Linked Life Data

20109439

Source:http://linkedlifedata.com/resource/pubmed/id/20109439

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2010-3-9
pubmed:abstractText
Compound A, 1-{(3R,3aR)-3-[3-(4-acetylpiperazin-1-yl)propyl]-7-fluoro-3-phenyl-3a,4-dihydro-3H-pyrazolo[5,1-c][1,4]benzoxazin-2-yl}ethanone, is a novel and potent inhibitor of the mitotic kinesin spindle protein. Metabolism studies with human hepatocytes showed that Compound A underwent significant ketone reduction to its biologically active metabolite M1. Here, we describe the studies that characterized the metabolic interconversion between Compound A and M1 in vitro in human tissues. LC-MS/MS analysis showed that the ketone reduction was stereospecific for M1 with no diastereomer of M1 detected in incubations with human hepatocytes. Interestingly, such stereospecific ketone reduction was not observed with Compound B, the enantiomer of Compound A. No reductive products were observed when Compound B was incubated with human hepatocytes. Studies with human liver subcellular fractions showed that Compound A was reduced to M1 primarily by human liver cytosol with little contribution from human liver microsomes and mitochondria. NADPH was the preferred cofactor for the reduction reaction. Reverse oxidation of M1 back to Compound A was also observed, preferentially in human liver cytosol with NADP(+) as the cofactor. The interconversion between Compound A and M1 in human liver cytosol was inhibited significantly by flufenamic acid and phenolphthalein (potent inhibitors for aldo-keto reductase 1Cs, p<0.05), but not by menadione, a selective inhibitor for carbonyl reductase. In addition to the liver, S9 from human lung and kidney was also capable of catalyzing this interconversion. Collectively, the results implicated the aldo-keto reductase 1Cs as the most likely enzymes responsible for the metabolic interconversion of Compound A and its active metabolite M1.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1873-2968
pubmed:author
pubmed:copyrightInfo
2010 Elsevier Inc. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
79
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1526-33
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Stereospecific reduction of a potent kinesin spindle protein (KSP) inhibitor in human tissues.
pubmed:affiliation
Department of Drug Metabolism and Pharmacokinetics, West Point, PA 19486, USA. chunze.li@pfizer.com
pubmed:publicationType
Journal Article