Metabolic profiling of complex biological matrices based on liquid chromatography-mass spectrometry (LC-MS) allows detecting a wide range of metabolites with distinct concentrations and physicochemical properties. Given the complexity of samples and the necessity of a comprehensive approach in untargeted metabolomics, quality control strategies are mandatory to obtain high-quality data. The LC-MS performance must be monitored and evaluated to guarantee data reliability. In this study, a test mixture (TM) was developed, systematically evaluated, and applied to untargeted metabolomics of urine samples from individuals suspected of inborn errors of metabolism. The TM was composed of fifteen analytes that eluted across the entire gradient in reversed-phase columns and ionized in positive/negative electrospray modes. It helped set the LC-MS conditions for urine analysis, from sample reconstitution solvent to selecting the MS ion source parameters. The TM quickly indicated column stationary phase degradation during the batch analysis when employed to monitor and evaluate the LC-MS system in an untargeted metabolomic analysis. Thus, in addition to pooled QC samples, a TM can be employed in untargeted metabolomics to rapidly assess the system performance avoiding unnecessary efforts for further data treatment and multivariate analysis of poor-quality data.

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.

Ephedrines are widely used in therapy. Because of their stimulant properties, these substances are relevant in different forensic fields. At present, the state of the art for ephedrines quantification relay based on a liquid chromatography mass spectrometry, mainly because of the dilute-and-shoot approach. Notwithstanding, several gas chromatography based methods have already been described, all of them include cleanup steps, with the potential disadvantage of incurring errors and increasing the workload. In this paper, a straightforward method for ephedrine quantification based on gas chromatographic mass spectrometry, without cleanup and based on Doehlert matrix optimization is presented. Only 10 µL of a urine sample is necessary and for N-methyl-N-(trimethylsilyl)trifluoroacetamide/N-methyl-bis-trifluoracetamide derivatives, the intermediate precision was 2.77% for ephedrine, 9.20% for cathine, 8.29% for norephedrine and 4.27% for pseudoephedrine. The limit of detection was 20 ng mL-1 for ephedrine, 30 ng mL-1 for cathine and 40 ng mL-1 for norephedrine and pseudoephedrine.

ABSTRACT This study presents the bioreduction of six β-ketoesters by whole cells of Kluyveromyces marxianus and molecular investigation of a series of 13 β-ketoesters by hologram quantitative structure-activity relationship (HQSAR) in order to relate with conversion and enantiomeric excess of β-stereogenic-hydroxyesters obtained by the same methodology. Four of these were obtained as (R)-configuration and two (S)-configuration, among them four compounds exhibited >99% enantiomeric excess. The β-ketoesters series LUMO maps showed that the β-carbon of the ketoester scaffold are exposed to undergo nucleophilic attack, suggesting a more favorable β-carbon side to enzymatic reduction based on adopted molecular conformation at the reaction moment. The HQSAR method was performed on the β-ketoesters derivatives separating them into those provided predominantly (R)- or (S)-β-hydroxyesters. The HQSAR models for both (R)- and (S)-configuration showed high predictive capacity. The HQSAR contribution maps suggest the importance of β-ketoesters scaffold as well as the substituents attached therein to asymmetric reduction, showing a possible influence of the ester group carbonyl position on the molecular conformation in the enzyme catalytic site, exposing a β-carbon side to the bioconversion to (S)- and (R)-enantiomers.

Glicocorticosteroides estão incluídos na lista de substâncias proibidas da Agência Mundial Antidoping como analitos que dispensam quantificação. Entretanto, abordagens semiquantitativas são necessárias antes de relatar um resultado analítico adverso para essa classe de substâncias. Cromatografia líquida acoplada à espectrometria de massa (LC-MS) tem sido empregada com excelente seletividade e especificidade na análise de xenobiontes em misturas complexas. Foram analisadas amostras contendo glicocorticosteroides exógenos, a partir de diferentes vias de administração, utilizando o método proposto. Amostras geradas após administração sistêmica (via oral) apresentaram níveis de prednisolona ou prednisona superiores a 30 ng mL-1, limite mínimo de desempenho requerido usado como parâmetro de diagnóstico. Por outro lado, vias não-sistêmicas parecem não apresentar biodisponibilidade para gerar um caso adverso em análises de controle de dopagem. Considerando o número reduzido de estudos similares na literatura, mais estudos de excreção podem ser realizados usando o método relatado com o objetivo de fornecer mais informações sobre o perfil de excreção de glicocorticosteroides administrados por vias sistêmicas e não sistêmicas.

Glucocorticosteroids are included in the World Anti-Doping Agency (WADA) prohibited list as non-threshold analytes. Nevertheless, at least semi-quantitative approaches are necessary before reporting an adverse analytical finding for this class of substances. The liquid chromatography coupled to mass spectrometry (LC-MS) has been used with excellent selectivity and specificity in xenobiotic analysis in complex matrices. Real samples containing exogenous glucocorticosteroids from different administration routes were analyzed using the method proposed. Samples from systemic administration (oral route) presented levels of prednisolone or prednisone higher than 30 ng mL-1, the minimum requirement performance level used as diagnostic parameter. On the other hand, non-systemic routes seem to not have bioavailability to generate an adverse case in doping control analysis. Considering the low number of similar studies available in the literature, more urinary studies could be done using the method reported aiming to provide more information about the excretion profile of glucocorticosteroids administered by systemic and non-systemic routes.

No mundo das drogas de otimização de desempenho, hormônio gonadotrófico humano (hCG) é crescentemente usado sozinho em também em combinação com ciclos de Agentes Anabólicos Esteróides. Em homens o hCG mimetiza o hormônio Luteinizante (LH) e ajuda a aumentar a produção de testosterona nos testículos. Assim sendo, hCG é comumente usado durante e depois de ciclos de esteróides para restaurar o tamanho testicular assim como a produção de testosterona endógena. Controle de dopagem para hCG requer atenção especial, visto que, deve ser feita diferença entre a origem endógena e exógena de ambas substâncias. Na carência de um padrão mais claro do que seria um nível esperado de normalidade, os laboratórios de controle de dopagem tem aplicado valores de corte entre 5 e 25 mUI/mL. Por causa de grande diferença em desenhos de ensaios e especificidade para diferentes formas de hCG, as concentrações medidas são altamente dependentes do ensaio usado e população analisada. O objetivo do estudo é o estabelecimento do valor de corte para a caracterização do abuso exógeno por atletas obtido com a aplicação do Imunoensaio Enzimático por Micropartículas.

In the world of performance enhancing drugs, human Chorionic Gonadotrophin (hCG) is increasingly used alone and also in combination with various Anabolic Androgenic Steroid cycles. In males, hCG mimics luteinizing hormone (LH) and helps increase testosterone production in the testes. As such, hCG is commonly used during and after steroid cycles to maintain and restore testicular size as well as endogenous testosterone production. Doping control for hCG requires special attention since a difference must be made between the endogenous and exogenous origin of both substances. In the absence of a clearer pattern of what would be an expected level of normality, the doping control laboratories have been applying cut off values between 5 and 25 mUI/mL. Because of the large differences in assay design and specificity for different forms of hCG, the concentrations measured are highly dependent on the assay used and population analyzed. The aim of the study is the establishment of a cut off value for the characterization of exogenous misuse by athletes obtained with the usage of Microparticles Enzyme Immunoassays.

Uncaria tomentosa (Willd.) DC. e Uncaria guianensis (Aubl.) Gmel., conhecidas comercialmente como unha-de-gato, são trepadeiras lenhosas nativas das florestas tropicais amazônica e central-americana. Essas espécies de Rubiaceae enfrentam ultimamente um eminente risco de extinção devido tanto ao extrativismo indiscriminado quanto ao desflorestamento de seus habitats naturais. Esse trabalho descreve métodos de cultivo in vitro para as duas espécies, analisando o perfil e o teor dos alcalóides oxindólicos pentacíclicos marcadores por CLAE no material vegetal obtido. Os resultados mostraram que os métodos desenvolvidos foram capazes de produzir plantas com perfil e teor dos alcalóides alvos similares à plantas nativas e cultivadas in vivo, com a vantagem adicional de produção em menor tempo de mudas próprias para plantio no campo. Os dados evidenciaram que o cultivo in vitro pode ser uma ferramenta viável para a produção das duas espécies com impacto na sua comercialização e na preservação das florestas.

Uncaria tomentosa (Willd.) DC. and Uncaria guianensis (Aubl.) Gmel., commercially known as cat's claw, are large woody vines native of the Amazon and Central America rainforests. These Rubiaceae species face nowadays an imminent risk of extinction due to indiscriminate harvesting in the wild as well as to increasing deforestation of their natural habitat. This work describes in vitro cultivation methods for both species with determination, by HPLC, of the pentacyclic oxindole alkaloid contents and profiles of the plant material. The results have proved that the methods we developed were able to produce plants with alkaloid profiles and contents similar to the wild and in vivo cultivated species, and with the additional advantage of producing suitable young plants in a shorter period of time. The data showed that the in vitro technique can be a feasible tool for the growth of the species, and may thus be important for their commercialization and for their conservation as a forest resource.

Um procedimento é descrito para a determinação simultânea de substâncias androgênicas, incluindo esteróides e beta2-agonistas. O método envolve a análise de compostos anabólicos em urina hidrolisada, usando-se extração líquido-líquido com subseqüente conversão a derivados trimetilsililéteres, para análise por CG-EM. Injeção com divisão de fluxo de 1/10 dos derivados TMS a 280 °C, em uma coluna capilar, inicialmente mantida a 140 °C e então programada para 180 °C a 40 °C min-1, seguida por 3 ºC min-1 até 230 ºC, e então, 40 ºC min-1 até 300 ºC, resulta em uma boa resolução e formato de pico para todos os compostos. Os limites de detecção da maioria dos esteróides foi de 1 ng mL-1, exceto para a formebolona e trembolona (25 ng mL-1). Quando aplicado a amostras de urinas selecionadas com evidência de degradação bacteriana e metabólitos provenientes de medicação/vitaminas, o método permite a rápida triagem para androgênios e outras substâncias monitoradas em rotina. A resolução foi adequada para avaliar o perfil esteroidal endógeno, relevante para controle de dopagem e aplicações médicas.

A procedure is described for the simultaneous determination of androgenic substances including steroids and beta2-agonists. The method involves analysis of hydrolized urinary anabolic compounds using liquid-liquid extraction, with subsequent conversion to trimethylsilylether derivatives for the analysis by GC-MS. Pulse split injection 1/10 of the TMS derivatives at 280 °C into the capillary column, initially maintained at 140 °C then programmed to 180 °C at 40 °C min-1, followed by 3 ºC min-1 to 230 ºC and then 40 ºC min-1 to 300 ºC, resulted in good resolution and peak shape for all compounds. The detection limits of most of the steroids were 1 ng mL-1 except for formebolone and trenbolone (25 ng mL-1). When applied to selected urine samples with evidence of bacterial degradation and metabolites from usual medications/vitamins, the method allowed rapid screening for androgens and other substances monitored in routine. The resolution was adequate to evaluate the endogenous steroid profile relevant to doping control and medical applications.

In Brazil, very little experimental work on measurements of indoor air pollutant levels has been done. Nowadays, increasing attention is being given to indoor air quality and the health problems associated with buildings and the indoor work environment. The scope of this paper is to review the major pollutants found in indoor environments and their sources. Subsequently, exposure to indoor air pollutants and health effects are considered. The review concludes by briefly addressing assessment of indoor air quality in Brazil and research needs.