Arimistane: Degradation product or metabolite of 7‐oxo‐DHEA?
Bibliographic record
Abstract
RATIONALE: The instability of androst-5-ene-3,7-dione structures under acidic conditions is known. The formation of arimistane from 7-oxo-DHEA, influenced by the conditions of sample extraction, and mainly derivatization reaction and gas chromatography (GC) injector temperature, was described earlier, potentially leading to misinterpretation of results. By using a liquid chromatography (LC)-mass spectrometry (MS) (LC-MS) we investigated the stability of the 7-oxo-DHEA in two different solvents (methanol and dimethyl sulfoxide [DMSO]), and the arimistane formation after the application common analytical procedures. Additionally, in vitro and in vivo studies of 7-oxo-DHEA were performed. METHODS: The stability of 7-oxo-DHEA was studied in solutions after 60 days storage at -20°C. In vitro studies were performed by incubating 7-oxo-DHEA with human liver microsomes (HLMs). Healthy volunteers collected urine samples before and after the administration of a single dose of 7-oxo-DHEA. Analyses were performed using high-performance LC (HPLC) coupled to a triple quadrupole mass spectrometer (MS/MS) and GC combustion isotope ratio mass spectrometry (GC-C-IRMS) following HPLC purification. RESULTS: 7-oxo-DHEA was stable after 60 days in DMSO while a protic solvent as methanol promotes the degradation of 7-oxo-DHEA to arimistane. HLM incubations showed no formation of arimistane and the sample preparation only influenced the degradation of 7-oxo-DHEA when solvolysis was applied. After the administration study the presence of arimistane also after the hydrolysis with β-glucuronidase (Escherichia coli) was observed while using β-glucuronidase/arylsulfatase (Helix pomatia) showed the presence of arimistane already in blank samples collected before administration. CONCLUSIONS: Our results confirm arimistane as a valuable diagnostic marker of 7-oxo-DHEA administration, but also indicate that its formation is due to degradation processes rather than to metabolic biotransformation reactions.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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 teacher head, 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".