Linked Life Data

7487075

Source:http://linkedlifedata.com/resource/pubmed/id/7487075

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-11-29
pubmed:abstractText
A metal-catalyzed nucleophilic addition mechanism for the formation of radical adducts of the spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) has been described recently (K. Makino, T. Hagiwara, A. Hagi, M. Nishi, and A. Murakami, 1990, Biochem. Biophys. Res. Commun. 172, 1073-1080; P. M. Hanna, W. Chamulitrat, and R. P. Mason, 1992, Arch. Biochem. Biophys. 296, 640-644). In the present investigation, we have demonstrated that the recently reported inhibition of copper-dependent hydroxyl radical formation by the complexing agent 1,10-phenanthroline (OP), which appears to contradict the well-known chemical nuclease properties of CuI(OP)2, is an artifact resulting from an inhibition of the nucleophilic addition of water to DMPO by OP (A. C. Mello-Filho and R. Meneghini, 1991, Mutat. Res. 251, 109-113). Copper bound to OP was found to be a good catalyst of hydroxyl radical formation: the CuII(OP)2 complex can be reduced by H2O2 and the CuI(OP)2 generated reacts with the peroxide to form .OH. In contrast, no evidence could be obtained for oxidant formation from the CuII(aq)/H2O2 reaction system, despite the detection of a prominent signal from the DMPO hydroxyl radical adduct (DMPO/.OH) (the formation of which was due solely to the nucleophilic addition of water to DMPO). The failure to generate an oxidant in this reaction mixture was attributed to the failure of hydrogen peroxide to reduce CuII(aq), as hydroxyl radical formation did occur when CuI(aq) was added directly to H2O2. However, in order to account for the high concentration of alpha-hydroxyethanol radicals detected when ethanol was included in the CuI(aq)/H2O2 reaction, the possibility that an oxidant in addition to .OH (e.g., CuO+) is generated is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
323
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
63-70
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Generation of 5,5-dimethyl-1-pyrroline N-oxide hydroxyl and scavenger radical adducts from copper/H2O2 mixtures: effects of metal ion chelation and the search for high-valent metal-oxygen intermediates.
pubmed:affiliation
Boyd Orr Research Centre, Division of Biochemical Sciences, Rowett Research Institute, Bucksburn, Aberdeen, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't