title: Characterization of a non-approved selective androgen receptor modulator drug candidate sold via the Internet and identification of in vitro generated phase-I metabolites for human sports drug testing.
abstract: BACKGROUND
  Potentially performance-enhancing agents, particularly anabolic agents, are advertised and distributed by Internet-based suppliers to a substantial extent. Among these anabolic agents, a substance referred to as LGD-4033 has been made available, comprising the core structure of a class of selective androgen receptor modulators (SARMs).
  
  
  METHODS
  In order to provide comprehensive analytical data for doping controls, the substance was obtained and characterized by nuclear magnetic resonance spectroscopy (NMR) and liquid chromatography/electrospray ionization high resolution/high accuracy tandem mass spectrometry (LC/ESI-HRMS). Following the identification of 4-(2-(2,2,2-trifluoro-1-hydroxyethyl)pyrrolidin-1-yl)-2-(trifluoromethyl)benzonitrile, the substance was subjected to in vitro metabolism studies employing human liver microsomes and Cunninghamella elegans (C. elegans) preparations as well as electrochemical metabolism simulations.
  
  
  RESULTS
  By means of LC/ESI-HRMS, five main phase-I metabolites were identified as products of liver microsomal preparations including three monohydroxylated and two bishydroxylated species. The two most abundant metabolites (one mono- and one bishydroxylated product) were structurally confirmed by LC/ESI-HRMS and NMR. Comparing the metabolic conversion of 4-(2-(2,2,2-trifluoro-1-hydroxyethyl)pyrrolidin-1-yl)-2-(trifluoromethyl)benzonitrile observed in human liver microsomes with C. elegans and electrochemically derived metabolites, one monohydroxylated product was found to be predominantly formed in all three methodologies.
  
  
  CONCLUSIONS
  The implementation of the intact SARM-like compound and its presumed urinary phase-I metabolites into routine doping controls is suggested to expand and complement existing sports drug testing methods.
authors.affiliation: Center for Preventive Doping Research - Institute of Biochemistry, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany.|European Monitoring Center for Emerging Doping Agents (EuMoCEDA), Cologne/Bonn, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Thevis
authors.affiliation: Bayer CropScience AG, Alfred-Nobel-Str. 50, 40789, Monheim, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Lagojda
authors.affiliation: Bayer CropScience AG, Alfred-Nobel-Str. 50, 40789, Monheim, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Kuehne
authors.affiliation: Center for Preventive Doping Research - Institute of Biochemistry, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Thomas
authors.affiliation: Center for Preventive Doping Research - Institute of Biochemistry, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: Dib
authors.affiliation: Uppsala University, Division of Analytical Pharmaceutical Chemistry, P.O. Box 574, SE-751 23, Uppsala, Sweden.
authors.forename: Annelie
authors.initials: A
authors.lastname: Hansson
authors.affiliation: Uppsala University, Division of Analytical Pharmaceutical Chemistry, P.O. Box 574, SE-751 23, Uppsala, Sweden.|National Veterinary Institute (SVA), Department of Chemistry, Environment and Feed Hygiene, SE-751 89, Uppsala, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Hedeland
authors.affiliation: Uppsala University, Division of Analytical Pharmaceutical Chemistry, P.O. Box 574, SE-751 23, Uppsala, Sweden.|National Veterinary Institute (SVA), Department of Chemistry, Environment and Feed Hygiene, SE-751 89, Uppsala, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Bondesson
authors.affiliation: Westfälische Wilhelms-Universität Münster, Institute of Inorganic and Analytical Chemistry, Corrensstr. 30, 48149, Münster, Germany.
authors.forename: Tina
authors.initials: T
authors.lastname: Wigger
authors.affiliation: Westfälische Wilhelms-Universität Münster, Institute of Inorganic and Analytical Chemistry, Corrensstr. 30, 48149, Münster, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Karst
authors.affiliation: Center for Preventive Doping Research - Institute of Biochemistry, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany.
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Schänzer
mesh_terms: D045930:Anabolic Agents / Q000737:chemistry* / Q000191:economics / Q000378:metabolism*; D000728:Androgens / Q000737:chemistry* / Q000378:metabolism*; D002853:Chromatography, Liquid; D020093:Cunninghamella / Q000187:drug effects / Q000378:metabolism; D004300:Doping in Sports / Q000191:economics; D006801:Humans; D020407:Internet; D009682:Magnetic Resonance Spectroscopy; D008862:Microsomes, Liver / Q000737:chemistry / Q000378:metabolism; D015394:Molecular Structure; D011944:Receptors, Androgen / Q000378:metabolism*; D015813:Substance Abuse Detection; D053719:Tandem Mass Spectrometry
chemical_list: C410798:AR protein, human; D045930:Anabolic Agents; D000728:Androgens; D011944:Receptors, Androgen