111-06-8Relevant articles and documents
Esterification of stearic acid by isomeric forms of butanol in a microwave oven under homogeneous and heterogeneous reaction conditions
Chemat, Farid,Poux, Martine,Galema, Saskia A.
, p. 2371 - 2374 (1997)
In this paper the influence of conventional and dielectric heating on the esterification of stearic acid by butanol has been studied. The influences of different isomeric forms of butanol, a catalyst and conditions of reaction (homogeneous versus heterogeneous) upon esterification have been investigated. The difference between conventionally or dielectrically heated reactions has been studied. For heterogeneous reactions a significant temperature enhancement effect is observed. This effect can be enlarged by the application of heat captors, which have been mixed or impregnated with catalyst. Further rate enhancements are realised by the use of a combination of microwave heating and ultrasound for heterogeneously catalysed reactions.
Flow-through immobilization of Candida rugosa lipase on hierarchical micro-/macroporous carbon monolith
Luangon, Bordin,Siyasukh, Adisak,Winayanuwattikun, Pakorn,Tanthapanichakoon, Wiwut,Tonanon, Nattaporn
, p. 80 - 85 (2012)
Hierarchical micro-/macroporous carbon monoliths are prepared as enzyme carriers for flow-through process. The immobilization of Candida rugosa lipase on micro-/macroporous carbon monoliths is studied. Lipase is immobilized by physical adsorption which lipase solution is circulated through the micro-/macroporous carbon monolith. An accessibility of lipase to the surface inside the micro-/macroporous carbon monolith is enhanced by flow-through method which promotes enzyme-surface interaction and finally leads to rapid enzyme immobilization. After immobilization is conducted for 10 min, the maximum protein binding can be measured. In terms of substrate-immobilized lipase reactions, flowing of substrate through lipase immobilized micro-/macroporous carbon monolith promotes high efficiency in both reaction and product withdrawal. Moreover, at high flow rates of lipase solution in immobilization step, the lipase activity increases. Oxygenated surface of micro-/macroporous carbon monoliths support also demonstrates an interesting effect on lipase immobilization and biocatalyst activity. The initial reaction rate of lipase immobilized on oxygenated surface carbon monolith support has higher activity compared with normal surface.
Hydrothermal saline promoted grafting: A route to sulfonic acid SBA-15 silica with ultra-high acid site loading for biodiesel synthesis
Pirez,Lee,Manayil,Parlett,Wilson
, p. 4506 - 4509 (2014)
A simple grafting protocol is reported which affords a ten-fold enhancement in acid site density of mesoporous sulfonic acid silicas compared to conventional syntheses, offering improved process efficiency and new opportunities for tailored supported solid acids in sustainable chemistry. This journal is
Transesterification to biodiesel with superhydrophobic porous solid base catalysts
Liu, Fujian,Li, Wei,Sun, Qi,Zhu, Longfeng,Meng, Xiangju,Guo, Yi-Hang,Xiao, Feng-Shou
, p. 1059 - 1062 (2011)
Super combo: Superhydrophobic and porous solid bases are synthesized by co-polymerization of divinylbenzene (DVB) and 1-vinylimidazolate (VI). The materials show higher activities towards the transesterification of tripalmitin with methanol than conventional bases and VI mono-/polymer. Their performance is attributed to the synergy of superhydrophobicity combined with active VI sites. These catalysts also remain very active upon recycling.
Synthesis and characterization of the n-butyl palmitate as an organic phase change material
Ma, Liyun,Guo, Chuigen,Ou, Rongxian,Wang, Qingwen,Li, Liping
, p. 2033 - 2039 (2019)
In this research, the n-butyl palmitate was synthesized using the esterification reaction of the PA with n-butanol. The 1H nuclear magnetic resonance and Fourier transform infrared illustrated that the hydroxyl group and carboxyl group disappeared, and the ester bond appeared after the reaction, explaining that n-butyl palmitate was successfully fabricated. The differential scanning calorimetry indicated that the phase-transition temperature and latent heat are 12.6?°C and 127.1?J?g?1, which was suited to use in low-temperature fields such as food, pharmaceutical, and biomedical. The thermogravimetric analysis suggested that it had great thermal stability during the phase change process. In addition, the thermal conductivity of the n-butyl palmitate was slightly higher than other fatty acid ester, and the 500 thermal cycles test results indicated that it had excellent thermal reliability. Therefore, the n-butyl palmitate is deduced to share great thermal energy storage ability in terms of latent heat thermal energy system applications.
Charge-remote and charge-proximate fragmentation processes in alkali- cationized fatty acid esters upon high-energy collisional activation. A new mechanistic proposal
Claeys, Magda,Nizigiyimana, Liberata,Van Heuvel, Hilde Den,Vedernikova, Irina,Haemers, Achiel
, p. 631 - 643 (1998)
The effect of the metal ion on the high-energy collision-induced dissociation (CID) of alkali metal-cationized n-butyl and methyl ester derivatives of palmitic and oleic acid was examined. The results show that the alkali metal ion has a pronounced effect and does not act as a mere 'spectator' ion with respect to the fragmentation process. While C-H cleavage is a dominant process for [M + Li]+ as well as [M + Na]+ precursor ions, C- C cleavage is also significant for the [M + Na]+ ions. Homolytic mechanisms involving the formation of a transient biradical cation are proposed which enable us to rationalize in a straightforward manner all product ions formed by both charge-remote and charge-proximate fragmentations. The mechanistic proposal is discussed in view of available knowledge on electron impact, CID and related processes. In order to predict how the alkali metal ion could affect the reactivity of the postulated biradical state formed following electronic excitation of the alkali metal-cationized molecules, quantum chemical calculations were performed on methyl and n-butyl acetate as model substances. The decreased spin density at the carbonyl oxygen atom in the biradical state may provide an explanation for the greater tendency towards C-C cleavage reactions of the sodium-cationized fatty acid esters relative to the corresponding lithium complexes.
Activation of enzyme nanogel in organic solvents by PEG-substrate joint imprinting
Wang, Rui,Zhang, Yifei,Ge, Jun,Liu, Zheng
, p. 40301 - 40304 (2014)
A substrate or polyethyleneglycol (PEG) imprinted lipase nanogel displayed increased apparent activity in organic solvents by 2.5-4.7 folds, compared to native lipase. It enabled a one-step synthesis of chloramphenicol palmitate with a yield of ～99% and purity of ～99%, indicating that the imprinted lipase nanogel is an appealing catalyst in organic media. This journal is
Development and Validation of a Novel Free Fatty Acid Butyl Ester Gas Chromatography Method for the Determination of Free Fatty Acids in Dairy Products
Mannion, David T.,Furey, Ambrose,Kilcawley, Kieran N.
, p. 499 - 506 (2019/01/08)
Accurate quantification of free fatty acids in dairy products is important for both product quality control and legislative purposes. In this study, a novel fatty acid butyl ester method was developed, where extracted free fatty acids are converted to butyl esters prior to gas chromatography with flame ionization detection. The method was comprehensively validated to establish linearity (20-700 mg/L; R2 > 0.9964), limits of detection (5-8 mg/L), limits of quantification (15-20 mg/L), accuracy (1.6-5.4% relative error), interday precision (4.4-5.3% relative standard deviation), and intraday precision (0.9-5.6% relative standard deviation) for each individual free fatty acid. A total of 17 dairy samples were analyzed, covering diverse sample matrices, fat content, and degrees of lipolysis. The method was compared to direct on-column injection and fatty acid methyl ester methods and overcomes limitations associated with these methods, such as either column-phase absorption or deterioration, accurate quantification of short-chain free fatty acids, and underestimation of polyunsaturated free fatty acid.
USE OF ENDOCANNABINOID-LIKE COMPOUNDS FOR TREATING CNS DEGENERATIVE DISORDERS
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Paragraph 0111-0113, (2017/09/12)
no abstract published
Characterization, performance, and applications of a yeast surface display-based biocatalyst
Eby,Peretti
, p. 19166 - 19175 (2015/06/15)
This work demonstrates the efficacy and cost effectiveness of yeast surface display (YSD) as a method for producing and purifying enzyme catalysts. Lipase B from Candida antarctica (CalB) and lipase from Photobacterium lipolyticum sp. M37 (M37L) were individually displayed on the surface of yeasts via fusion with alpha-agglutinin. The enzyme is produced, purified, and immobilized in a single step. The population expressing the enzyme was quantified by flow cytometry. After lyophilization, the hydrolytic activity of the biocatalyst was assayed with p-nitrophenyl butyrate and p-nitrophenyl palmitate substrates. Esterification reactions involving octanoic acid and either butanol or octanol were used to evaluate esterification activity. The lyophilized YSD biocatalyst hydrolytic activity matched or exceeded commercial lipase (Novozym 435) immobilized on acrylic resin at equal catalyst loading, and achieved esterification levels 10-50% that of Novozyme 435. Factoring in the cost of production, the YSD biocatalyst represents a considerable savings over traditionally prepared and purchased enzyme catalysts. This promises to significantly expand the catalytic applications of immobilized lipases, and immobilized enzymes more generally, in commercial processes. This journal is
