Metabolism of metandienone in man: Identification and synthesis of conjugated excreted urinary metabolites, determination of excretion rates and gas chromatographic-mass spectrometric identification of bis-hydroxylated metabolites

Abstract

After oral administration of metandienone (17α-methyl-androsta-1,4-dien-17β-ol-3-one) to male volunteers conjugated metabolites are isolated from urine via XAD-2-adsorption, enzymatic hydrolysis and preparative high-performance liquid chromatography (HPLC). Four conjugated metabolites are identified by gas chromatography-mass spectrometry (GC/MS) with electron impact (EI)-ionization after derivatization with N-methyl- N-trimethyl- silyl-trifluoroacetamide/trimethylsilyl-imidazole (MSTFA/TMS-Imi) and comparison with synthesized reference compounds: 17α-methyl-5β-androst-1-en-17β-ol-3-one (II), 17α-methyl-5β-androst-1-ene-3α,17β-diol (III), 17β-methyl-5β-androst-1-ene-3α,17α-diol (IV) and 17α-methyl-5β-androstane-3α,17β-diol (V). After administration of 40 mg of metandienone four bis-hydroxy-metabolites—6β,12-dihydroxy-metandienone (IX), 6β,16β-dihydroxy-metandienone (X), 6β,16α-dihydroxy-metandienone (XI) and 6β,16β-dihydroxy-17-epimetandienone (XII)—were detected in the unconjugated fraction. The metabolites III, IV and V are excreted in a comparable amount to the unconjugated excreted metabolites 17-epimetandienone (VI), 6β-hydroxy-metandienone (VII and 6β- hydroxy-17-epimetandienone (VIII). Whereas the unconjugated excreted metabolites show maximum excretion rates between 4 and 12 h after administration the conjugated metabolites III, IV and V are excreted with maximum rates between 12 and 34 h.