Ethers
Mostrando 1-12 de 99 artigos, teses e dissertações.
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1. Cell damage induced by polybrominated diphenyl ethers on Chironomus sancticaroli (Diptera: Chironomidae)
Abstract Histological effects of polybrominated diphenyl ethers (PBDEs) were observed in Chironomus sancticaroli larvae which underwent acute exposure. 2,2′,4-triBDE (BDE-17), 2,2′,4,4′-tetraBDE (BDE-47) and 2,2′,4,4′,5-pentaBDE (BDE-99) were evaluated at 0.5, 2.0 and 20 μg L-1. Cytoplasm vacuolisation of oenocytes was observed in the larvae expos
Rev. Bras. entomol.. Publicado em: 17/01/2020
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2. Comparative Study on Catalytic Dehydration of Glycerol with Alcohols
A comparative study of glycerol dehydration with alcohols (methanol, ethanol, tert-butyl alcohol) over ion exchange resin Amberlyst-35 was performed. The effect of catalyst amounts (1-15 wt.% to glycerol), reaction temperature (50-100 ºC), reaction time (5-10 h), and the molar ratio of alcohols to glycerol (3:1-8:1) were carried out in 50 mL stainless steel
J. Braz. Chem. Soc.. Publicado em: 2019-04
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3. Synthesis, characterization and antibacterial activity of novel poly(silyl ether)s based on palm and soy oils
Abstract In this research, palm oil and soy oil were used as a natural polyol to prepare novel poly(silyl ether)s. Palm oil and soy oil were first converted to monoglyceride by one step via alcoholysis process in the presence of 0.1% CaO as a catalyst. The monoglycerides were characterized by Fourier transform infrared spectrometer (FT-IR), nuclear magnetic
Polímeros. Publicado em: 29/11/2018
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4. ÉTERES DIFENÍLICOS POLIBROMADOS (PBDE) COMO CONTAMINANTES PERSISTENTES: OCORRÊNCIA, COMPORTAMENTO NO AMBIENTE E ESTRATÉGIAS ANALÍTICAS
Flame retardants are substances mixed with numerous materials to inhibit the combustion process, reducing risks and damages caused by fires. Among these substances, polybrominated diphenyl ethers (PBDEs) have been widely used for decades due to their low cost and high efficiency. However, since they are mixed and not chemically bonded to the materials, PBDEs
Quím. Nova. Publicado em: 2018-07
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5. Identification of Ethyl and t-Butyl Glyceryl Ethers Using Gas Chromatography Coupled with Mass Spectrometry
The ethers produced through the etherification reaction of glycerol with ethanol or t-butanol are used as oxygenated fuel additives, intermediates in the pharmaceutical industry, and non-ionic surfactants. However, the identification of these ethers has not been accurately done, because only some mass spectra of these compounds are available in the libraries
J. Braz. Chem. Soc.. Publicado em: 2018-06
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6. Synthesis and in vitro Antiproliferative Activity of Flavone and 6-Hydroxyflavone Oxime Ethers Derivatives
Herein we report the synthesis of a series of O-alkyl oximes of flavone and 6-hydroxyflavone using a simple experimental protocol under solvent free conditions with yields up to 87%. Cytotoxicity of all compounds was evaluated against MDA-MB-231, PC-3, A-549 and MRC-5 cells. IC50 values for two compounds were determined to be in the range 28.7-47.8 µM again
J. Braz. Chem. Soc.. Publicado em: 2018-01
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7. Lipophilicity Study of 1-(Benzofuran-2-yl)ethan-1-one Oxime and its Substituted O-Benzyl Ethers
Heterocyclic oxime ethers play a significant role in organisms due to their biological activity. Lipophilicity is an important parameter that may affect biological activity of the compounds 1-(benzofuran-2-yl)ethan-1-one oxime and its nine biologically active ethers. The relationship between the structure and lipophilicity parameters (log kw values) of the t
J. Braz. Chem. Soc.. Publicado em: 2017-11
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8. Synthetic Niobium Oxyhydroxide as a Bifunctional Catalyst for Production of Ethers and Allyl Alcohol from Waste Glycerol
A synthetic niobia was modified by treatment with hydrogen peroxide to be used as a catalyst for converting glycerol into petrochemical compounds. The catalytic properties of niobium oxyhydroxide were obtained by generating acidic and oxygenated groups (peroxo groups) on the solid surface. Compounds like ethers and allyl alcohol were obtained. A very active
J. Braz. Chem. Soc.. Publicado em: 2017-11
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9. Identification of phenolic compounds in Myricaria bracteata leaves by high-performance liquid chromatography with a diode array detector and liquid chromatography with tandem mass spectrometry
Abstract Myricaria bracteata Royle, Tamaricaceae, is a species with a wide geographic range that encompasses Eastern Europe, Western and Central Siberia, Central Asia, and the Himalayas. This plant is used in traditional folk medicine in Russia (Siberia) and in China typically as an analgesic and for the treatment of some infections and certain types of into
Rev. bras. farmacogn.. Publicado em: 2017-10
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10. Retardantes de chama bromados: uma revisão
Polybrominated diphenyl ethers (PBDEs), Polybrominated biphenyls (PBBs), Hexabromocyclododecane (HBCD) and Tetrabromobisphenol A (TBBP-A) are flame retardant widely used in plastics, textiles, furniture, consumer electronics, automobiles, among others.They are important components added to retard the spread of flame and, thus,mitigate deaths and destruction
Quím. Nova. Publicado em: 2017-04
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11. Efeito da dexmedetomidina em crianças submetidas à anestesia geral com sevoflurano
Resumo Justificativa e objetivos: Sevoflurano é frequentemente usado em anestesia pediátrica e está associado à alta incidência de agitação psicomotora ao despertar. Nesses casos a dexmedetomidina (dex) tem sido usada, porém permanecem incertos seus benefícios e suas implicações. Foram avaliados os efeitos da dex sobre a agitação no despertar d
Rev. Bras. Anestesiol.. Publicado em: 2017-04
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12. Synthesis and Anti-Staphylococcal Activity of 2,4-Disubstituted Diphenylamines
Infections caused by Staphylococcus aureus are ubiquitous and life threatening. Evolution of resistant strains has necessitated the need to continuously discover new drugs to combat such organisms. Diphenyl ethers, such as triclosan, have recently shown potential as antibacterial agents. In this study, a series of diphenyl amines were synthesized and evaluat
J. Braz. Chem. Soc.. Publicado em: 2016-06