title: In vitro biotransformation of xanthohumol, a flavonoid from hops (Humulus lupulus), by rat liver microsomes.
abstract: Xanthohumol (XN) is the major prenylated flavonoid of the female inflorescences (cones) of the hop plant (Humulus lupulus). It is also a constituent of beer, the major dietary source of prenylated flavonoids. Recent studies have suggested that XN may have potential cancer-chemopreventive activity, but little is known about its metabolism. We investigated the biotransformation of XN by rat liver microsomes. Three major polar metabolites were produced by liver microsomes from either untreated rats or phenobarbital-pretreated rats as detected by reverse-phase high-performance liquid chromatography analysis. Liver microsomes from isosafrole- and beta-naphthoflavone-pretreated rats formed another major nonpolar metabolite in addition to the three polar metabolites. As determined by liquid chromatography/mass spectrometry and (1)H NMR analyses, the three major polar microsomal metabolites of XN were tentatively identified as 1) 5"-isopropyl-5"-hydroxydihydrofurano[2",3":3',4']-2',4-dihydroxy-6'-methoxychalcone; 2) 5"-(2"'-hydroxyisopropyl)-dihydrofurano[2",3":3',4']-2',4-dihydroxy-6'-methoxychalcone; and 3) a derivative of XN with an additional hydroxyl function at the B ring. The nonpolar XN metabolite was identified as dehydrocycloxanthohumol.
authors.affiliation: Department of Environmental and Molecular Toxicology, Oregon State University, ALS 1007 Corvallis, OR 97331, USA.
authors.forename: M
authors.initials: M
authors.lastname: Yilmazer
authors.forename: J F
authors.initials: JF
authors.lastname: Stevens
authors.forename: M L
authors.initials: ML
authors.lastname: Deinzer
authors.forename: D R
authors.initials: DR
authors.lastname: Buhler
mesh_terms: D000818:Animals; D001515:Beer; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D019684:Magnoliopsida; D013058:Mass Spectrometry; D008862:Microsomes, Liver / Q000201:enzymology / Q000378:metabolism*; D015394:Molecular Structure; D011427:Propiophenones / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D012451:Safrole / Q000378:metabolism; D019324:beta-Naphthoflavone / Q000378:metabolism
chemical_list: D065607:Cytochrome P-450 Enzyme Inhibitors; D004791:Enzyme Inhibitors; D005419:Flavonoids; D011427:Propiophenones; D019324:beta-Naphthoflavone; D003577:Cytochrome P-450 Enzyme System; D012451:Safrole; C104536:xanthohumol; C015959:isosafrole