Stereospecificity
Mostrando 1-12 de 100 artigos, teses e dissertações.
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1. ENANTIOPURE R(-)-3-AMINOISOBUTYRIC ACID SYNTHESIS USING Pseudomonas aeruginosa AS ENANTIOSPECIFIC BIOCATALYST
Abstract The main goal of this research was the synthesis of enantiopure R(-)-3-aminoisobutyric acid from dihydrothymine with good yield, high stereospecificity and relative simplicity. Seventy two percent yield of the product was obtained in three steps. Step one consisted of dihydrothymine racemization. Step two was a dihydropyrimidinase reaction involving
Braz. J. Chem. Eng.. Publicado em: 2015-03
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2. Determinação estrutural e estudo da estereoespecificidade de compostos de paládio II / Structural determination and stereospecificity studies of the palladium II compounds
Neste trabalho estão apresentadas as estruturas cristalinas e moleculares e o estudo da estereoespecificidade de compostos de paládio com geometria de coordenação quadrado planar. Estas estruturas foram determinadas com o objetivo de verificar a relação entre a geometria e sua potencialidade como um possível agente anti-cancerígeno.
No estudo dePublicado em: 2010
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3. Vladimir Prelog e a estereoquímica das moléculas orgânicas: um centenário de nascimento
The Croatian chemist Vladimir Prelog shared in 1975 the Nobel Prize in chemistry with J. W. Cornforth for his research into the stereochemistry of organic molecules and reactions. His studies gave new horizons to the comprehension of steric effects on the reactivity of medium-sized rings, to conformational analysis and to the stereospecificity associated to
Química Nova. Publicado em: 2007-08
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4. Emprego de catalisadores à base de níquel para homo- e copolimerização de estireno
This review deals with the homo- and copolymerization of styrene with nickel catalysts. The catalytic activity, polymer stereoregularity, polymer molecular weight and polydispersity are dependent upon nickel ligands and reaction parameters. Catalysts supported on silica, treated with methylaluminoxane (MAO), have shown higher stereospecificity and activity c
Química Nova. Publicado em: 2004-12
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5. 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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6. Adição de IN3 a derivados de acidos -alquil cinamicos : obtenç2o de 2-alquil-3-fenil-1-azirinas e 3-azido-2-azetidinonas
The present study began with the preparation of 2- phenyl-3-carbomethoxy-1-azirine (16) with the intention of examining the reactivites of the two electrophilic centers of the molecule, that is, the carbon of the imine group and the carbonil of the ester. Reaction of system 16 with hidrazine in benzene produces the 4-aminopyrazol-3-one 26, intercepted in the
Publicado em: 1987
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7. Stereospecificity in meta-fission catabolic pathways.
The stereospecificities of 2-keto-4-pentenoate hydratase and 4-hydroxy-2-ketovalerate aldolase were studied in Escherichia coli, Pseudomonas putida, and Acinetobacter sp. Hydration was stereospecific in all three; however, only P. putida and Acinetobacter sp. showed stereospecificity in their aldolase reactions.
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8. The Contribution of Electrostatic and van der Waals Interactions to the Stereospecificity of the Reaction Catalyzed by Lactate Dehydrogenase
Continuum electrostatic calculations in conjunction with molecular dynamics simulations have been used to investigate the source of the stereospecificity in the hydride transfer reaction catalyzed by lactate dehydrogenase (LDH). These studies show that favorable electrostatic interactions between the carboxamide group of the reduced nicotinamide adenine dinu
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9. The stereospecificity of flobufen metabolism in isolated guinea pig hepatocytes
BioMed Central.
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10. Stereospecificity of Citrate Synthetase in Relation to Glutamate Biosynthesis by Extracts of Chloropseudomonas ethylicum
The synthesis of citric and glutamic acids by extracts of Chloropseudomonas ethylicum was studied with labeled precursors. When acetyl-coenzyme A-1-14C was used as substrate, only 0.1% of the total radioactivity was found in the C-5 position of citric acid; whereas, with oxalacetate-4-14C as substrate, 100% of the total radioactivity was found in C-5. These
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11. STEREOSPECIFICITY AND FIREFLY BIOLUMINESCENCE, A COMPARISON OF NATURAL AND SYNTHETIC LUCIFERINS
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12. Stereospecificity of hydride removal from NADH by reductases of multicomponent nonheme iron oxygenase systems.
The stereospecificity of hydride removal from the 4 position of the pyridine ring of NADH by reductases from all three classes of multicomponent nonheme iron oxygenases was examined. The class I and II reductases, modules of which show significant sequence similarity with and which belong to the ferredoxin-NADP+ reductase family of flavin-dependent oxidoredu