title: Mass spectrometric identification and characterization of new fluoxymesterone metabolites in human urine by liquid chromatography time-of-flight tandem mass spectrometry.
abstract: In this study fluoxymesterone urinary profiles were investigated by liquid chromatography quadrupole time-of-flight tandem mass spectrometry (LC-QTOFMS) with accurate mass measurement. Twelve metabolites including the parent drug were detected in two fluoxymesterone positive control urine samples. Three parameters were employed for evaluation of the accuracy of the chemical formulae in positive full scan experiment, which contained error between actual and calculated mass weights of prontonated and isotopic molecules together with abundance match between prontonated and isotopic molecules. The 13 analytes were determined with mass accuracy less than 1.1 ppm and isotopic abundance match more than 94 marks. Based on the ionization, CID fragmentation, the accurate mass of the product ion and comparison of the accurate mass weight and retention time with reference standard, fluoxymesterone and its 12 metabolites containing three unreported ones were detected. The chemical structures of three unreported metabolites were identified as: 9-fluro-17β-ol-17-methyl-11-en-5α-androstan-3-one (F13), 9-fluro-17β-ol-17-methyl-11-en-5β-androstan-3-one (F8) and 9-fluro-17β-ol-17-methyl-5-androstan-3,6,11-trione, and meanwhile a dihydroxylated metabolite (F12), 6,16-dihydroxylated fluoxymesterone, was also detected in human urine, which was previously reported to be available only in equine urine.
authors.affiliation: National Anti-Doping Laboratory, China Anti-Doping Agency, ChaoYang District, Beijing, PR China. lujianghai@chinada.cn
authors.forename: Jianghai
authors.initials: J
authors.lastname: Lu
authors.forename: Genye
authors.initials: G
authors.lastname: He
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Wang
authors.forename: Youxuan
authors.initials: Y
authors.lastname: Xu
authors.forename: Yun
authors.initials: Y
authors.lastname: Wu
authors.forename: Ying
authors.initials: Y
authors.lastname: Dong
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Zhenwen
authors.initials: Z
authors.lastname: He
authors.forename: Jian
authors.initials: J
authors.lastname: Zhao
authors.forename: Hong
authors.initials: H
authors.lastname: Yuan
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D005474:Fluoxymesterone / Q000737:chemistry / Q000652:urine*; D006801:Humans; D015394:Molecular Structure; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D005474:Fluoxymesterone