2-fluorenyl)acetamide (N-OH-2-FAA) via one-electron (1e-) oxidation to equimolar 2-nitrosofluorene (2-NOF) and N-acetoxy-2-FAA and via oxidative cleavage to 2-NOF by chemically and myeloperoxidase (MPO)/H2O2 generated oxidants of Cl- and/or Br- were investigated. 2-NOF was determined spectrophotometrically in the reaction mixtures and by HPLC of their extracts; N-acetoxy-2-FAA was determined by HPLC. In the presence of individual or mixed halides at their physiologic concentrations (0.1 M Cl- and/or 0.1 mM Br-) and pH 4-6, MPO/H2O2-catalyzed oxidation of N-OH-2-FAA to 2-NOF via oxidative cleavage was much greater than 1e- oxidation. At the respective pH optima, oxidation was much more rapid with Br- and Br- + Cl- than with Cl-. HOBr or HOCl + Br- oxidized N-OH-2-FAA more rapidly than HOCl, also chiefly via oxidative cleavage. This suggested that, in the presence of MPO/H2O2 + Cl- + Br-, oxidation was due to HOBr from HOCl oxidation of Br- and/or oxidation of Br- by MPO/H2O2. In the presence of taurine (1 or 10 mM), a scavenger of hypohalous acids, MPO/H2O2 catalysis of oxidative cleavage was unaffected with Br-, prevented with Cl-, and partially prevented with Cl- + Br-. These results were linked to N-halotaurine formation since it was found that N-bromotaurine, but not N-chlorotaurine, oxidized N-OH-2-FAA chiefly to 2-NOF. With time N-chlorotaurine and N-bromotaurine appeared to undergo a pH-dependent halide exchange with Br- and Cl-, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0893-228X
pubmed:author
pubmed:issnType
Print
pubmed:volume
2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
325-33
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:articleTitle
Oxidations of the carcinogen N-hydroxy-N-(2-fluorenyl)acetamide by enzymatically or chemically generated oxidants of chloride and bromide.
pubmed:affiliation
Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.