title: Regioselective O-demethylation of scoparone: differentiation between rat liver cytochrome P-450 isozymes.
abstract: The ratios of the scoparone O-demethylation products scopoletin to isoscopoletin were determined for reconstituted complexes of NADPH-P-450 reductase and each of four P-450 isozymes in a 2:1 molar ratio with a 1:1 mixture of [7-O-methyl-14C]- and [6-O-methyl-14C]-scoparone as substrate. The two phenobarbital inducible forms P-450PB-B and P-450PB-D have a 1:0.8 +/- 0.05 scopoletin to isoscopoletin ratio, and the two beta-naphthoflavone inducible forms P-450 beta NF-B and P-450 beta NF/ISF-G have ratios of 1:4.4 +/- 0.1 and 1:3.8 +/- 0.1, respectively. The scoparone-O-demethylation activities of the reconstituted preformed complexes of the four P-450 isozymes are given.
mesh_terms: D003374:Coumarins / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000378:metabolism*; D003640:Dealkylation; D004790:Enzyme Induction / Q000187:drug effects; D007527:Isoenzymes / Q000096:biosynthesis / Q000378:metabolism*; D008099:Liver / Q000201:enzymology*; D008748:Methylcholanthrene / Q000494:pharmacology; D010634:Phenobarbital / Q000494:pharmacology
chemical_list: D003374:Coumarins; D007527:Isoenzymes; D008748:Methylcholanthrene; D003577:Cytochrome P-450 Enzyme System; C018145:scoparone; D010634:Phenobarbital