In Vitro and In Vivo Human Metabolism of Ostarine, a Selective Androgen Receptor Modulator and Doping Agent.

Ostarine (enobasarm) is a selective androgen receptor modulator with great therapeutic potential. However, it is also used by athletes to promote muscle growth and enhance performances without the typical adverse effects of anabolic steroids. Ostarine popularity increased in recent years, and it is currently the most abused "other anabolic agent" (subclass S1.2. of the "anabolic agents" class S1) from the World Anti-Doping Agency's (WADA) prohibited list. Several cases of liver toxicity were recently reported in regular users. Detecting ostarine or markers of intake in biological matrices is essential to document ostarine use in doping. Therefore, we sought to investigate ostarine metabolism to identify optimal markers of consumption. The substance was incubated with human hepatocytes, and urine samples from six ostarine-positive cases were screened. Analyses were performed via liquid chromatography-high-resolution tandem mass spectrometry (LC-HRMS/MS) and software-assisted data mining, with in silico metabolite predictions. Ten metabolites were identified with hydroxylation, ether cleavage, dealkylation, O-glucuronidation, and/or sulfation. The production of cyanophenol-sulfate might participate in the mechanism of ostarine liver toxicity. We suggest ostarine-glucuronide (C25H22O9N3F3, diagnostic fragments at m/z 118, 185, and 269) and hydroxybenzonitrile-ostarine-glucuronide (C25H22O10N3F3, diagnostic fragments at m/z 134, 185, and 269) in non-hydrolyzed urine and ostarine and hydroxybenzonitrile-ostarine (C19H14O4N3F3, diagnostic fragments at m/z 134, 185, and 269) in hydrolyzed urine as markers to document ostarine intake in doping.

Synthesis of polyethylene glycol-grafted magnetic nanoparticles for the fast and efficient extraction of anabolic substances from human urine.

Anabolic steroids and ß-agonists are commonly prohibited substances found in doping control studies; therefore, the determination of anabolic substances in biological samples is crucial. To analyze the anabolic compounds in urine, an adsorbent, polyethylene glycol (PEG)-grafted magnetic nanoparticle material (Fe3O4@SiO2-PEG), with low toxicity and strong biocompatibility was prepared in this investigation. Compared to those of Fe3O4 and Fe3O4@SiO2, the grafted PEG chains (approximately 5.4 wt.%) on the magnetic nanoparticles improved the extraction efficiencies by factors of 3.9-17.0 and 2.5-2.9, respectively, likely due to the electrostatic attraction and hydrogen bonding. To achieve maximum extraction efficiency, several extraction parameters were optimized, including the kind and volume of desorption solvent, pH, and the extraction and desorption time. The standard curves were linear within the range of 0.5-20 µg/L for methyltestosterone and trenbolone, and 0.02-5 µg/L for clenbuterol. The limits of detection for the three drugs were 0.01-0.12 µg/L. The limits of quantification were 0.02-0.40 µg/L. The levels of precision of the optimized method were assessed based on the respective intra- and inter-day and batch-to-batch relative standard deviations in the ranges of 3.2-5.2 % (n = 5), 5.9-11.3 % (n = 4), and 6.7-9.2 % (n = 3). The Fe3O4@SiO2-PEG nanoparticles could exclude urine matrix interferences (matrix effect of 91.8-98.1 %) and achieve satisfactory recoveries (75.5-116.1 %), affording sensitive and accurate determination of trace anabolic substances in urine.

Novel dummy molecularly imprinted polymer for simultaneous solid-phase extraction of stanozolol metabolites from urine.

Stanozolol, a synthetic derivative of testosterone, is one of the common doping drugs among athletes and bodybuilders. It is metabolized to a large extent and metabolites are detected in urine for a longer duration than the parent compound. In this study, a novel dummy molecularly imprinted polymer (DMIP) is developed as a sorbent for solid-phase extraction of stanozolol metabolites from spiked human urine samples. The optimized DMIP is composed of stanozolol as the dummy template, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as the cross-linker in a ratio of 1:10:80. The extracted analytes were quantitively determined using a newly developed and validated ultrahigh-performance liquid chromatography tandem mass spectrometry method, where the limits of detection and quantitation were 0.91 and 1.81 ng mL-1, respectively, fulfilling the minimum required performance limit decided on by the World Anti-Doping Agency. The mean percentage extraction recoveries for 3'-hydroxystanozolol, 4ß-hydroxystanozolol, and 16ß-hydroxystanozolol are 97.80% ± 13.80, 83.16% ± 7.50, and 69.98% ± 2.02, respectively. As such, the developed DMISPE can serve as an efficient cost-effective tool for doping and regulatory agencies for simultaneous clean-up of the stanozolol metabolites prior to their quantification.

On-site monitoring of nandrolone in cattle farming samples by portable atmospheric pressure chemical ionization mass spectrometry with ambient sampling.

Nandrolone (NT) is a type of androgen anabolic steroid that is often illegally used in cattle farming, leading to unpredictable harm to human health via the food chain. In this study, a rapid detection method for NT in the samples of cattle farming was established using a portable mass spectrometer. The instrument parameters were optimized, including a thermal desorption temperature of 220 °C, a pump speed of 30 %, an APCI ionization voltage of 3900 v, and an injection volume of 6 µL. The samples of bovine urine, feed, sewage, and tissue were selected, and extracted using a solution of methanol:acetonitrile (1:1, v/v), followed by spiking a NT standard solution (1000 ng·mL-1) and ionization through the APCI ion source for detection. The results showed that NT could not be detected in beef and feed due to the complexity of the matrix, while clear signals of NT ions were observed in bovine urine and sewage samples, with LODs of 1000 and 100 ng·mL-1, respectively. Furthermore, quantitative analysis was attempted, and a good linear relationship (R2 = 0.9952) was observed for NT in sewage within the range of 100 to 1000 ng·mL-1. At spiked levels of 100, 500, 1000 and 2000 ng mL-1, the recovery rates ranged from 74.3 % to 92.8 %, with a relative standard deviation (n = 6) of less than 15 %. In conclusion, this detection method offers the advantages of simplicity, rapidity, strong timeliness, and specificity, making it suitable for on-site detection. It can be used for qualitative screening of nandrolone in bovine urine and quantitative analysis of nandrolone in sewage.

Screening anabolic androgenic steroids in human urine: an application of the state-of-the-art gas chromatography-Orbitrap high-resolution mass spectrometry.

Over the past few decades, anabolic androgenic steroids (AASs) have been abused in and out of competition for their performance-enhancing and muscle-building properties. Traditionally, AASs were commonly detected using gas chromatography-mass spectrometry in the initial testing procedure for doping control purposes. Gas chromatography-Orbitrap high-resolution mass spectrometry (GC-Orbitrap-HRMS) is a new technology that has many advantages in comparison with GC-MS (e.g., a maximum resolving power of 240,000 (FWHM at m/z 200), excellent sub-ppm mass accuracy, and retrospective data analysis after data acquisition). Anti-doping practitioners are encouraged to take full advantage of the updated techniques of chromatography-mass spectrometry to develop sensitive, specific, and rapid screening methods for AASs. A new method for screening a wide range of AASs in human urine using GC-Orbitrap-HRMS was developed and validated. The method can qualitatively determine 70 anabolic androgenic steroids according to the minimum required performance limit of the World Anti-Doping Agency. Moreover, the validated method was successfully applied to detect six metabolites in urine after the oral administration of metandienone, and their excretion curves in vivo were studied. Metandienone M6 (17ß-hydroxymethyl-17α-methyl-18-nor-androst-1,4,13-trien-3-one) has been identified as a long-term urinary metabolite which can be detected up to 7 weeks, thus providing a longer detection window compared with previous studies. This study provides a rationale for GC-Orbitrap-HRMS in drug metabolism and non-targeted screening.

Body fluid contamination in the context of an adverse analytical finding in doping: About a case involving ostarine.

Ostarine, also known as MK-2866 or enobosarm, is a selective androgen receptor modulator (SARM). It has anabolic properties and as such is widely used in doping, accounting in 2021 for 25 % of the adverse analytical findings (AAF) among the class S1.2 "Other anabolic agents" of products banned by the World Anti-Doping Agency, to which it belongs. But in some cases, it can be responsible for an AAF following contamination. We report the case of an athlete who contaminated herself by exchanging body fluids while kissing her boyfriend, who took 25 mg per day of MK-2866 for 9 days prior to the athlete's AAF (urinary concentration evaluated at 13 ng/mL) without her knowledge. Both subjects came to our lab for hair testing. The athlete's hair was black and slightly frizzy. Six segments of 2 cm then 7 × 3 cm (33 cm) were analysed and showed increasing concentrations, from 2 pg/mg on the first segment to 17.8 pg/mg on the last segment. The boyfriend's hair, light-brown, analyzed on 4 × 2 cm, also showed increasing values, from 65 to 143 pg/mg. These gradients of concentration in the hair's athlete and in her boyfriend were compatible with external contamination of the hair, confirmed by analysis of washing baths, pillowcases (150 pg on each), and the athlete's hairbrush (250 pg). Fingernails were also contaminated, with 21 pg/mg in the athlete and 1041 pg/mg in the boyfriend, with highly contaminated washing baths, and toenails were less contaminated, with 2 pg/mg in the athlete and 17.3 pg/mg in the boyfriend. Urine samples taken 35 days after the start of MK-2866 treatment showed a value of 3690 ng/mL in the boyfriend and 5.7 ng/mL in the athlete. After 6 days off, these concentrations were 3.3 ng/mL and 0.1 ng/mL, respectively. A controlled transfer study was carried out 12 days after discontinuation (urine concentrations returned to negative level). After administration of 17 mg (the 25 mg/mL vial having been controlled at 17 mg/mL), urine samples were taken from the boyfriend and the athlete (n = 10 for each) for more than 25 h after they had been living normally with each other (regular kissing in particular). The boyfriend's urine concentrations ranged from 681 ng/mL to 12822 ng/mL (Tmax = 8:30 hrs), and the athlete's from 0.3 ng/mL to 13 ng/mL with Tmax = 8:30 hrs, i.e. at 22:30 hrs, which corresponded exactly to the time of collection of the urine that showed AAF, with a similar concentration. The dose ingested by the athlete was estimated at 15 µg. These results demonstrate the transfer of ostarine via body fluids between two subjects, with a high risk of AAF in one athlete, as observed in our case.

Detection of boldenone in the urine of female horses-ex vivo formation versus administration.

Boldenone is an anabolic-androgenic steroid (AAS) that is prohibited in equine sports. However, in certain situations, it is endogenous, potentially formed by the microbes in urine. An approach to the differentiation based on the detection of the biomarkers Δ1-progesterone, 20(S)-hydroxy-Δ1-progesterone and 20(S)-hydroxyprogesterone was assessed, and their concentrations were monitored in the urine of untreated female horses (n = 291) alongside boldenone, boldienone, testosterone and androstenedione. Using an ultra-sensitive analytical method, boldenone (256 ± 236 pg/mL, n = 290) and the biomarkers (Δ1-progesterone up to 57.6 pg/mL, n = 8; 20(S)-hydroxy-Δ1-progesterone 85.3 ± 181 pg/mL, n = 130; 20(S)-hydroxyprogesterone 43.5 ± 92.1 pg/mL, n = 158) were detected at low concentrations. The ex vivo production of Δ1-steroids was artificially induced following the storage of urine samples at room temperature for 7 days in order to assess the concentrations and ratios of the monitored steroids. The administration of inappropriately stored feed source also resulted in an increase in 20(S)-hydroxy-Δ1-progesterone concentrations and the biomarker ratios. Using the results from different datasets, an approach to differentiation was developed. In situations where the presence of boldenone exceeds a proposed action limit of 5 ng/mL, the presence of the biomarkers would be investigated. If Δ1-progesterone is above 50 pg/mL or if 20(S)-hydroxy-Δ1-progesterone is above 100 pg/mL with the ratio of 20(S)-hydroxy-Δ1-progesterone:20(S)-hydroxyprogesterone greater than 5:1, then this would indicate ex vivo transformation or consumption of altered feed rather than steroid administration. There remains a (small) possibility of a false negative result, but the model increases confidence that adverse analytical findings reported in female horses are caused by AAS administrations.

A comprehensive and high-throughput screening method for multiple prohibited substances by UPLC-QE Plus-HRMS and HPLC-QQQ-MS in human urine for doping control.

Since the World Anti-Doping Agency's (WADA) Prohibited List is updated on an annual basis, screening methods must be continually adapted to align with these changes. In accordance with Technical Document-MRPL 2022, a newly combined, comprehensive, rapid and high-throughput doping control screening method has been developed for the analysis of 350 substances with different polarities in human urine using ultra-high performance liquid chromatography coupled with Q Exactive Plus Hybrid Quadrupole-Orbitrap mass spectrometer (UPLC-QE Plus-HRMS) and ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometer (UPLC-QQQ-MS). The limits of detection were in the range of 0.12-50 ng mL-1 for beta-2 agonists, hormone and metabolic modulators, narcotics, cannabinoids and glucocorticoids, 0.1-14 ng mL-1 for the manipulation of blood and blood components, beta blockers, anabolic agents and hypoxia-inducible factor (HIF) activating agents, and 2.5-100 000 ng mL-1 for substances of Appendix A, diuretics & masking agents and stimulants. The sample preparation consisted of two parts: one is the dilute & shoot part analyzed in UPLC-QQQ-MS, another is a mixture of the dilute & shoot part and a liquid-liquid extraction part of hydrolyzed human urine analyzed in UPLC-QE Plus-HRMS in full scan mode with polarity switching and parallel reaction monitoring (PRM) mode. The method has been fully validated for doping control purposes. All the substances were compliant with WADA's required 1/2 minimum requirement performance level (MRPL) or minimum reporting level (MRL), and this method was successfully used in the 2022 Beijing Winter Olympic Games and Winter Paralympic Games for anti-doping purpose.

Performance assessment of an equine metabolomics model for screening a range of anabolic agents.

INTRODUCTION: Despite their ban, Anabolic Androgenic Steroids (AAS) are considered as the most important threat for equine doping purposes. In the context of controlling such practices in horse racing, metabolomics has emerged as a promising alternative strategy to study the effect of a substance on metabolism and to discover new relevant biomarkers of effect. Based on the monitoring of 4 metabolomics derived candidate biomarkers in urine, a prediction model to screen for testosterone esters abuse was previously developed. The present work focuses on assessing the robustness of the associated method and define its scope of application. MATERIALS AND METHODS: Several hundred urine samples were selected from 14 different horses of ethically approved administration studies involving various doping agents' (AAS, SARMS, ß-agonists, SAID, NSAID) (328 urine samples). In addition, 553 urine samples from untreated horses of doping control population were included in the study. Samples were characterized with the previously described LC-HRMS/MS method, with the objective of assessing both its biological and analytical robustness. RESULTS: The study concluded that the measurement of the 4 biomarkers involved in the model was fit for purpose. Further, the classification model confirmed its effectiveness in screening for testosterone esters use; and it demonstrated its ability to screen for the misuse of other anabolic agents, allowing the development of a global screening tool dedicated to this class of substances. Finally, the results were compared to a direct screening method targeting anabolic agents demonstrating complementary performances of traditional and omics approaches in the screening of anabolic agents in horses.

Detection of anabolic androgenic steroids in serum samples.

When testing for anabolic androgenic steroids (AAS) outside sports communities, for example, in healthcare and forensic medicine, urine is the matrix of choice. However, there are drawbacks with urinary sampling, and serum might be useful as a complementary matrix. The aim was to develop an LC-MS/MS method for serum measuring AAS frequently used outside of sport, including testosterone (T), steroid esters, and eight other synthetic AAS. The sample pretreatment included sample precipitation and evaporation. Limit of quantification for the AAS was 0.05-0.5 ng/mL, and linearity was 0.05-20 ng/mL for most of the substances. Generally, the within- and between-day CV results, matrix effect, and process efficiency were <15%. The AAS were stable for at least 6 months at -20°C. Serum samples were obtained from previous studies. A novel finding from an administration study was that T enanthate was present in serum even after 5 years of storage at -20°C. Serum samples from self-reporting AAS individuals, where T esters were detected, were positive for testosterone using the urinary testosterone/epitestosterone criterion >10. Of those identified as positive in traditional urinary doping tests (n = 15), AAS in serum were found in 80% of the subjects. Our results show that serum may be a valid complementary matrix to urine samples for AAS testing.

Post-mortem investigation into a death involving doping agents: The case of a body builder.

INTRODUCTION: A young male was found dead on the bed of a hotel room. He was expected to take part in a bodybuilding competition the day after. During the site inspection, drugs of different types were found. The next day, an autopsy was performed. The evidence of cardiomegaly with organ congestion involving lung, liver, kidneys, adrenal glands, spleen and brain was confirmed by both the autoptic and the histopathological exam. However, the cause of death needed to be investigated. METHODS: A thorough toxicological investigation was undertaken by gas chromatography-mass spectrometry (GC-MS), liquid chromatography-high resolution mass spectrometry (LC-HRMS) and liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) on samples of urine, blood and hair. RESULTS AND DISCUSSION: Clenbuterol, a long-acting selective beta2 agonist, was found in both blood (1 ng/ml) and urine (1 ng/ml), and evidence of its use was provided by the analysis of the 3-cm hair (25 pg/mg). The main metabolite of drostanolone (2 alpha-methyl-androsterone), an anabolic steroid, was found in the urine (202 ng/ml), where an increased ratio of testosterone/epitestosterone (T/E = 11) emerged. Due to the results of the hair analysis, a long-term use of various anabolic steroids was supposed. The integrated analysis of the results and the absence of other possible causes (such as trauma or cardiac conduction anomalies) led to the identification of the abuse of doping substances as the underlying cause of death. CONCLUSION: Hair analysis has proven to be crucial in identifying drug misuse and the contributing cause of death.

Detectability of oxandrolone, metandienone, clostebol and dehydrochloromethyltestosterone in urine after transdermal application.

Situations of both, intentional and inadvertent or accidental doping, necessitate consideration in today's doping controls, especially in the light of the substantial consequences that athletes are facing in case of so-called adverse analytical findings. The aim of this study was to investigate, whether a transdermal uptake of doping substances would be possible. In addition to the period of detectability of the particular substances or respective characteristic metabolites, the possibility of deducing the route of administration by metabolite patterns was also assessed. Twelve male subjects were included in the study. Four common anabolic androgenic steroids (AAS) were dissolved in dimethylsulfoxide to facilitate transdermal administration on different skin regions. One half of the test persons received only oxandrolone (17α-methyl-2-oxa-4,5α-dihydrotestosterone), and the other half were applied a mixture of oxandrolone, metandienone (17ß-hydroxy-17α-methylandrosta-1,4-dien-3-one), clostebol (4-chlorotestosterone-17ß-acetate) and dehydrochloromethyltestosterone (DHCMT). Urine samples were collected 1 h, 6 h and one sample per day for the next 14 consecutive days. Measurements were conducted on a tandem-gas chromatography-mass spectrometry (GC-MS/MS) or tandem-liquid chromatography-MS/MS (LC-MS/MS) system. Substance findings were obtained at least 1 day after application on nearly all skin locations. The results indicated inter-individual variability in detection windows, also varying between the different analytes and possible impact of skin location and skin thickness, respectively. Nevertheless, a rapid and rather long detectability of all substances (or respective metabolites) was given, in some cases within hours after administration and for up to 10-14 days. Hence, the transdermal application or exposure to the investigated AAS is a plausible scenario that warrants consideration in anti-doping.

Differentiation of boldenone administration from ex vivo transformation in the urine of castrated male horses.

Boldenone is an anabolic-androgenic steroid that is prohibited in equine sports. However, in certain situations, it is endogenous or is believed to be formed by microbes in urine, and therefore, an approach for the differentiation is required. Following the identification of Δ1-progesterone and 20(S)-hydroxy-Δ1-progesterone as potential biomarkers of microbial activity, the presence of six steroids was investigated in the postrace urine of castrated male horses (geldings, n = 158). In line with endogenous findings from several other species when ultrasensitive methods are employed, boldenone was detected at low concentrations in all urine samples (27.0-1330 pg/ml). Furthermore, testosterone and androstenedione were detected in 157 samples (≤12,400 and 944 pg/ml, respectively), boldienone in two samples (≤22.0 pg/ml) and 20(S)-hydroxy-Δ1-progesterone in 20 samples (≤66.0 pg/ml). Δ1-Progesterone was not detected in any population samples analysed on arrival at the laboratory. The ex vivo transformation of boldienone, boldenone, androstenedione, Δ1-progesterone and 20(S)-hydroxy-Δ1-progesterone was induced following the storage of urine samples at room temperature for 7 days but not after refrigeration. Because the administration of inappropriately stored feed sources also resulted in an increase in 20(S)-hydroxy-Δ1-progesterone concentrations, a biomarker approach to distinguish steroid administrations was proposed. In situations where the presence of boldenone would exceed a proposed action limit, the presence of Δ1-progesterone and 20(S)-hydroxy-Δ1-progesterone would be investigated. If either Δ1-progesterone or 20(S)-hydroxy-Δ1-progesterone would exceed 50 and 100 pg/ml, respectively, for instance, then this would indicate ex vivo transformation or consumption of altered feed rather than steroid administration.

HepG2 as promising cell-based model for biosynthesis of long-term metabolites: Exemplified for metandienone.

In order to detect the abuse of substances in sports, the knowledge of their metabolism is of undisputable importance. As in vivo administration of compounds faces ethical problems and might even not be applicable for nonapproved compounds, cell-based models might be a versatile tool for biotransformation studies. We coincubated HepG2 cells with metandienone and D3 -epitestosterone for 14 days. Phase I and II metabolites were analyzed by high-performance liquid chromatography (HPLC)-tandem mass spectrometry and confirmed by gas chromatography-mass spectrometry (GC-MS). The metandienone metabolites formed by HepG2 cells were comparable with those renally excreted by humans. HepG2 cells also generated the two long-term metabolites 17ß-hydroxymethyl-17α-methyl-18-nor-androst-1,4,13-trien-3-one and 17α-hydroxymethyl-17ß-methyl-18-nor-androst-1,4,13-trien-3-one used in doping analyses, though in an inverse ratio compared with that observed in human urine. In conclusion, we showed that HepG2 cells are suitable as model for the investigation of biotransformation of androgens, especially for the anabolic androgenic steroid metandienone. They further proved to cover phase I and II metabolic pathways, which combined with a prolonged incubation time with metandienone resulted in the generation of its respective long-term metabolites known from in vivo metabolism. Moreover, we showed the usability of D3 -epitestosterone as internal standard for the incubation. The method used herein appears to be suitable and advantageous compared with other models for the investigation of doping-relevant compounds, probably enabling the discovery of candidate metabolites for doping analyses.

Nandrolone and estradiol biomarkers identification in bovine urine applying a liquid chromatography high-resolution mass spectrometry metabolomics approach.

With the aim of specifically investigating patterns associated with three steroid treatments (17ß-nandrolone, 17ß-estradiol, and 17ß-nandrolone + 17ß-estradiol) in bovine, an reversed phase liquid chromatography (RPLC)-electrospray ionization (ESI)(+/-)-high-resolution mass spectrometry (HRMS) study was conducted to characterize the urinary profiles of involved animals. Although specific fingerprints with strong differences could be highlighted between urinary metabolite profiles within urine samples collected on control and treated animals, it appeared further that significant discriminations could also be observed between steroid treatments, evidencing thus specific patterns and candidate biomarkers associated to each treatment. An MS-2 structural elucidation step enabled level-1 identification of two biomarkers mainly involved in energy pathways, in relation to skeletal muscle functioning. These results make it possible to envisage a global strategy for the detection of anabolic practices involving steroids, while at the same time providing clues as to the compounds used, which would facilitate the confirmation stage to follow.

The in vivo metabolism of Furazadrol in greyhounds.

Samples of the 'dietary supplement' Furazadrol sourced through the internet have been reported to contain the designer anabolic androgenic steroids [1',2']isoxazolo[4',5':2,3]-5α-androstan-17ß-ol (furazadrol F) and [1',2']isoxazolo[4',3':2,3]-5α-androstan-17ß-ol (isofurazadrol IF). These steroids contain an isoxazole fused to the A-ring and were designed to offer anabolic activity while evading detection, raising concerns over the potential for abuse of this preparation in sports. The metabolism of Furazadrol (F:IF, 10:1) was studied by in vivo methods in greyhounds. Urinary phase II Furazadrol metabolites were detected as glucuronides after a controlled administration. These phase II metabolites were subjected to enzymatic hydrolysis by Escherichia coli ß-glucuronidase to afford the corresponding phase I metabolites. Using a library of synthetically derived reference materials, the identities of seven urinary Furazadrol metabolites were confirmed. Major confirmed metabolites were isofurazadrol IF, 4α-hydroxyfurazadrol 4α-HF and 16α-hydroxy oxidised furazadrol 16α-HOF, whereas the minor confirmed metabolites were furazadrol F, 4ß-hydroxyfurazadrol 4ß-HF, 16ß-hydroxyfurazadrol 16ß-HF and 16ß-hydroxy oxidised furazadrol 16ß-HOF. One major hydroxyfurazadrol and two dihydroxyfurazadrol metabolites remained unidentified. Qualitative excretion profiles, limits of detection and extraction recoveries were established for furazadrol F and major confirmed metabolites. These investigations identify the key urinary metabolites of Furazadrol following oral administration, which can be incorporated into routine screening by anti-doping laboratories to aid the regulation of greyhound racing.

Ultra-fast retroactive processing by MetAlign of liquid chromatography/high-resolution full-scan Orbitrap mass spectrometry data in WADA Human Urine Sample Monitoring Program.

RATIONALE: The World Antidoping Agency (WADA) Monitoring program concentrates analytical data from the WADA Accredited Laboratories for substances which are not prohibited but whose potential misuse must be known. The WADA List of Monitoring substances is updated annually, where substances may be removed, introduced or transferred to the Prohibited List, depending on the prevalence of their use. Retroactive processing of old sample datafiles has the potential to create information for the prevalence of use of candidate substances for the Monitoring List in previous years. MetAlign is a freeware software with functionality to reduce the size of liquid chromatography (LC)/high-resolution (HR) full-scan (FS) mass spectrometry (MS) datafiles and to perform a fast search for the presence of substances in thousands of reduced datafiles. METHODS: Validation was performed to the search procedure of MetAlign applied to Anti-Doping Lab Qatar (ADLQ)-screened LC/HR-FS-MS reduced datafiles originated from antidoping samples for tramadol (TRA), ecdysterone (ECDY) and the ECDY metabolite 14-desoxyecdysterone (DESECDY) of the WADA Monitoring List. Searching parameters were related to combinations of accurate masses and retention times (RTs). RESULTS: MetAlign search validation criteria were based on the creation of correct identifications, false positives (FPs) and false negatives (FNs). The search for TRA in 7410 ADLQ routine LC/HR-FS-MS datafiles from the years 2017 to 2020 revealed no false identification (FPs and FNs) compared with the ADLQ WADA reports. ECDY and DESECDY were detected by MetAlign search in approximately 5% of the same cohort of antidoping samples. CONCLUSIONS: MetAlign is a powerful tool for the fast retroactive processing of old reduced datafiles collected in screening by LC/HR-FS-MS to reveal the prevalence of use of antidoping substances. The current study proposed the validation scheme of the MetAlign search procedure, to be implemented per individual substance in the WADA Monitoring program, for the elimination of FNs and FPs.

Stanozolol-N-glucuronide metabolites in human urine samples as suitable targets in terms of routine anti-doping analysis.

The exogenous anabolic-androgenic steroid (AAS) stanozolol stays one of the most detected substances in professional sports. Its detection is a fundamental part of doping analysis, and the analysis of this steroid has been intensively investigated for a long time. This contribution to the detection of stanozolol doping describes for the first time the unambiguous proof for the existence of 17-epistanozolol-1'N-glucuronide and 17-epistanozolol-2'N-glucuronide in stanozolol-positive human urine samples due to the access to high-quality reference standards. Examination of excretion study samples shows large detection windows for the phase-II metabolites stanozolol-1'N-glucuronide and 17-epistanozolol-1'N-glucuronide up to 12 days and respectively up to almost 28 days. In addition, we present appropriate validation parameters for the analysis of these metabolites using a fully automatic method online solid-phase extraction (SPE) method already published before. Limits of identification (LOIs) as low as 100 pg/ml and other validation parameters like accuracy, precision, sensitivity, robustness, and linearity are given.

New Insights into the Metabolism of Methyltestosterone and Metandienone: Detection of Novel A-Ring Reduced Metabolites.

Metandienone and methyltestosterone are orally active anabolic-androgenic steroids with a 17α-methyl structure that are prohibited in sports but are frequently detected in anti-doping analysis. Following the previously reported detection of long-term metabolites with a 17ξ-hydroxymethyl-17ξ-methyl-18-nor-5ξ-androst-13-en-3ξ-ol structure in the chlorinated metandienone analog dehydrochloromethyltestosterone ("oral turinabol"), in this study we investigated the formation of similar metabolites of metandienone and 17α-methyltestosterone with a rearranged D-ring and a fully reduced A-ring. Using a semi-targeted approach including the synthesis of reference compounds, two diastereomeric substances, viz. 17α-hydroxymethyl-17ß-methyl-18-nor-5ß-androst-13-en-3α-ol and its 5α-analog, were identified following an administration of methyltestosterone. In post-administration urines of metandienone, only the 5ß-metabolite was detected. Additionally, 3α,5ß-tetrahydro-epi-methyltestosterone was identified in the urines of both administrations besides the classical metabolites included in the screening procedures. Besides their applicability for anti-doping analysis, the results provide new insights into the metabolism of 17α-methyl steroids with respect to the order of reductions in the A-ring, the participation of different enzymes, and alterations to the D-ring.

Detection of the selective androgen receptor modulator GSK2881078 and metabolites in urine and hair after single oral administration.

Hair and urine concentrations of the nonsteroidal selective androgen receptor modulator GSK2881078 were examined following single oral administration to investigate its hair incorporation and estimate the general suitability of hair testing for selected androgen receptor modulators. Hair segments were collected following a single dose of 1.5 mg GSK2881078 by repeated shaving of scalp hair at Week 0 (blank), Week 1 (representing the pre-application period), Week 3 (ideally focusing the time of incorporation), and Weeks 5 and 9 (post-administration period). The intact compound and various (at least 4) hydroxy-metabolites exhibited similar elimination profiles. The peak urinary concentration (approximately 920 pg/ml) was observed after 8 h and is reduced to the detection limit (2 pg/ml) on Day 42 following administration of 760 µg GSK2881078. Correspondingly, hair concentrations of GSK2881078 (intact compound only) following a single oral dose of 1.5 mg GSK2881078 reached a peak concentration of 1.7 pg/mg in the segments collected 3 weeks post administration, representing the time of ingestion. The concentration rapidly declined to trace amounts of 0.7 (Week 5) and 0.2 pg/mg (Week 9), respectively. In conclusion, measurement of the intact compound GSK2881078 is feasible for both urine and hair analysis. However, concentrations in hair after single oral administration are in the low pg/mg range and can only be detected, if the segments cover the administration period.