title: Biosynthesis of dobutamine monoglucuronides and glucuronidation of dobutamine by recombinant human UDP-glucuronosyltransferases.
abstract: Selected aspects of dobutamine glucuronidation were studied in detail. There are potentially four sites at which dobutamine can be conjugated to glucuronic acid. Three of the four dobutamine monoglucuronides that can be formed were enzymatically synthesized using pig liver microsomes, isolated, and characterized by tandem mass spectrometry, and (1)H and (13)C NMR spectroscopy. Analysis of dobutamine glucuronidation by liver microsomes from various sources revealed large variability in the ratios of the three regioisomers. Interestingly, catecholic dobutamine meta-O-glucuronide, by far the major product synthesized with human liver microsomes, was only a minor product for rat liver microsomes. Rabbit liver microsomes yielded diglucuronides, in addition to monoglucuronides. Activities of individual recombinant human UDP-glucuronosyltransferases (UGTs) were investigated, and the results suggested that dobutamine glucuronidation in the human liver is mainly carried out by UGTs 2B7 and 1A9. Among the extrahepatic UGTs, the formation of monoglucuronides, mainly catecholic meta-O-glucuronide, by UGTs 1A7 and 1A8 was similar to that by 1A9, whereas UGT1A10 also efficiently catalyzed the formation of catecholic dobutamine para-O-glucuronide.
authors.affiliation: Division of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Helsinki, Finland.
authors.forename: Anna
authors.initials: A
authors.lastname: Alonen
authors.forename: Olli
authors.initials: O
authors.lastname: Aitio
authors.forename: Kati
authors.initials: K
authors.lastname: Hakala
authors.forename: Leena
authors.initials: L
authors.lastname: Luukkanen
authors.forename: Moshe
authors.initials: M
authors.lastname: Finel
authors.forename: Risto
authors.initials: R
authors.lastname: Kostiainen
mesh_terms: D000318:Adrenergic beta-Agonists / Q000378:metabolism*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004280:Dobutamine / Q000378:metabolism*; D020719:Glucuronides / Q000378:metabolism*; D014453:Glucuronosyltransferase / Q000378:metabolism*; D006801:Humans; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008862:Microsomes, Liver / Q000201:enzymology; D011817:Rabbits; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D012015:Reference Standards; D013056:Spectrophotometry, Ultraviolet; D013552:Swine
chemical_list: D000318:Adrenergic beta-Agonists; D020719:Glucuronides; D011994:Recombinant Proteins; D004280:Dobutamine; D014453:Glucuronosyltransferase