110-27-0Relevant articles and documents
Efficient, stable, and reusable Lewis acid-surfactant-combined catalyst: One-pot Biginelli and solvent-free esterification reactions
Qiu, Yunfeng,Sun, Hongnan,Ma, Zhuo,Xia, Wujiong
, p. 76 - 82 (2014)
Cerium(III) trislaurylsulfonate (Ce(LS)3), a Lewis acid and surfactant combined catalyst, was prepared and characterized by SEM, SEM-EDX, XRD, NMR, FT-IR, TG, and elemental analysis. Ce(LS)3 was found to be stable and efficient to catalyze one-pot Biginelli and solvent-free esterification reactions. Furthermore, Ce(LS)3 is easy to recycle after reaction by pouring into cold water and filtration. Present work will shed deep insight into the understanding of the catalytic nature of LASCs, and extend its application in important organic transformations.
Lipases from Candida antarctica: Unique biocatalysts from a unique origin
Kirk, Ole,Christensen, Morten Wuertz
, p. 446 - 451 (2002)
The specificity of the A-lipase from Candida antarctica (CALA) has been characterized to further clarify the scope of the biocatalyst. The lipase was found to exhibit an almost uniform activity towards various straight-chained primary alcohols and carboxylic acids, only exhibiting a low activity towards very short-chained acids. More interestingly, the enzyme was found to exhibit a high activity towards a surprising diversity of sterically hindered alcohols, including both secondary and tertiary alcohols. These results indicate that CALA can have a unique applicability for the conversion of highly branched substrates where most other lipases fail to display any activity. A new, potentially highly cost-effective, immobilization technology using silica-based granulation has been applied in the immobilization of the B-lipase from the same yeast (CALB). Highly stable particles were obtained with an activity comparable to that of the commercially available immobilized preparations of this enzyme.
Kinetics and mechanism of myristic acid and isopropyl alcohol esterification reaction with homogeneous and heterogeneous catalysts
Yalcinyuva, Tuncer,Deligoez, Hueseyin,Boz, Ismail,Guerkaynak, Mehmet Ali
, p. 136 - 144 (2008)
The reaction of myristic acid (MA) and isopropyl alcohol (IPA) was carried out by using both homogeneous and heterogeneous catalysts. For a homogeneously catalyzed system, the experimental data have been interpreted with a second order, using the power-law kinetic model, and a good agreement between the experimental data and the model has been obtained. In this approach, it was assumed that a protonated carboxylic acid is a possible reaction intermediate. After a mathematical model was proposed, reaction rate constants were computed by the Polymath program. For a heterogeneously catalyzed system, interestingly, no pore diffusion limitation was detected. The influences of initial molar ratios, catalyst loading and type, temperature, and water amount in the feed have been examined, as well as the effects of catalyst size for heterogeneous catalyst systems. Among used catalysts, p-toluene sulfonic acid (p-TSA) gave highest reaction rates. Kinetic parameters such as activation energy and frequency factor were determined from model fitting. Experimental K values were found to be 0.54 and 1.49 at 60°C and 80°C, respectively. Furthermore, activation energy and frequency factor at forward were calculated as 54.2 kJ mol-1 and 1828 L mol-1 s-1, respectively.
ESTERIFICATION OF CARBOXYLIC ACIDS WITH OLEFINS USING A ZEOLITIC MATERIAL HAVING A BEA-TYPE FRAMEWORK STRUCTURE
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Page/Page column 43; 44; 45, (2019/08/08)
The present invention relates to a catalytic process for the preparation of an ester starting from a carboxylic acid and an alkene using a zeolitic material having a BEA-type framework structure as the catalyst.
Use of Lecitase-Ultra immobilized on styrene-divinylbenzene beads as catalyst of esterification reactions: Effects of ultrasounds
Alves, Joana S.,Garcia-Galan, Cristina,Danelli, Daiane,Paludo, Natália,Barbosa, Oveimar,Rodrigues, Rafael C.,Fernandez-Lafuente, Roberto
, p. 27 - 32 (2015/08/06)
Abstract In this work it was evaluated for the first time, the ester synthesis catalyzed by the phospholipase Lecitase-Ultra immobilized styrene-divinylbenzene beads (MCI-Lecitase), comparing the mechanical stirring and the ultrasonic energy. It was studied the specificity of the enzyme using carboxylic acids from C4 to C18, as well as the effects of alcohol chain, organic solvents, biocatalyst content, reaction temperature and substrate concentration. Caprylic and myristic acids were those with the highest reaction rates and yields, using ethanol as substrate. The shorter the alcohol chain, the higher the enzyme activity. Regarding the secondary alcohols, while MCI-Lecitase had no activity versus isopropanol, using 2-pentanol the activity was similar to that with 1-pentanol. Comparing the agitation systems, MCI-Lecitase presented an initial reaction rate more than 2-times higher in the ultrasound-assisted reaction than under traditional mechanical stirring. Moreover, under ultrasonic energy the maximum rate was achieved using 0.5 M of substrates, while under mechanical stirring the maximum enzyme activity was reached at 0.3 M of substrates. Concerning the operational stability, MCI-Lecitase was quite unstable, losing its activity after 6 reaction cycles. By adding molecular sieves in the reaction medium, MCI-Lecitase retained 30% of its initial activity after 6 cycles.
COMBINATION COMPOSITION COMPRISING BENZOYL PEROXIDE AND ADAPALENE
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, (2012/10/08)
An aqueous gel composition of the present invention comprising about 0.1 to 0.3 wt % adapalene and about 2.5 to 5.0 wt % benzoyl peroxide, as active ingredients, wherein both the active ingredients are stabilized in hydrophilic gelling matrix of pH dependent gelling agent comprising crosslinked, acrylic acid-based polymer(s).
Composition and method of preparing a tomato-based topical formulation for enhanced healing of burns, ultraviolet and radiation erythema
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, (2013/03/26)
The present invention is a topical treatment. which can be in the form of cream, ointment, spray or other topically administered composition, which is used to enhance healing of burns, ultraviolet and radiation erythema. The treatment not only reduces pain and inflammation, prevents blistering, and maintains flexibility of the skin, but also accelerates the normal healing process.
Synthesis and evaluation of different fatty acid esters formulated into Precirol ATO-based lipid nanoparticles as vehicles for topical delivery
Sanna, Vanna,Mariani, Alberto,Caria, Giuseppe,Sechi, Mario
experimental part, p. 680 - 684 (2009/12/26)
A series of isopropyl fatty esters having different chain length (C 13-C23) were synthesized and formulated in lipid nanoparticles based on Precirol ATO to evaluate their effect on the physicochemical properties of these latter. Moreover, drug loading and skin permeation of Econazole nitrate, chosen as a lipophilic model drug, were evaluated as well. The obtained nanosystems, prepared by high shear homogenization method, had a mean diameter ranging from 180 to 280 nm and showed an encapsulation efficiency of about 100%. Ex vivo permeation results demonstrated a parabolic correlation between permeation effect and chain length of the fatty esters present in the lipid nanoparticles formulated in hydrophilic gels. The maximum flux of drug was observed for the nanoparticles containing esters with 17 and 19 carbon atoms, suggesting that these formulations may constitute a potential carrier for topical delivery of econazole nitrate.
Design, synthesis, antibacterial, and QSAR studies of myristic acid derivatives
Narasimhan, Balasubramanian,Mourya, Vishnukant,Dhake, Avinash
, p. 3023 - 3029 (2008/09/20)
A series of esters and amides of myristic acid was synthesized and tested in vitro for antibacterial activity against Gram-positive and Gram-negative bacteria. All the compounds showed activity comparable to that of the standard drug, ciprofloxacin. The structural characteristics governing antibacterial activity of myristic acid derivatives was studied using QSAR methodology. The results showed that the antibacterial activity could be modeled using the topological descriptor, valence molecular connectivity index. The predictive ability of the models was cross-validated by construction of a test set. The low residual activity and high cross-validated r2 values ( rcv2 ) observed indicated the predictive ability of the developed QSAR models.
An eco-friendly method for the synthesis of aryl and alkyl esters of carboxylic acids using acid activated Indian bentonite
Vijayakumar,Iyengar, Pushpa,Nagendrappa, Gopalpur,Prakash, B. S. Jai
, p. 922 - 925 (2007/10/03)
Esterification of various carboxylic acids with phenol and alcohols has been achieved using acid activated Indian bentonite (AAIB) as catalyst. The catalyst is versatile, and the reaction is found to work well for primary, secondary and tertiary alcohols. The yields are very good under specific reaction conditions.
