title: In vitro metabolism of a novel PPAR gamma agonist, KR-62980, and its stereoisomer, KR-63198, in human liver microsomes and by recombinant cytochrome P450s.
abstract: 1. KR-62980 and its stereoisomer KR-63198 are novel and selective peroxisome proliferator-activated receptor gamma (PPAR gamma) modulators with activity profiles different from that of rosiglitazone. This study was performed to identify the major metabolic pathways for KR-62980 and KR-63198 in human liver microsomes. 2. Human liver microsomal incubation of KR-62980 and KR-63198 in the presence of a beta-nicotinamide adenine dinucleotide phosphate (NADPH)-generating system resulted in hydroxy metabolite formation. In addition, the specific cytochrome P450s (CYPs) responsible for KR-62980 and KR-63198 hydroxylation were identified by using a combination of chemical inhibition in human liver microsomes and metabolism by recombinant P450s. It is shown that CYP1A2, CYP2D6, CYP3A4, and CYP3A5 are the predominant enzymes in the hydroxylation of KR-62980 and KR-63198. 3. The intrinsic clearance through hydroxylation was consistently and significantly higher for KR-62980 than for KR-63198, indicating metabolic stereoselectivity (CL(int) of 0.012 +/- 0.001 versus 0.004 +/- 0.001 microl min(-1) pmol(-1) P450, respectively). 4. In a drug-drug interaction study, KR-62980 and KR-63198 had no effect on the activities of the P450s tested (IC(50) > 50 microM), suggesting that in clinical interactions between KR-62980 and KR-63198 the P450s tested would not be expected.
authors.affiliation: Department of Pharmacology and PharmacoGenomics Research Center, Inje University College of Medicine, Busan, Korea.
authors.forename: K-B
authors.initials: KB
authors.lastname: Kim
authors.forename: K-A
authors.initials: KA
authors.lastname: Seo
authors.forename: Y-J
authors.initials: YJ
authors.lastname: Yoon
authors.forename: M-A
authors.initials: MA
authors.lastname: Bae
authors.forename: H G
authors.initials: HG
authors.lastname: Cheon
authors.forename: J-G
authors.initials: JG
authors.lastname: Shin
authors.forename: K-H
authors.initials: KH
authors.lastname: Liu
mesh_terms: D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D006801:Humans; D007192:Indenes / Q000378:metabolism* / Q000494:pharmacology; D007700:Kinetics; D013058:Mass Spectrometry; D008862:Microsomes, Liver / Q000378:metabolism*; D015394:Molecular Structure; D009025:Morpholines / Q000378:metabolism* / Q000494:pharmacology; D047495:PPAR gamma / Q000819:agonists*; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: C513115:1-(methylimino-N-oxy)-6-(2-morpholinoethoxy)-3-phenyl-1H-indene-2-carboxylic acid ethyl ester; D065607:Cytochrome P-450 Enzyme Inhibitors; D007192:Indenes; D009025:Morpholines; D047495:PPAR gamma; D011994:Recombinant Proteins; D003577:Cytochrome P-450 Enzyme System