title: Detection and characterization of clostebol sulfate metabolites in Caucasian population.
abstract: Anabolic androgenic steroids (AAS) are synthetic testosterone derivatives which undergo extensive metabolism in man. Differences in the excretion of phase II metabolites are strongly associated with inter-individual and inter-ethnic variations. Sulfate metabolites have been described as long-term metabolites for some AAS. Clostebol is the 4-chloro derivative of testosterone and the aim of the present study was the evaluation of clostebol sulfate metabolites in Caucasian population by LC-MS/MS technology. Clostebol was orally administered to four healthy Caucasian male volunteers, and excretion study urines were collected up to 31 days. Several analytical strategies (neutral loss scan, precursor ion scan and selected reaction monitoring acquisitions modes) were applied to detect sulfate metabolites in post-administration samples. Sixteen sulfate metabolites were detected, five of them having detectability times above 10 days (S1a, S2a, S3b, S3g and S4b). Interestingly, metabolite S1a could be detected up to the last collected sample of all excretion studies and it was characterized by LC-MS/MS and GC-MS as 4ξ-chloro-5α-androst-3β-ol-17-one 3β-sulfate. Thus, monitoring of S1a improves the detection time of clostebol misuse with respect to the commonly monitored metabolites, excreted in the glucuronide fraction. Importantly, this new metabolite can be incorporated into recently developed LC-MS/MS screening methods base on the direct detection of phase II metabolites.
authors.affiliation: Bioanalysis Research Group, IMIM, Hospital del Mar Medical Research Institute, Doctor Aiguader 88, 08003 Barcelona, Spain; Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Doctor Aiguader 88, 08003 Barcelona, Spain.
authors.forename: Georgina
authors.initials: G
authors.lastname: Balcells
authors.affiliation: Bioanalysis Research Group, IMIM, Hospital del Mar Medical Research Institute, Doctor Aiguader 88, 08003 Barcelona, Spain.
authors.forename: Oscar J
authors.initials: OJ
authors.lastname: Pozo
authors.affiliation: Bioanalysis Research Group, IMIM, Hospital del Mar Medical Research Institute, Doctor Aiguader 88, 08003 Barcelona, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Garrostas
authors.affiliation: Bioanalysis Research Group, IMIM, Hospital del Mar Medical Research Institute, Doctor Aiguader 88, 08003 Barcelona, Spain; Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Doctor Aiguader 88, 08003 Barcelona, Spain.
authors.forename: Argitxu
authors.initials: A
authors.lastname: Esquivel
authors.affiliation: Bioanalysis Research Group, IMIM, Hospital del Mar Medical Research Institute, Doctor Aiguader 88, 08003 Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Matabosch
authors.affiliation: Bioanalysis Research Group, IMIM, Hospital del Mar Medical Research Institute, Doctor Aiguader 88, 08003 Barcelona, Spain; Department of Biological Chemistry and Molecular Modeling, Instituto de Química Avanzada de Cataluña, Consejo Superior de Investigaciones Científicas (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Aristotelis
authors.initials: A
authors.lastname: Kotronoulas
authors.affiliation: Department of Biological Chemistry and Molecular Modeling, Instituto de Química Avanzada de Cataluña, Consejo Superior de Investigaciones Científicas (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Joglar
authors.affiliation: Bioanalysis Research Group, IMIM, Hospital del Mar Medical Research Institute, Doctor Aiguader 88, 08003 Barcelona, Spain; Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Doctor Aiguader 88, 08003 Barcelona, Spain. Electronic address: rventura@imim.es.
authors.forename: Rosa
authors.initials: R
authors.lastname: Ventura
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D004300:Doping in Sports; D006801:Humans; D057230:Limit of Detection; D008297:Male; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013739:Testosterone / Q000031:analogs & derivatives* / Q000378:metabolism / Q000493:pharmacokinetics / Q000652:urine; D044465:White People
chemical_list: D013739:Testosterone; C076775:clostebol
keywords: Anabolic steroid; Clostebol; Doping analysis; LC–MS/MS; Sulfate metabolites