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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1981-9-25
pubmed:abstractText
alpha-Naphthoflavone (ANF) or 7,8-benzoflavone, a synthetic flavonoid, has been widely used in biochemical and biological studies concerning the mechanisms of action of chemical carcinogens. It has been shown previously that ANF inhibits benzo(a)pyrene metabolism by beta-naphthoflavone (BNF)-induced rat liver microsomes but has no inhibitory effects on benzo(a)pyrene metabolism in phenobarbital (PB)-induced rat liver microsomes. This study shows that ANF gives type 1 binding spectra with and is metabolized by both BNF- and PB-induced rat liver microsomes. Specific metabolites identified by ultraviolet and mass spectra and in some cases by cochromatography with authentic standards were: 6-hydroxy-alpha-naphthoflavone, 9-hydroxy-alpha-naphthoflavone, alpha-naphthoflavone-5,6-oxide, and 5,6-dihydro-5,6-dihydroxy-alpha-naphthoflavone. Metabolism at the 5,6 bond of ANF accounted for 73 and 86% of the total organic soluble metabolites produced by PB- and BNF-induced microsomes, respectively. This result is in concert with previous observations on the role of 6 substitution and the loss of inhibitory activity of ANF in BNF-induced rat liver microsomes. Metabolism of ANF is mediated by the cytochrome P-450 mixed-function oxidases, because it is dependent on NADPH and inhibited by carbon monoxide and other cytochrome P-450 inhibitors. BNF-induced microsomes metabolize ANF to 5,6-dihydro-5,6-dihydroxy-alpha-naphthoflavone to a much greater extent than do PB-induced microsomes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2621-6
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Metabolism of alpha-naphthoflavone by rat liver microsomes.
pubmed:publicationType
Journal Article