DEFAR - Departamento de Farmácia
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/530
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2 resultados
Resultados da Pesquisa
Item A high throughput approach for determination of dermorphin in human urine using LC-HRMS and LC-MS/MS for doping control purposes.(2020) Castro, Juliana de Lima; Martucci, Maria Elvira Poleti; Pereira, Henrique Marcelo Gualberto; Sousa, Valéria P. deDermorphin is a peptide with analgesic actions similar to morphine, but with greater effect and less potential to cause tolerance. The use of dermorphin has been documented in race horses, and its use in humans has already been reported. Considering the potential advantages from the use of dermorphin over morphine, a method to monitor it, and its main metabolite dermorphin (1-4), in humans becomes necessary for doping control. Here, we present two orthogonal methods for this purpose: a high-throughput liquid chromatography coupled to high resolution mass spectrometry (HRMS) as an Initial Testing Procedure and liquid chromatography-tandem mass spectrometry (MS/MS) in the Selected Reaction Monitoring (SRM) acquisition mode for a Confirmation Procedure. For urine samples pre-treatment through a mixed-mode weak cation exchange solid phase extraction (WCX-SPE) emerged as an effective approach to extract peptides from the biological sample. For the HRMS analysis, a Full-MS scan acquisition mode was selected to detect the exact masses of dermorphin and dermorphin (1-4) at m/z 803.37226 and 457.20816, respectively. The SRM method used in the MS/MS confirmation protocol presented high specificity and sensitivity. The selected product ions for dermorphin were 602.2, 202.1 and 574.3 and for dermorphin (1-4) were 207.1, 223.1 and 235.1. Both methods were evaluated for specificity, repeatability, carryover, matrix effects and recovery. No carryover and matrix effects were detected. The Limit of Detection for Initial Testing Procedure and the Limit of Identification for Confirmation Procedure was 2,5 ng/mL. Also, specificity and robustness were acceptable for the application. Together, the developed methods proved to be efficient for the analysis of dermorphin and metabolite for human doping control purpose.Item High resolution mass spectrometry elucidation of captopril´s ozonation and chlorination by-products.(2017) Quintão, Frederico Jehár Oliveira; Brandão, Geraldo Célio; Silva, Silvana de Queiroz; Aquino, Sergio Francisco de; Afonso, Robson José de Cássia FrancoThe article evaluated the degradation of the captopril in aqueous solution after ozonation and chlorination. The process was continuously monitored focusing on the identification, mass spectrometry and elucidation of its by-products by applying direct infusion and high performance liquid chromatography, electrospray ionization high resolution mass spectrometry, in the negative ion mode. The cytotoxicity of its by-products solutions were evaluated with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. It was observed through that after 30 min of ozonation and chlorination, there was complete oxidation of captopril, i .e ., 100% removal efficiency. At these conditions, the rate of mineralization, by total organic carbon, was only 7.63% for ozonation and 6.40% for chlorination, evidencing the formation of degradation by-products. Ten captopril by-products were identified and their respective chemical structures elucidations are proposed. The treated samples and their by-products were nontoxic to HepG2 cells by MTT assay.