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Arimistane: Degradation product or metabolite of 7‐oxo‐DHEA?
Author(s) -
Martínez Brito Dayamín,
Leogrande Patrizia,
Colamonici Cristiana,
Curcio Davide,
Botre Francesco,
Torre Xavier
Publication year - 2021
Publication title -
drug testing and analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.065
H-Index - 54
eISSN - 1942-7611
pISSN - 1942-7603
DOI - 10.1002/dta.3036
Subject(s) - chemistry , chromatography , derivatization , mass spectrometry , metabolite , high performance liquid chromatography , gas chromatography–mass spectrometry , triple quadrupole mass spectrometer , dimethyl sulfoxide , hydrolysis , tandem mass spectrometry , selected reaction monitoring , organic chemistry , biochemistry
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.