- 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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- 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 0112; 0113
(2017/08/28)
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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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- 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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- Melting points and viscosities of fatty acid esters that are potential targets for engineered oilseed
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Our previous isolation of branched-chain fatty acid (BCFA) methyl esters from lanolin was improved and scaled up. Also, oleate esters of isopropanol, oleyl alcohol and normal alcohols of 1-12 carbons chain lengths were prepared. Esters were made by interesterification with sodium alcoholates and by esterification with Candida antarctica lipase. It proved easier to obtain pure esters by the enzymatic synthesis. Melting points and viscosities over the range of 0-70 °C were determined in order to better identify potential lubricant targets that might be produced by genetically modified oilseed crops. Isopropyl and butyl oleate have melting points of -33 and -32 °C, respectively and viscosities that range from ~17 cp (0 °C) to ~2.5 cp (70 °C). They should have suitable stability for lubricants. BCFA esters had viscosities similar to their straight chain analogs. Viscosities increased with alcohol chain length and decreased with temperature. The dependence of viscosity on temperature was fit with an equation based on Erying's rate equation. Some esters with branched acid or branched alcohol moieties, and some oleate esters might be utilized as biolubricants or biofuels on the basis of their melting points and viscosities.
- Yao, Linxing,Hammond, Earl,Wang, Tong
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- Solvent-free esterification catalyzed by surfactant-combined catalysts at room temperature
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Solvent-free esterifications of various carboxylic acids and alcohols can be catalyzed by surfactant-combined catalysts dodecylbenzene sulfonic acid (DBSA) and copper dodecylbenzene sulfonate (CDBS) in moderate to excellent yield at room temperature. The esterification method has two notable advantages: first, there is no need for any solvent, even water, and secondly, no need for energy, the reaction can proceed smoothly at room temperature. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
- Gang, Li,Xinzong, Li,Eli, Wumanjiang
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p. 348 - 351
(2008/02/10)
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- Synthesis and characterization of oleic succinic anhydrides: Structure-property relations
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Alkenyl succinic anhydrides (ASA) were prepared by an -ene reaction of n-alkyl (C1 to C5) oleates with maleic anhydride. The purified compounds were characterized by FTIR, 1H NMR, and MS analytical methods to elucidate their structures. Their physicochemical properties were systematically studied and found to depend on the length of the alkyl radical. Structure-property relations were established for viscosity, m.p., and density. The combination of a long hydrophobic chain and a highly polar group with density values close to that of water implied good emulsification properties for some of these molecules. Comparison of the thermal properties of alkyl oleates and their respective ASA demonstrated that the grafting of maleic anhydride allowed the synthesis of compounds with very low melting temperatures (less than -60°C) and good stability at high temperatures (greater than 350°C) under both air and helium atmospheres. All these properties suggest a strong potential for application in the biolubricant or surfactant fields. The combined influences of the succinic part and variable ester moieties imply that each ASA molecule has its own characteristics, based on which applications could be developed. Copyright
- Candy, Laure,Vaca-Garcia, Carlos,Borredon, Elisabeth
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p. 271 - 277
(2007/10/03)
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