Reduced and rearranged metabolite structures after metandienone administration: New promising metabolites for potential long-term detection.

Metandienone (MD) is a representative of the group of anabolic androgenic steroids and is commonly used in professional and amateur sports despite being a banned substance by the World Anti-Doping Agency (WADA). Metabolites of MD show high structural similarity to related anabolic androgenic steroids (AAS) such as dehydrochloromethyltestosterone (DHCMT). This led to the hypothesis that metabolites of MD with structures similar to long-term metabolites of DHCMT may be detectable. Therefore, a human administration study of MD was carried out and analyzed with the focus on metabolite structures with partly or fully reduced A-rings and eventually with rearranged D-rings with 17ξ-hydroxymethyl-17ξ-methyl substructures. Synthesized diastereomeric reference material allowed the establishment of a confident identification and characterization of excreted targeted compounds by gas chromatography-mass spectrometry. In this way, the excretion of inter alia 17α-methyl-5β-androstane-3α,17β-diol (T3), 17β-methyl-5β-androstane-3α,17α-diol (T7), 17α-hydroxymethyl-17β-methyl-18-nor-5β-androst-13-en-3α-ol (N3), 17α-hydroxymethyl-17β-methyl-18-nor-5β-androsta-1,13-dien-3α-ol (E3) and 17,17-dimethyl-18-nor-5β-androst-13-en-3α-ol (3α5βnorTHMT) was confirmed. Excretion curves of previously known and newly discovered metabolites enabled the assessment of the relationship between the chemical structure and the time of excretion. In addition to further assembling the picture of human metabolism of AAS with newly discovered metabolites, the detection of E3 allows the presumption to be a promising future candidate for a new long-term marker in anti-doping analyses with indications for an increased detection window.