- 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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- Guanidine based task specific ionic liquids for the synthesis of biolubricant range esters under solvent-free condition
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Guanidine-based task specific ionic liquids (ILs) were synthesized from the reaction of 1,1,3,3-tetramethyl guanidine with protic acids and used for the synthesis of higher alcohol esters of fatty acids as biolubes under solvent free condition. The synthesized 1,1,3,3-tetramethylguanidinium hydrogen sulphate (TMG·HSO4) was found to be most effective among the different ILs including 1,1,3,3-tetramethylguanidinium acetate (TMG·Ac), 1,1,3,3-tetramethylguanidinium hydrogen phosphate (TMG·H2PO4) and 1,1,3,3-tetramethylguanidinium trifluoro acetate (TMG·TFA). The effect of various reaction parameters such as reaction temperature, reaction time, catalyst amount etc. has been studied. After completion the reaction the esterification product was isolated and the recovered IL was reused for several runs without loss in catalytic activity.
- Porwal, Jyoti,Kumar, Subodh,Kaul, Savita,Jain, Suman L.
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p. 93640 - 93644
(2016/10/18)
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- Synthesis of fatty monoester lubricant base oil catalyzed by Fe-Zn double-metal cyanide complex
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Fatty monoester lubricant base oils as high as 96.7 mol% were prepared by reacting methyl oleate with long-chain alcohols viz., 2-ethyl-1-hexanol (C 8-OH), 1-decanol (C10OH) and 1-dodecanol (C 12OH) in the presence of a solid Fe-Zn double-metal cyanide (DMC) complex catalyst. Unlike many other acid catalysts, DMC doesn't produce undesired ether side products. The catalyst was reusable in four recycling experiments with little loss in catalytic activity and ester yield. The long-chain esters prepared in the study have the desired physical properties for their application as lubricant base oils.
- Raut, Ravindra K,Shaikh, Mehejabeen,Darbha, Srinivas
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p. 997 - 1003
(2014/11/08)
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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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- Influence du gonflement sur l'activite catalytique de solides resines echangeuses d'ions et enzymes insolubles
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Some solid catalysts swell in the reactional medium (ion exchange resins, solid enzymes).The kinetic effect of swelling is shown by examples in esterification and hydrolysis reactions.
- Boyer, Jean-Louis,Gilot, Bernard,Guiraud, Roland
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p. 260 - 263
(2007/10/02)
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- Isobutylene polymer active compound release systems
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In a therapeutic system such as a plaster for administration of an active compound through the skin and comprising a covering layer which is essentially impermeable to the active compound an active compound reservoir layer and a protective layer which can be pulled off and which is essentially impermeable to the active compound, the improvement wherein the reservoir layer contains about 1-30% of active compound in an elastomer mixture comprising at least one of polyisobutylene, polybutadiene oil and paraffin oil, and a tackifying resin. Thereby the active compound can be released in regulated relatively large quantity over a prolonged period of time.
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