Structure and mechanism of formation of an important ion in doping control

Borges, Chad R.; Taccogno, James L.; Crouch, Dennis J.; Le, Ly; Truong, Thanh N.

doi:10.1016/j.ijms.2005.08.013

Cited by 11 publications

(7 citation statements)

References 17 publications

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“…Benfenati et al conducted ring A deuterium labelling experiments which supported the proposed identifications and particularly showed that the m/z 143 ion in the mass spectra resulted from fragmentation of the derivatised, enolised A ring. The elemental composition of this ion, also postulated by Rowland and Sutton (2017) for the spectrum of ambrein-TMSi ether, was confirmed by accurate mass studies (Borges et al 2005). Benfenati et al (1994) reported that derivatisation of the Δ 2 and/or Δ 3 5β(H) isomers produced a compound which eluted before the corresponding ketone, whereas derivatisation of the Δ 2 and/or Δ 3 5α(H) isomer produced a compound which eluted after the corresponding ketone.…”

Section: Resultssupporting

confidence: 57%

Ambrein: a minor, but common constituent of mammalian faeces?

Rowland

Sutton

Lühe

et al. 2020

Natural Product Research

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For nearly 200 years, the only natural source of the alcohol, ambrein, has been coproliths produced in about 1% of sperm whales and in related jetsam. However, the finding of ambrein in adipocere/faeces of human corpses, led us to hypothesise that ambrein might occur in the faeces of other mammals.Herein, we used a recently developed gas chromatography-mass spectrometry method, with suitable derivatisation of the hindered hydroxy group of ambrein, to screen a number of extracts of mammalian faeces.Minor proportions of ambrein were detected in digested human sewage sludge and in the dung of elephant, domestic cattle, giraffe and buffalo, as well as the faeces of a sperm whale. Whether ambrein formation in the terrestrial species is associated with coprolith formation, is unknown, but solid deposits known as enteroliths and fecaliths occur in humans and some domestic animals.

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Section: Resultssupporting

confidence: 57%

Ambrein: a minor, but common constituent of mammalian faeces?

Rowland

Sutton

Lühe

et al. 2020

Natural Product Research

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“…The EI spectrum showed an ion at m / z 143, which although common for the 17‐methyl,17‐hydroxyl steroids, has also been reported for steroids with an A‐ring bearing an unconjugated keto function 21. Therefore, because of the absence of a 17‐hydroxy‐17‐methyl function, an unconjugated A‐ring was proposed for A6.…”

Section: Resultsmentioning

confidence: 62%

“…The ion at m / z 143 has been earlier reported to result from 17‐methyl, 17‐hydroxy function of the steroid structure,20, 21 and was therefore present in the EI spectra of A1 and A2 but absent in A3.…”

Section: Resultsmentioning

confidence: 82%

Elucidation of urinary metabolites of fluoxymesterone by liquid chromatography‐tandem mass spectrometry and gas chromatography‐mass spectrometry

et al. 2007

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The suitability of liquid chromatography tandem mass spectrometry (LC-MS/MS) and gas chromatography mass spectrometry (GC-MS) for the elucidation of fluoxymesterone metabolism has been evaluated. Electrospray ionization (ESI) and collision induced dissociation (CID) fragmentation in LC-MS/MS and electron impact spectra (EI) in GC-MS have been studied for fluoxymesterone and two commercially available metabolites. MS(n) experiments and accurate mass measurements performed by an ion-trap analyser and a QTOF instrument respectively have been used for the elucidation of the fragmentation pathway. The neutral loss scan of 20 Da (loss of HF) in LC-MS/MS has been applied for the selective detection of fluoxymesterone metabolites. In a positive fluoxymesterone doping control sample, 9 different analytes have been detected including the parent compound. Seven of these metabolites were also confirmed by GC-MS including 5 previously unreported metabolites. On the basis of the ionization, the CID fragmentation, the accurate mass of the product ions and the EI spectra of these analytes, a tentative elucidation as well as a proposal for the metabolic pathway of fluoxymesterone has been suggested. The presence of these compounds has also been confirmed by the analysis of five other positive fluoxymesterone urine samples.

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“…Taking into account the expected phase I metabolism routes for methasterone, diagnostic fragments were selected to find their respective metabolite TMS derivatives. The search for metabolites with intact D rings was performed by using their most abundant fragment, m/z 143, 27 while the C16-hydroxylated metabolites were searched by their abundant fragments, m/z 218 and 231. 28 Screening for C12-hydroxylated metabolites was accomplished through the fragments m/z 170 15,17 and 185 to find metabolites with intact D rings.…”

Section: Detection Of Methasterone and Its Phase I Metabolites From Gmentioning

confidence: 99%

Human Metabolism of The Anabolic Steroid Methasterone: Detection and Kinetic Excretion of New Phase I Urinary Metabolites and Investigation of Phase II Metabolism by GC-MS and UPLC-MS/MS

Magalhães

Garrido

Cavalcanti

et al. 2019

J. Braz. Chem. Soc.

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Methasterone is a designer anabolic steroid that is prohibited for athletes and is monitored by anti-doping laboratories. In this work, our objective is to discover new human phase I metabolites, define their excretion kinetics for 30 days and analyze their phase II metabolism (sulfate, cysteine and N-acetylcysteine conjugates). Urine samples from four volunteers were analyzed by chromatographic techniques. Through gas chromatography coupled to mass spectrometry analysis it was possible to detect methasterone and its nine phase I metabolites in the urine samples after glucuronide enzymatic hydrolysis, from which one were previously unreported. These nine compounds were not excreted in free form. The new proposed metabolite is 17β-hydroxy-2α,17α-dimethyl-5β-androstan-3-one, obtained from the epimerization at C5. The 3α-hydroxy metabolite, currently monitored by anti-doping laboratories, was the most abundant and was detected for the longest time. Furthermore, four other long-term metabolites were identified. By ultra-performance liquid chromatography coupled to tandem mass spectrometry, only the drug and a known metabolite were detected after glucuronide hydrolysis, and phase II metabolites were not found. Thus, our results contribute to elucidating methasterone metabolism, including long-term metabolites besides of the 3α-hydroxy in routine doping analysis, which is very important due to variation in human metabolism.

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Structure and mechanism of formation of an important ion in doping control

Cited by 11 publications

References 17 publications

Ambrein: a minor, but common constituent of mammalian faeces?

Ambrein: a minor, but common constituent of mammalian faeces?

Elucidation of urinary metabolites of fluoxymesterone by liquid chromatography‐tandem mass spectrometry and gas chromatography‐mass spectrometry

Human Metabolism of The Anabolic Steroid Methasterone: Detection and Kinetic Excretion of New Phase I Urinary Metabolites and Investigation of Phase II Metabolism by GC-MS and UPLC-MS/MS

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