Dimethyl Ether
Mostrando 1-12 de 29 artigos, teses e dissertações.
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1. Identification of volatile compounds in cultivars barker, collinson, fortuna and geada of avocado (Persea americana, Mill.) fruit
Abstract The objective of this paper was to determine the volatile profile of four cultivars - Barker, Collinson, Fortuna and Geada of avocado (Persea americana, Mill.) fruit and to perform a detailed study on the effect of volatiles extraction conditions. The best conditions for extraction for Collinson and Fortuna cultivars were by using a mixture of penta
Food Sci. Technol. Publicado em: 20/06/2016
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2. Chemical Composition and Cytotoxic Activity of the Root Essential Oil from Jatropha ribifolia (Pohl) Baill (Euphorbiaceae)
The essential oil of roots of Jatropha ribifolia, obtained by hydrodistillation, was characterized in terms of its chemical composition by chromatographic method with flame ionization detection (GC-FID) and gas chromatography coupled to electron ionization mass spectrometry (GC-MS). The analyses and identification pointed by mass fragmentation pattern and re
J. Braz. Chem. Soc.. Publicado em: 2015-02
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3. Avaliação da ação espasmolítica do flavonoide 3,6-Dimetil éter galetina, isolado de Piptadenia stipulacea (Benth.) Ducke e investigação do mecanismo de ação em traqueia de cobaia e aorta de rato / Evaluation of spasmolytic action of the flavonoid galetin 3,6-dimethyl ether isolated from Piptadenia stipulacea (Benth.) Ducke and investigation of the mechanism of action in guinea pig trachea and rat aorta
O flavonoide 3,6-dimetil éter galetina (FGAL) foi isolado das partes aéreas de Piptadenia stipulacea (Benth.) Ducke e foi investigada sua possível atividade hemolítica em eritrócitos de rato e espasmolítica em vários músculos lisos isolados como útero de rata, íleo e traqueia de cobaia, e aorta de rato. FGAL não causou efeito hemolítico em eritr�
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/03/2012
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4. Nitro derivatives and other constituents of Aristolochia melastoma
A phytochemical study of Aristolochia melastoma Manso has led to the isolation and identification of 20 known compounds, including aristolochic acids, sodium aristolochates, lignan, flavonoids, and nitro phenylethyl derivatives. Their structures were established by spectroscopic analysis. The presence of thalictricoside and secoisolariciresinol dimethyl ethe
Química Nova. Publicado em: 2012
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5. Antifungal iridoids, triterpenes and phenol compounds from Alibertia myrciifolia Sprunge Ex. Schum
The new iridoid glucoside 10-O-vanilloyl-geniposidic acid has been isolated from the aerial parts of Alibertia myrciifolia along with hydroxyhopanone, 3α,22-dihydroxyhopane, ursolic acid, luteolin-3´,4´-dimethyl ether, caffeic acid and geniposidic acid. The structures of the isolated compounds were determined by means of mass spectrometry and nuclear magn
Química Nova. Publicado em: 2010
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6. Constituintes químicos de Vernonia chalybaea mart.
The chemical investigation of the hexane and ethanol extracts from aerial parts of Vernonia chalybaea conducted to the isolation and characterization of a new aliphatic tetrahydroxyl ether, along with a series of known compounds such as 4 α,10 α-epoxyaromadendrane, friedelin, taraxasteryl acetate, pseudotaraxasteryl acetate, lupeyl acetate, lupeol, α-amir
Química Nova. Publicado em: 2008
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7. Novel catalyst systems based on Ni(II), Ti(IV), and Cr(III) complexes for oligo-and polymerization of ethylene
The complex of Brookhart Ni(α-diimine)Cl2 (1) (α-diimine = 1,4-bis(2,6- diisopropylphenyl)-acenaphthenediimine) has been characterized after impregnation on silica (S1) and MAO-modified silicas (4.0, 8.0 and 23.0 wts.% Al/SiO2 called S2, S3 and S4, respectively). The treatment of these heterogeneous systems with MAO produces some active catalysts for the p
Publicado em: 2007
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8. SÃntese e caracterizaÃÃo de silicoaluminofosfatos para a produÃÃo de olefinas leves a partir do dimetilÃter
Methanol/dimethylether to olefin (MTO) process provides an additional route for production of ethylene and propylene for the chemical industry. This process has some advantages over the current ethylene and propylene production process, the steam cracking of liquefied natural gas, naphtha or other light fractions of petroleum, because MTO can provide a wider
Publicado em: 2007
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9. Dependência das vias de dissociação unimolecular com a energia interna da molécula de éter dimetílico
Internal energy dependence of the competitive unimolecular dissociation channels of dimethyl ether were studied with the statistical RRKM formalism. The C-O and C-H fission reactions and the 1,2-H and 1,3-H shifts, and 1,1-H2 and 1,3-H2 molecular eliminations are discussed as a function of energy dependence of k a(E*), the microcanonical rate constant for pr
Química Nova. Publicado em: 2004-02
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10. BASED BIFUNCTIONAL CATALYSTS IN ZEOLITE H-FERRIERITE FOR THE DIRECT SYNTHESIS OF DIMETHYL ETHER FROM SYNTHESIS GAS / CATALISADORES BIFUNCIONAIS BASEADOS EM ZEÓLITA H-FERRIERITA PARA A SÍNTESE DIRETA DE DIMETIL ÉTER A PARTIR DE GÁS DE SÍNTESE
The direct synthesis of dimethyl ether from syngas is catalyzed by bifunctional catalysts: the hydrogenation function that catalyzes the methanol formation and the dehydration function to produce dimethyl ether from methanol. Bifunctional catalysts with Cu, Zn and Al as hydrogenation component and Hferrierite zeolite as dehydration component had been synthes
Publicado em: 2004
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11. Cicloprogramação de 1,3-dienos substituidos pela reação de Simmons-Smith
The cyclopropanation of 1,3-diene by the Simmons-Smith reaction is normally inefficient and generates very low yields in products. The objective of this work was to verify the reactivity, site-selectivity, and stereospecificity of cyclopropanation of substituted 1,3-dienes, under drastic conditions of pressure (up to 4 kbar) and temperature (from 80 to 120°
Publicado em: 1993
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12. Obligate methylotrophy: evaluation of dimethyl ether as a C1 compound.
The suitability of dimethyl ether as a C1 compound was examined with the obligate methylobacterium Methylococcus capsulatus (Texas). The ether did not support growth and was not formed during growth on methane; it was an inhibitor of growth and oxidation of methane and a poor oxidation substrate for cell suspensions. NADH stimulation of methane, but not dime