RESUMEN
Formoterol is a long acting ß(2)-agonist and has proven to be a very effective bronchodilating agent. Hence it is frequently applied therapeutically for the treatment of asthma. Because ß(2)-agonists might be misused in sports for the stimulatory effects and for growth-promoting action their use is restricted. Since January 2012, formoterol is prohibited in urinary concentrations higher than 30 ng/mL. The objective of this study was to develop and validate a simple and robust ultra high performance liquid chromatographic-tandem mass spectrometric (UHPLC-MS/MS) method for the direct quantification of formoterol in urine. Sample preparation was limited to an enzymatic hydrolysis step after which 2 µL was injected in the chromatographic system. Chromatography was performed on a C(8)-column using gradient conditions. The mobile phase consisted of water/methanol (H(2)O/MeOH) both containing 0.1% acetic acid (HOAc) and 1mM ammonium acetate (NH(4)OAc). Calibration curve were constructed between 15 and 60 ng/mL. Validation data showed bias of 1.3% and imprecision of 5.4% at the threshold. Ion suppression/enhancement never exceeded 7%. Calculating measurement uncertainty showed proof of applicability of the method. Stability of formoterol was also investigated at 56 °C (accelerated stability test) at pH 1.0/5.2/7.0 and 9.5. At the physiological pH values of 5.2 and 7.0, formoterol showed good stability. At pH 1.0 and 9.5 significant degradation was observed.
Asunto(s)
Agonistas de Receptores Adrenérgicos beta 2/orina , Broncodilatadores/orina , Cromatografía Líquida de Alta Presión , Doping en los Deportes , Etanolaminas/orina , Sustancias para Mejorar el Rendimiento/orina , Detección de Abuso de Sustancias/métodos , Espectrometría de Masas en Tándem , Acetatos/química , Ácido Acético/química , Biomarcadores/orina , Calibración , Cromatografía Líquida de Alta Presión/normas , Estabilidad de Medicamentos , Fumarato de Formoterol , Humanos , Concentración de Iones de Hidrógeno , Hidrólisis , Metanol/química , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Detección de Abuso de Sustancias/normas , Espectrometría de Masas en Tándem/normas , Temperatura , Urinálisis , Agua/químicaRESUMEN
Further lipophilic flavonols present in Vellozia graminifolia have been determined by high temperature high resolution gas chromatography (HTHRGC) and by HTHRGC coupled to mass spectrometry (MS). These methods resulted in the detection, isolation and characterisation of a monoisoprenylated flavonol 3,5,4'-trimethoxy-3'-hydroxy-6,7-(2"-isopropenyldihydrofurano)flavone from the ethyl acetate extract of the whole plant. The structural elucidation was accomplished using spectral data, including two-dimensional NMR, and on chemical transformations. Both HTHRGC and HTHRGC-MS were shown to be alternative and extremely valuable methods for the quick screening of flavonoid aglycones and other chemical metabolites of the Velloziaceae.
Asunto(s)
Cromatografía de Gases/métodos , Flavonoides/análisis , Calor , Magnoliopsida/química , FlavonolesRESUMEN
The terpenes, sterols, alkaloid (glaucine) and alpha-tocopherol show seasonal variation for Croton hemiargyreus hemiargyreus and Croton echinocarpus. The amounts of triterpenes are higher during the tropical summer and in most samples the major sesquiterpene was characterized as caryophyllene. The seasonal variation of glaucine showed a maximum between June and October for C. hemiargyreus, and was present only in January and June in C. echinocarpus.
Asunto(s)
Euphorbiaceae/química , Euphorbiaceae/fisiología , Fitosteroles/aislamiento & purificación , Plantas Medicinales/química , Sesquiterpenos/aislamiento & purificación , Triterpenos/aislamiento & purificación , Brasil , Cromatografía de Gases y Espectrometría de Masas , Medicina Tradicional , Fitosteroles/química , Fitoterapia , Plantas Medicinales/fisiología , Estaciones del Año , Sesquiterpenos/química , Triterpenos/química , Clima TropicalRESUMEN
The crude ethanol extracts from the leaves of three Croton hemiargyrus hemiargyreus plants are fractionated by thin-layer chromatography, yielding five fractions. The fractions and the crude extract are analyzed by high-temperature high-resolution gas chromatography coupled with mass spectrometry (HT-HRGC-MS). Several natural products, including thermolabile components, can be characterized directly in the samples, such as alkaloids, terpenes, flavonoids, acids, alcohols, etc. The cold on-column technique proves to be appropriate for the injection of these thermolabile compounds. HT-HRGC-MS is shown to be a valuable tool and an alternative technique to classical phytochemical procedures for the simple and fast routine analysis of natural products in crude extracts.
Asunto(s)
Cromatografía de Gases/métodos , Hojas de la Planta/química , Plantas/química , Alcoholes/análisis , Alcaloides/análisis , Cromatografía en Capa Delgada , Etanol , Cromatografía de Gases y Espectrometría de Masas/métodos , Calor , Hidrocarburos/análisis , Peso Molecular , Extractos Vegetales/química , Terpenos/análisisRESUMEN
The fractions of hexane and dichloromethane extraction from marupá (Simaruba amara) and (Bertholletia excelsa) leaves were analyzed by HT-HRGC (high temperature high resolution gas chromatography) and HT-HRGC coupled to mass spectrometry (HT-HRGC-MS). Several compounds can be characterized including unusual high molecular weight compounds.
Asunto(s)
Cromatografía de Gases y Espectrometría de Masas/métodos , Extractos Vegetales/química , Plantas/química , Calor , Peso Molecular , Triglicéridos/químicaRESUMEN
The improvement of the biocatalytic reduction of 2-allyl-carboethoxy-cyclopentanone (2) to the corresponding cyclopentanol derivative (+)-(1R,2R)-(1) was accomplished employing baker's yeast in organic media. This chiral cyclopentanol derivative (1), analyzed by high resolution gas chromatography performed over beta-cyclodextrin stationary phase, was obtained in 38% yield (> 99% e.e.).
