Ring Expansion
Mostrando 1-12 de 37 artigos, teses e dissertações.
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1. Strategies towards expansion of chemical space of natural product-based compounds to enable drug discovery
Natural products (NPs) are an excellent source of biologically active molecules that provide many biologically biased features that enable innovative designing of synthetic compounds. NPs are characterized by high content of sp3-hybridized carbon atoms; oxygen; spiro, bridged, and linked systems; and stereogenic centers, with high structural diversity. To da
Braz. J. Pharm. Sci.. Publicado em: 08/11/2018
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2. On the Machinability and Surface Finish of Superalloy GH909 Under Dry Cutting Conditions
GH 909 alloy is a kind of low thermal expansion superalloy with high strength and low expansion coefficient. It is mainly used for manufacturing of aero-engine turbine casings, sealing ring, vanes and other gap control parts, to improve the working efficiency and thrust of the engine as well as to reduce gas loss and fuel consumption. However, the machinabil
Mat. Res.. Publicado em: 21/05/2018
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3. Methods for Quantifying Shrinkage in Latossolos (Ferralsols) and Nitossolos (Nitisols) in Southern Brazil
ABSTRACT Brown Nitossolos (Nitisols) and Latossolos (Ferralsols), according to the Brazilian System of Soil Classification (SiBCS), have a “caráter retrátil” as their distinctive property. Because this is a new topic, it is necessary to propose methods for evaluation. The objectives of this study were to evaluate methodologies for quantifying the shrin
Rev. Bras. Ciênc. Solo. Publicado em: 15/05/2017
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4. Metátese de fechamento de anel: espiro-anelação estereosseletiva / Reações multicomponentes de Diels-Alder na síntese de compostos tricíclicos
In this work, a study of different synthetic ways was made in order to obtain spiro compounds starting from R-(-)-carvone, getting to the formation of cycloheptenone as an intermediate, which undergoes two consecutives alkylations to the formation of a bis alkylated compound which would be submitted to a ring closing metathesis and consequently reaching the
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/02/2011
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5. Reações de expansão de anel e de ciclização promovidas por iodo (III) e elucidação do mecanismo de desproporção de iodobenzeno diacetato e de hidróxi(tosilóxi)iodobenzeno por espectrometria de massas por electrospray / (III) promoted ring expansion and cyclization reactions and elucidation of disproportionation mechanism from iodobenzene diacetate and hydroxy(tosyloxy)iodobenzene by electrospray mass spectrometry
Esta tese de doutorado está dividida em três partes. Na primeira parte é tratada a expansão de anéis de 1-alquenil-cicloalcanóis promovida por hidróxi(tosilóxi)iodobenzeno (HTIB), com ênfase na síntese de anéis de sete membros. A metodologia se mostrou versátil, possibilitando que diferentes compostos de anéis expandidos pudessem ser obtidos a p
Publicado em: 2010
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6. Caracterização do espectro fenotípico de pacientes com fissuras labiopalatinas associadas a múltiplas anomalias congênitas e alterações cromossômicas estruturais / Characterization of phenotypic spectrum in patients with cleft lip and palate associated with multiple congenital anomalies and structural chromosome abnormalities
Objective: Characterization of syndromes presented by patients with cleft lip and palate (CL/P) associated with associated with multiple congenital anomalies (MMC) and chromosomal abnormalities and expansion of the phenotyipc spectrum of syndromes already described. Setting: Human Cytogenetics Laboratory and Clinical Genetics Service, HRAC-USP, Bauru-SP. Par
Publicado em: 2009
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7. Great geomagnetic storms in the rise and maximum of solar cycle 23
Geomagnetic storms are intervals of time when a sufficiently intense and long-lasting interplanetary convection electric field leads, through a substantial injection of energy into the magnetosphere-ionosphere system, to an intensified ring current, strong enough to exceed some key threshold of the quantifying storm time Dst index. We have studied all the 9
Brazilian Journal of Physics. Publicado em: 2004-12
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8. Ions acilio : estrutura e reatividade na fase gasosa
The structure and reactivity in the gas phase of several acylium ions ( R-CO ) and their sulfur analogues were studied using pentaquadrupole mass spectrometry. Cyclic ionic ketal were formed via ketalization reactions of acylium ions with diols and analogues; the products were characterized via sequential MS spectra and isotopic labeling with R-C=O. The diss
Publicado em: 1999
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9. Estudo de reações ion/molecula na fase gasosa por espectrometria de massa de estagios multiplos (MS2 e MS3) em um espectrometro pentaquadrupolar
This work presents the results of four distinct projects which have been focused on combined studies of ion/molecule reactions, collision-induced dissociation of ions and ab initio calculations. In the first project it was verified the occurrence in the gas phase of novel ionic 1,3-dipolar cycloaddition reactions between carbonyl compounds and the simplest c
Publicado em: 1996
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10. Analysis of penicillin N ring expansion activity from Streptomyces clavuligerus by ion-pair high-pressure liquid chromatography.
An ion-pair, reversed-phase, high-pressure liquid chromatographic method for the analysis of penicillin N ring expansion activity has been developed which allows simultaneous measurement of both substrate and product. The high-pressure liquid chromatography conditions were as follows: stationary phase, C18; flow rate, 2 ml/min; detection, 220 nm. The station
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11. Copurification and characterization of deacetoxycephalosporin C synthetase/hydroxylase from Cephalosporium acremonium.
Deacetoxycephalosporin C synthetase (expandase), which catalyzes ring expansion of penicillin N to deacetoxycephalosporin C (DAOC), has been stabilized in vitro and purified to near homogeneity from the industrially important fungus Cephalosporium acremonium. Throughout the purification, the expandase activity remained physically associated with and in a con
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12. Elucidation of conditions allowing conversion of penicillin G and other penicillins to deacetoxycephalosporins by resting cells and extracts of Streptomyces clavuligerus NP1
Using resting cells and extracts of Streptomyces clavuligerus NP1, we have been able to convert penicillin G (benzylpenicillin) to deacetoxycephalosporin G. Conversion was achieved by increasing by 45× the concentration of FeSO4 (1.8 mM) and doubling the concentration of α-ketoglutarate (1.28 mM) as compared with standard conditions used for the normal cel
The National Academy of Sciences.