111-62-6Relevant articles and documents
Characterization of lipases and esterases from metagenomes for lipid modification
Bertram, Mark,Hildebrandt, Petra,Weiner, David P.,Patel, Jesal S.,Bartnek, Flash,Hitchman, Timothy S.,Bornscheuer, Uwe T.
, p. 47 - 53 (2008)
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.
Synthesis of Civetone from Palm Oil Products
Choo, Yuen-May,Ooi, Kay-Eng,Ooi, Ing-Hong
, p. 911 - 913 (1994)
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.
Purification of 2-monoacylglycerols using liquid CO2 extraction
Compton, David L.,Eller, Fred J.,Laszlo, Joseph A.,Evans, Kervin O.
, p. 1529 - 1536 (2012)
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%.
Acidic characterization and activity of (NH4)xCs 2.5-xH0.5PW12O40 catalysts in the esterification reaction of oleic acid with ethanol
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.
, p. 33 - 39 (2012)
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.
About the role of typical spacer/crosslinker on the design of efficient magnetic biocatalysts based on nanosized magnetite
Nicolás, Paula,Lassalle, Verónica L.,Ferreira, María L.
, p. 296 - 304 (2015)
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.
The Esterification of Oleic Acid with Ethanol Accompanied by Membrane Separation
Kita, Hidetoshi,Tanaka, Kazuhiro,Okamoto, Ken-ichi,Yamamoto, Masuji
, p. 2053 - 2056 (1987)
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.
Conversion of a carboxylesterase into a triacylglycerol lipase by a random mutation
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
, p. 7553 - 7557 (2005)
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).
HYDROGENATION OF FATTY ACIDS ESTERS. II. KINETICS OF HYDROGENATION OF METHYL (Z)- AND (E)-9-OCTADECENOATE CATALYZED BY A ZIEGLER NICKEL CATALYST
Krupickova, Jana,Vcelak, Jaroslav,Hetflejs, Jiri
, p. 2583 - 2592 (1992)
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).
Cellulose as an efficient matrix for lipase and transaminase immobilization
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.
, p. 6665 - 6671 (2016)
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).
Synthesis and characterization of a CaFe2O4 catalyst for oleic acid esterification
Ong, Huei Ruey,Rahman Khan, Md Maksudur,Yousuf, Abu,Hussain, Nor Amalina,Cheng, Chin Kui
, p. 100362 - 100368 (2015)
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.
