RESUMEN
The aim of this work was to investigate the technical as well as the economic feasibility of producing 2-ethyl hexyl oleate (2-EHO), a non-phthalate plasticizer in a solvent free medium. The esterification reaction between oleic acid and 2-ethyl hexyl alcohol was carried out in a packed bed reactor (PBR) using Candida antarctica lipase B (Novozym 435; Novozymes; Copenhagen-Denmark) as biocatalyst. RSM was employed to optimize the esterification reaction conditions. The optimum reaction conditions were found to be flow rate of 1.5 mL/min, No. of cycles of 12 and molar ratio of 4:1 2-ethyl hexanol to oleic acid. The maximum experimental and predicated conversions were found to be 95.8% and 95.61% respectively. Formation of 2-EHO was approved by FTIR, 1HNMR and 13CNMR. From the economic prospective, PBR was capable of producing 2-EHO with a purity of more than 94% over 480 h without remarkable reduction of enzyme activity. This revealed an economic production of 2-EHO at a yield of 2 tons kg-1 lipase. The manufacturing cost was found to be $ 1.88 /kg 2-EHO, this contributed to a profit of about 30% compared to the commercial price of 2-EHO. Such results approve the technical and economic feasibility for this sustainable method in esters production.
Asunto(s)
Reactores Biológicos , Éteres de Etila/síntesis química , Plastificantes/síntesis química , Reactores Biológicos/economía , Costos y Análisis de Costo , Enzimas Inmovilizadas , Esterificación , Éteres de Etila/química , Proteínas Fúngicas , Lipasa/química , Ácido Oléico/química , Plastificantes/químicaRESUMEN
In this work, the ethanolysis of triglycerides catalyzed by immobilized lipase was studied, focusing on the secondary reaction of acyl migration. The catalytic tests were performed in a solvent-free reaction medium using Novozym 435 as biocatalyst. The selected experimental variables were biocatalyst loading (5-20mg), reaction time (30-90min), and chain length of the fatty acids in triglycerides with and without unsaturation (short (triacetin), medium (tricaprylin) and long (tripalmitin/triolein)). The formation of 2-monoglyceride by ethanolysis of triglycerides was favored by long reaction times and large biocatalyst loading with saturated short- to medium-chain triglycerides. In the case of long-chain triglycerides, the formation of this monoglyceride was widely limited by acyl migration. In turn, acyl migration increased the yield of ethyl esters and minimized the content of monoglycerides and diglycerides. Thus, the enzymatic synthesis of biodiesel was favored by long-chain triglycerides (which favor the acyl migration), long reaction times and large biocatalyst loading. The conversion of acylglycerides made from long-chain fatty acids with unsaturation was relatively low due to limitations in their access to the active site of the lipase.
Asunto(s)
Lipasa/química , Lipasa/metabolismo , Modelos Químicos , Triglicéridos/síntesis química , Biocombustibles , Cromatografía de Gases/métodos , Diglicéridos/síntesis química , Diglicéridos/química , Enzimas/química , Enzimas Inmovilizadas/química , Ésteres/síntesis química , Éteres de Etila/síntesis química , Éteres de Etila/química , Grasas Insaturadas/síntesis química , Grasas Insaturadas/química , Ácidos Grasos/química , Ácidos Grasos/metabolismo , Proteínas Fúngicas , Glicerol/síntesis química , Glicerol/química , Cinética , Monoglicéridos/síntesis química , Monoglicéridos/química , Solventes/química , Triglicéridos/químicaRESUMEN
An efficient synthesis of novel antifungal 3a,9a-dihydro-1-ethoxycarbonyl-1-cyclopenteno[5,4-b]benzopyran-4-ones (10a-j) through 1,3-dipolar cycloaddition of all carbon 1,3-dipole (7) with substituted 3-formylchromones (8a-j) has been developed. The synthesized compounds were characterized spectroscopically and evaluated in vitro for antifungal activity against various strains. Some of the compounds 10b, 10d and 10i exhibit significant inhibitory potential against Aspergillus niger, Saccahromyces cerevisiae and Candida albicans.
Asunto(s)
Antifúngicos/síntesis química , Éteres de Etila/síntesis química , Pirenos/síntesis química , Antifúngicos/farmacología , Aspergillus niger/efectos de los fármacos , Candida albicans/efectos de los fármacos , Éteres de Etila/farmacología , Hidrogenación , Estructura Molecular , Pirenos/farmacología , Saccharomyces cerevisiae/efectos de los fármacos , Relación Estructura-ActividadRESUMEN
The present work describes the preparation of new chitosan complex with 4-(ethoxycarbonyl) phenyl-1-amino-oxobutanoic acid (ETHA), as a matrix for silver nanoparticles to obtain a nanocomposite film by solution casing method. The characterization of the prepared nanocomposite film was made by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry (TG) and scanning electron microscopy (SEM). The optical property of nanocomposite film was analyzed by UV-Visible and photo-luminescence (PL) spectroscopy. The nanocomposite film was screen for antibacterial activity with Staphylococcus aureus (gram positive), Pseudomonas aurigionasa (gram negative) and Escherichia coli (gram negative) bacteria by adopting the disk diffusion method. The result of antibacterial study revealed that the prepared nanocomposite film may be a promising candidate for wide range of bio-medical applications.
Asunto(s)
Compuestos de Anilina/síntesis química , Butiratos/síntesis química , Quitosano/química , Éteres de Etila/síntesis química , Nanotecnología/métodos , Plata/química , Compuestos de Anilina/farmacología , Antiinfecciosos/síntesis química , Antiinfecciosos/farmacología , Butiratos/farmacología , Rastreo Diferencial de Calorimetría , Quitosano/metabolismo , Materiales Biocompatibles Revestidos/síntesis química , Materiales Biocompatibles Revestidos/farmacología , Pruebas Antimicrobianas de Difusión por Disco , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Éteres de Etila/farmacología , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Nanocompuestos/química , Espectroscopía de Fotoelectrones , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/crecimiento & desarrollo , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Termogravimetría , Difracción de Rayos XRESUMEN
Ethyl esters from uncommon fatty acids, such as valproic, azelaic, and sorbic acids, were chemically synthesized and identified by gas chromatography or liquid chromatography coupled to mass spectrometry. Some properties were evaluated to determine their potential for use as biofuels or in other commercial applications. They have remarkable and pleasant odors and, in the case of ethyl ester in valproic acid, display marked resistance to clouding and crystallization.
Asunto(s)
Biocombustibles/análisis , Ácidos Grasos/química , Éteres de Etila/análisis , Éteres de Etila/síntesis químicaRESUMEN
The synthesis of new pharmaceutically interesting 3-(2-N,N-diethylaminoethoxy)indole derivatives is described. Starting from 3-silyloxy-2-methylindoles, deprotection and in situ aminoalkylation provided 3-(2-N,N-diethylaminoethoxy)indoles in good yield. Further sulfonylation of these novel indoles gave access to potential 5-HT(6) receptor ligands.
Asunto(s)
Éteres de Etila/síntesis química , Etilaminas/química , Indoles/síntesis química , Receptores de Serotonina/metabolismo , Compuestos de Cloro/química , Éteres de Etila/química , Éteres de Etila/metabolismo , Indoles/química , Indoles/metabolismo , Ligandos , Estructura MolecularRESUMEN
The synthesis of hexakis (3,6-anhydro)-tetrakis[2(I,II,IV,V)-O-(2-ethoxyethyl)] cyclomaltohexaose (AEOE) was designed to obtain cation complexing properties. 1H NMR study showed ionic radius dependence of AEOE cation affinity, markedly observed for Cs+ and Rb+. Besides, AEOE was found haemolytic (HC50 = 9 mM) and superficial tension measurements revealed positive tensio active properties. A 31P and 2HNMR study of phospholipid dispersions (dimyristoyl phosphatidyl cholin, DMPC) in the presence of AEOE was performed; it was found that, beside the typical lineshape of phospholipid bilayers, two new NMR lines were detected in the presence of AEOE: (a) an isotropic line consistent with a detergent effect (b) another isotropic resonance of 1 Hz linewidth over phase transition temperature (298 K), indicating a true solubilization. Coupling constant measurements confirmed that the main conformation at the polar head group level was close to that observed in chloroform/methanol solution. It was finally concluded that AEOE could form true solutions of DMPC, similarly to those induced by diethyl ether interactions with membranes, while giving soluble complexes.
Asunto(s)
Éteres de Etila/química , Concentración de Iones de Hidrógeno , alfa-Ciclodextrinas/química , Cationes/química , Fenómenos Químicos , Química Física , Dimetilsulfóxido , Dimiristoilfosfatidilcolina , Éteres de Etila/síntesis química , Hemólisis/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Membranas Artificiales , Soluciones/química , Solventes , Tensión Superficial , alfa-Ciclodextrinas/síntesis químicaRESUMEN
Cornstarch derivative (ES), prepared using diethyl sulfate as an etherifying reagent, was blended with castor oil-based polyurethane (PU) prepolymer to obtain a series of semi-interpenetrating polymer network (semi-IPN) materials, named as UES films. Simultaneously, other kinds of semi-IPN (UBS2) were prepared from PU and benzyl starch (BS2) to compare the effects of the substitute groups. The differences in the miscibility and properties of the two series of materials were investigated using attenuated total reflection Fourier transform infrared spectroscopy, atomic force microscopy, dynamic mechanical thermal analysis, ultraviolet-visible spectroscopy, water-sensitivity and tensile testing. The experimental results revealed that UBS2 films exhibit stronger interfacial attraction and better phase mixing than the UES films, as a result of specific interactions between the PU hard segments and BS2 phenyl groups. The optical transmittance, water-resistivity, tensile strength, and elongation at break of the UBS2 films were clearly higher than those of the UES films containing the same concentration of PU. In particular, the miscibility and properties of the UES film with 40 wt.-% ES, were very poor, whereas the semi-IPN films containing 70 wt.-% benzyl starch still had a certain miscibility and good properties. Therefore, the phenyl groups play an important role in the improvement of the miscibility and properties of the semi-IPN materials.
Asunto(s)
Aceite de Ricino/química , Polímeros/química , Poliuretanos/química , Almidón/química , Compuestos de Bencilo/síntesis química , Compuestos de Bencilo/química , Éteres de Etila/síntesis química , Éteres de Etila/química , Microscopía de Fuerza Atómica , Peso Molecular , Transición de Fase , Polímeros/síntesis química , Poliuretanos/síntesis química , Reología , Espectrofotometría , Espectroscopía Infrarroja por Transformada de Fourier , Resistencia a la Tracción , Temperatura de Transición , Viscosidad , Agua/químicaRESUMEN
N-(2-Dimethylaminoethyl)carboxamide (1a-d), 2-dimethylaminoethyl alkyl ether (2a, b), and 2-dimethylaminoethyl 2-hydroxy-2-phenethyl ether (3a-c) and its amino and methylene analogues (3d, 4) have been screened for antiamnestic and antihypoxic activities in mice. A clear reversing effect on electroconvulsive shock-induced amnesia was found with 1a-d, 2a,b, and 2-dimethylaminoethyl 2-hydroxy-2-phenylethyl ether (3a). However, a protective effect against hypoxia was only observed with 3a. Compound 3a, which displayed the dual activity, was further investigated for ameliorating effect on CO2-induced memory impairment, and it was found to be more potent than indeloxazine and bifemelane. In addition, the acute toxicity of 3a in mice was significantly lower than that of tacrine, but its serum-to-brain penetration ability in rats was less than that of the reference drugs.
Asunto(s)
Amnesia/tratamiento farmacológico , Dimetilaminas/síntesis química , Éteres de Etila/síntesis química , Hipoxia Encefálica/tratamiento farmacológico , Nootrópicos/síntesis química , Amnesia/psicología , Animales , Reacción de Prevención/efectos de los fármacos , Barrera Hematoencefálica , Cristalización , Dimetilaminas/farmacología , Dimetilaminas/toxicidad , Electrochoque , Éteres de Etila/farmacología , Éteres de Etila/toxicidad , Hipoxia Encefálica/psicología , Dosificación Letal Mediana , Masculino , Ratones , Ratones Endogámicos , Nootrópicos/farmacología , Nootrópicos/toxicidad , Ratas , Ratas WistarRESUMEN
Reductive cleavage of fully methylated, partially O-ethylated cellulose or fully ethylated, partially O-methylated cellulose and subsequent acetylation had previously been shown to produce 4-O-acetyl-1,5-anhydro-2,3,6-tri-O-methyl-, -6- O-ethyl-2,3-di-O-methyl-, -3-O-ethyl-2,6-di-O-methyl-, -2-O-ethyl-3,6-di-O- methyl-, -2,3-di-O-ethyl-6-O-methyl-, -2,6-di-O-ethyl-3-O-methyl-, -3,6-di-O- ethyl-2-O-methyl-, and -2,3,6-tri-O-ethyl-D-glucitol. Described herein is the independent synthesis of these derivatives, except for the first (which had been reported); and their 1H-n.m.r. spectra, chemical-ionization (NH3) mass spectra, and electron-impact mass spectra are tabulated.
Asunto(s)
Química , Éteres de Etila/síntesis química , Sorbitol/análogos & derivados , Fenómenos Químicos , Éteres de Etila/análisis , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Éteres Metílicos/análisis , Éteres Metílicos/síntesis química , Sorbitol/análisis , Sorbitol/síntesis química , EstereoisomerismoRESUMEN
The 3-[(2-ethoxyphenoxy)methyl]piperidine derivatives 3-5 were synthesized and screened as potential antidepressant agents by the reserpine interaction test in mice and the evaluation of reuptake inhibition of biogenic amines in pig brain synaptosomal fractions. In addition, their anticonvulsant activity, tested by pentyleneetrazole antagonism, and approximate acute toxicity were evaluated. In vivo and in vitro tests showed that compounds 3 and 5 possess a biological activity comparable to that of the antidepressant drug viloxazine.