- Characterization of lipases and esterases from metagenomes for lipid modification
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Three hundred and fifty novel lipases and esterases discovered from environmental DNA samples were characterized for their fatty acid profile using GC-analysis. Enzymes were selected for further study based on activity and fatty acid chain length specificity. Additional characterization was based on enzyme activity towards tributyrin and 4-methylumbelliferyl butyrate, and enzyme heat stability. Several lipases were identified, which show high specificity towards short-chain fatty acids similar to pregastric lipases from kid and calf and a lipase from Mucor javanicus. Additionally, the metagenome-derived enzymes were thermostable. Selected metagenomic lipases were immobilized on Celite and used for the synthesis of structured triglycerides.
- Bertram, Mark,Hildebrandt, Petra,Weiner, David P.,Patel, Jesal S.,Bartnek, Flash,Hitchman, Timothy S.,Bornscheuer, Uwe T.
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- Synthesis of Civetone from Palm Oil Products
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Methathesis of ethyl oleate, catalyzed by WCl6 and SnMe4, provided diethyl 9-octadecenedioate (the desired starting material for the synthesis of civetone) in 99percent yield.Dieckmann condensation of diethyl 9-octadecenedioate gave 2-ethoxycarbonyl-9-cycloheptadecenone (63percent yield), the hydrolysis-decarboxylation reaction of which yielded civetone (93percent).Identiffication of all products was by 1H nuclear magnetic resonance, infrared and mass spectroscopic data.This is the first report of the synthesis of civetone from palm oil-derived products.KEY WORDS: Civet, civetone, diethyl 9-octadecenedioate, 2-ethoxycarbonyl-9-cycloheptadecenone, ethyl oleate, metathesis, palm oil.
- Choo, Yuen-May,Ooi, Kay-Eng,Ooi, Ing-Hong
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- Purification of 2-monoacylglycerols using liquid CO2 extraction
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The fatty acid moiety of 2-monoacyl-sn-glycerol (2-MAG) undergoes spontaneous acyl migration to the sn-1(3) position, resulting in a thermodynamic equilibrium of approximately 1:9 of 2-MAG to 1(3)-monoacyl-sn-glycerol (1-MAG). Spontaneous acyl migration is an impediment to synthesizing and isolating specific 2-MAG for use as intermediates in the synthesis of structured triacylglycerols. 2-Monooleoyl-sn-glycerol was synthesized by the enzymatic ethanolysis of triolein and isolated by liquid CO2 extraction. The resultant MAG, diacylglycerol, and fatty acid ethyl esters were quantified by 1H NMR and supercritical fluid chromatography. The low polarity of the CO2 and mild extraction temperature (25 °C) resulted in very low spontaneous acyl migration rates, allowing the MAG to be isolated in 80% yield and in a very high 2-MAG:1-MAG ratios of ≥93 mol%.
- Compton, David L.,Eller, Fred J.,Laszlo, Joseph A.,Evans, Kervin O.
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- Acidic characterization and activity of (NH4)xCs 2.5-xH0.5PW12O40 catalysts in the esterification reaction of oleic acid with ethanol
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Ammonium and cesium derivatives from H3PW12O 40 (H3PW), namely (NH4)xCs 2.5-xH0.5PW12O40 (x = 0.5, 1, 1.5, 2), were synthesized and structurally characterized by FT-Raman spectroscopy, and their thermal stability was evaluated by FTIR and TGA/DTA. The acidity was characterized by the adsorption/desorption of gaseous pyridine, by FTIR and TGA/DTA as well as by the reaction of oleic acid and ethanol. The stability of the mixed salts regarding the Keggin structure was much higher than the parent acid, with the onset decomposition around 520 °C. Nonetheless, calcination up to 300 °C is recommended for the integrity of the mixed salt. The FTIR of adsorbed pyridine displayed only Bronsted acidic sites, which was confirmed by TGA measurements of the formation of Py-H+?Py adducts. The best esterification result was for (NH4)2Cs 0.5H0.5PW12O40 with TOF = 1.314 molEO mol-1 proton s-1 with a 1:6 (oleic acid:ethanol) molar ratio, at 80 °C and 10 wt% catalyst in relation to the acid.
- Santos, Joicy S.,Dias, José A.,Dias, Sílvia C.L.,De MacEdo, Julio L.,Garcia, Fillipe A.C.,Almeida, Liana S.,De Carvalho, Eduardo N.C.B.
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- About the role of typical spacer/crosslinker on the design of efficient magnetic biocatalysts based on nanosized magnetite
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The immobilization of Candida antarctica lipase B (CALB) was carried out using glutaraldehyde (GLUT) and/or 3-aminopropyl-triethoxisilane (APTS). The aim of this work was to elucidate the role of these crosslinkers/functionalizers on the efficiency of the prepared nanosized catalysts in solvent-free oleic acid esterification. A series of biocatalysts were prepared in presence or absence of GLUT and APTS. The impact of the amount of initial CALB was also explored. An experimental design was utilized to study the variables that maximize biocatalyst activity. A strong dependence of enzymatic activity with the nominal amount of GLUT as well as the final protein/CALB loading was found. Nominal quantity of APTS did not affect catalyst's activity when used in combination with GLUT. Additional studies demonstrated that stability during storage was mainly dependent on the enzyme loading. The optimum biocatalyst was reused six cycles without mass loss. Biocatalyst's performance decreased with reuse. Mechanisms justifying these results were proposed. The role of GLUT and APTS on stability during storage and on differences between initial enzymatic activity and the performance in the reaction after two months was discussed. The problem of mixed interaction of CALB (covalent bonding plus simple adsorption) was carefully addressed to explain leaching of the lipase. Leaching and stability on storage should be included in the analysis of modifiers impact when support's modifiers are used. The fresh and stored biocatalyst enzymatic activity has to be addressed looking at the practical aspects of implementation in technological settings.
- Nicolás, Paula,Lassalle, Verónica L.,Ferreira, María L.
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- The Esterification of Oleic Acid with Ethanol Accompanied by Membrane Separation
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The use of water-permeable membranes for gas separation in the esterification of oleic acid with ethanol was studied.The perfect conversion due to the equilibrium shift was obtained by using a polyimide membrane for removal of water vapor generated by the esterification.
- Kita, Hidetoshi,Tanaka, Kazuhiro,Okamoto, Ken-ichi,Yamamoto, Masuji
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- Conversion of a carboxylesterase into a triacylglycerol lipase by a random mutation
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A true convert: The carboxylesterase enzyme R.34 (see picture) can be converted into a triacylglycerol lipase without modification of the shape, size, or hydrophobicity of the substrate binding site. The substitution of Asn33 by Asp results in a salt bridge between the Asp33 and Arg49, which causes a distortion of the enzyme structure that makes the catalytic site more accessible to larger substrates but also more labile. (Figure Presented).
- Reyes-Duarte, Dolores,Polaina, Julio,Lopez-Cortes, Nieves,Alcalde, Miguel,Plou, Francisco J.,Elborough, Kieran,Ballesteros, Antonio,Timmis, Kenneth N.,Golyshin, Peter N.,Ferrer, Manuel
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- HYDROGENATION OF FATTY ACIDS ESTERS. II. KINETICS OF HYDROGENATION OF METHYL (Z)- AND (E)-9-OCTADECENOATE CATALYZED BY A ZIEGLER NICKEL CATALYST
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Kinetics of the title reactions has been studied, using nickel(II) 2,4-pentanedionate/triethylaluminium system as a model catalyst.Initial rate measurements showed that in both cases the hydrogenation is first order in hydrogen, zero order in the octadecenoate and a fractional order (close to one) in the catalyst.Both hydrogenations have similar activation energies (30.2 +/- 2.3 kJ mol-1 and 28.9 +/- 2.6 kJ mol-1 for the (Z)- and (E)-9-octadecenoate, respectively).Based on these data and the results of competition experiments, two models have been proposed to describe isomerization of the octadecenoates (either direct of via an intermediate).
- Krupickova, Jana,Vcelak, Jaroslav,Hetflejs, Jiri
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- Cellulose as an efficient matrix for lipase and transaminase immobilization
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Immobilization of enzymes is important to improve their stability and to facilitate their recyclability, aiming to make biocatalytic processes more efficient. One of the important aspects is the utilization of cheap, abundant, and environmentally friendly carriers for enzyme immobilization. Here we report the use of functionalized cellulose for lipase and transaminase immobilization. High immobilization efficiencies (up to 90%) could be achieved for the transaminase from Vibrio fluvialis. For immobilized lipase CAL-B as well as the transaminase, good conversions and recyclability could be demonstrated in kinetic resolutions to afford chiral alcohols or amines. Moreover, such application of the immobilized transaminase enabled very high conversions in a continuous-flow process in the asymmetric synthesis of (S)-phenylethylamine (80% conversion, >99% ee).
- De Souza, Stefania P.,Junior, Ivaldo I.,Silva, Guilherme M. A.,Miranda, Leandro S. M.,Santiago, Marcelo F.,Leung-Yuk Lam, Frank,Dawood, Ayad,Bornscheuer, Uwe T.,De Souza, Rodrigo O. M. A.
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- Synthesis and characterization of a CaFe2O4 catalyst for oleic acid esterification
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Esterification of free fatty acid (oleic acid) with ethanol over a calcium ferrite catalyst was investigated in the present study. The calcium ferrite catalyst (CaFe2O4) was synthesized by the sol-gel method, which exhibited high catalytic activity for esterification of oleic acid. The morphology and size (500-1000 nm) of the synthesized catalyst were observed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) was used to ensure the absence of impurities. The orthorhombic structure of calcium ferrite was exposed by X-ray diffractometry (XRD). The effects of reaction variables such as catalyst loading, methanol to acid ratio, reaction time and temperature on the conversion of fatty acids were studied. The optimum conditions for the esterification process was a molar ratio of alcohol to oleic acid at 12:1 with 5 wt% of CaFe2O4 at 70 °C with a reaction time of 2 h. XRD patterns of the recycled catalyst evidenced that the catalyst structure was unchanged up to the 3rd cycle, which indicated the long life of the catalyst.
- Ong, Huei Ruey,Rahman Khan, Md Maksudur,Yousuf, Abu,Hussain, Nor Amalina,Cheng, Chin Kui
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p. 100362 - 100368
(2015)
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- Zirconocene-catalysed biodiesel synthesis from vegetable oil with high free fatty acid contents
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A highly efficient transformation of vegetable oils into biodiesel catalysed by air-stable and water-tolerant zirconocene perfluorooctanesulfonate Lewis acid has been developed. By combining the direct esterification of free fatty acids (FFAs) and transesterification of triglycerides (TGs), the simultaneous transformation of the two components to biodiesel is achieved in good yields. Furthermore, this catalyst, when used in the synthesis of biodiesel from commercial oleifera, behaves as a reaction-induced self-separation catalyst. During the course of the reaction, it switches from homogeneous to heterogeneous; upon completion of the reaction, the catalyst precipitates as a white solid, which can be easily recycled.
- Deng, Yiqiang,Hu, Xiaojian,Cheng, Lihua,Wang, Hanlu,Duan, Linhai,Qiu, Renhua
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- Proline derivatives incorporating hydrophobic long-chain derived from natural and synthetic fatty acids
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The α-hydrophobic long chain-α-amino esters are prepared by α-hydroxylation of a series of fatty acid esters [derived from oleic acid (OA), linoleic acid (LA), arachidonic acid (ARA) and docosahexaenoic acid (DHA)] followed by Mitsunobu reaction and hydrazinolysis of the phthalimide. These amino esters are mixed with aldehydes and electrophilic alkenes to give very good chemical yields and diastereoselectivities of prolinate derivatives incorporating a hydrophobic long chain at the α-position. This multicomponent 1,3-dipolar cycloaddition (1,3-DC) takes place at room temperature. The synthesis of the homologue hydrophobic chain of OA is performed by its oxidation to aldehyde/racemic N-tert-butylsulfinyl imine/Neff reaction. Final 1,3-DC with benzaldehyde and N-methylmaleimide affords homologue prolinate derivative in good yield.
- Selva, Elisabet,Soto, J. Javier,Nájera, Carmen,Foubelo, Francisco,Sansano, José M.
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- Synthesis of a Palm-Based Star-Shaped Hydrocarbon via Oleate Metathesis
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10,11-Dioctyleicosane, a star-shaped hydrocarbon, has been successfully synthesized from 9-octadecene (a product from metathesis of methyl oleate or ethyl oleate) through dimerization followed by hydrogenation.The product was determined by 13C nuclear magnetic resonance spectroscopic and gas chromatography/mass spectrometric techniques.This hydrocarbon likely exhibits lubricating properties that can be used as high-performance functional fluids in automotive lubrication.We also report the presence of a novel product, a trimer that was formed during the synthesis. - Key words: Diethyl 9-octadecenedioate; 10,11-dioctyl eicosane; ethyl and methyl oleates; metathesis; 9-octadecene; palm oil; star-shaped hydrocarbon.
- Choo, Yuen-May,Ooi, Kay-Eng,Ooi, Ing-Hong,Tan, Daniel D. H.
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- Efficient delivery of therapeutic small nucleic acids to prostate cancer cells using ketal nucleoside lipid nanoparticles
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A novel nucleoside lipid derived from dioleyl ketal was synthesized from uridine in three steps starting from dioleyl ketone. Electronic microscopy studies show that Ketals Nucleoside Lipids (KNL) self-assemble to form liposome-like structures in aqueous solutions. KNL is able to bind siRNA as demonstrated by electrophoresis experiment and standard ethidium bromide fluorescence displacement assay. Transfection assays of stable hepatic cell lines HupIRF, carrying a luciferase reporter gene demonstrate that KNL is able to transfect siRNA and exhibits protein knockdown more efficiently than its diester analog (DOTAU) and lipofectamine. Herein, we also report that KNLs are suitable transfecting reagents for the development of novel therapeutic approaches involving either siRNA or antisense oligonucleotide against human prostate cancer PC-3 cells resistant to chemotherapy.
- Luvino, Delphine,Khiati, Salim,Oumzil, Khalid,Rocchi, Palma,Camplo, Michel,Barthélémy, Philippe
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- Evaluating the kinetics of the esterification of oleic acid with homo and heterogeneous catalysts using in-line real-time infrared spectroscopy and partial least squares calibration
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Biodiesel is a mixture of fatty acid alkyl esters with properties similar to petroleum-based diesel. Thus, biodiesel can be used as either a substitute for diesel fuel or, more commonly, in a fuel blend. Biodiesel production can be catalyzed with mineral acids or bases or enzymes. The use of real-time techniques for monitoring the reaction and evaluating the efficiency of the catalyst can be of great use for optimizing the reaction and monitoring the process. In the present work, an in-line real-time methodology was used to evaluate and compare the kinetics of a reaction catalyzed with homo (hydrochloric acid) and heterogeneous (the enzymes Novozym 435, Lipozyme RM, and Lipozyme TL) catalysts. The esterification of oleic acid with ethanol was used as the reaction model. The study used attenuated total reflexion/Fourier transform infrared (ATR/FT-IR) and a single partial least squares (PLS) regression model to evaluate the kinetics of the various catalysts, without multiple calibrations, with validation by GC-MS. Novozym 435, which showed complete conversion after 165 min, was the best catalyst for this reaction. Lipozyme RM and Lipozyme TL had inferior conversion after the same amount of time, in agreement with the literature. All enzymatic catalysts showed higher conversion than hydrochloric acid at the same reaction conditions.
- Kartnaller, Vinicius,Junior, Ivaldo I.,De Souza, Adriana V.A.,Costa, Ingrid C.R.,Rezende, Michelle J.C.,Da Silva, Jo?o F. Cajaiba,De Souza, Rodrigo O.M.A.
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- Sporopollenin as an efficient green support for covalent immobilization of a lipase
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Sporopollenin exine capsules (SECs), derived from the spores of Lycopodium clavatum, have been functionalised with 1,n-diamines and the resulting aminoalkyl microcapsules used to immobilize Candida antarctica lipase B (Cal B) via a glutaradehyde-based diimine covalent linker. The supported enzyme efficiently catalyzes the esterification of oleic acid with ethanol. Initial rates using the SEC-CalBs were comparable to the commercial enzyme Novozym 435, but displayed up to 20-fold higher specific activity. The supported enzymes could also be recycled and after four cycles displayed only a modest decrease in conversions. In a kinetic resolution the SEC-CalBs efficiently acetylated rac-1-phenylethanol, with conversions up to 37% after 5 hours and product enantiomeric excesses of >99%. Related to this, the dynamic resolution of rac-1-phenylethylamine, in the presence of Pd-BaSO4 and ammonium formate, led to the acetylated amine with a 94% conversion and >99% ee.
- De Souza, Stefania P.,Bassut, Jonathan,Marquez, Heiddy V.,Junior, Ivaldo I.,Miranda, Leandro S. M.,Huang, Youkui,Mackenzie, Grahame,Boa, Andrew N.,De Souza, Rodrigo O. M. A.
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- Palladium-Catalyzed Directed meta-Selective C?H Allylation of Arenes: Unactivated Internal Olefins as Allyl Surrogates
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Palladium(II)-catalyzed meta-selective C?H allylation of arenes has been developed utilizing synthetically inert unactivated acyclic internal olefins as allylic surrogates. The strong σ-donating and π-accepting ability of pyrimidine-based directing group facilitates the olefin insertion by overcoming inertness of the typical unactivated internal olefins. Exclusive allyl over styrenyl product selectivity as well as E stereoselectivity were achieved with broad substrate scope, wide functional-group tolerance, and good to excellent yields. Late-stage functionalisations of pharmaceuticals were demonstrated. Experimental and computational studies shed light on the mechanism and point to key steric control in the palladacycle, thus determining product selectivities.
- Achar, Tapas Kumar,Zhang, Xinglong,Mondal, Rahul,Shanavas,Maiti, Siddhartha,Maity, Sabyasachi,Pal, Nityananda,Paton, Robert S.,Maiti, Debabrata
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- New phosphonic acid polysilsesquioxane mild solid acid catalysts
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A simple easily scalable one-pot route to new phosphonic acid polysilsesquioxanes, PAPSQ, [(O3/2SiCH2R) x(O3/2SiCHR(CH2)2SiO 3/2)y]n where R = CH2PO 3H2, is described in this paper. Nuclear magnetic resonance (NMR), electron microscopy (SEM), thermogravimetric analysis, nitrogen sorption porosimetry, phosphorus and available acid analysis were used to characterise the new PAPSQ materials. The materials were shown to be very efficient and recyclable mild solid acid catalysts for organic transformations including those relevant to biomass conversion such as esterification, transesterification and dehydration of fructose to the important intermediate 5-hydroxymethylfurfural.
- Sebah, Majda,Maddala, Sai P.,Haycock, Peter,Sullivan, Alice,Toms, Harold,Wilson, John
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- Enzyme-Decorated Covalent Organic Frameworks as Nanoporous Platforms for Heterogeneous Biocatalysis
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Sustainability in chemistry heavily relies on heterogeneous catalysis. Enzymes, the main catalyst for biochemical reactions in nature, are an elegant choice to catalyze reactions due to their high activity and selectivity, although they usually suffer from lack of robustness. To overcome this drawback, enzyme-decorated nanoporous heterogeneous catalysts were developed. Three different approaches for Candida antarctica lipase B (CAL-B) immobilization on a covalent organic framework (PPF-2) were employed: physical adsorption on the surface, covalent attachment of the enzyme in functional groups on the surface and covalent attachment into a linker added post-synthesis. The influence of the immobilization strategy on the enzyme uptake, specific activity, thermal stability, and the possibility of its use through multiple cycles was explored. High specific activities were observed for PPF-2-supported CAL-B in the esterification of oleic acid with ethanol, ranging from 58 to 283 U mg?1, which was 2.6 to 12.7 times greater than the observed for the commercial Novozyme 435.
- Oliveira, Felipe L.,de Souza, Stefania P.,Bassut, Jonathan,álvarez, Heiddy M.,Garcia-Basabe, Yunier,Alves de Souza, Rodrigo O. M.,Esteves, Pierre M.,Gon?alves, Raoni S. B.
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- Covalent immobilization of organic solvent tolerant lipase on aluminum oxide pellets and its potential application in esterification reaction
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This study was carried out to covalently immobilize the partially purified lipase from Bacillus sp. DVL2 on glutaraldehyde-activated aluminum oxide pellets and subsequently use the immobilized enzyme for esterification of oleic acid and ethanol. The immobilization process parameters were optimized through response surface methodology. Under optimized conditions, maximum immobilization yield of the enzyme was 78.20%. The immobilized lipase could be reused for 5 consecutive cycles without any loss of enzyme activity. However, the enzyme showed 75% residual activity after 10th cycle. The stability of the immobilized enzyme towards pH, temperature and organic solvents was enhanced as compared with its soluble counterpart. Higher values of half-lives, D-values, enthalpy and free energy change after covalent immobilization implied an improvement in enzyme stability. The Km and Vmax values of the enzyme were enhanced after immobilization. The immobilized lipase was found to be most stable in DMSO followed by toluene, hexane and xylene, exhibiting more than 90% residual activity in these solvents after 24 h of incubation. The immobilized lipase was more efficient in catalyzing the esterification between oleic acid and ethanol in hexane. The formation of ethyl oleate was confirmed by TLC and 1H NMR spectroscopy.
- Kumar, Davender,Nagar, Sushil,Bhushan, Indu,Kumar, Lalit,Parshad, Rajinder,Gupta, Vijay Kumar
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- In situ monitoring of turbid immobilized lipase-catalyzed esterification of oleic acid using fiber-optic Raman spectroscopy
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Raman spectroscopy with a fiber-optic probe was used to monitor the immobilized Candida antarctica lipase B (Novozym 435)-catalyzed esterification of oleic acid with ethanol in iso-octane as an organic solvent. The effects of reaction temperature and molar ratio of substrates were studied. An optimal reaction rate was found at 60 °C, beyond which deactivation due to denaturing of the lipase was observed. The variation in molar ratio of substrates suggests that the esterification of oleic acid and ethanol proceeds via a Ping-Pong Bi-Bi mechanism with ethanol exhibiting an inhibitory effect. A good fit was obtained between the experimental results and the best-fit Ping-Pong Bi-Bi mechanism. This current work shows that fiber-optic Raman spectroscopy is indeed a suitable instrument to monitor immobilized lipase-catalyzed reaction in turbid organic systems in situ. Since this approach is reliable, simple to use, allows automatic data acquisition, and accurate, it should be applicable to the detailed kinetic analysis on other immobilized enzymatic reactions as well.
- Elfanso, Erick,Garland, Marc,Loh, Kai Chee,Talukder, M.M. Rahman,Widjaja, Effendi
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- Esterification of oleic acid in [Bmim]BF4/[Hmim]HSO4 + TX-100/cyclohexane ionic liquid microemulsion
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Esterification of oleic acid was carried out in a 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4)/Triton X-100 + 1-hexyl-3-methylimidazolium hydrogen sulfate ([Hmim]HSO4)/cyclohexane microemulsion. A pseudo ternary phase diagram of the designed systems was drawn to investigate the phase behavior of the microemulsion, with the surfactant [Hmim]HSO4 acting as a catalyst. The effects of various reaction parameters were explored. The results showed that the maximum yield of lauryl oleate reaches 91.17% and its selectivity reaches 98.55% under optimum reaction conditions. The reaction was carried out with 8 wt% catalyst at 373 K for 6 h. The molar ratios of [Bmim]BF4 to the surfactant and of oleic acid to lauryl alcohol were 0.24 and 0.2, respectively. Comparison reactions between different alcohols and oleic acid were also performed, and the results showed that long alkyl chain alcohols promote the reaction rate. UV-vis absorption spectra demonstrated that the generated water enters the [Bmim]BF4 microdomain of the ionic liquid microemulsions. A possible mechanism of the reaction was also presented. All the results indicate that the [Bmim]BF4/TX-100 + [Hmim]HSO4/cyclohexane microemulsion is a very efficient catalyst system for esterification reactions. This journal is
- Jiang, Dongyu,Chen, Li,Wang, Aili,Yan, Zongcheng
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- IONIZABLE LIPIDS FOR NUCLEIC ACID DELIVERY
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The present document describes compounds, or pharmaceutically acceptable salt thereof, of a core formula (I) Wherein R1 includes an amino group. These compounds are particularly useful in the formulation and in vivo and ex vivo delivery of nucleic acid and protein therapeutics for preparing and implementing T cell transfection, gene editing, cancer therapies, cancer prophylactics, and in the preparation of vaccines.
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Paragraph 00330-00332
(2021/01/23)
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- Chemically Modified Lipase from Thermomyces lanuginosus with Enhanced Esterification and Transesterification Activities
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Lipase from Thermomyces lanuginosus is one of the most explored enzymes for the esterification of several added-value industrial compounds, such as biodiesel, fragrances, and flavors. Its selectivity in these reactions is mostly related with its activity towards small alcohols. In this work, the impact of the chemical modification, with 4 dodecyl chains at its surface, was evaluated regarding its transesterification and esterification activities, comparing with the native form. Linear size-differentiated alcohols (from 1 to 20 carbons in the aliphatic chain) were used to explore for the first time the effect of the chain length in both transesterification and esterification reactions, using p-nitrophenyl palmitate and oleic acid as model compounds, respectively. The chemically modified lipase showed an outstanding improvement of its catalytic performance than the native enzyme, being this increase directly proportional to the size of the alcohols chain used as substrates. The enormous potential and remarkable versatility of this novel super catalyst was here demonstrated, where diverse types of esters, differing in their potential applications (biodiesel, cosmetics, fine chemistry), were efficiently synthesized. The produced esters were fully characterized by 1H NMR, GC-MS, and FTIR.
- Noro, Jennifer,Cavaco-Paulo, Artur,Silva, Carla
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p. 4524 - 4531
(2021/09/02)
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- NATURAL BIOSURFACTANT OF ESTER AND MANUFACTURING METHOD THEREOF
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The present invention relates to an ester natural surfactant and a manufacturing method thereof. The present invention relates to an eco-friendly ester natural surfactant having excellent solubility in water and biodegradability, and a manufacturing method thereof. The present invention relates to an ester natural surfactant, and more particularly, to an ester natural surfactant and a method for preparing the same. (by machine translation)
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Paragraph 0125; 0126; 0129-0132
(2020/12/11)
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- IONIZABLE LIPIDS FOR NUCLEIC ACID DELIVERY
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The present document describes compounds, or pharmaceutically acceptable salt thereof, of a core formula (I) where R1 features an amine group, particularly useful in the formulation of lipid particles including nucleic acid therapeutic agents, or proteins, or both, and for delivery of nucleic acid and protein therapeutics to cells in vivo or ex vivo, including anticancer and vaccine applications.
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Paragraph 00367
(2021/01/22)
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- Method for synthesizing oleic acid low-alcohol ester
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The invention relates to the technical field of organic synthesis and particularly discloses a method for synthesizing oleic acid low-alcohol ester. According to the method, specific Bronsted-Lewis acidic ionic liquid is taken as a catalyst, catalytic oleic acid and low alcohols are subjected to an esterification reaction, and thus corresponding oleate is obtained. The selected ionic liquid has high selectivity to the esterification reaction of the oleic acid and the low alcohols, the use amount is small, and the catalytic efficiency is high.
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Paragraph 0046-0051
(2019/11/12)
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- Catalytic transfer hydrogenation of oleic acid to octadecanol over magnetic recoverable cobalt catalysts
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Efficient transformation of biomass into fuel and chemicals under mild conditions with cost-effective and environmentally friendly characters is highly desirable but still challenging. Herein, a scalable and Earth-abundant cobalt catalyst was used for selective catalytic transfer hydrogenation (CTH) of unsaturated fatty acids to fatty alcohols with sustainable isopropanol as a hydrogen donor. By tuning the surface Co composition by varying the reduction temperature, the catalytic performance could be easily boosted. At 200 °C in 4 h, the optimal catalyst Co-350 (reduced at 350 °C) gives 100% oleic acid conversion with 91.9% octadecanol selectivity. Various characterization studies reveal that the co-existence of Coδ+ and Co0 over the cobalt core might be responsible for its high performance for CTH of oleic acid. This catalyst could be magnetically separated and is highly stable for reusing ten times. Moreover, this cobalt catalyst is relatively cheap and easy to scale-up, thus achieving a low-cost transformation of biomass into high value-added chemicals.
- Wang, Juncheng,Nie, Renfeng,Xu, Ling,Lyu, Xilei,Lu, Xiuyang
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p. 314 - 320
(2019/01/28)
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- A catalyst-free, waste-less ethanol-based solvothermal synthesis of amides
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A green, one-pot approach based on the solvothermal amidation of carboxylic acids with amines has been developed for the synthesis of diverse aliphatic and aromatic amides. It does not require the use of catalysts or coupling reagents and it occurs in the presence of ethanol that has been proved to have a key role in the process. The proposed strategy is also extendable to biologically active amides and could represent a low-cost and waste-less alternative to the common synthetic pathways.
- Dalu, Francesca,Scorciapino, Mariano A.,Cara, Claudio,Luridiana, Alberto,Musinu, Anna,Casu, Mariano,Secci, Francesco,Cannas, Carla
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supporting information
p. 375 - 381
(2018/02/07)
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- Clean and Green Procedure for the Synthesis of Biodiesel from the Esterification of Free Fatty Acids and Alcohol Catalyzed by 6-O-(sulfobutyl)-Β-cyclodextrin
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The catalyst of 6-O-(sulfobutyl)-β-cyclodextrin (SB-CD) is renewable, non-toxic, environmentally benign and biocompatible, which could be used as efficient and recyclable catalyst for the synthesis of biodiesel from free long-chain fatty acids with low-chain alcohols as substrates. The reaction was accomplished at 60°C for 1.5 h, while the products were separated from the catalyst system by liquid/liquid at room temperature with good conversion of 91–98%. The catalyst can be reused for 10 times. The novel and clean procedure offers advantages including short reaction time, good conversion, operational simplicity, and environmentally benign characteristics.
- Zhang, Guangqing,He, Leqin,Yuan, Mingxia,Li, Hui,Chang, Tao,Qin, Shenjun
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p. 1123 - 1128
(2018/10/24)
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- Surfactant-like Br?nsted acidic ionic liquid as an efficient catalyst for selective Mannich reaction and biodiesel production in water
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Abstract: The current study deals with the applications of a surfactant-like Br?nsted acidic ionic liquid (IL) 1-dodecyl-3-methylimidazolium hydrogen sulfate ([DMIm]HSO4) for Mannich reaction at room temperature. The reaction was efficiently preceded in water as solvent without using any harmful and expensive organic additives. Our findings showed that the reaction is selective for cyclohexanone and no Mannich product was observed when cyclopentanone was used as starting material. Density functional theory (DFT) calculations were performed to provide an evidence about the nature of reactivity of the cyclohexanone/cyclopentanone. The activity of the catalyst was also tested for biodiesel production of fatty acids with methanol and ethanol at mild thermal condition without applying additional water removal steps such as using additives or performing special methodologies like azeotropic distillation. In both reactions, the IL can be recycled and reused several times with relatively constant efficiency. Graphical Abstract: [Figure not available: see fulltext.]
- Vafaeezadeh, Majid,Karbalaie-Reza, Mina,Hashemi, Mohammad Mahmoodi,Soleimany, Kasra Qasempour
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p. 907 - 914
(2017/02/26)
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- Zirconocene-catalyzed direct (trans)esterification of acyl acids (esters) and alcohols in a strict 1:1 ratio under solvent-free conditions
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A highly efficient way for the direct (trans)esterification of acyl acids (esters) and alcohols in a strict 1:1 ratio using a zirconocene complex (1, 1 mol%), a strong Lewis acid of good water tolerance, as a catalyst under solvent-free conditions has been developed. A wide range of acid and alcohol (esters) substrates undergo (trans)esterification to produce carboxylic ester motifs in moderate to good or excellent yields with good functional tolerance, such as that towards C-Br as well as CC and CC bonds. And complex 1 can be recycled six times without showing a significant decline in catalytic efficiency. It was demonstrated that cyclandelate, which is used to treat high blood pressure as well as heart and blood-vessel diseases, can be directly synthesized on a gram scale with 81% yield (6.70 g) using complex 1.
- Tang, Zhi,Jiang, Qiutao,Peng, Lifen,Xu, Xinhua,Li, Jie,Qiu, Renhua,Au, Chak-Tong
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supporting information
p. 5396 - 5402
(2017/11/22)
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- Catalytic Biodiesel Production Mediated by Amino Acid-Based Protic Salts
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Hetero- and homogeneous acid catalysts are effective catalysts for the production of biodiesel from oils containing high free fatty acids. The protic salts synthesized from natural amino acids were examined for catalytic activity and efficiency for the esterification of oleic acid after structural identification and characterization. In the esterification reaction of oleic acid with methanol, [Asp][NO3] was the best catalyst, and its high activity correlated to its high Hammett acidity. The optimal reaction conditions for the esterification of oleic acid to achieve 97 % biodiesel yield were: 70 °C, 10 % catalyst loading (w/w, on oleic acid basis), methanol/oleic acid ratio 7.5:1, and 5 h. Generally, [Asp][NO3] could be a good catalyst for the esterification of oleic acid with alcohols with chain lengths of up to six. The biodiesel yield of 93.86 % obtained from palm fatty acid distillate implies that the catalyst has potential for industrial application. A study of the kinetics indicated that the reaction followed pseudo-first-order kinetics with an activation energy and pre-exponential of 57.36 kJ mol?1 and 44.24×105 min?1, respectively. The aspartic acid-derived protic salt is a promising, operationally simply, sustainable, renewable, and possibly biodegradable catalyst for the conversion of free fatty acids into biodiesel.
- Li, Jingbo,Guo, Zheng
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p. 1792 - 1802
(2017/04/27)
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- Subsititue Material As Well As Production Process And Application
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The invention relates to a production process of a functionalized material containing acid groups and an application thereof. The material is used as a nonhomogenous catalyst, and can be used for removing organic and inorganic compounds in product streams, process streams and waste liquid, or can be used as a cation and anion exchanger, a metal chromatography material, a solid phase purifying or extracting material, a fixed biological moleculaar material, a solid phase sythesizing material and a chromatography material. The invention also relates to a novel sulfonic acid or hypophosphorous organic funtionalized silica gel and metal salts thereof.
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-
Paragraph 0110; 0111
(2017/08/28)
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- Revealing the Roles of Subdomains in the Catalytic Behavior of Lipases/Acyltransferases Homologous to CpLIP2 through Rational Design of Chimeric Enzymes
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The lipases/acyltransferases homologous to CpLIP2 of Candida parapsilosis efficiently catalyze acyltransfer reactions in lipid/water media with high water activity (aW>0.9). Two new enzymes of this family, CduLAc from Candida dubliniensis and CalLAc8 from Candida albicans, were characterized. Despite 82 % sequence identity, the two enzymes have significant differences in their catalytic behaviors. In order to understand the roles played by the different subdomains of these proteins (main core, cap and C-terminal flap), chimeric enzymes were designed by rational exchange of cap and C-terminal flap, between CduLAc and CalLAc8. The results show that the cap region plays a significant role in substrate specificity; the main core was found to be the most important part of the protein for acyltransfer ability. Similar exchanges were made with CAL-A from Candida antarctica, but only the C-terminal exchange was successful. Yet, the role of this domain was not clearly elucidated, other than that it is essential for activity.
- Jan, Anne-Hélène,Dubreucq, éric,Subileau, Maeva
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p. 941 - 950
(2017/05/26)
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- In situ immobilization of Candida antarctica B lipase in polyurethane foam support
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Candida antarctica B (CALB) lipase was immobilized using polyurethane (PU) foam as support by confinement method. This can be a promising technique due to the low cost of the support, simple procedure of immobilization and the possibility of using the derivative as catalyst for the food industry reactions. CALB immobilization on PU was performed using 6 mL polyol and 4 mL isocyanate (60-40%, v/v), with 1 mL of enzymatic solution (0.8 g enzyme in 5 mL distilled water). The immobilization process resulted in a 535% increase in activity for the enzymatic derivative. The enzyme was stable for 360 days at room (10-25 °C) and low (2-8 °C) temperatures, for 300 days at 40 and 60 °C and for 150 days at 80 °C in wet ambient conditions. The synthesis of geranyl propionate and ethyl oleate catalyzed by the immobilized derivative presented conversions of around 97 and 83%, respectively. The immobilized CALB in PU was reused consecutively different behavior occurred which stored in dry ambient conditions at different temperatures (room: 10-25 °C, refrigeration: 2-8 °C and 40 °C) resisted 30 cycles, for both forms of storage, keeping more than 87, 95 and 83% of its activity, respectively.
- Nyari, Nadia Ligianara D.,Fernandes, Ilizandra A.,Bustamante-Vargas, Cindy E.,Steffens, Clarisse,De Oliveira, Débora,Zeni, Jamile,Rigo, Elisandra,Dallago, Rogério M.
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- P-Sulfonic acid calix[4]arene-functionalized alkyl-bridged organosilica in esterification reactions
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Two new p-sulfonic acid calix[4]arene- and p-sulfonic acid calix[6]arene-functionalized organosilica have been synthesized using a sol-gel method and applied as heterogeneous catalysts in esterification reactions. The catalytic performance was evaluated using the esterification of carboxylic acids with ethanol, and good catalytic activity (i.e., 55-88%) was observed under the optimum reaction conditions. This study reports the first promising example of the successful employment of calix[n]arenes as a heterogeneous catalyst for catalytic esterification. The catalyst was easily separated by filtration and reused five times without any significant loss of activity.
- De Assis,Abranches,Braga,Zu?iga,Sathicq,Romanelli,Sato,Fernandes
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p. 24285 - 24289
(2016/03/15)
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- Synthesis, characterization and catalytic performance of a novel picolinic acid-12-molybdophosphoric acid hybrid catalyst
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A novel 12-molybdophosphoric acid (HPM)-based complex (H2 PI)2(H 3 O)[PMo12O 40] [Mo2 O5 (H2 O)2 (PI)2 ]?11H2 O (PI-HPM) was prepared by modification with picolinic acid (HPI) and characterized by the methods of Fourier transform infrared (FTIR) spectroscopy, thermogravimetry (TG), X-ray powder and single crystal diffraction. The complex retained the classical Keggin structure of bulk HPM, there were some strong hydrogen bonds existing between the [PMo12 O40 ]3- polyanion, the [Mo2 O5 (H2 O)2 (PI)2 ] coordination moiety, the protonated HPI and the lattice water molecules. Then PI-HPM was employed as heterogeneous catalyst for esterification reaction to evaluate its acid-catalytic activity. The complex exhibited high activity and good durability in reaction mixtures, indicating that it was a promising heterogeneous acid catalyst for esterification that including the conversion of oleic acid to oleates.
- Liu, Lijun,Wang, Honghong,Gong, Shuwen,Lu, Jing,Zhang, Qian
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p. 1007 - 1013
(2016/06/15)
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- Immobilization of a thiol-functionalized ionic liquid onto HKUST-1 through thiol compounds as the chemical bridge
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A novel heterogeneous catalyst [HVIm-(CH2)3SO3H]HSO4@HKUST-1 (IL@HKUST-1), with both Lewis and Br?nsted acid sites, was developed for the esterification of oleic acid with short-chain alcohols. HKUST-1 was chemically modified with ethanedithiol, and the vinyl-containing ionic liquid was then grafted onto the carrier through thiol groups. The catalyst IL@HKUST-1 was characterized by XRD, N2 adsorption-desorption, FT-IR, SEM, TG, elemental analysis, and ICP. The results proved that HKUST-1 had typical microporous structure, and the thiol groups were incorporated into the channels of the carrier. Through the reaction of vinyl and thiol, the ionic liquid was successfully immobilized onto SH-HKUST-1 by chemical covalent bonds. The catalyst was applied in the esterification of oleic acid with ethanol, and the optimal conditions were determined as follows: molar ratio of ethanol to oleic acid 12 : 1, catalyst amount 15 wt% (based on oleic acid), reaction time 4 h, and reaction temperature 90 °C. Under the conditions, the conversion of oleic acid was 92.1%. After 5 times of recycling, there was no significant decrease in conversion, showing a certain stability and good reusability of the catalyst. The catalyst also exhibited high catalytic activity in esterification of oleic acid with other short-chain alcohols.
- Chen, Chong,Wu, Zuowang,Que, Yigen,Li, Bingxue,Guo, Qirui,Li, Zhong,Wang, Lei,Wan, Hui,Guan, Guofeng
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p. 54119 - 54128
(2016/07/06)
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- Novel porous and hydrophobic POSS-ionic liquid polymeric hybrid as highly efficient solid acid catalyst for synthesis of oleate
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A novel porous and hydrophobic Br?nsted acidic solid catalyst (POSS-[VMPS][H2SO4]) was successfully synthesized by copolymerization of polyhedral oligomeric vinylsilsesquioxanes (POSSs) and sulfonic acid-functionalized imidazole ionic liquids. Catalytic tests for the esterification of oleic acid with methanol have shown that this newly obtained polymeric hybrid exhibits very high catalytic activity and selectivity, which was more active or comparable to those of the common solid acid Amberlite-732 and liquid acid H2SO4. Moreover, the catalyst has a good recyclability without significant loss in the activity.
- Lu, Dan,Zhao, Jiwei,Leng, Yan,Jiang, Pingping,Zhang, Chenjun
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- The 3D model of the lipase/acyltransferase from Candida parapsilosis, a tool for the elucidation of structural determinants in CAL-A lipase superfamily
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Abstract Because lipids are hydrophobic, the development of efficient bioconversions in aqueous media free of organic solvents is particularly challenging for green oleochemistry. Within this aim, enzymes exhibiting various abilities to catalyze acyltransfer reaction in water/lipid systems have been identified. Among these, CpLIP2 from Candida parapsilosis has been characterized as a lipase/acyltransferase, able to catalyze acyltransfer reactions preferentially to hydrolysis in the presence of particularly low acyl acceptor concentration and high thermodynamic activity of water (aw > 0.9). Lipase/acyltransferases are thus of great interest, being able to produce new esters at concentrations above the thermodynamic equilibrium of hydrolysis/esterification with limited to no release of free fatty acids. Here, we present a 3D model of CpLIP2 based on homologies with crystallographic structures of Pseudozyma antarctica lipase A. Indeed, the two enzymes have 31% of identity in their primary sequence, yielding a same general structure, but different catalytic properties. The quality of the calculated CpLIP2 model was confirmed by several methods. Limited proteolysis confirmed the location of some loops at the surface of the protein 3D model. Directed mutagenesis also supported the structural model constructed on CAL-A template: the functional properties of various mutants were consistent with their structure-based putative involvement in the oxyanion hole, substrate specificity, acyltransfer or hydrolysis catalysis and structural stability. The CpLIP2 3D model, in comparison with CAL-A 3D structure, brings insights for the elucidation and improvement of the structural determinants involved in the exceptional acyltransferase properties of this promising biocatalyst and of homologous enzymes of the same family.
- Subileau, Maeva,Jan, Anne-Hélène,Nozac'h, Hervé,Pérez-Gordo, Marina,Perrier, Véronique,Dubreucq, Eric
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p. 1400 - 1411
(2015/08/03)
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- Heterogenization of ionic liquid based on mesoporous material as magnetically recyclable catalyst for biodiesel production
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To develop green and reusable catalysts for the biodiesel preparation, a novel magnetically separable nanocatalyst was fabricated by covalent bonding of 3-sulfopropyl-1-(3-propyltrimethoxysilane) imidazolium hydrogen sulfate ([SO3H-PIM-TMSP]HSO4) on mesoporous silica modified Fe3O4 nanoparticle. The catalyst possessed uniform core-shell structure with magnetic response core and Br?nsted ionic liquid functionalized mesoporous silica shell. The multifunctional catalyst also exhibited appealing physicochemical features like high specific surface area, mesoporous channel, magnetic response, and fine catalytic activity in esterification of oleic acid with alcohol. Under mind conditions, the conversion of oleic acid was up to 93.5%. The catalyst exhibited recyclable property based on magnetism and the separation of the catalyst would be simply using external magnetic field without obvious mass loss, allowing a clean biodiesel product.
- Wan, Hui,Wu, Zuowang,Chen, Wen,Guan, Guofeng,Cai, Yuan,Chen, Chong,Li, Zhong,Liu, Xiaoqin
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p. 127 - 132
(2015/02/18)
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- SYNTHESIS OF CROSS-LINKED PLANT-OIL BASED POLYMERS USING BISMALEIMIDES AS CROSSLINKERS
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A method of preparing a plant oil based polymer comprising heating a plant oil in the presence of a bismaleimide crosslinker in the substantial absence of a solvent at a temperature at or above the melting temperature of the bismaleimide crosslinker, where the bismaleimide crosslinker is defined by the formula (I) where R1 is a divalent organic group.
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Paragraph 0069
(2015/03/28)
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- Encapsulation of heteropolyanion-based ionic liquid within the metal-organic framework MIL-100(Fe) for biodiesel production
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A new strategy was proposed to construct the ionic liquid, polyoxometalate (POM), and metal-organic framework (MOF) composite. The POM-based MOF was synthesized by using the direct hydrothermal method. The sulfonic acid group-functionalized ionic liquid was used for further modification of the hybrid material to realize the encapsulation of the heteropolyanion-based ionic liquid within the cages of the MOF. The catalysts were characterized by using XRD, N2 adsorption-desorption, FTIR, SEM, TEM, elemental analysis, and TGA. The results indicated that the heteropolyanion-based ionic liquid had been successfully encapsulated within the cages and the structure of MIL-100 (MIL=Materials of Institut Lavoisier) remained intact. The POM-ionic-liquid-functionalized MOF, with high content of the active component, had both Lewis and Bronsted acid sites, which led to high catalytic activity for the esterification of oleic acid with ethanol. The esterification reaction conditions were optimized by using response surface methodology (RSM), and the corresponding conversion of oleic acid reached 94.6-%. The catalyst could be easily recovered and reused six times without significant loss of activity. Be more active: A new strategy is proposed to construct the ionic liquid, polyoxometalate (POM), and metal-organic framework (MOF) composite. POM bridges the gap between the ionic liquid and the carrier (MOF); thus, the heteropolyanion-based ionic liquid can be encapsulated within the cages of MIL-100 (MIL=Materials of Institut Lavoisier) through anion exchange. The POM-ionic-liquid-functionalized MOF demonstrates high catalytic activity for the esterification of oleic acid with ethanol and is stable in the liquid-phase reaction, with no obvious leaching of the active component.
- Wan, Hui,Chen, Chong,Wu, Zuowang,Que, Yigen,Feng, Yu,Wang, Wei,Wang, Lei,Guan, Guofeng,Liu, Xiaoqin
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p. 441 - 449
(2015/03/04)
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- Zirconium-containing metal organic frameworks as solid acid catalysts for the esterification of free fatty acids: Synthesis of biodiesel and other compounds of interest
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Zr-containing metal organic frameworks (MOFs) formed by terephthalate (UiO-66) and 2-aminoterephthalate ligands (UiO-66-NH2) are active and stable catalysts for the acid catalyzed esterification of various saturated and unsaturated fatty acids with MeOH and EtOH, with activities comparable (in some cases superior) to other solid acid catalysts previously reported in literature. Besides the formation of the corresponding fatty acid alkyl esters as biodiesel compounds (FAMEs and FAEEs), esterification of biomass-derived fatty acids with other alcohols catalyzed by the Zr-MOFs allows preparing other compounds of interest, such as oleyl oleate or isopropyl palmitate, with good yields under mild conditions.
- Cirujano,Corma,Llabrés I Xamena
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p. 213 - 220
(2015/02/19)
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- Lipase immobilization towards improved productivity on kinetic resolutions by a continuous-flow process
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Development of asymmetric transformations for the synthesis of chiral molecules has achieved great results in the last decade. Besides the great evolution achieved during recent years in the biotechnology and biocatalysis fields, industrial processes using enzymatic approaches are few and a more broad application of such technology towards the synthesis of chiral molecules is still under development. Herein we report our results on the immobilization of lipase B from Candida antarctica on five different commercial supports for the development of a continuous-flow kinetic resolution of alcohol. Immobilization on Accurel MP1000 gave the best results arriving at productivities of around 140 g per h per g of protein and the immobilized biocatalyst could be recycled 5 times without significant loss of activity.
- Silva, Marcus V. M.,Bassut, Jonathan F.,Junior, Ivaldo I.,De Souza, Stefania P.,Estrada, Melissa L. G.,Miranda, Leandro S. M.,De Souza, Rodrigo O. M. A.
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p. 102409 - 102415
(2015/12/11)
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- Br?nsted acid surfactant-combined dicationic ionic liquids as green catalysts for biodiesel synthesis from free fatty acids and alcohols
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Quaternary ammonium Br?nsted acid surfactant-combined dicationic ionic liquids (BASDILs) based on zwitterionic 1,2-bis[N-methyl-N-(3-sulfopropyl)-alkylammonium]ethane betaines and various anions were prepared and characterized. BASDILs possess properties similar to those of phase-separated catalysts and were applied to the catalytic synthesis of biodiesel from free fatty acids and alcohols. Several factors were investigated and the results indicated that [C12Sb][p-CH3C6H4SO3] was the optimal catalyst, with good catalytic performance and reusability under mild conditions.
- Chang, Tao,He, Leqin,Zhang, Xiaojing,Yuan, Mingxia,Qin, Shenjun,Zhao, Jiquan
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p. 982 - 986
(2015/07/01)
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- Carica papaya by-products as new biocatalysts for the synthesis of oleic acid esters
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Carica papaya lipase is a versatile biocatalyst that is employed for many biotechnological purposes. Its lipase activity was first observed to be tightly linked to the insoluble fraction of latex. Nevertheless, recent studies have shown that this activity is also present in the fruit peel and seeds, suggesting that the lipase activity occurs in other parts of the plant. In the present work, the hydrolytic activity on trioctanoin was determined in various plant by-products, including latex, leafs, petioles, meristems, fruits, and the stem. The most hydrolytic activity was found in the latex (11 U/mL), followed by the petioles (1.7 U/mL). The hydrolytic selectivity was determined using triacetin, tripropionin, tributyrin, and trioctanoin. The enzymes present in the latex showed a higher rate of hydrolysis of tributyrin, while those present in the petioles had a preference for tripropionin, possibly indicating the occurrence of at least two different triacylglycerol hydrolases. Five self-immobilized biocatalysts were obtained: lyophilized latex (LL), lyophilized petioles (LP), bagasse from petioles (BP), and, after a simple cold water washing treatment, treated lyophilized latex (TLL), and treated lyophilized petioles (TLP). This procedure yielded a 5- and 10-fold increase in the latex and petiole activity, respectively, on tributyrin. The selected biocatalysts, TLL and BP, were tested for the synthesis of oleic acid esters (OAE), reaching conversions over 80%. Unexpectedly, only BP preferentially synthesized dodecyl oleate (DO) and showed the highest thermostability. Therefore, BP was further assayed for DO synthesis in a packed bed reactor (PBR), achieving 96% conversion over 40 h. This study shows the great potential of C. papaya by-products, particularly BP, as biocatalysts for the synthesis of OAE.
- Armendáriz-Ruiz, Mariana,Mateos-Díaz, Eduardo,Rodríguez-González, Jorge Alberto,María Camacho-Ruiz, Rosa,Gutiérrez-Mora, Antonia,Sandoval-Fabian, Georgina,Gallegos-Tintoré, Santiago,Mateos-Díaz, Juan Carlos
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p. 216 - 223
(2015/12/23)
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- Electrochemistry for biofuel generation: Transformation of fatty acids and triglycerides to diesel-like olefin/ether mixtures and olefins
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Abstract Electroorganic synthesis can be exploited for the production of biofuels from fatty acids and triglycerides. With Coulomb efficiencies (CE) of up to 50%, the electrochemical decarboxylation of fatty acids in methanolic and ethanolic solutions leads to the formation of diesel-like olefin/ether mixtures. Triglycerides can be directly converted in aqueous solutions by using sonoelectrochemistry, with olefins as the main products (with a CE of more than 20%). The latter reaction, however, is terminated at around 50% substrate conversion by the produced side-product glycerol. An energy analysis shows that the electrochemical olefin synthesis can be an energetically competitive, sustainable, and - in comparison with established processes - economically feasible alternative for the exploitation of fats and oils for biofuel production. From fat to fuel: Electrochemical decarboxylation of fatty acids and triglycerides leads to the formation of olefins and ethers (see scheme). This electroorganic synthesis is an energetically competitive, sustainable, and economically feasible alternative for the exploitation of fats and oils for biofuel production.
- Dos Santos, Tatiane R.,Harnisch, Falk,Nilges, Peter,Schr?der, Uwe
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p. 886 - 893
(2015/06/02)
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- Biodiesel synthesis from the esterification of free fatty acids and alcohol catalyzed by long-chain Bronsted acid ionic liquid
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A long-chain Bronsted acid ionic liquid (IL), 3-(N,N- dimethyldodecylammonium)propanesulfonic acid p-toluenesulfonate ([DDPA][Tos]), was prepared and characterized by FT-IR, 1H NMR, 13C NMR, UV/vis and TGA. The H0 (Hammett function) value of the IL was also determined. The IL as catalyst was applied to the catalytic synthesis of biodiesel from free fatty acids (FFAs). The influencing factors, such as the type and amount of catalyst, reaction time, molar ratio of fatty acid to methanol and reaction temperature, were investigated. The results indicated that the long-chain Bronsted acid IL showed high catalytic activity and fair reusability. Esterification was accomplished under the following optimized conditions: molar ratio of alcohols to FFA at 1.5:1, mole fraction of ionic liquid at 10%, 60 °C, and 3 h. The products could be separated from the catalyst system by liquid-liquid biphase separation at room temperature with good yields of 92.5% to 96.5%. The catalyst could be reused nine times after the removal of water and alcohol. Therefore, the long-chain Bronsted acid IL has good potential for the synthesis of biodiesel from low-cost feedstocks such as waste oil and woody plant oils.
- He, Leqin,Qin, Shenjun,Chang, Tao,Sun, Yuzhuang,Gao, Xiaorui
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p. 1102 - 1107
(2013/04/24)
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- Studies on the lipase-catalyzed esterification of alkyl oleates in solvent-free systems
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The alkyl oleates were prepared by esterification of oleic acid with alkyl alcohols catalyzed by the lipase from Candida sp. 99-125 in solvent-free system. The influence of several factors, including enzyme concentration, temperature, molar ratio between oleic acid and alkyl alcohols, the structure of alcohols and water content, was also investigated. The results indicated that the reactions catalyzed by Candida sp. lipase at 20 °C, in the presence of 5% (w/w) lipase, on the molar ratio of 1:1 between oleic acid and alcohols, afforded products in high yield and showed high selectivity to primary alcohols. The enzymatic synthesis gave purer products, compared with the conventional chemical synthesis. The lipase from Candida sp. 99-125 was identified to be an effective catalyst in the esterification of alcohol and oleic acid at low temperature.
- Zhong, Hui,Fang, Zheng,Zou, Baohua,Li, Xin,Ouyang, Pingkai,Guo, Kai
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p. 114 - 117
(2013/05/08)
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- Well-dispersed sulfated zirconia nanoparticles as high-efficiency catalysts for the synthesis of bis(indolyl)methanes and biodiesel
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Well-dispersed sulfated zirconia nanoparticles were synthesized with poly(N-vinylpyrrolidone) as a surfactant. The resultant sulfated zirconia nanoparticles are characterized by SEM, XRD, FT-IR and XPS. These nanoparticles were directly used as catalysts for the synthesis of bis(indolyl)methanes and biodiesel via electrophilic substitution reaction of indole with various aldehydes and the esterification of long-chain free fatty acids and exhibited excellent catalytic activity. The mechanism of the formation of the synthesized zirconia nanoparticles was also proposed.
- Chen, Guochang,Guo, Cun-Yue,Qiao, Hongbin,Ye, Mingfu,Qiu, Xiaoning,Yue, Caibo
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- Enzymatic Esterification of Oleic Acid with Aliphatic Alcohols for the Biodiesel Production by Candida antarctica Lipase
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Biodiesel can be obtained by esterification reactions of free fatty acids with enzymatic catalysts (lipases). In this study, the immobilized Candida antarctica lipase was employed in enzymatic esterifications of oleic acid with aliphatic alcohols (methanol, ethanol, n-propanol, n-butanol). Some features that influence the enzymatic esterification reaction, such as amount of biocatalysts, reaction time, hydration level and biocatalyst turnover were evaluated. The products were determined by GC-FID and 1H NMR analyses and these analytical methods were compared. The enzymatic catalyst (C. antarctica lipase) was efficient providing high yields of biodiesel (above 90 %) in less than 24 h to ethanol, n-propanol and n-butanol, whereas for methanol, the enzyme was inactive after ten cycles of reaction. Two new quantitative easy methods were also developed to quantify esters produced by 1H NMR based on the α-CH2 protons of oleic acid and esters. The quantification method used in the enzymatic reactions by 1H NMR showed effective with small differences in comparison with GC-FID analyses. Graphical Abstract: C. antarctica lipase was employed in enzymatic esterifications of oleic acid with aliphatic alcohols (methanol, ethanol, n-propanol, n-butanol) for the biodiesel production. A new method was developed to quantify esters produced (biodiesel) by 1H NMR based on the α-CH2 protons. [Figure not available: see fulltext.]
- Rosset, Isac G.,Cavalheiro, Maria Cecilia H. T.,Assaf, Elisabete M.,Porto, Andre L. M.
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p. 863 - 872
(2013/10/08)
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- Novel and highly efficient SnBr2-catalyzed esterification reactions of fatty acids: The notable anion ligand effect
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In this work, the efficiency of Lewis acid catalysts, SnX2 (X = F-, Cl-, Br-, or -OAc), was investigated on the esterification reactions of fatty acids (i.e., myristic, palmitic, stearic, oleic, linoleic, and linoleic) with different alcohols (i.e., methyl, ethyl, propyl, isopropyl, and butyl alcohol). Tin(II) bromide was the most active catalyst in all reactions studied. We investigated the effects of main reaction parameters, such as catalyst concentration, temperature, and nature of alcohol and fatty acid. The highest activity of SnBr2 catalyst was discussed in terms of its lower activation energy, higher Lewis acid strength, and higher softness of anionic ligand. Finally, the SnBr 2 catalyst can be easily recovered and reused without loss of catalytic activity. Graphical Abstract: Effect of the tin catalyst nature on the oleic acid esterification with ethyl alcohol. [Figure not available: see fulltext.]
- Ferreira, Arthur Batista,Cardoso, Abiney Lemos,Da Silva, Marcio Jose
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p. 1240 - 1246
(2014/01/06)
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- One-pot transformation of carboxylic acids into nitriles
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A variety of aromatic and aliphatic carboxylic acids were smoothly converted into the corresponding nitriles in good yields in a one-pot procedure by treatment with ethyl iodide/K2CO3/18-crown-6, followed by sodium diisobutyl-tert-butoxyaluminium hydride (SDBBA-H), and finally treatment with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH), and aqueous ammonia. This method is useful for the conversion of various aromatic and aliphatic carboxylic acids into the corresponding nitriles in a one-pot procedure. A variety of aromatic and aliphatic carboxylic acids were smoothly converted into the corresponding nitriles in good yields in a one-pot procedure by treatment with ethyl iodide/K2CO3/18-crown-6, followed by sodium diisobutyl-tert-butoxyaluminium hydride (SDBBA-H), and finally treatment with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH), and aqueous ammonia. Copyright
- Miyagi, Kotaro,Moriyama, Katsuhiko,Togo, Hideo
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p. 5886 - 5892
(2013/09/23)
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- An efficient activity ionic liquid-enzyme system for biodiesel production
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The efficient production of biodiesel in hydrophobic ionic liquids using immobilized lipase was demonstrated. The use of ionic liquids containing long alkyl chains on the cation has the important advantage of producing homogeneous systems at the start of the reaction but, when the reaction is complete, a three-phase system is created that allows selective extraction of the products using straightforward separation techniques, while the ionic liquid and the enzyme can be reused. Fifteen ionic liquids based on different alkyl chain length of the methyl imidazolium cation ([C10MIM], [C 12MIM], [C14MIM], [C16MIM] and [C 18MIM]) combined with [BF4], [PF6] or [NTf 2] anions were assayed as reaction media for two immobilized lipases (Candida antarctica lipase B and Pseudomonas fluorescens lipase AK) for biodiesel production. The highest synthetic activity was obtained in [C 16MIM] [NTf2] using Novozym 435 (immobilized Candida antarctica lipase with 245.13 U g-1 IME), its activity being more than three times higher than in a solvent-free system. Additionally, in this IL the fatty acid methyl esters production was 90.29% after 3 h, while in the solvent-free system it was 27.3%. The influence of several reaction parameters, such as temperature, methanol-to-oil molar ratio, alkyl-chain length of the alcohols, IL:substrate volume ratios, amount of enzyme, and oils feedstock were studied and optimized.
- De Diego, Teresa,Manjon, Arturo,Lozano, Pedro,Vaultier, Michel,Iborra, Jose L.
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experimental part
p. 444 - 451
(2011/04/18)
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- Investigation of the catalytic efficiency of a new mesoporous catalyst SnO2/WO3 towards oleic acid esterification
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The synthesis of a new, effective and reusable heterogeneous catalyst, mesoporous SnO2/WO3 (SW) to promote the esterification involving oleic acid and ethanol for the production of ethyl oleate is presented here. The developed mesoporous SnO2/WO3 with surface area of 130 m2/g and pore size of 3.9 nm exhibits up to 90% conversion of oleic acid (for 2 h reaction, at 80 °C) with high yield (~92%) to the ethyl oleate, a product of the esterification reaction of oleic acid. The catalyst exhibits a comparable activity of H2SO4, which is a known catalyst for esterification of organic acids. Kinetic investigation reveals that the experimental data follows a first order dependency on the concentration of the oleic acid and the catalyst. The conversion of oleic acid also has noticeable dependency on the reaction temperatures and different alcohols. Regeneration through heating of the used mesoporous SnO 2/WO3 catalyst at 400 °C for 3 h allows it for reuse without losing of its catalytic activity.
- Sarkar, Arpita,Ghosh, Sudip K.,Pramanik, Panchanan
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scheme or table
p. 73 - 79
(2010/11/17)
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