- Efficient, stable, and reusable Lewis acid-surfactant-combined catalyst: One-pot Biginelli and solvent-free esterification reactions
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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.
- Qiu, Yunfeng,Sun, Hongnan,Ma, Zhuo,Xia, Wujiong
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- Lipases from Candida antarctica: Unique biocatalysts from a unique origin
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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.
- Kirk, Ole,Christensen, Morten Wuertz
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- Kinetics and mechanism of myristic acid and isopropyl alcohol esterification reaction with homogeneous and heterogeneous catalysts
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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.
- Yalcinyuva, Tuncer,Deligoez, Hueseyin,Boz, Ismail,Guerkaynak, Mehmet Ali
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- ESTERIFICATION OF CARBOXYLIC ACIDS WITH OLEFINS USING A ZEOLITIC MATERIAL HAVING A BEA-TYPE FRAMEWORK STRUCTURE
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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.
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Page/Page column 43; 44; 45
(2019/08/08)
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- Use of Lecitase-Ultra immobilized on styrene-divinylbenzene beads as catalyst of esterification reactions: Effects of ultrasounds
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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.
- Alves, Joana S.,Garcia-Galan, Cristina,Danelli, Daiane,Paludo, Natália,Barbosa, Oveimar,Rodrigues, Rafael C.,Fernandez-Lafuente, Roberto
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- COMBINATION COMPOSITION COMPRISING BENZOYL PEROXIDE AND ADAPALENE
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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).
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- Composition and method of preparing a tomato-based topical formulation for enhanced healing of burns, ultraviolet and radiation erythema
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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.
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- Synthesis and evaluation of different fatty acid esters formulated into Precirol ATO-based lipid nanoparticles as vehicles for topical delivery
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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.
- Sanna, Vanna,Mariani, Alberto,Caria, Giuseppe,Sechi, Mario
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experimental part
p. 680 - 684
(2009/12/26)
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- Design, synthesis, antibacterial, and QSAR studies of myristic acid derivatives
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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.
- Narasimhan, Balasubramanian,Mourya, Vishnukant,Dhake, Avinash
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p. 3023 - 3029
(2008/09/20)
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- An eco-friendly method for the synthesis of aryl and alkyl esters of carboxylic acids using acid activated Indian bentonite
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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.
- Vijayakumar,Iyengar, Pushpa,Nagendrappa, Gopalpur,Prakash, B. S. Jai
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p. 922 - 925
(2007/10/03)
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- Pharmaceutical compositions for transdermal administration of anti-inflammatory agents
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The invention concerns a pharmaceutical composition for transdermal administration comprising: a polymeric release matrix capable of forming a soft film after drying, selected among cellulose polymers or copolymers, said matrix being present at a concentration not exceeding 6% of the composition weight; an active principle selected among the group of non-steroid anti-inflammatory agents comprising at least a metal carboxylic or carboxitate group; a transcutaneous absorption promoter of the active principle; water; and at least a physiologically acceptable non-aqueous solvent capable of dissolving the release matrix, the active principle and transcutaneous absorption promoter and to be rapidly eliminated by evaporation in contact with the skin.
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- Perfume fixatives comprising polyvinylpyrrolidone and hydroxypropyl cellulose
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A perfume fixative consisting essentially of polyvinylpyrrolidone, hydroxy propyl cellulose and hydrophobic oil. The perfume fixative is being incorporated in a perfume-containing formulation or product. The fixative is found to be effective in enhancing perfume life, even when utilized at low levels.
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- Lip treatment composition
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A lip-treatment composition for topical application to the lips comprising a base comprising oil, water and a structurant, and at least one active component active with regard to the lips, gums, teeth, throat, or oral mucosa.
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- Composition and process for augmenting, enhancing or imparting a leather aroma to consumable materials
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Described is the process for augmenting, enhancing or imparting leather aromas to consumable materials including perfume compositions, colognes, perfumed polymers and perfumed articles including solid or liquid anionic, cationic, nonionic or zwitterionic detergents, fabric softener compositions, fabric softener articles, hair preparations, cosmetic powders and the like, by adding thereto a composition of matter consisting of the following ingredients: "A": At least one substance having the structure: STR1 in an amount of from about 1% up to about 5% wherein R9 represents C9 -C11 straight-chain alkyl and wherein R10 represents methyl and X is a moiety selected from the group consisting of: STR2 "B": At least one compound having the structure: STR3 in an amount of from about 3 up to about 7% wherein each of R12 -R15 represents hydrogen or C1 -C4 alkyl with the proviso that at least two of R12 -R15 represents hydrogen; "C": At least one compound having the structure: STR4 in an amount of from about 2% up to about 6% wherein R1, R2, R3, R4 and R5 each represents hydrogen or C1 -C4 alkyl with the proviso that one, two or three of R1, R2, R3, R4 and R5 represents C1 -C4 alkyl; "D": Optionally, at least one compound having the structure: STR5 in an amount of from 0% up to about 1.2% wherein R6 represents hydrogen or methyl and R11 represents hydrogen or methyl with the proviso that at least one of R6 or R11 is hydrogen; "E": At least one compound defined according to the structure: STR6 in an amount of from about 30% up to about 70% wherein R7 represents C11, C13, or C15 straight-chain alkyl and R8 represents C1 -C3 lower alkyl; "F": At least one compound having the structure: STR7 in an amount of from about 20% up to about 60% wherein n represents an integer of from 8 up to 28; "G": Optionally, the compound having the structure: STR8 in an amount of from 0 up to about 6%; and "H": Optionally, the compound having the structure: STR9 in an amount of from 0 up to about 6% with the requirement that: STR10 equal 100%.
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