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Analytical and Bioanalytical Chemistry Jul 2015A method for the determination and quantification of ketosteroid hormones in meat by mass spectrometry, based on the derivatization of the carbonyl moiety of steroids by...
A method for the determination and quantification of ketosteroid hormones in meat by mass spectrometry, based on the derivatization of the carbonyl moiety of steroids by O-methylhydroxylamine, is presented. The quantitative assay is performed by means of multiple-reaction-monitoring (MRM) scan mode and using the corresponding labelled species, obtained by reaction with d 3-methoxylamine, as internal standard. The accuracy of the method was established by evaluating artificially spiked samples, obtaining values in the range 90-110%. Recovery tests were performed on blank matrix samples spiked with non-natural steroids including trenbolone and melengestrol acetate. The latter experiment revealed that the yield of the extraction processes was approximately 60%. Good values of LOQ and LOD were achieved, making this method competitive with current hormone assay methods.
Topics: Ketosteroids; Meat; Solid Phase Microextraction; Tandem Mass Spectrometry
PubMed: 26014285
DOI: 10.1007/s00216-015-8772-5 -
Journal of Chromatography. B,... Apr 2015An ultra-performance convergence chromatography (UPC2) system coupled tandem mass spectrometry was successfully utilised to analyse chlormadinone acetate, delmadinone...
An ultra-performance convergence chromatography (UPC2) system coupled tandem mass spectrometry was successfully utilised to analyse chlormadinone acetate, delmadinone acetate, fluorogestone acetate, medroxyprogesterone acetate, megestrol acetate, melengestrol acetate, chlortestasterone acetate in bovine and porcine kidney fat. This novel approach obtained an improved resolution in comparison to previously reported chromatographic methods combined with MS detector in a shorter analytical time. All the acetylgestagen compounds were well separated on a ACQUITY UPC(2) HSS C18 column (3.0 × 100 mm, 1.7 μm) by applying methanol and carbon dioxide (2/98). The LOQ of delmadinone acetate, melengestrol acetate, medroxyprogesterone acetate and megestrol acetate are 0.5 μg/kg, fluorogestone acetate, chlormadinone acetate and chlortestasterone acetate 1.0 μg/kg. The recoveries of gestagens spiked in kidney fats at a concentration range of 0.5 to 4 μg/kg were above 86.1% with relative standard deviations (RSD) less than 13.1%. These rapid and reliable methods can be used to efficiently separate, characterize and quantify the residues of gestagens in kidney fats with advantages of shorter time, more sensitive and environmental friendly.
Topics: Adipose Tissue; Animals; Cattle; Chromatography, High Pressure Liquid; Kidney; Linear Models; Progestins; Reproducibility of Results; Sensitivity and Specificity; Swine; Tandem Mass Spectrometry
PubMed: 25777477
DOI: 10.1016/j.jchromb.2015.02.034 -
Journal of Agricultural and Food... Dec 2014This work examines the fate of synthetic growth promoters (trenbolone acetate, melengestrol acetate, and zeranol) in sterilized soil systems, focusing on their sorption...
This work examines the fate of synthetic growth promoters (trenbolone acetate, melengestrol acetate, and zeranol) in sterilized soil systems, focusing on their sorption to organic matter and propensity for mineral-promoted reactions. In organic-rich soil matrices (e.g., Pahokee Peat), the extent and reversibility of sorption did not generally correlate with compound hydrophobicity (e.g., K(ow) values), suggesting that specific binding interactions (e.g., potentially hydrogen bonding through C17 hydroxyl groups for the trenbolone and melengestrol families) can also contribute to uptake. In soils with lower organic carbon contents (1-5.9% OC), evidence supports sorption occurring in parallel with surface reaction on inorganic mineral phases. Subsequent experiments with pure mineral phases representative of those naturally abundant in soil (e.g., iron, silica, and manganese oxides) suggest that growth promoters are prone to mineral-promoted oxidation, hydrolysis, and/or nucleophilic (e.g., H2O or OH(-)) addition reactions. Although reaction products remain unidentified, this study shows that synthetic growth promoters can undergo abiotic transformation in soil systems, a previously unidentified fate pathway with implications for their persistence and ecosystem effects in the subsurface.
Topics: Adsorption; Growth Hormone; Kinetics; Melengestrol Acetate; Minerals; Oxidation-Reduction; Soil; Soil Pollutants; Trenbolone Acetate; Zeranol
PubMed: 25426694
DOI: 10.1021/jf5035527 -
Steroids Aug 2014Biotransformation of melengestrol acetate (MGA, 17α-acetoxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione) (1) was investigated for the first time by using fungal...
Biotransformation of melengestrol acetate (MGA, 17α-acetoxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione) (1) was investigated for the first time by using fungal cultures. Incubation of compound 1 with Cunninghamella blakesleeana yielded a new major metabolite, 17α-acetoxy-11β-hydroxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione (2). The metabolite 2 was purified by using HPLC, followed by characterization through (1)H- and (13)C-NMR and other spectroscopic techniques. Single crystal X-ray diffraction analysis was used to deduce the three dimensional structures of melengestrol acetate (1) and metabolite 2 for the first time. T-cell proliferation assay was employed to evaluate the immunosuppressant effect of compounds 1 and 2 with IC50=0.5±0.07 and 0.6±0.08μg/mL, respectively. The results indicated that these compounds possess sixfold potent T-cell proliferation inhibitory activity as compared to the standard prednisolone (IC50<3.1μg/mL). Both compounds were found to be non-toxic in a 3T3 (mouse fibroblast) cell-based cytotoxicity assay. This discovery of potent anti-inflammatory activity of compounds 1 and 2 can lead the way to develop new immunosuppressant compounds for clinical application.
Topics: 3T3 Cells; Animals; Anti-Inflammatory Agents, Non-Steroidal; Biotransformation; Cell Proliferation; Cunninghamella; Dose-Response Relationship, Drug; Immunosuppressive Agents; Melengestrol Acetate; Mice; Models, Molecular; Molecular Conformation; Structure-Activity Relationship; T-Lymphocytes
PubMed: 24793568
DOI: 10.1016/j.steroids.2014.04.012