PT  - JOURNAL ARTICLE
AU  - Meltem Yilmazer
AU  - Jan F. Stevens
AU  - Max L. Deinzer
AU  - Donald R. Buhler
TI  - In Vitro Biotransformation of Xanthohumol, a Flavonoid from Hops (<em>Humulus lupulus</em>), by Rat Liver Microsomes
DP  - 2001 Mar 01
TA  - Drug Metabolism and Disposition
PG  - 223--231
VI  - 29
IP  - 3
4099  - http://dmd.aspetjournals.org/content/29/3/223.short
4100  - http://dmd.aspetjournals.org/content/29/3/223.full
SO  - Drug Metab Dispos2001 Mar 01; 29
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