title: Discovery, biosynthesis, and structure elucidation of metabolites of a doping agent and a direct analogue, tetrahydrogestrinone and gestrinone, using human hepatocytes.
abstract: Tetrahydrogestrinone (18a-homo-pregna-4,9,11-trien-17beta-ol-3-one, THG) is an anabolic androgenic steroid sold to athletes as an undetectable performance enhancer. Being an unapproved substance, no legitimate in vivo human excretion studies could be performed to identify urinary markers of this doping agent. In vitro systems were used as an alternative approach to study the human metabolism of THG and the gestrinone analogue, which is a marketed drug. Incubations of both compounds in the presence of human hepatocytes led to formation of oxidative and glucuroconjugated metabolites. Microgram quantities of the major in vitro metabolites were biosynthesized using human hepatocytes, characterized by HPLC/MS/MS, and their structures elucidated by NMR. Due to high structure similarity, both THG and gestrinone had an analogous in vitro metabolic pathway leading to successive addition of a hydroxyl and a beta-glucuronic acid at C-18. This in vitro metabolite of gestrinone was consistent with a previously reported major but unknown human urinary metabolite. The structure of another metabolite of THG was proposed to be a glucuroconjugate of an oxidative product with a hydroxyl group most likely at C-16epsilon. In vitro information reported therein could significantly impact the identification of new urinary markers of THG for doping control purposes.
authors.affiliation: Merck Frosst Centre for Therapeutic Research, P.O. Box 1005, Pointe-Claire/ Dorval, Québec, Canada H9R 4P8. jeanfrancois_levesque@merck.com
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Lévesque
authors.forename: Erin
authors.initials: E
authors.lastname: Templeton
authors.forename: Laird
authors.initials: L
authors.lastname: Trimble
authors.forename: Carl
authors.initials: C
authors.lastname: Berthelette
authors.forename: Nathalie
authors.initials: N
authors.lastname: Chauret
mesh_terms: D045930:Anabolic Agents / Q000494:pharmacology*; D015415:Biomarkers; D002851:Chromatography, High Pressure Liquid; D004300:Doping in Sports; D005867:Gestrinone / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000652:urine*; D020723:Glucuronic Acid / Q000378:metabolism; D006001:Glycoconjugates / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D006900:Hydroxylation; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism
chemical_list: D045930:Anabolic Agents; D015415:Biomarkers; D006001:Glycoconjugates; D011948:Receptors, Antigen, T-Cell; C061836:antigen T cell receptor, epsilon chain; D005867:Gestrinone; C479553:tetrahydrogestrinone; D020723:Glucuronic Acid