Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2007-5-8
pubmed:abstractText
Involvement of cytochrome P450 (P450 or CYP) 2C19, 2C9, and 3A4 in N-oxidation of voriconazole, a new triazole antifungal agent, has been demonstrated using human liver microsomes. To confirm the precise roles of P450 isoforms in voriconazole clearance in individuals, we investigated the oxidative metabolism of voriconazole catalyzed by recombinant P450s as well as human liver microsomes genotyped for the CYP2C19 gene. Among recombinant P450 isoforms using Escherichia coli expression systems, CYP2C19 and CYP3A4 had voriconazole N-oxidation activities, but not CYP2C9. Apparent K(m) and V(max) values of CYP2C19 and CYP3A4 for voriconazole N-oxidation were 14+/-6 microM and 0.22+/-0.02 nmol/min/nmol CYP2C19 and 16+/-10 microM and 0.05+/-0.01 nmol/min/nmol CYP3A4, respectively (mean+/-S.E.). CYP3A4 produced a new methyl hydroxylated metabolite from voriconazole, detected by LC/UV and LC/MS/MS and confirmed by 1H and 13C NMR analyses, with K(m) and V(max) values of 11+/-3 microM and 0.10+/-0.01 nmol/min/nmol CYP3A4. The voriconazole 4-hydroxylation to N-oxidation metabolic ratios in liver microsomes from the wild-type CYP2C19*1/*1 individuals (0.07) were lower than those observed in other genotypes (0.20-0.27) at a substrate concentration of 25 microM based on the reported clinical plasma level. These results suggest that the CYP2C19 genotype, but not CYP2C9 genotype, would be evaluated as a key factor in the pharmacokinetics of voriconazole and that 4-hydroxyvoriconazole formation may become an important pathway for voriconazole metabolism in individuals with poor CYP2C19 catalytic function.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Antifungal Agents, http://linkedlifedata.com/resource/pubmed/chemical/Aryl Hydrocarbon Hydroxylases, http://linkedlifedata.com/resource/pubmed/chemical/CYP2C19 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/CYP3A4 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 CYP3A, http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 Enzyme System, http://linkedlifedata.com/resource/pubmed/chemical/Isoenzymes, http://linkedlifedata.com/resource/pubmed/chemical/Mixed Function Oxygenases, http://linkedlifedata.com/resource/pubmed/chemical/Pyrimidines, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Triazoles, http://linkedlifedata.com/resource/pubmed/chemical/voriconazole
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2952
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
73
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2020-6
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:17433262-Antifungal Agents, pubmed-meshheading:17433262-Aryl Hydrocarbon Hydroxylases, pubmed-meshheading:17433262-Chromatography, Liquid, pubmed-meshheading:17433262-Cytochrome P-450 CYP3A, pubmed-meshheading:17433262-Cytochrome P-450 Enzyme System, pubmed-meshheading:17433262-Escherichia coli, pubmed-meshheading:17433262-Humans, pubmed-meshheading:17433262-Hydroxylation, pubmed-meshheading:17433262-Isoenzymes, pubmed-meshheading:17433262-Kinetics, pubmed-meshheading:17433262-Magnetic Resonance Spectroscopy, pubmed-meshheading:17433262-Microsomes, Liver, pubmed-meshheading:17433262-Mixed Function Oxygenases, pubmed-meshheading:17433262-Models, Chemical, pubmed-meshheading:17433262-Molecular Structure, pubmed-meshheading:17433262-Oxidation-Reduction, pubmed-meshheading:17433262-Pyrimidines, pubmed-meshheading:17433262-Recombinant Proteins, pubmed-meshheading:17433262-Spectrophotometry, Ultraviolet, pubmed-meshheading:17433262-Tandem Mass Spectrometry, pubmed-meshheading:17433262-Triazoles
pubmed:year
2007
pubmed:articleTitle
Roles of CYP3A4 and CYP2C19 in methyl hydroxylated and N-oxidized metabolite formation from voriconazole, a new anti-fungal agent, in human liver microsomes.
pubmed:affiliation
Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, 3-3165 Higashi-tamagawa Gakuen, Machida, Tokyo 194-8543, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't