Investigations into Annona fruit consumption as a potential source of dietary higenamine intake in the context of sports drug testing.

Higenamine is prohibited in sports as a ß2 -agonist by the World Anti-Doping Agency. As a key component of a great variety of plants, including the Annonaceae family, one aim of this research project was to evaluate whether the ingestion of Annona fruit could lead to higenamine adverse analytical findings. Single-dose administration studies including three Annona species (i.e., Annona muricata, Annona cherimola, and Annona squamosa) were conducted, leading to higenamine findings below the established minimum reporting level (MRL) of 10 ng/mL in urine. In consideration of cmax values (7.8 ng/mL) observed for higenamine up to 24 h, a multidose administration study was also conducted, indicating cumulative effects, which can increase the risk of exceeding the applicable MRL doping after Annona fruit ingestion. In this study, however, the MRL was not exceeded at any time point. Further, the major urinary excretion of higenamine in its sulfo-conjugated form was corroborated, its stability in urine was assessed, and in the absence of reference material, higenamine sulfo-conjugates were synthesized and comprehensively characterized, suggesting the predominant presence of higenamine 7-sulfate. In addition, the option to include complementary biomarkers of diet-related higenamine intake into routine doping controls was investigated. A characteristic urinary pattern attributed to isococlaurine, reticuline, and a yet not fully characterized bismethylated higenamine glucuronide was observed after Annona ingestion but not after supplement use, providing a promising dataset of urinary biomarkers, which supports the discrimination between different sources of urinary higenamine detected in sports drug testing programs.

Assessing limits of detection in qualitative methods: A simple implementation of logistic regression in a web-based R Shiny application environment and its potential in toxicology and doping control.

The estimation of limits of detection (LOD) for solely qualitative methods in analytical chemistry may prove challenging because all the approaches with which chemists are familiar require some type of numeric data input. The best model to describe the binary response in these methods (detected/not detected) is a logistic model; however, these models are not easily handled by most of the laboratories and generally demand expensive statistical software packages. In this work, the advantages of applying this approach are discussed and its implementation using commercial spreadsheet software is demonstrated. A free online application based on the R environment using shinyapps was developed and its application was validated and discussed with a dataset of 57 different target compounds analyzed in urine according to the requirements of the World Anti-Doping Agency (WADA). This tool allows free, extremely quick, and easy determinations of LOD in qualitative analyses as well as the determination of the probabilities of detection in any given concentration.

Implementation and Performance of the Gas Chromatography/Combustion/Isotope Ratio Mass Spectrometry-Based Method for the Confirmatory Analysis of Endogenous Anabolic Steroids during the Rio de Janeiro Olympic and Paralympic Games 2016.

Carbon isotope ratio (CIR) confirmation is one of the most complex and delicate analyses in the doping control field, due to the nature of the molecules to be confirmed, normally present in urinary samples as a consequence of an endogenous production. The requirements for method validation established by the World Anti-Doping Agency (WADA) have been pushing the accredited laboratories to improve their methods. The choice of the method is always a cost benefit ratio involving a hard-working and time-consuming analysis and the guarantee of reporting of reliable results. This work presents the method fully validated by the Brazilian Doping Control Laboratory as part of the preparation for the Rio de Janeiro Summer Olympic and Paralympic Games 2016. Sample preparation encompassed solid-phase extraction, liquid-liquid extraction, enzymatic hydrolysis, acetylation, and purification by preparative high-performance liquid chromatography, and analyses were performed by gas chromatography/combustion/isotope ratio mass spectrometry. This proved to be a robust method to CIR confirmation in a big event, as demonstrated by the analysis of 179 samples during the Games 2016, from clearly negative results and adverse findings for testosterone (T) and related substances, boldenone and its metabolite, 19-norandrosterone and formestane. Two atypical findings were also reported for T and metabolites.

Zebrafish (Danio rerio) water tank model for the investigation of drug metabolism: Progress, outlook, and challenges.

Zebrafish (Danio rerio) water tank (ZWT) approach was investigated as an alternative model for metabolism studies based on six different experiments with four model compounds. Sibutramine was applied for the multivariate optimization of ZWT conditions, also for the comparison of the metabolism among ZWT, humans and mice, beyond for the role of CYP2B6 in ZWT. After the optimization, 18 fish and 168 hours of experiments is the minimum requirement for a relevant panel of biotransformation products. A comparison among the species resulted in the observation of the same hydroxylated metabolites, with differences in metabolites concentration ratio. However, the ZWT allowed tuning of the conditions to obtain a specific metabolic profile, depending on the need. In addition, by utilizing CYP2B6 inhibition, a relevant ZWT pathway for the demethylation of drugs was determined. The stereospecificity of the ZWT metabolism was investigated using selegiline and no racemization or inversion transformations were observed. Moreover, the investigation of metabolism of cannabimimetics was performed using JWH-073 and the metabolites observed are the same described for humans, except for the hydroxylation at the indol group, which was explained by the absence of CYP2C9 orthologs in zebrafish. Finally, hexarelin was used as a model to evaluate studies by ZWT for drugs with low stability. As a result, hexarelin displays a very fast metabolization in ZWT conditions and all the metabolites described for human were observed in ZWT. Therefore, the appropriate conditions, merits, and relevant limitations to conduct ZWT experiments for the investigation of drug metabolism are described.

Non-targeted acquisition strategy for screening doping compounds based on GC-EI-hybrid quadrupole-Orbitrap mass spectrometry: A focus on exogenous anabolic steroids.

This is a first look at a non-targeted screening method based on Orbitrap gas chromatography-mass spectrometry (GC-MS) technology for a large number of banned compounds in sports found in urine, including exogenous anabolic steroids, ß-agonists, narcotics, stimulants, hormone modulators, and diuretics. A simple sample preparation was processed in four steps: an enzymatic hydrolysis, liquid-liquid extraction, evaporation, and trimethylsilylation. All compounds were able to meet the World Anti-Doping Agency's sensitivity criteria with mass accuracies less than 1 ppm and with sufficient points across the peak by running the Orbitrap GC-MS in full-scan mode. In addition, we discuss our initial findings of using a full-scan selected ion monitoring-tandem mass spectrometry (SIM-MS/MS) approach as a way to obtain lower detection limits and reach desirable selectivity for some exogenous anabolic steroids.

Doping control analysis at the Rio 2016 Olympic and Paralympic Games.

This paper summarises the results obtained from the doping control analyses performed during the Summer XXXI Olympic Games (August 3-21, 2016) and the XV Paralympic Games (September 7-18, 2016). The analyses of all doping control samples were performed at the Brazilian Doping Control Laboratory (LBCD), a World Anti-Doping Agency (WADA)-accredited laboratory located in Rio de Janeiro, Brazil. A new facility at Rio de Janeiro Federal University (UFRJ) was built and fully operated by over 700 professionals, including Brazilian and international scientists, administrative staff, and volunteers. For the Olympic Games, 4913 samples were analysed. In 29 specimens, the presence of a prohibited substance was confirmed, resulting in adverse analytical findings (AAFs). For the Paralympic Games, 1687 samples were analysed, 12 of which were reported as AAFs. For both events, 82.8% of the samples were urine, and 17.2% were blood samples. In total, more than 31 000 analytical procedures were conducted. New WADA technical documents were fully implemented; consequently, state-of-the-art analytical toxicology instrumentation and strategies were applied during the Games, including different types of mass spectrometry (MS) analysers, peptide, and protein detection strategies, endogenous steroid profile measurements, and blood analysis. This enormous investment yielded one of the largest Olympic legacies in Brazil and South America. Copyright © 2017 John Wiley & Sons, Ltd.

Optimization of an online heart-cutting multidimensional gas chromatography clean-up step for isotopic ratio mass spectrometry and simultaneous quadrupole mass spectrometry measurements of endogenous anabolic steroid in urine.

Measuring carbon isotope ratios (CIRs) of urinary analytes represents a cornerstone of doping control analysis and has been particularly optimized for the detection of the misuse of endogenous steroids. Isotope ratio mass spectrometry (IRMS) of appropriate quality, however, necessitates adequate purities of the investigated steroids, which requires extensive pre-analytical sample clean-up steps due to both the natural presence of the target analytes and the high complexity of the matrix. In order to accelerate the sample preparation and increase the automation of the process, the use of multidimensional gas chromatography (MDGC) prior to IRMS experiments, was investigated. A well-established instrumental configuration based on two independent GC ovens and one heart-cutting device was optimized. The first dimension (1D) separation was obtained by a non-polar column which assured high efficiency and good loading capacity, while the second dimension (2D), based on a mid-polar stationary phase, provided good selectivity. A flame ionization detector monitored the 1D, and the 2D was simultaneously recorded by isotope ratio and quadrupole mass spectrometry. The assembled MDGC set-up was applied for measuring testosterone, 5α- and 5ß-androstanediol, androsterone, and etiocholanolone as target compounds and pregnanediol as endogenous reference compound. The urine sample were pretreated by conventional sample preparation steps comprising solid-phase extraction, hydrolysis, and liquid-liquid extraction. The extract obtained was acetylated and different aliquots were injected into the MDGC system. Two high performance liquid chromatography steps, conventionally adopted prior to CIR measurements, were replaced by the MDGC approach. The obtained values were consistent with the conventional ones. Copyright © 2016 John Wiley & Sons, Ltd.

Salbutamol extraction from urine and its stability in different solutions: identification of methylation products and validation of a quantitative analytical method.

Salbutamol is commonly used in asthma treatment, being considered a short-effect bronchodilator. This drug poses special interest in certain fields of chemical analysis, such as food, clinical and doping analyses, in which it needs to be analyzed with quantitative precision and accuracy. Salbutamol, however, is known to degrade under certain conditions and this is critical if quantitative results must be generated. The present work aimed to investigate salbutamol extraction from urine samples, to determine whether salbutamol is unstable in other solvents as well as in urine samples, to elucidate the structures of the possible degradation products and to validate an analytical method using the extraction procedure evaluated. Stability investigations were performed in urine at different pH values, in methanol and acetone at different temperatures. Semi-preparative liquid chromatography was performed for the isolation of degradation products, and gas chromatography coupled to mass spectrometry as well as nuclear magnetic resonance were used for identification. Three unreported methylation products were detected in methanolic solutions and had their structures elucidated. Urine samples showed a reduction in salbutamol concentration of up to 25.8% after 5 weeks. These results show that special care must be taken regarding salbutamol quantitative analyses, since degradation either in standard solutions or in urine could lead to incorrect values.

Detection of designer steroid methylstenbolone in "nutritional supplement" using gas chromatography and tandem mass spectrometry: elucidation of its urinary metabolites.

The use of "nutritional supplements" containing unapproved substances has become a regular practice in amateur and professional athletes. This represents a dangerous habit for their health once no data about toxicological or pharmacological effects of these supplements are available. Most of them are freely commercialized online and any person can buy them without medical surveillance. Usually, the steroids intentionally added to the "nutritional supplements" are testosterone analogues with some structural modifications. In this study, the analyzed product was bought online and a new anabolic steroid known as methylstenbolone (2,17α-dimethyl-17ß-hydroxy-5α-androst-1-en-3-one) was detected, as described on label. Generally, anabolic steroids are extensively metabolized, thus in-depth knowledge of their metabolism is mandatory for doping control purposes. For this reason, a human excretion study was carried out with four volunteers after a single oral dose to determine the urinary metabolites of the steroid. Urine samples were submitted to enzymatic hydrolysis of glucuconjugated metabolites followed by liquid-liquid extraction and analysis of the trimethylsilyl derivatives by gas chromatography coupled to tandem mass spectrometry. Mass spectrometric data allowed the proposal of two plausible metabolites: 2,17α-dimethyl-16ξ,17ß-dihydroxy-5α-androst-1-en-3-one (S1), 2,17α-dimethyl-3α,16ξ,17ß-trihydroxy-5α-androst-1-ene (S2). Their electron impact mass spectra are compatible with 16-hydroxylated steroids O-TMS derivatives presenting diagnostic ions such as m/z 231 and m/z 218. These metabolites were detectable after one week post administration while unchanged methylstenbolone was only detectable in a brief period of 45 h.

Detection of new urinary exemestane metabolites by gas chromatography coupled to mass spectrometry.

Exemestane is an aromatase enzyme complex inhibitor. Its metabolism in humans is not fully described and there is only one known metabolite: 17ß-hydroxyexemestane. In this work, excretion studies were performed with four volunteers aiming at the detection of new exemestane metabolites in human urine by gas chromatography coupled to mass spectrometry (GC-MS) after enzymatic hydrolysis and liquid-liquid extraction. Urine samples collected from four volunteers were analyzed separately. The targets of the study were mainly the 6-exomethylene oxidized metabolites. Two unreported metabolites were identified in both free and glucuconjugated urine fractions from all four volunteers, both of them were the result of the 6-exomethylene moiety oxidation: 6ξ-hydroxy-6ξ-hydroxymethylandrosta-1,4-diene-3,17-dione (metabolite 1) and 6ξ-hydroxyandrosta-1,4-diene-3,17-dione (metabolite 2). Furthermore, only in glucoconjugated fractions from all volunteers, one metabolite arising from the A-ring reduction was identified as well, 3ξ-hydroxy-5ξ-androst-1-ene-6-methylene-17-one (metabolite 3). The molecular formulae of all these metabolites were ascertained by the determination of exact masses using gas chromatography coupled to high resolution mass spectrometry (GC-HRMS). Moreover, all metabolites were confirmed using an alternative derivatization with methoxyamine and MSTFA/TMS-imidazole.

Tetrahydrogestrinone analysis and designer steroids revisited.

Anabolic steroids are the main abused class of prohibited substances in doping control. These steroids are associated with enhancement of muscular mass and aggressiveness, resulting in increased performance. Chromatography and MS have a key role among methods developed to detect anabolic steroids in doping control laboratories. However, the classical analytical approach fails in detection of the so-called 'designer steroids'. This review focuses on the rise of tetrahydrogestrinone, a drug that became synonymous with designer steroids. The reasons why classical methods fail in tetrahydrogestrinone detection are discussed and how the detection was implemented is shown. Alternative strategies for detection of new drugs designed to cheat current analytical methodology are highlighted. Concern for the abuse of veterinary designer drugs and supplements is also acknowledged.

Analysis of synthetic 19-norsteroids trenbolone, tetrahydrogestrinone and gestrinone by gas chromatography-mass spectrometry.

Tetrahydrogestrinone, gestrinone and trenbolone are synthetic 19-norsteroids with androgenic properties sharing a labile conjugated ketotrienyl motif. Their LC-MS analyses tend to overcome classical derivatization problems, a shortcoming to the use of GC-MS. Therefore, alternative derivatization procedures were evaluated. The procedure with methoxylamine: pyridine followed by TMSImid: MSTFA gave the best results. This is attributed to the stability of the MO-TMS derivatives hindering the formation of artifacts and tautomerism. A full method is presented including SPE, hydrolysis and liquid-liquid extraction. It was possible to confirm the analytes below 2 ng/mL in urine, being the method robust and cost effective also for screening proposes.

Electrospray ionization mass and tandem mass spectra of a series of N-pyrazolylmethyl and N-triazolylmethyl N-phenylpiperazines: new dopaminergic ligands with potential antipsychotic properties.

Recently, two analogous series of N-pyrazolylmethyl and N-triazolylmethyl N-phenylpiperazines have been prepared and found to be potential antipsychotic drugs acting as new selective ligands of the dopamine D2 receptor. Herein we report a systematic study of their high-resolution electrospray ionization mass and tandem mass spectra in which the main dissociation routes of their protonated molecules are determined and rationalized. The ESI-MS/MS data is very characteristic for both series allowing straightforward isomeric differentiation. A single and dominant fragment ion for the pyrazole series and four major fragment ions for the triazole series are useful for selective reaction MS monitoring of these potential drugs in biological fluids.