Sensitive detection of 3′-hydroxy-stanozolol glucuronide by liquid chromatography–tandem mass spectrometry

New long-standing metabolites of 17α-methyltestosterone are detected in HepG2 cell in vitro metabolic model and in human urine

Novel metabolites of the anabolic androgenic steroid 17α-methyltestosterone have been detected in HepG2 cell in vitro metabolic model and in human urine. Their detection was accomplished through targeted gas chromatography-(tandem) mass spectrometry analysis that has been based on microscale synthesized standards. The related synthesis and the gas chromatography-(tandem) mass spectrometry characterization of the analytical standards are described. All newly presented metabolites have a fully reduced steroid A-ring with either an 17,17-dimethyl-18-nor-Δ13 structure or they have been further oxidized at position 16 of the steroid backbone. Metabolites with 17,17-dimethyl-18-nor-Δ13 structure may be considered as side products of phase II metabolic sulfation of the 17β-hydroxy group of methyltestosterone or its reduced tetrahydro-methyltestosterone metabolites 17α-methyl-5β-androstane-3α,17β-diol and 17α-methyl-5α-androstane-3α,17β-diol that produce the known epimeric 17β-methyl-5β-androstane-3α,17α-diol and 17β-methyl-5α-androstane-3α,17α-diol metabolites. The prospective of these new metabolites to increase detection time windows and improve identification was investigated by applying the World Anti-doping Agency TD2021IDCR criteria. The new metabolites, presented herein, complement the current knowledge on the 17α-methyltestosterone metabolism and in some cases can be used as additional long-term markers in the frame of sport doping drug testing.

Effects of structural characteristics of (un)conjugated steroid metabolites in their collision cross section value

In this work, the collision cross section (CCS) value of 103 steroids (including unconjugated metabolites and phase II metabolites conjugated with sulfate and glucuronide groups) was determined by liquid chromatography coupled to traveling wave ion mobility spectrometry (LC-TWIMS). A time of flight (QTOF) mass analyzer was used to perform the analytes determination at high-resolution mass spectrometry. An electrospray ionization source (ESI) was used to generate [M+H]⁺, [M + NH₄]⁺ and/or [M - H]^- ions. High reproducibility was observed for the CCS determination in both urine and standard solutions, obtaining RSD lower than 0.3% and 0.5% in all cases respectively. CCS determination in matrix was in accordance with the CCS measured in standards solution showing deviations below 2%. In general, CCS values were directly correlated with the ion mass and allowed differentiating between glucuronides, sulfates and free steroids although differences among steroids of the same group were less significant. However, more specific information was obtained for phase II metabolites observing differences in the CCS value of isomeric pairs concerning the conjugation position or the α/β configuration, which could be useful in the structural elucidation of new steroid metabolites in the anti-doping field. Finally, the potential of IMS reducing interferences from the sample matrix was also tested for the analysis of a glucuronide metabolite of bolasterone (5β-androstan-7α,17α-dimethyl-3α,17β-diol-3-glucuronide) in urine samples.

Androgens, sports, and detection strategies for anabolic drug use

For decades, anabolic androgenic agents have represented the substance class most frequently observed in doping control samples. They comprise synthetic and pseudoendogenous anabolic androgenic steroids and other, mostly non-steroidal compounds with (presumed) positive effects on muscle mass and function. While exogenous substances can easily be detected by gas/liquid chromatography and mass spectrometry, significantly more complex methodologies including the longitudinal monitoring of individual urinary steroid concentrations/ratios and isotope ratio mass spectrometry are required to provide evidence for the exogenous administration of endogenous compounds. This narrative review summarizes the efforts made within the last 5 years to further improve the detection of anabolic agents in doping control samples. Different approaches such as the identification of novel metabolites and biomarkers, the acquisition of complementary mass spectrometric data, and the development of new analytical strategies were employed to increase method sensitivity and retrospectivity while simultaneously reducing method complexity to facilitate a higher and faster sample throughput.

Detection of DHCMT long-term metabolite glucuronides with LC-MSMS as an alternative approach to conventional GC-MSMS analysis

Dehydrochloromethyltestosterone (DHCMT) is one of the most detected illicit used anabolic-androgenic steroids in professional sports. Therefore, a fast and accurate analysis of this substance is of great importance for a constructive fight against doping abuse. The conventional method for the analysis of this drug, GC-MSMS, is very sensitive and selective but also very time- and resource-consuming. With the presented work, a new approach for simple detection with LC-HRMSMS without any sample preparation is introduced. The method is based on the direct analysis of two newly described phase-II metabolites of the DHCMT long-term metabolite 4-chloro-18-nor-17β-hydroxymethyl-17α-methyl-5β-androst-13-en-3α-ol (M3). LC-HRMSMS, GC-MSMS, fractionation and derivatization experiments are combined to identify and characterize for the first time two different glucuronide-acid conjugates of this metabolite in positive human urine samples. In addition, a third glucuronide metabolite was identified, however without isomeric structure determination. The detection of these metabolites is particularly interesting for confirmation analyses, as the method is rapid and requires little sample material.

Recent advances in identifying and utilizing metabolites of selected doping agents in human sports drug testing

Probing for evidence of the administration of prohibited therapeutics, drugs and/or drug candidates as well as the use of methods of doping in doping control samples is a central assignment of anti-doping laboratories. In order to accomplish the desired analytical sensitivity, retrospectivity, and comprehensiveness, a considerable portion of anti-doping research has been invested into studying metabolic biotransformation and elimination profiles of doping agents. As these doping agents include lower molecular mass drugs such as e.g. stimulants and anabolic androgenic steroids, some of which further necessitate the differentiation of their natural/endogenous or xenobiotic origin, but also higher molecular mass substances such as e.g. insulins, growth hormone, or siRNA/anti-sense oligonucleotides, a variety of different strategies towards the identification of employable and informative metabolites have been developed. In this review, approaches supporting the identification, characterization, and implementation of metabolites exemplified by means of selected doping agents into routine doping controls are presented, and challenges as well as solutions reported and published between 2010 and 2020 are discussed.

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.

Liquid chromatography-mass spectrometry behavior of Girard's reagent T derivatives of oxosteroid intact phase II metabolites for doping control purposes

Intact phase II steroid metabolites have poor product ion mass spectra under collision-induced dissociation (CID) conditions. Therefore, we present herein the liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/(MS)) behavior of intact phase II metabolites of oxosteroids after derivatization. Based on the fact that Girard's reagent T (GRT), as derivatization reagent, was both convenient and efficient in terms of the enhancement in the ionization efficiency and the production of diagnostic product ions related to the steroid moiety, the latter was preferably selected between methoxamine and hydroxylamine upon the model compounds of androsterone glucuronide and androsterone sulfate. Sixteen different glucuronides and 29 sulfate conjugated metabolites of anabolic androgenic steroids (AASs), available either as pure reference materials or synthesized/extracted from administration studies, were derivatized with GRT, and their product ion spectra are presented. Product ion spectra include in all cases high number of product ions that in some cases are characteristic for certain structures of the steroid backbone. More specifically, preliminary results have shown major differences in fragmentation pattern for 17α/17β-isomers of the sulfate conjugates, but limited differentiation for 17α/17β-isomers of glucuronide conjugates and for 3α/3β- and 5α/5β-stereoisomers of both sulfate and glucuronide conjugates. Further to the suggestion of the current work, application on mesterolone administration studies confirmed-according to the World Anti-Doping Agency (WADA) TD2015IDCR-the presence of seven intact phase II metabolites, one glucuronide and six sulfates with use of LC-ESI-MS/(MS).

Do dried blood spots have the potential to support result management processes in routine sports drug testing?-Part 2: Proactive sampling for follow-up investigations concerning atypical or adverse analytical findings

Capillary blood sampled as dried blood spot (DBS) has shown substantial potential as test matrix in sports drug testing in various different settings, enabling the analysis of numerous different drugs and/or their respective metabolites. In addition to established beneficial aspects of DBS specimens in general (such as the minimally invasive and non-intrusive nature, and simplified sample transport), a yet unexplored advantage of DBS in the anti-doping context could be the opportunity of preserving a source of information complementary to routine doping controls performed in urine or venous blood. Whenever follow-up investigations are warranted or required, frequently collected and stored (but yet not analyzed) DBS samples could be target-tested for the compound(s) in question, in order to contribute to results management and decision-making processes.

Phase II stanozolol metabolism study using the zebrafish water tank (ZWT) model

Stanozolol (STAN) is an androgen anabolic steroid often misused in sports competitions and prohibited at all times by the World Anti-Doping Agency (WADA). It can be long term detected by the analysis of human urine for traces of intact glucuronide metabolites. The Zebrafish Water Tank (ZWT) experimental setup can produce phase I STAN metabolites. In the present study, we investigated the in vivo phase II metabolism of STAN through the ZWT model to determine whether the ZWT produces metabolites relevant for doping control. We added STAN to a 200 mL recipient containing eight fish at 32 ± 1 °C. We analyzed the noninvasive samples (recipient water) both with and without pretreatment using Liquid Chromatography coupled with High-Resolution Mass Spectrometry (LC-HRMS/MS) in positive ionization mode. Our data show that four hydroxylated-sulfate and four hydroxylated-glycoconjugate metabolites were formed, two of the last ones being 3'OH-STAN-Glucuronide and 16β-OH-STAN-Glucuronide. Additionally, two STAN-Glucuronide derivatives were produced: one was confirmed to be 17epi-STAN-N-Glucuronide, and the other was presumed to be STAN-O-Glucuronide. After eight hours of the experiment, STAN-O-Glucuronide was the most intense phase II metabolite produced. The accumulation curves suggest that high concentrations of fish and substrate in water are required to form phase II metabolites.

Doping control analysis of 13 steroids and structural-like analytes in human urine using Quadrupole-Orbitrap LC-MS/MS with parallel reaction monitoring (PRM) mode

Anabolic androgenic steroids (AASs) and structural-like substances are commonly prohibited substances found in doping control studies that can be difficult to accurately detect. In the present study, 11 AASs and 2 structural-like substances that are commonly detected were examined. Currently, such analytes are detected using low resolution GC-MS/MS or LC-MS/MS, with detection not always possible. Herein, the high resolution Quadrupole-Orbitrap liquid chromatography-tandem mass spectrometry LC-MS/MS system Q Exactive was utilized to increase the specificity. This approach was then combined for the first time with parallel reaction monitoring (PRM) during the screening procedure. The results confirmed high specificity, with the LODs of all 13 analytes being at least 25-fold lower than corresponding MRPLs as defined by WADA. Furthermore, the extraction recoveries were above 70% and the intra- and inter-day precisions were lower than 15%. This approach was successfully applied to analyze over 10,000 samples with no false-positive or false-negative results, thus suggesting that Quadrupole-Orbitrap LC-MS/MS when combined with PRM is an effective method for doping control analysis.

Ionization and collision induced dissociation of steroid bisglucuronides

Studies on steroid metabolism are of utmost importance to improve the detection capabilities of anabolic androgenic steroids (AASs) misuse in sports drug testing. In humans, glucuronoconjugates are the most abundant phase II metabolites of AAS. Bisglucuronidation is a reaction where two separated functional groups on the same molecule are conjugated with glucuronic acid. These metabolites have not been studied in depth for steroids and could be interesting markers for doping control. The aim of the present work was to study the ionization and collision-induced dissociation of steroid bisglucuronides to be able to develop mass spectrometric analytical strategies for their detection in urine samples after AAS administration. Because steroid bisglucuronides are not commercially available, 19 of them were qualitatively synthesized to study their mass spectrometric behavior. Bisglucuronides ionized as [M+NH₄ ]⁺ in positive mode, and as [M-H]^- and [M-2H]^2- in negative mode. The most specific product ions of steroid bisglucuronides in positive mode resulted from the neutral losses of 387 and 405 Da (corresponding to [M+NH₄ -NH₃ -2gluc-H₂ O]⁺ and [M+NH₄ -NH₃ -2gluc-2H₂ O]⁺ , respectively, being "gluc" a dehydrated glucuronide moiety), and in negative mode, the fragmentation of [M-2H]^2- showed ion losses of m/z 175 and 75 (gluc^- and HOCH₂ CO₂^- , respectively). On the basis of the common behavior, a selected reaction monitoring method was developed to detect bisglucuronide metabolites in urine samples. As a proof of concept, urines obtained after administration of norandrostenediol were studied, and a bisglucuronide metabolite was detected in those urines. The results demonstrate the usefulness of the analytical strategy to detect bisglucuronide metabolites in urine samples, and the formation of these metabolites after administration of AAS.

Inhibitory Effects of Diclofenac on Steroid Glucuronidation In Vivo Do Not Affect Hair-Based Doping Tests for Stanozolol

In vitro studies show that diclofenac inhibits enzymatic steroid glucuronidation. This study was designed to investigate the influence of diclofenac on the excretion of stanozolol and 3′-hydroxystanozolol via analyses in hair, blood and urine in vivo in a rat study. Brown Norway rats were administered with stanozolol (weeks 1–3) and diclofenac (weeks 1–6). Weekly assessment of steroid levels in hair was complemented with spot urine and serum tests. Levels of both stanozolol and 3′-hydroxystanozolol steadily increased in hair during stanozolol treatment and decreased post-treatment, but remained readily detectable for 6 weeks. In contrast, compared to control rats, diclofenac significantly reduced urinary excretion of 3′-hydroxystanozolol which was undetectable in most samples. This is the first report of diclofenac altering steroid metabolism in vivo, detrimentally affecting detection in urine, but not in hair, which holds considerable advantages over urinalysis for anti-doping tests.

Analytical progresses of the World Anti-Doping Agency Olympic laboratories: a 2016 update from London to Rio

The 2016 Olympic and Paralympic Games, the biggest event in human sports, was held in Rio de Janeiro with more than 10,500 athletes from 206 countries over the world competing for the highest of sports honors, an Olympic medal. With the hope that the Olympic ideal accompanies all aspects of the XXXI Olympiad, WADA accredited antidoping laboratories use the spearhead of analytical technology as a powerful tool in the fight against doping. This review summarizes the main analytical developments applied in antidoping testing methodology combined with the main amendments on the WADA regulations regarding analytical testing starting from the 2012 London Olympics until the 2016 Olympic Games in Rio de Janeiro.

Simplifying and expanding analytical capabilities for various classes of doping agents by means of direct urine injection high performance liquid chromatography high resolution/high accuracy mass spectrometry

So far, in sports drug testing compounds of different classes are processed and measured using different screening procedures. The constantly increasing number of samples in doping analysis, as well as the large number of substances with doping related, pharmacological effects require the development of even more powerful assays than those already employed in sports drug testing, indispensably with reduced sample preparation procedures. The analysis of native urine samples after direct injection provides a promising analytical approach, which thereby possesses a broad applicability to many different compounds and their metabolites, without a time-consuming sample preparation. In this study, a novel multi-target approach based on liquid chromatography and high resolution/high accuracy mass spectrometry is presented to screen for more than 200 analytes of various classes of doping agents far below the required detection limits in sports drug testing. Here, classic groups of drugs as diuretics, stimulants, β₂-agonists, narcotics and anabolic androgenic steroids as well as various newer target compounds like hypoxia-inducible factor (HIF) stabilizers, selective androgen receptor modulators (SARMs), selective estrogen receptor modulators (SERMs), plasma volume expanders and other doping related compounds, listed in the 2016 WADA prohibited list were implemented. As a main achievement, growth hormone releasing peptides could be implemented, which chemically belong to the group of small peptides (<2kDa) and are commonly determined by laborious and time-consuming stand-alone assays. The assay was fully validated for qualitative purposes considering the parameters specificity, robustness (rRT: <2%), intra- (CV: 1.7-18.4 %) and inter-day precision (CV: 2.3-18.3%) at three concentration levels, linearity (R²>0.99), limit of detection (0.1-25ng/mL; 3'OH-stanozolol glucuronide: 50pg/mL; dextran/HES: 10μg/mL) and matrix effects.

Markers of mesterolone abuse in sulfate fraction for doping control in human urine

This manuscript describes the direct detection of mesteroloe sulfo-conjugated metabolites by liquid chromatography/quadrupole/time of flight mass spectrometry (LC/Q/TOFMS) with special focus on evaluation of their retrospective detectability and their structure elucidation. A comparison of their long-term detectability, with the mesterolone main metabolite (1α-methyl-5α-androstan-3α-ol-17-one) excreted in glucuronide fraction and detected by gas chromatography/high resolution mass spectrometry (GC/HRMS), is also presented. Studies on mesterolone were performed with samples obtained from two excretion studies after single oral administration of Proviron© by healthy volunteers. Potential sulfate metabolites were detected in post administration samples after liquid-liquid extraction (LLE) with ethyl acetate and LC/TOFMS analysis, in negative mode. Twelve mesterolone sulfate metabolites from the first excretion study and nine from the second were subsequently confirmed by LC/Q/TOFMS. Finally, six mesterolone sulfate metabolites were considered important taking into account their abundance and long-term detectability, encoded as M1, M2, M4, M5, M6 and M7. The proposed mesterolone sulfate metabolites M1, M2, M4 and M5 (excreted as sulfates) have the same retrospectivity with the main mesterolone metabolite, excreted in glucuronide fraction. For metabolite characterization, LC fractionation was performed. The metabolites were identified and characterized by GC/MS, after solvolysis and derivatization. Combined mass spectra data from trimethyl-silyl (TMS), TMS-enolTMS and methoxime-TMS derivatives were taken into account for the characterization of these metabolites. It was concluded that M1 is 1α-methyl-5α-androstan-3β-ol-17 one, M2 is 1α-methyl-5α-androstan-3α-ol-17 one, M4 is 1α-methyl-5a-androstan-3β, 16z-diol-17-one, M5 is 1α-methyl-5α-androstan-17z,4ξ-diol-3one, M6 is 1α-methyl-5α-androstan-3z,6z-diol-17-one and M7 is 4z-hydroxy-1α-methyl-5α-androstan-3,17-dione.

Comparison of sulfo-conjugated and gluco-conjugated urinary metabolites for detection of methenolone misuse in doping control by LC-HRMS, GC-MS and GC-HRMS

Methenolone (17β-hydroxy-1-methyl-5α-androst-1-en-3-one) misuse in doping control is commonly detected by monitoring the parent molecule and its metabolite (1-methylene-5α-androstan-3α-ol-17-one) excreted conjugated with glucuronic acid using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography mass spectrometry (LC-MS) for the parent molecule, after hydrolysis with β-glucuronidase. The aim of the present study was the evaluation of the sulfate fraction of methenolone metabolism by LC-high resolution (HR)MS and the estimation of the long-term detectability of its sulfate metabolites analyzed by liquid chromatography tandem mass spectrometry (LC-HRMSMS) compared with the current practice for the detection of methenolone misuse used by the anti-doping laboratories. Methenolone was administered to two healthy male volunteers, and urine samples were collected up to 12 and 26 days, respectively. Ethyl acetate extraction at weak alkaline pH was performed and then the sulfate conjugates were analyzed by LC-HRMS using electrospray ionization in negative mode searching for [M-H](-) ions corresponding to potential sulfate structures (comprising structure alterations such as hydroxylations, oxidations, reductions and combinations of them). Eight sulfate metabolites were finally detected, but four of them were considered important as the most abundant and long term detectable. LC clean up followed by solvolysis and GC/MS analysis of trimethylsilylated (TMS) derivatives reveal that the sulfate analogs of methenolone as well as of 1-methylene-5α-androstan-3α-ol-17-one, 3z-hydroxy-1β-methyl-5α-androstan-17-one and 16β-hydroxy-1-methyl-5α-androst-1-ene-3,17-dione were the major metabolites in the sulfate fraction. The results of the present study also document for the first time the methenolone sulfate as well as the 3z-hydroxy-1β-methyl-5α-androstan-17-one sulfate as metabolites of methenolone in human urine. The time window for the detectability of methenolone sulfate metabolites by LC-HRMS is comparable with that of their hydrolyzed glucuronide analogs analyzed by GC-MS. The results of the study demonstrate the importance of sulfation as a phase II metabolic pathway for methenolone metabolism, proposing four metabolites as significant components of the sulfate fraction.