RESUMO
Clenbuterol (Clb) (4-amino-α-[(tert-butylamine) methyl]-3,5-dichlorobenzyl alcohol) is a sympathomimetic agent that exhibits ß2-agonist activity. It is applied as a bronchodilatory, tocolytic, and mucolytic agent and is authorized for clinical management in both human and veterinary therapeutics as a racemic mixture. However, its use is strictly prohibited in animals destined for food production in countries in the European Union and in the United States and Mexico, among many others. The R-(-) enantiomer in clenbuterol stimulates ß2-receptors, whereas the S-(+) enantiomer blocks the effect of ß1-receptors. The aims of this study were to develop a method for detecting and quantifying Clb and its enantiomeric distribution in several bovine tissues. The UHPLC-MS/MS method developed to quantify the target compound at trace levels in these tissues combines high sensitivity with good selectivity and short chromatographic run time. The tissue samples tested were found to contain racemic Clb in concentrations of 5-447 pg g-1 . The enantiomeric analysis of Clb showed that R-(-)-Clb is present at higher concentrations in some tissues, whereas S-(+)-Clb was detected in a ratio of 55/45 in the liver and heart tissues.
Assuntos
Clembuterol , Humanos , Animais , Bovinos , Clembuterol/análise , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Alimentos/análise , Carne/análise , Fatores de RiscoRESUMO
Clenbuterol (Clb) can be present in Mexico often but not all over the world in animal tissues and organs, therefore, potentially is derived from animal sources as well. The aims of this study were to develop and validate a method for detecting traces of clenbuterol in beef sausages. A calibration curve showed linearity in the range of 20-500 pg ml-1 . The limit of detection (LOD) and lower limit of quantification (LLOQ) were 5 and 10 pg g-1 , respectively. The analyte recovery was from 95.70% to 100.40% with an intraday relative standard deviation (RSD%) of 0.99%-2.10% and an interday RSD% of 0.54%-2.34%, R2 = 0.9998. The methodology developed was applied successfully in 15 samples of beef sausage, and 73.3% of the samples tested contained racemic clenbuterol in concentrations between 30 and 471 pg g-1 . The UHPLC-MS/MS method developed combines high sensitivity with good selectivity and short chromatographic run time. Additionally, the enantiomeric analysis of clenbuterol performed in beef sausages showed a 59% for R-(-)-Clb and 41% for S-(+)-Clb. The presence of clenbuterol in beef sausages could represent a risk of unintentional doping in sport field, because the clenbuterol is a banned substance included in the World Anti-Doping Agency's (WADA) list of prohibited substances.
Assuntos
Clembuterol , Dopagem Esportivo , Animais , Bovinos , Cromatografia Líquida de Alta Pressão/métodos , Clembuterol/análise , Estereoisomerismo , Espectrometria de Massas em Tandem/métodosRESUMO
Clenbuterol (4-amino-α-[(tert-butylamino)methyl]-3,5-dichlorobenzylalcohol) is a ß2-adrenergic agonist. The consumption of meat contaminated with clenbuterol can lead to increased heart rate, blood pressure, anxiety, palpitations and skeletal muscle tremors. Several analytical methods have been developed to identify and quantify clenbuterol in different biological matrices. In this report, we have developed a specific and sensitive analytical method for quantifying clenbuterol and performed an in-depth enantiomeric analysis in bovine urine. The method was evaluated in accordance with international guidelines, and we used an isotopically labeled analog as an internal standard. The extraction efficiency for clenbuterol in bovine urine was > 98%, the limit of detection was 0.05 ng/mL and the limit of quantification was 0.10 ng/mL. Our assay showed high specificity, no carryover was observed and the assay was linear in the range 0.10-8.0 ng/mL. Fifteen bovine urine samples were analyzed (containing clenbuterol), and an enantiomeric analysis was performed. The clenbuterol concentration range was 0.10-10.56 ng/mL across these samples. The levorotatory enantiomer was detected at greater concentrations than the dextrorotatory enantiomer, the ratio being 1.7 ± 0.6 (n = 15), and a statistical difference was observed (P < 0.05) using the Wilcoxon test.
Assuntos
Clembuterol/urina , Animais , Bovinos , Cromatografia Líquida , Contaminação de Alimentos , Carne , Estereoisomerismo , Espectrometria de Massas em TandemRESUMO
The objective of this research was to evaluate the effect of extraction solvent on phenolic compounds content (total phenols, total flavonoids) and antioxidant capacity levels (DPPH, ABTS and FRAP) of a commercial food supplement from Moringa oleifera leaves. The content of total phenols, total flavonoids and total non-flavonoids ranged from 55.98 to 226.20 mg ChlAE/g, from 17.63 to 23.46 mg CatE/g and from 38.34 to 202.73 mg CatE/g mg/g, respectively, while condensed tannins were not detected in none of the extracts. Non-flavonoids compounds were the most abundant group of phenolics in all the extracts ranging from 68 to 90% of the total phenols content. Levels of antioxidant capacity ranged from 22.43 to 124.93, 101.03 to 245.25 and 77.06 to 214.17 µmolTE/g in ABTS, DPPH and FRAP, respectively. In addition, EtOH 50% and EtOH 100% extracts showed the highest and lowest content in phenolics content and antioxidant capacity level. Finally, data obtained in the content of phenolics and antioxidant capacity levels of the present study are higher than most of data of scientific literature reported previously by other authors(AU)
El objetivo de esta investigación fue evaluar el efecto del solvente de extracción en el contenido de compuestos fenólicos (fenoles totales, flavonoides totales) y los niveles de capacidad antioxidante (DPPH, ABTS y FRAP) de un suplemento comercial de hojas de Moringa oleifera. El contenido de fenoles totales, flavonoides totales, no-flavonoides totales oscilaron de 55.98 a 226.20 mg ChlAE/g, de 17.63 a 23.46 mg CatE/g y de 38.34 a 202.73 mg/g, respectivamente, mientras que no fue detectada la presencia de taninos condensados en ninguno de los extractos. Los compuestos fenólicos noflavonoides fueron el grupo más abundante de compuestos fenólicos en todos los extractos y oscilaron de 68 a 90% del total de los fenoles totales. Los niveles de capacidad oscilaron de 22.43 a 124.93, de 101.03 a 245.25 y de 77.06 a 214.17 µmolTE/g en ABTS, DPPH y FRAP, respectivamente. Además, los extractos con EtOH 50% y EtOH 100% mostraron el contenido más alto y más bajo de fenólicos y niveles de capacidad antioxidante, respectivamente. Finalmente, los datos obtenidos en el contenido de compuestos fenólicos y los niveles de capacidad antioxidante del presente estudio son más altos que la mayoría de los datos reportados previamente en literatura por otros autores(AU)