Linked Life Data

2605239

Source:http://linkedlifedata.com/resource/pubmed/id/2605239

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
1990-2-22
pubmed:abstractText
Noncompetitive and competitive intermolecular deuterium isotope effects were measured for the cytochrome P-450 catalyzed hydroxylation of a series of selectively deuterated chlorobenzenes. An isotope effect of 1.27 accompanied the meta hydroxylation of chlorobenzene-2H5 as determined by two totally independent methods (EC-LC and GC-MS assays). All isotope effects associated with the meta hydroxylation of chlorobenzenes-3,5-2H2 and -2,4,6-2H3 were approximately 1.1. In contrast, competitive isotope studies on the ortho and para hydroxylation of chlorobenzenes-4-2H1, -3,5-2H2, and -2,4,6-2H3 resulted in significant inverse isotope effects (approximately 0.95) when deuterium was substituted at the site of oxidation whereas no isotope effect was observed for the oxidation of protio sites. These results eliminate initial epoxide formation and initial electron abstraction (charge transfer) as viable mechanisms for the cytochrome P-450 catalyzed hydroxylation of chlorobenzene. The results, however, can be explained by a mechanism in which an active triplet-like oxygen atom adds to the pi system in a manner analogous to that for olefin oxidation. The resulting tetrahedral intermediate can then rearrange to phenol directly or via epoxide or ketone intermediates.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9019-27
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Isotopically labeled chlorobenzenes as probes for the mechanism of cytochrome P-450 catalyzed aromatic hydroxylation.
pubmed:affiliation
Laboratory of Chemical Pharmacology, National Heart, Lung and Blood Institute, Bethesda, Maryland 20892.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.