Nonlinear pharmacokinetics of imipramine and its active metabolite, desipramine

研究科: 千葉大学大学院薬学研究院学位:千大院薬博乙第80

Fases estacionárias quirais para cromatografia líquida de alta eficiência

The development of Chiral Stationary Phases (CSPs) for high performance liquid chromatography has been studied by various researches around the world, especially, since 1980. This simple interest has been transformed into a tool of great technological value for the industrial community and scholars in general providing the existence of several CSPs, which act through different mechanisms of chiral discrimination. This paper describes the main types of CSPs that are used for the resolution of the majority of chiral compounds

Degradation of Fluoroquinolone Antibiotics and Identification of Metabolites/Transformation Products by LC-MS/MS

Antibiotics are a therapeutic class widely found inenvironmental matrices and extensively studied due to its persistence and implications for multi-resistant bacteria development. Degradation of four fluoroquinolone antibiotics, namely Ofloxacin (OFL), Norfloxacin (NOR), Ciprofloxacin (CPF) and Moxifloxacin (MOX), at 10 mg L-1 using a mixed bacterial culture, was assessed for 60 days. The assays were followed by a developed and validated analytical method of HPLC with Fluorescence Detection using a Luna PFP (2) 3µm column. The optimized conditions allowed picturing metabolites/transformation products formation and accumulation during the process, stating an incomplete mineralization, also shown byfluoride release. OFL and MOX presented the highest (98.3%) and the lowest (80.5%) extent of degradation after 19 days of assay, respectively. Some of these intermediate compounds were identified by LCMS/MS in selected degradation samples. Most of the intermediates were already described as biodegradation and/or photodegradationproducts in different conditions, but new and/or unknown metabolites were also present

Structural insights into the molecular basis responsible for the effects of immobilization on the kinetic parameters of glyceraldehyde-3-phosphate dehydrogenase from Trypanosoma cruzi and human

O desenvolvimento de métodos rápidos e eficazes para a identificação de novas moléculas bioativas é fundamental para o processo de descoberta e planejamento de fármacos. A integração de um sistema de cromatografia liquida de alta eficiência (CLAE), com biorreatores como fase estacionária (IMER) é uma estratégia atrativa e versátil para a triagem de coleções de compostos visando à identificação de novos agentes terapêuticos. Os parâmetros cinéticos da enzima imobilizada gliceraldeído-3-fosfato desidrogenase (GAPDH) de Trypanosoma cruzi e humana foram determinados (T. cruzi: ‘K IND. M POT. G3P’ = 0.50 mmol ‘ L POT. -1’; ‘K IND. M POT. NAD+” = 0.67 mmol ‘L POT. -1’; humana: ‘K IND. M POT. G3P’ = 3.7 mmol ‘L POT. -1’; ‘K IND. M POT. NAD+’ = 0.75 mmol ‘L POT. -1’) e comparados com aqueles observados em solução (T. cruzi: ‘K IND. M POT. G3P’ = 0.42 mmol ‘L POT. -1’; ‘K IND. M POT. NAD+’ = 0.26 mmol ‘L POT. -1’; humana: ‘K IND. M POT. G3P’ = 0.16 mmol ‘L POT. -1’; ‘K IND. M POT. NAD+” = 0.18 mmol ‘L POT. -1’). Os resultados indicaram uma diminuição na afinidade das enzimas imobilizadas, entretanto, os elementos estruturais necessários para o processo de reconhecimento molecular e atividade biológica permaneceram inalterados, aumentando a estabilidade das enzimas. Além disso, a análise estrutural forneceu dados moleculares importantes envolvidos nos efeitos da imobilização sobre as interações entre ligante e receptor e, consequentemente, sobre a atividade enzimática e parâmetros cinéticosThe development of fast and reliable methods for the identification of new bioactive compounds is of utmost importance to boost the process of drug discovery and development. Immobilized enzyme reactors (IMERs), integrated with high performance liquid chromatography (HPLC), are attractive and versatile tools for screening collections consisting of natural products and synthetic small molecules. Standard kinetic parameters of the immobilized enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from both Trypanosoma cruzi de and human have been determined (T. cruzi: ‘K IND. M POT. G3P’ = 0.50 mmol ‘L POT. -1’; ‘K IND. M POT. NAD+” = 0.67 mmol ‘L POT. -1’; humana: ‘K IND. M POT. G3P’ = 3.7 mmol ‘L POT. -1’; ‘K IND. M POT. NAD+” = 0.75 mmol ‘L POT. -1’), and comparisons of these values with those of the parasite and human free enzymes indicate a decrease in the affinity for the immobilized system (T. cruzi: ‘K IND. M POT. G3P’ = 0.42 mmol ‘L POT. -1’; ‘K IND. M POT. NAD+” = 0.26 mmol ‘L POT. -1’; humana: ‘K IND. M POT. G3P’ = 0.16 mmol ‘L POY. -1’; ‘K IND. M POT. NAD+” = 0.18 mmol ‘L POT. -1’). Interestingly, despite the kinetic differences between the two systems, the immobilized GAPDHs retained the required structural requirements for molecular recognition and biological activity, increasing the stability the enzyme. In the present work, we described an integrated structural analysis which has provided important insights into the molecular basis underlying the effects of immobilization on the ligand-receptor interactions and consequent enzymatic activity and kinetics parametersFAPESPCNP

Antimicrobial activity of Alternanthera brasiliana Kuntze (Amaranthaceae): a biomonitored study

In an attempt to identify new antimicrobial compounds with potential to be used as a bactericidal/ fungicidal agent, a biomonitored study of extracts of Alternanthera brasiliana, which is used in Brazilian folk medicine as bactericidal, analgesic and anti-inflammatory, was developed. Different techniques of evaluation have been used in the partitioned extracts of the antimicrobial activity associated with chromatographic methodologies. The work led to the isolation of two substances in the ethyl acetate extract, identified as quercetin and sitosterol glycoside and the antibacterial evaluation of these substances demonstrated that the flavonoid presented antibacterial action against S. aureus. Further studies intend to identify new substances with antibacterial activity in extracts of A. brasiliana.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Enantioselectivity Effects in Clinical Metabolomics and Lipidomics

Metabolomics and lipidomics have demonstrated increasing importance in underlying biochemical mechanisms involved in the pathogenesis of diseases to identify novel drug targets and/or biomarkers for establishing therapeutic approaches for human health. Particularly, bioactive metabolites and lipids have biological activity and have been implicated in various biological processes in physiological conditions. Thus, comprehensive metabolites, and lipids profiling are required to obtain further advances in understanding pathophysiological changes that occur in cells and tissues. Chirality is one of the most important phenomena in living organisms and has attracted long-term interest in medical and natural science. Enantioselective separation plays a pivotal role in understanding the distribution and physiological function of a diversity of chiral bioactive molecules. In this context, it has been the goal of method development for targeted and untargeted metabolomics and lipidomic assays. Herein we will highlight the benefits and challenges involved in these stereoselective analyses for clinical samples

Imobilização de enzimas em suportes cromatográficos: uma ferramenta na busca por substâncias bioativas Immobilization of the enzymes on chromatographic supports: a tool to research of inhibitor compounds

<abstract language="eng">The development and characterization of bioreactors or IMER (immobilized enzyme reactors) as research tools are important in the scope of medicinal chemistry and constitute an alternative for the rational development of drugs. This approach does not require highly purified enzymes or a great amount of protein, but increase the enzymatic stability against heat, organic solvents and pH, without too much loss of catalyst activity. Immobilized enzyme reactors (IMER) can be used for the accomplishment of high efficiency screening on-line and, thus inhibitors can be quickly identified. Here, we emphasize the development of IMER by use of different methods of immobilization and chromatographic supports. Their applications, in different areas of research, are also fully discussed