Linked Life Data

8839061

Source:http://linkedlifedata.com/resource/pubmed/id/8839061

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-1-14
pubmed:abstractText
The novel 5-lipoxygenase inhibitor [1S,5R]-3-cyano-1-(3-furyl)-6-(6-[3-(3 alpha-hydroxy-6,8-dioxabicyclo[3.2.1]octanyl)]pyridin-2-yl- methoxyl)naphthalene (L-739,010), when administered to rats and rhesus monkeys, was found to produce metabolites which appeared to be covalently bound to plasma proteins. Incubation of [14C]L-739,010 with rat liver microsomes did not yield appreciable amounts of soluble metabolites but resulted in covalent binding to microsomal proteins. The covalent binding was NADPH-dependent and was enhanced by 1.5- and 2-fold in liver microsomes from rats, pretreated with phenobarbital and dexamethasone, respectively. Addition of triacetyloleandomycin and diethyldithiocarbamate to the incubation mixture inhibited the covalent binding by 60% and 46%, respectively. These findings suggest that the cytochrome P450 3A family of enzymes play an important role in the bioactivation of L-739,010. The presence of GSH attenuated the covalent binding by 50%, while methoxylamine, an aldehyde trapping agent, blocked the covalent binding completely and, concurrently, produced several soluble metabolic adducts. Subsequently, major methoxylamine adducts were identified by LC-MS/MS and NMR as O-methyloximes of the ring-opened furan moiety of L-739,010. Incubation of L-739,010 with methoxylamine and hepatic microsomes from dog, rhesus monkey, and human produced similar metabolic adducts as those formed by rat liver microsomes. Therefore, under these experimental conditions, the furan moiety, which undergoes oxidative cleavage to the highly reactive 2-butene-1,4-dialdehyde, represents the major site of L-739,010 biotransformation. This putative reactive intermediate could react with microsomal proteins in vitro and physiological proteins in vivo. Since furan bioactivation is believed to be responsible for the toxicity of many furan-containing compounds, the furan moiety of L-739,010 may be regarded as undesirable.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0893-228X
pubmed:author
pubmed:issnType
Print
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
547-54
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Microsomal metabolism of the 5-lipoxygenase inhibitor L-739,010: evidence for furan bioactivation.
pubmed:affiliation
Department of Drug Metabolism I, Merck Research Laboratories, West Point, Pennsylvania 19486, USA.
pubmed:publicationType
Journal Article