904 resultados para pyrylium and thiopyrylium salts
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Pós-graduação em Ciências Biológicas (Microbiologia Aplicada) - IBRC
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Química - IQ
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Pós-graduação em Engenharia Mecânica - FEG
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Pós-graduação em Química - IQ
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The sol-gel process and the wide variety of alkoxides commercially available have facilitated the processing of various Organic-Inorganic Hybrid Materials. In general, the hybrids are excellents matrix to incorporate organic or inorganic dopants that presents photochromic, thermochromic, and halochromic effects and in some cases photorefractive effects. The GPTS-TEOS hybrid matrix when deposited in the form of film is very resistant, adherent, has excellent transparency in visible region and allows to be doped with various azo-dye and metal salts of unusual oxidation states. One of the main characteristics of the azo-dyes when immersed in some hybrid matrix , is the capacity to isomerizes through group Azo (-N = N-) would can be commutated between the Cis (Z) and Trans (E) configurations by means of light or heat. Our goal was through the sol-gel process to prepare hybrid films of GPTS-TEOS doped with azo-dyes Methyl Red and Disperse Red 1, and characterize them optically. The characterizations are performed using techniques of UV / Vis spectroscopy, to identify changes in the absorption band of azo-dyes in the presence of optical pumping, (photochromic effects), in function of temperature (thermochromic effect). These properties are of wide scientific and technological interest because they will contribute to the confection Smart Windows (windows sensible to light), temperature sensors monitored optically and also in the recording of amplitude and phase diffraction gratings
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Brazil processes much of its fruit by producing natural juices, candy preserves, extracts and pulps; however, almost 60% of their total weight derives from peels, leaves and seeds. As a result, the emphasis lies most strongly on the use of waste, especially waste that is not commonly used by the food industry or by consumers. The use of seeds would increase the viable sources of raw materials, lower operating costs of industries and would promote the development of new food products, since they are our main sources of protein, fat, fiber, functional compounds, vitamins and minerals salts. This paper presents alternatives for the use of pumpkin seeds (Cucurbita sp), which are often underutilized or discarded. It also demonstrates the bioactive and anti-nutritional compounds and their health effects.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Little is known about the ability of methanogens to grow and produce methane in estuarine environments. In this study, traditional methods for cultivating strictly anaerobic microorganisms were combined with Fluorescence in situ hybridization (FISH) technique to enrich and identify methanogenic Archaea cultures occurring in highly polluted sediments of tropical Santos-So Vicente Estuary (So Paulo, Brazil). Sediment samples were enriched at 30A degrees C under strict anaerobic and halophilic conditions, using a basal medium containing 2% of sodium chloride and amended with glucose, methanol, and sodium salts of acetate, formate and lactate. High methanogenic activity was detected, as evidenced by the biogas containing 11.5 mmol of methane at 20 days of incubation time and methane yield of 0.138-mmol CH(4)/g organic matter/g volatile suspense solids. Cells of methanogenic Archaea were selected by serial dilution in medium amended separately with sodium acetate, sodium formate, or methanol. FISH analysis revealed the presence of Methanobacteriaceae and Methanosarcina sp. cells.
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The nucleophile/electrophile combination in the aromatic substitution reaction using aminothiazole derivatives as nucleophiles has been the subject of this study. The reaction between 2,4-dipyrrolidinylthiazole and the neutral carbon electrophile 1,3,5-trinitrobenzene gave a stable Wheland-Meisenheimer (WM) complex. This represents another example, among those already found by the research group in which this work has been carried out, of stable zwitterionic σ-intermediates. When the reaction was carried out with halonitrobenzene derivatives, it produced the substitution product in position 5 of the thiazole ring. 2,4-dipyrrolidinylthiazole and arenediazonium salts gave the coupling product at the C5 of the thiazole ring together with many byproducts and the stable Wheland intermediate formed by attack of the proton on the C5 of the starting thiazole reagent. Arenediazonium salts were coupled also with 2-pyrrolidinylthiazole. In this case quantitative formation of the substitution product deriving from the attack of the electrophile on the carbon nucleophilic position of the thiazole ring was obtained. In conclusion, the results had allowed to expand the knowledge on electrophilic/nucleophilic interactions in the aromatic substitution involving thiazole heteroaromatics and provided a further example of stable Wheland-Meisenheimer intermediates.