THE METHYL-5-ALPHA-DIHYDROTESTOSTERONES MESTEROLONE AND DROSTANOLONE - GAS-CHROMATOGRAPHIC MASS-SPECTROMETRIC CHARACTERIZATION OF THE URINARY METABOLITES

Before including the detection of the methyl-5-alpha-dihydrotestosterones mesterolone (1-alpha-methyl-17-beta-hydroxy-5-alpha-androstan-3-one) and drostanolone (2-alpha-methyl-17-beta-hydroxy-5-alpha-androstan-3-one) in doping control procedures, their urinary metabolites were characterized by gas chromatography/mass spectrometry. Several metabolites were found after enzymatic hydrolysis and conversion of the respective metabolites to their trimethylsilyl-enol-trimethylsilyl ether derivatives. The major metabolites of mesterolone and drostanolone were identified as 1-alpha-methyl-androsterone and 2-alpha-methyl-androsterone, respectively. The parent compounds and the intermediate 3-alpha,17-beta-dihydroxysteroid metabolites were detected as well. The reduction into the corresponding 3-beta-hydroxysteroids was a minor metabolic pathway. All metabolites were found to be conjugated to glucuronic acid.