As-synthesized TEA-BEA zeolite: Effect of Si/Al ratio on the Knoevenagel condensation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of Chlorogenic Acid (5-Caffeoylquinic Acid) Isolated from Baccharis oxyodonta on the Structure and Pharmacological Activities of Secretory Phospholipase A2 from Crotalus durissus terrificus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudos estruturais por difração de raios X de fosfolipases A2 em presença de íons com importância funcional

Snakes from Bothrops genus are responsible for more than 90% of the ophidian accidents in Brazil. One of the main complications from this kind of accident is muscular necrosis, which is related to the action of phospholipases A2 and metalloproteases, two groups of enzymes found in the venom of these animals. Although this complication cannot be solved by serum therapy administration, a great number of studies have been performed with the attempt to know the pharmacological sites of these toxins aiming, in the future, the development of complementary treatments to serum therapy. This work proposes structural studies of bothropic phospholipases A2 (PLA2s) in the presence of ions relevant to their activity, using the X-ray crystallography technique. Recently, it was demonstrated ions, as manganese, calcium and others, interfere in the biological activity of the PLA2s. Particularly, Lys49-PLA2s in the presence of manganese ions have miotoxicity reduced. Asp49-PLA2s show catalytic activity dependent of calcium, although structural studies with a miotoxic Asp49-PLA2, BthTX-II, suggest a possible catalytic mechanism independent of calcium. Therefore, co-crystallization of BthTX-II in the presence of calcium ions and of PrTX-I in the presence of manganese ions were performed. Comparative structural studies among obtained results and others already published in the literature were performed aiming a better understanding of the structure-function relationship of these toxins. The BthTX-II with the presence of calcium do not show this ion in the loop of coordination of calcium, presence necessary to develop the catalyses. After comparison of this model with the native one, only one distortion was found, but no apparent relationship with the residues responsible for its activity. In the PrTX-I structure, regions candidates of manganese ions were also found... (Complete abstract click electronic access below)

Preparação e propriedades de zeólitas faujasita contendo cátions amônio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Reuse of Cyclodextrin Glycosyltransferase through Immobilization on Magnetic Carriers

National Council for Scientific and Technological Development (CNPq)

Oxidação de carboidratos via catálise metálica não enzimática para aplicação em sensores

This work has main aim of is to propose the synthesis and characterization of nanostructured materials for oxidation of carbohydrates such as glucose, with non-enzymatic catalysis. The proposed pathway of synthesis of metal catalysts is the polyol method and techniques of physical characterization proposals for analysis of prepared catalyst pass through diffraction technique of ray-x (DRX), scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy ray-x (EDX). Technical proposals for the electrochemical characterization of the synthesized catalysts are Cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The prospects of this work are compared by the catalytic activity of the sensor designed with non-enzymatic sensors and biosensors also known in the literature

Catalisadores de cobre suportados em óxidos de zircônio hierarquicamente estruturados para a reação de desidrogenação de etanol

Pós-graduação em Química - IQ

Eletro-oxidação de metanol e etanol sobre catalisadores suportados de 'PD''AU'

Pós-graduação em Química - IQ

Desenvolvimento de sensores eletroquímicos e métodos de extração em fase sólida baseados em sistemas biomiméticos para análise de poluentes ambientais

Pós-graduação em Química - IQ

Activation of the low molecular weight protein tyrosine phosphatase in keratinocytes exposed to hyperosmotic stress

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Single precursor route to efficient cobalt sulphide counter electrodes for dye sensitized solar cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Agelotoxin: a phospholipase A(2) from the venom of the neotropical social wasp cassununga (Agelaia pallipes pallipes) (Hymenoptera-Vespidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Production, purification, and characterization of an extracellular acid protease from the marine Antarctic yeast Rhodotorula mucilaginosa L7

The production, purification, and characterization of an extracellular protease released by Rhodotorula mucilaginosa L7 were evaluated in this study. This strain was isolated from an Antarctic marine alga and previously selected among others based on the capacity to produce the highest extracellular proteolytic activity in preliminary tests. R. mucilaginosa L7 was grown in Saboraud-dextrose medium at 25 °C, and the cell growth, pH of the medium, extracellular protease production and the glucose and protein consumption were determined as a function of time. The protease was then purified, and the effects of pH, temperature, and salt concentration on the catalytic activity and enzyme stability were determined. Enzyme production started at the beginning of the exponential phase of growth and reached a maximum after 48 h, which was accompanied by a decrease in the pH as well as reductions of the protein and glucose concentrations in the medium. The purified protease presented optimal catalytic activity at pH 5.0 and 50 °C. Finally, the enzyme was stable in the presence of high concentrations of NaCl. These characteristics are of interest for future studies and may lead to potential biotechnological applications that require enzyme activity and stability under acidic conditions and/or high salt concentrations.

Production and Characterization of β-glucosidase Obtained by the Solid-State Cultivation of the Thermophilic Fungus Thermomucor indicae-seudaticae N31

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Eletro-oxidação de metanol e etanol sobre PtAu/C em meio alcalino

The development of electrocatalysts for the oxidation of methanol and ethanol is very important, because these alcohols may be used in the anode fuel cells which convert chemical energy directly into electrical energy with high efficiency, cleanly and with low noise. Thus, this study reports to the synthesis of nanocatalysts of PtAu supported on carbon by microemulsion method. The physical characterization of these catalysts is performed through the techniques of X-ray diffraction and transmission electron microscopy. The catalytic activity of the prepared materials was studied using conventional electrochemical techniques and also the technique of spectro-electrochemical in situ FTIR, which allows identification of intermediates and products of the reactions. From the x-ray diffraction, it was observed that the thermal treatment applied to catalysts favored incorporation of Au into the crystal lattice of Pt,that is, increased the formation of PtAu alloy. Micrographs indicated particle size about 3 nm to materials not heat treated and 9 nm to materials subjected to thermal treatment (heating at 150 ° C for 1h and 30 min in argon atmosphere). Current density oxidation of methanol on PtAu / C were superior to pure platinum. Spectroscopic results indicated the presence of formate in solution in 50:50 and the composition showed bands for CO2, indicating complete oxidation, in lower potential. During ethanol oxidation on the catalyst PtAu, the main product formed was acetate, product of incomplete oxidation. The good performance for methanol oxidation can be attributed to large amounts of oxygen species adsorbed on the catalyst surface, or an electronic effect.