6α‐Methylandrostenedione: gas chromatographic mass spectrometric detection in doping control
Bibliographic record
Abstract
In recent years products containing 6alpha-methylandrost-4-ene-3,17-dione have appeared on the sport supplement market. Scientific studies have proven aromatase inhibition and anabolic and mild androgenic properties; however, no preparation has been approved for medical use up to now. In sports 6alpha-methylandrost-4-ene-3,17-dione has to be classified as a prohibited substance according to the regulations of the World Anti-Doping Agency (WADA). For the detection of its misuse the metabolism was studied following the administration of two preparations obtained from the Internet (Formadrol and Methyl-1-Pro). Several metabolites as well as the parent compounds were synthesized and the structures of 3alpha-hydroxy-6alpha-methyl-5beta-androstan-17-one, 6alpha-methylandrost-4-ene-3,17-dione, and 5beta-dihydromedroxyprogesterone were confirmed by nuclear magnetic resonance (NMR) spectroscopy. The main metabolite, 3alpha-hydroxy-6alpha-methyl-5beta-androstan-17-one, was found to be excreted as glucuronide and was still detectable in microg/mL amounts until urine collection was terminated (after 25 h). Additionally, samples from routine human sports doping control had already tested positive for the presence of metabolites of 6alpha-methylandrost-4-ene-3,17-dione. Screening analysis can be easily performed by the existing screening procedure for anabolic steroids using 3alpha-hydroxy-6alpha-methyl-5beta-androstan-17-one as target substance (limit of detection <10 ng/mL). Its discrimination from the closely eluting drostanolone metabolite, 3alpha-hydroxy-2alpha-methyl-5alpha-androstan-17-one, is possible as the mono-TMS derivative.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.004 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.003 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".