ABSTRACT
Hypoxen, a poly(dihydroxyphenylene) thiosulfonate-based drug, has been investigated concerning its effect on mitochondrial respiration and the utilization of lactate, especially in the context of strenuous exercise. Since 2023, patterns of use regarding hypoxen amongst the athletic population are monitored by the World Anti-Doping Agency (WADA) and its accredited anti-doping laboratories, necessitating information on suitable urinary markers indicative of the administration of hypoxen. In this exploratory study, urine samples collected post-administration of 1.5 and 2.0 g of hypoxen were analyzed by means of liquid chromatography-high resolution/high mass accuracy (tandem) mass spectrometry, which allowed for the identification of eight analytes that were plausibly attributable to metabolites of hypoxen. The identified species were assigned to the unconjugated species of S-(2,2',5,5'-tetrahydroxy-[1,1'-biphenyl]-3-yl) sulfurothioate and its glucuronide and additional tentatively identified analytes comprising a mercaptobenzene core structure. Including the identified markers into routine doping control analytical procedures enabled the detection of hypoxen use in athletes' doping control samples, thus contributing relevant information to WADA's monitoring program.
ABSTRACT
2-(Dimethylamino)ethan-1-ol (Deanol) is a widely produced chemical used by both industry and consumers in a variety of applications. Meclofenoxate, a stimulant classified on the World Anti-Doping Agency Prohibited List, metabolizes into deanol and, presumably, its main metabolite deanol-N-oxide. Hence, using liquid chromatography-tandem mass spectrometry, a quantitative detection method for deanol-N-oxide in urine was developed. Subsequently, the urinary excretion of deanol-N-oxide after oral application of 130 mg of deanol was determined in six volunteers, and urine samples of a cohort of 180 male and female athletes from different sports were analyzed. In addition, urinary deanol-N-oxide was determined in an exploratory study with one volunteer ingesting 250 mg of meclofenoxate. The developed test method allowed for limits of detection and quantification for deanol-N-oxide at 0.05 and 0.15 µg/mL, respectively. Urinary deanol-N-oxide cmax levels were found between 100 and 250 µg/mL 2-5 h post-administration of 130 mg of deanol. Similarly, urine samples collected after the administration of 250 mg of meclofenoxate exhibited cmax levels of 115 µg/mL. In contrast, deanol-N-oxide urine concentrations of pre-administration specimens and 180 routine doping control urine sample were between 0.3 and 1.3 µg/mL and below limit of quantification and 1.8 µg/mL, respectively. The study suggests that the use of deanol and meclofenoxate results in significantly elevated urinary deanol-N-oxide levels. Whether or not monitoring deanol-N-oxide in doping controls can support decision-making processes concerning the detection of meclofenoxate use necessitates further investigations taking into consideration the elimination kinetics of 4-chlorophenoxyacetic acid, the main metabolite of meclofenoxate, and deanol-N-oxide.
Subject(s)
Deanol , Doping in Sports , Humans , Male , Female , Meclofenoxate , Mass Spectrometry , Eating , Substance Abuse Detection/methodsABSTRACT
Among anabolic agents, selective androgen receptor modulators (SARMs) represent a new class of potential drugs that can exhibit anabolic effects on muscle and bone with reduced side effects due to a tissue-selective mode of action. Besides possible medical applications, SARMs are used as performance-enhancing agents in sports. Therefore, they are prohibited by the World Anti-Doping Agency (WADA) in and out of competition. Since their inclusion into the WADA Prohibited List in 2008, there has been an increase in not only the number of adverse analytical findings, but also the total number of SARMs, making continuous research into SARMs an ongoing topic in the field of doping controls. 4-((2R,3R)-2-Ethyl-3-hydroxy-5-oxopyrrolidin-1-yl)-2-(trifluoromethyl)benzonitrile (SARM 2f) is a novel SARM candidate and is therefore of particular interest for sports drug testing. This study describes the synthesis of SARM 2f using a multi-step approach, followed by full characterization using liquid chromatography-high-resolution mass spectrometry (LC-HRMS) and nuclear magnetic resonance spectroscopy (NMR). To provide the first insights into its biotransformation in humans, SARM 2f was metabolized using human liver microsomes and the microsomal S9 fraction. A total of seven metabolites, including phase I and phase II metabolites, were found, of which three metabolites were chemically synthesized in order to confirm their structure. Those can be employed in testing procedures for routine doping controls, further improving anti-doping efforts.
