RT Journal Article
SR Electronic
T1 In Vitro Biotransformation of Xanthohumol, a Flavonoid from Hops (<em>Humulus lupulus</em>), by Rat Liver Microsomes
JF Drug Metabolism and Disposition
JO Drug Metab Dispos
FD American Society for Pharmacology and Experimental Therapeutics
SP 223
OP 231
VO 29
IS 3
A1 Meltem Yilmazer
A1 Jan F. Stevens
A1 Max L. Deinzer
A1 Donald R. Buhler
YR 2001
UL http://dmd.aspetjournals.org/content/29/3/223.abstract
AB 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 β-naphthoflavone-pretreated rats formed another major nonpolar metabolite in addition to the three polar metabolites. As determined by liquid chromatography/mass spectrometry and 1H 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. The American Society for Pharmacology and Experimental Therapeutics