- Biocatalytic esterification of palm oil fatty acids for biodiesel production using glycine-based cross-linked protein coated microcrystalline lipase
-
Conversion of feedstocks containing high free fatty acid contents to alkyl esters is limited by the currently used alkali-catalyzed biodiesel synthesis process. In this study, esterification of palm fatty acids to ethyl esters was studied using heterogeneous cross-linked protein coated microcrystalline (CL-PCMC) lipase. Optimization of biocatalyst synthesis by variation of matrix components and organic solvents showed that highly active CL-PCMCs could be prepared from Thermomyces lanuginosus lipase with glycine as the core matrix in acetone. The optimized reaction contained 20% (w/w) glycine-based CL-PCMC-lipase, a 1:4 fatty acid molar equivalence to ethanol in the presence of an equimolar amount of tert-butanol which led to production of 87.2% and 81.4% (mol/mol) of ethyl ester from palmitic acid and industrial palm fatty acid distillate (PFAD), respectively after incubation at 50 °C for 6 h. CL-PCMC-lipase is more catalytically efficient than protein coated microcrystalline (PCMC) lipase, Novozyme435 and Lipolase 100T for both free fatty acids and palm fatty acid distillate. The CL-PCMC-lipase showed high operational stability with no significant loss in product yield after 8 consecutive batch cycles. The glycine-based microcrystalline lipase is thus a promising alternative economical biocatalyst for biodiesel production from inexpensive feedstocks with high free fatty acid contents.
- Raita, Marisa,Laothanachareon, Thanaporn,Champreda, Verawat,Laosiripojana, Navadol
-
-
Read Online
- Novel synthesized microporous ionic polymer applications in transesterification of Jatropha curcas seed oil with short Chain alcohol
-
New suites of sulfonic acid-functionalized microporous ionic polymers (PIPs) catalysts were synthesized with polymer, alkyl bromides, and 1, 3-propane sultone via a two-step procedure. The synthesized microporous PIP catalysts were characterized using FT-IR, SEM-Mapping, XPS, N2 adsorption–desorption isotherms, solid NMR spectroscopy, and element analysis. Esterification of several fatty acids with ethanol, which was used as a model reaction in the stabilization of Jatropha curcas seed oil, was checked over functionalized PIP. We tested the catalytic performance of PIP-C8 on the synthesis of fatty acid esters via the transesterification of J. curcas seed oil with a mixture of short-chain alcohols such as ethanol, ethanol–to–diethyl carbonate (1;1 molar ratio), and ethanol–to–dimethyl carbonate (1:1 molar ratio) with 170 mg of PIP-C8 at reflux temperature with agitation. The PIP-C8 catalyst was particularly effective, having achieved yields of 85%, 94%, and 70% for J. curcas seed oil with ethanol, J. curcas seed oil with ethanol–to–DEC, and J. curcas seed oil with ethanol–to–DMC, respectively, under the optimized reaction conditions. The catalyst could be recycled more than five times without significant deactivation. Kinetic studies performed at different temperatures revealed that the conversion of oleic acid to an ethyl ester follows a first-order reaction. The best catalysts with microporous structure (average pore diameter: 1.7–1.9 nm, pore volume: 0.23–0.33 cm3 g–1) and –SO3H density (0.70–0.84 mmol/gcat) were obtained by 1, 3-propane sultone of the chemically activated. The results indicate that the site activity of functionalized microporous ionic polymer materials shows promising approach for the development of environmentally friendly technology.
- Chang, Tao,Hao, Yongjing,Jinxi, Jinxi,Kai, Kai,Panchal, Balaji,Qin, Shenjun,Sun, Yuzhuang,Zhao, Cunling,Zhao, Qiaojing,Zhu, Zheng
-
-
- NATURAL BIOSURFACTANT OF ESTER AND MANUFACTURING METHOD THEREOF
-
The present invention relates to an ester natural surfactant and a manufacturing method thereof. The present invention relates to an eco-friendly ester natural surfactant having excellent solubility in water and biodegradability, and a manufacturing method thereof. The present invention relates to an ester natural surfactant, and more particularly, to an ester natural surfactant and a method for preparing the same. (by machine translation)
- -
-
Paragraph 0125; 0126; 0129-0132
(2020/12/11)
-
- Highly ordered mesoporous functionalized pyridinium protic ionic liquids framework as efficient system in esterification reactions for biofuels production
-
Polysiloxane acidic ionic liquids containing pyridinium trifluoroacetate salts (PMO-Py-IL) were synthesized from pyridine containing organosilane precursors. Characterization by SEM, XRD, TGA, and nitrogen porosimetry confirmed that both pyridinium cation and trifluoroacetate anion were successfully incorporated within the organosilica network. The resulting organic-inorganic hybrid nanomaterial (PMO-Py-IL) was studied as nanocatalyst in free fatty acids esterification into biodiesel-like compounds. Remarkably, the synergistic hydrophilic/hydrophobic effect of pyridinium and trifluoroacetate ionic liquid in the well-ordered channels of PMO-Py-IL nanomaterial enhanced the activity toward sustainable biodiesel-like esters production. More importantly, PMO-Py-IL nanocatalyst also exhibited an exceptional activity and stability. The catalyst could be easily separated to reuse at least in ten reactions runs preserving almost intact its catalytic activity under otherwise identical conditions to those employed for the fresh catalysts.
- Luque, Rafael,Rajabi, Fatemeh
-
-
- Method for synthesizing ethyl palmitate by using deep eutectic solvent catalyst based on dodecyltrimethylammonium chloride
-
The invention discloses a method for preparing ethyl palmitate by using a deep eutectic solvent DTAC-DES based on dodecyltrimethylammonium chloride as a catalyst. The catalyst DTAC-DES is prepared bymixing dodecyltrimethylammonium chloride and p-toluenesulfonic acid according to a molar ratio of 1:3; and the ethyl palmitate is prepared by performing an esterification reaction on palmitic acid andexcessive anhydrous ethanol at a certain temperature, and sequentially performing phase separation, atmospheric distillation, reduced pressure distillation and other processes. The method has the advantages of mild reaction conditions, small corrosion of the catalyst to equipment, no waste acid discharge, no pollution and environmental friendliness; and the acidic eutectic solvent is high in catalytic activity, can be repeatedly used after being recycled, and is low in industrial production cost.
- -
-
Paragraph 0010-0013
(2020/06/05)
-
- Method for synthesis of long-chain fatty acid ester derivative
-
The invention relates to a method for synthesis of a long-chain fatty acid ester derivative. Specifically, a hydrochloride of glycine methyl ester or glycine ethyl ester is used as a catalyst to catalyze the esterification reaction of long-chain fatty acid. The method includes: subjecting alcohol and long-chain fatty acid to esterification reaction under the action of the catalyst at certain temperature condition, then conducting extraction and precipitation with ethyl acetate, performing flushing with a sodium chloride aqueous solution for purification. A hydrochloride of glycine methyl esteror glycine ethyl ester is adopted as the catalyst, which belongs to a green catalyst, is the development trend of modern chemistry, has the characteristics of no corrosion to the reaction kettle, lowprice, no toxicity and the like, and is suitable for use as a catalyst to produce palmitate and laurate perfume raw materials.
- -
-
Paragraph 0025-0026
(2020/01/12)
-
- Preparation method of long-chain ester
-
The invention relates to the field of organic synthesis and provides a preparation method of long-chain ester, which comprises the following steps: carrying out esterification reaction of the carboxylic acid and the alcohol through a catalyst and obtaining a long-chain ester phase and a water phase post the standing and layering of the reaction liquid; the catalyst comprises ionic liquid or eutectic solvent; purifying and separating the long-chain ester phase to obtain high-purity long-chain ester; introducing the residual substance again into the esterification reaction system for reaction after the water in the water phase is removed. The yield and the purity of the long-chain ester prepared by the invented method are as high as 99.8% and 99% respectively as indicated by the embodiment of the preparation method.
- -
-
Paragraph 0124; 0125; 0126
(2019/03/23)
-
- A porous Br?nsted superacid as an efficient and durable solid catalyst
-
The development of catalysts able to assist industrial chemical transformations is a topic of high importance. In view of the versatile catalytic capabilities of acid catalysts, extensive research efforts are being made to develop porous superacid materials with a high density of accessible active sites to replace molecular acid catalysts. Herein, we report the rational development of a porous Br?nsted superacid by combining important elements that target high strength acidity into one material, as demonstrated by grafting the sulfonic acid group onto a highly fluorinated porous framework, where the acid strength and stability are greatly enhanced by an electron-withdrawing environment provided by the polymer backbone, reminiscent of that seen in Nafion resin. In addition, the densely arranged acid groups that are confined in the three-dimensional nanospace facilitate the transfer of hydrons, thereby further increasing the acidity. By virtue of the pore structure and strong acidity, this system exhibits excellent performance for a wide range of reactions, far outperforming commercial acid resins under repeated batch and flow reaction conditions. Our findings demonstrate how this synthetic approach may instruct the future design of heterogeneous acid catalysts with advantageous reaction capabilities and stability.
- Sun, Qi,Hu, Kewei,Leng, Kunyue,Yi, Xianfeng,Aguila, Briana,Sun, Yinyong,Zheng, Anmin,Meng, Xiangju,Ma, Shengqian,Xiao, Feng-Shou
-
supporting information
p. 18712 - 18719
(2018/10/15)
-
- A new class of human fatty acid synthase inhibitors: Synthesis and their anticancer evaluation
-
A series of 3-pentadecyl/heptadecyl-6-subsituted phenyl[l,2,4]triazolo[3,4-&][l,3,4]thiadiazoles have been designed, synthesized and screened for their in vitro antitumour activity against breast cancer cell Jines. Three compounds namely, 3- pentadecyl-6-phenyl[l,2,4]triazolo[3,4-b][l,3,4]thiadiazole (6e), 3-heptadecyl-6-phenyl[l,2,4]triazolo[3,4-i][l,3,4]thiadiazole (6j) and 3-heptadecyl-6(3-nitrophenyl)[l,2,4]triazolo[3,4b][l,3,4]-thiadiazole (6g) have displayed comparable activities towards human breast cancer lines. Molecular docking studies have been carried out on the crystal structure of human fatty acid synthase thioesterase domain (2PX6) by using GLIDE integrated Maestro 9.3 version. The designed compounds have shown good binding interactions with the active site residues present in the enzyme and have given very good G-scores when compared to the known inhibitor orlistat.
- Jubie,Bincy,Jameera Begam,Ashish,Kalirajan,Afzal Azam
-
p. 671 - 678
(2019/05/22)
-
- 8 - hydroxy quinoline sensitive ionic liquid preparation and its catalytic long-chain fatty acid b method of esterification of
-
The invention discloses a preparation method of a temperature sensitive ionic liquid, and a method for catalyzing long-chain fatty acid esterification by using the ionic liquid. A general formula (I) shown in the specification represents the structure of the temperature sensitive ionic liquid, the ionic liquid is formed by a 8-hydroxyquinoline cation and anions comprising a tetrafluoroborate radical, a methane sulfonate radical, a bisulfate ion and a dihydrogen phosphate radical, and the solubility of ionic liquid in ethanol is temperature sensitive. The introduction of a hydroxy group to 8-position of aquinoline ring greatly increases the acidity and improves the esterification reaction yield. The ionic liquid can be mixed with ethanol to form one phase at a high temperature, and the ionic liquid and a product rapidly separate to different phases at room temperature or a low temperature, so the whole reaction system ensures high catalytic efficiency of a homogeneous reaction and makes separation and recovery simple, avoids the limitations of limited two-phase catalytic efficiency and the disadvantage of difficult ion liquid recovery of homogeneous catalysis, and accords with the principle of green chemistry. The esterification yield of the esterification reaction of the long-chain fatty acid under the catalysis of the ionic liquid reaches 90.6-95.5%.
- -
-
Paragraph 0080; 0081; 0082; 0083; 0084; 0085-0091
(2017/06/22)
-
- Surfactant-like Br?nsted acidic ionic liquid as an efficient catalyst for selective Mannich reaction and biodiesel production in water
-
Abstract: The current study deals with the applications of a surfactant-like Br?nsted acidic ionic liquid (IL) 1-dodecyl-3-methylimidazolium hydrogen sulfate ([DMIm]HSO4) for Mannich reaction at room temperature. The reaction was efficiently preceded in water as solvent without using any harmful and expensive organic additives. Our findings showed that the reaction is selective for cyclohexanone and no Mannich product was observed when cyclopentanone was used as starting material. Density functional theory (DFT) calculations were performed to provide an evidence about the nature of reactivity of the cyclohexanone/cyclopentanone. The activity of the catalyst was also tested for biodiesel production of fatty acids with methanol and ethanol at mild thermal condition without applying additional water removal steps such as using additives or performing special methodologies like azeotropic distillation. In both reactions, the IL can be recycled and reused several times with relatively constant efficiency. Graphical Abstract: [Figure not available: see fulltext.]
- Vafaeezadeh, Majid,Karbalaie-Reza, Mina,Hashemi, Mohammad Mahmoodi,Soleimany, Kasra Qasempour
-
p. 907 - 914
(2017/02/26)
-
- P-Sulfonic acid calix[4]arene-functionalized alkyl-bridged organosilica in esterification reactions
-
Two new p-sulfonic acid calix[4]arene- and p-sulfonic acid calix[6]arene-functionalized organosilica have been synthesized using a sol-gel method and applied as heterogeneous catalysts in esterification reactions. The catalytic performance was evaluated using the esterification of carboxylic acids with ethanol, and good catalytic activity (i.e., 55-88%) was observed under the optimum reaction conditions. This study reports the first promising example of the successful employment of calix[n]arenes as a heterogeneous catalyst for catalytic esterification. The catalyst was easily separated by filtration and reused five times without any significant loss of activity.
- De Assis,Abranches,Braga,Zu?iga,Sathicq,Romanelli,Sato,Fernandes
-
p. 24285 - 24289
(2016/03/15)
-
- Zirconium-containing metal organic frameworks as solid acid catalysts for the esterification of free fatty acids: Synthesis of biodiesel and other compounds of interest
-
Zr-containing metal organic frameworks (MOFs) formed by terephthalate (UiO-66) and 2-aminoterephthalate ligands (UiO-66-NH2) are active and stable catalysts for the acid catalyzed esterification of various saturated and unsaturated fatty acids with MeOH and EtOH, with activities comparable (in some cases superior) to other solid acid catalysts previously reported in literature. Besides the formation of the corresponding fatty acid alkyl esters as biodiesel compounds (FAMEs and FAEEs), esterification of biomass-derived fatty acids with other alcohols catalyzed by the Zr-MOFs allows preparing other compounds of interest, such as oleyl oleate or isopropyl palmitate, with good yields under mild conditions.
- Cirujano,Corma,Llabrés I Xamena
-
p. 213 - 220
(2015/02/19)
-
- Use of Lecitase-Ultra immobilized on styrene-divinylbenzene beads as catalyst of esterification reactions: Effects of ultrasounds
-
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
-
-
- Activation of enzyme nanogel in organic solvents by PEG-substrate joint imprinting
-
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
- Wang, Rui,Zhang, Yifei,Ge, Jun,Liu, Zheng
-
p. 40301 - 40304
(2015/01/09)
-
- Efficient microwave-assisted esterification reaction employing methanesulfonic acid supported on alumina as catalyst
-
A rapid and efficient protocol assisted by microwave irradiation for the synthesis of esters using methanesulfonic acid (CH3SO3H) supported on Al2O3 (AMA) as catalyst and free of solvent is described. The products were obtained in good yields and purity, with reduced reaction time, and the process is simple and environmentally benign. Copyright
- Fabian, Lucas,Gomez, Matias,Kuran, Juan A. Caturelli,Moltrasio, Graciela,Moglioni, Albertina
-
p. 2386 - 2392
(2014/07/22)
-
- A study on the catalytic activity and theoretical modeling of a novel dual acidic mesoporous silica
-
A novel mesoporous silica-functionalized dual Bronsted acidic species has been introduced as an efficient catalyst for solvent-free esterification of fatty acids with ethanol. The structure of the catalyst has been characterized by FT-IR spectroscopy, thermal gravimetric analysis (TGA), TEM and N2 adsorption-desorption. TGA of catalyst 1 showed no weight loss before 200 °C, indicating a high degree of hydrophobicity of the surface of the mesoporous silica. TEM images and nitrogen adsorption-desorption showed no noticeable changes to the structure of the catalyst before and after acid treatment. pH metric analysis was performed for the catalyst to determine the loading of the acidic sites. The structure of the catalyst was modeled by mimicking the surface of functionalized silica gel in the form of a cage-like cluster. Various conformers from the proposed structures were selected and optimized at the B3LYP/6-311++G** level of calculation. Natural bond orbital (NBO) analysis was performed to investigate the nature of hydrogen bonding of the catalyst in more detail. Based on the data gained from the optimized structures of the catalyst, a mechanism was proposed for the esterification reaction.
- Vafaeezadeh, Majid,Fattahi, Alireza
-
p. 16647 - 16654
(2014/05/06)
-
- Enzymatic production of cocoa butter equivalents high in 1-palmitoyl-2-oleoyl-3-stearin in continuous packed bed reactors
-
This study aimed to optimize the lipase-catalyzed transesterification of high oleic sunflower oil (A) with a mixture of ethyl palmitate and ethyl stearate (B) to produce cocoa butter equivalents with a weight ratio of 1-palmitoyl-2-oleoyl-3-stearoyl-rac-glycerol (POS) to total symmetric monounsaturated triacylglycerols (SMUT) that is similar to that of cocoa butter by response surface methodology. The reaction was performed in a continuous packed bed reactor, using 0.45 g of Lipozyme RM IM as the biocatalyst. The effects of temperature (Te), residence time (RT), substrate molar ratio (SR, B/A), and water content (WC) of the substrates on the composition of reaction products were elucidated using the models established. Optimal reaction conditions for maximizing total SMUT and POS contents while minimizing the levels of diacylglycerol formation and acyl migration were: Te, 60°C; RT, 28.5 min; SR, 8.5; WC, 300 mg/kg. The contents of total SMUT, POS, and diacylglycerol in the reaction products and the content of palmitoyl and stearoyl residues at the sn-2 position of triacylglycerols in the products were 52.0, 25.1, 9.4, and 4.8 %, respectively, under these conditions. Successful scale-up of the reaction was achieved under the optimal conditions, using 5 g of the lipase. A silver-ion high performance liquid chromatography analysis showed that the products obtained by the larger scale reaction contained 49.1 % total SMUT and 6.1 % of their positional isomers.
- Kim, Sohee,Kim, In-Hwan,Akoh, Casimir C.,Kim, Byung Hee
-
p. 747 - 757
(2014/06/09)
-
- One-pot transformation of carboxylic acids into nitriles
-
A variety of aromatic and aliphatic carboxylic acids were smoothly converted into the corresponding nitriles in good yields in a one-pot procedure by treatment with ethyl iodide/K2CO3/18-crown-6, followed by sodium diisobutyl-tert-butoxyaluminium hydride (SDBBA-H), and finally treatment with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH), and aqueous ammonia. This method is useful for the conversion of various aromatic and aliphatic carboxylic acids into the corresponding nitriles in a one-pot procedure. A variety of aromatic and aliphatic carboxylic acids were smoothly converted into the corresponding nitriles in good yields in a one-pot procedure by treatment with ethyl iodide/K2CO3/18-crown-6, followed by sodium diisobutyl-tert-butoxyaluminium hydride (SDBBA-H), and finally treatment with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH), and aqueous ammonia. Copyright
- Miyagi, Kotaro,Moriyama, Katsuhiko,Togo, Hideo
-
p. 5886 - 5892
(2013/09/23)
-
- Substrate imprinted lipase nanogel for one-step synthesis of chloramphenicol palmitate
-
Enzymatic catalysis with high enantio- and regio-selectivity, which is attractive for green synthesis of chemicals, often suffers from low activity in organic solvents utilized as reaction media. Here, we describe a 'substrate-imprinted' lipase nanogel that displays high activity in organic solvents. The first step was to encapsulate lipase into polyacrylamide nanogel by an aqueous in situ polymerization. Then the lipase nanogel was lyophilized in the presence of palmitic acid, a substrate of lipase, followed by extraction with petroleum ether to remove palmitic acid from the lyophilized lipase nanogel. The imprinting treatment increased the adsorption capacity of palmitic acid by 2.9-fold and the apparent activity by 2-fold in catalyzing the transesterification reaction between para-nitrophenyl palmitate and ethanol. The effects of solvent and temperature on the yield and selectivity of the enzymatic synthesis of chloramphenicol palmitate were examined, respectively. One-step synthesis of chloramphenicol palmitate with the imprinted lipase nanogel gave a yield of ~99% and a purity of ~99% within 12 hours at 20 °C, whereas the imprinted free lipase gave a yield below 60% in 20 hours. The high activity and selectivity make the substrate-imprinted enzyme nanogel an attractive catalyst for green synthesis of chemicals having complex structures.
- Wang, Rui,Zhang, Yifei,Huang, Jinhai,Lu, Diannan,Ge, Jun,Liu, Zheng
-
supporting information
p. 1155 - 1158
(2013/06/27)
-
- Well-dispersed sulfated zirconia nanoparticles as high-efficiency catalysts for the synthesis of bis(indolyl)methanes and biodiesel
-
Well-dispersed sulfated zirconia nanoparticles were synthesized with poly(N-vinylpyrrolidone) as a surfactant. The resultant sulfated zirconia nanoparticles are characterized by SEM, XRD, FT-IR and XPS. These nanoparticles were directly used as catalysts for the synthesis of bis(indolyl)methanes and biodiesel via electrophilic substitution reaction of indole with various aldehydes and the esterification of long-chain free fatty acids and exhibited excellent catalytic activity. The mechanism of the formation of the synthesized zirconia nanoparticles was also proposed.
- Chen, Guochang,Guo, Cun-Yue,Qiao, Hongbin,Ye, Mingfu,Qiu, Xiaoning,Yue, Caibo
-
-
- Novel and highly efficient SnBr2-catalyzed esterification reactions of fatty acids: The notable anion ligand effect
-
In this work, the efficiency of Lewis acid catalysts, SnX2 (X = F-, Cl-, Br-, or -OAc), was investigated on the esterification reactions of fatty acids (i.e., myristic, palmitic, stearic, oleic, linoleic, and linoleic) with different alcohols (i.e., methyl, ethyl, propyl, isopropyl, and butyl alcohol). Tin(II) bromide was the most active catalyst in all reactions studied. We investigated the effects of main reaction parameters, such as catalyst concentration, temperature, and nature of alcohol and fatty acid. The highest activity of SnBr2 catalyst was discussed in terms of its lower activation energy, higher Lewis acid strength, and higher softness of anionic ligand. Finally, the SnBr 2 catalyst can be easily recovered and reused without loss of catalytic activity. Graphical Abstract: Effect of the tin catalyst nature on the oleic acid esterification with ethyl alcohol. [Figure not available: see fulltext.]
- Ferreira, Arthur Batista,Cardoso, Abiney Lemos,Da Silva, Marcio Jose
-
p. 1240 - 1246
(2014/01/06)
-
- Zn(OTf)2-promoted chemoselective esterification of hydroxyl group bearing carboxylic acids
-
Selective esterification of aliphatic and aromatic carboxylic acids with various alcohols is studied using triphenylphosphine, I2, and a catalytic amount of Zn(OTf)2. Use of this catalyst allows the formation of esters at a faster rate with good to excellent yield by activating the in situ generated acyloxyphosphonium ion intermediate. During the esterification process, both their aromatic and aliphatic hydroxyl groups are fully preserved from transesterification. The results show that the bulkiness and the reactivity of this doubly activated intermediate III control the selectivity and the rate of the reaction, respectively. The method is also useful for direct amidation reactions.
- Mamidi, Narsimha,Manna, Debasis
-
p. 2386 - 2396
(2013/05/21)
-
- Specific enzyme-catalyzed hydrolysis and synthesis in aqueous and organic medium using biocatalysts with lipase activity from Aspergillus niger MYA 135
-
In the present study, the specific hydrolytic activity of three biocatalysts such as the constitutive mycelium-bound lipase, the induced mycelium-bound lipase and the lyophilized induced supernatant from A. niger MYA 135 was evaluated in both aqueous and organic media.A direct correlation between activity in water and n-hexane was not observed for the same hydrolytic reaction. The n-hexane/water activity ratio (RO/A) was applied to characterize the activity in organic medium. The three biocatalysts showed RO/A values higher than 1 for hydrolysis of long-chain fatty acid esters, demonstrating a higher specific hydrolytic activity in organic solvent than in water. A different behavior was observed during hydrolysis of middle-chain fatty acid esters, which was higher in aqueous medium (R O/Adw) observed in a reaction mixture containing propanol and p-nitrophenyl laurate. Finally, both p-nitrophenyl caprate (C10) and p-nitrophenyl laurate (C12) were preferentially methanolized by the lyophilized induced supernatant, being this lipase activity the most specific biocatalyst preparation under transesterification conditions. A selectivity-based analysis of each lipase preparation toward transesterification or hydrolysis in organic medium was evaluated as well. Springer Science+Business Media, LLC 2012.
- Romero, Cintia M.,Pera, Licia M.,Loto, Flavia,Baigori, Mario D.
-
p. 1361 - 1368
(2013/01/15)
-
- SBA-15-functionalized sulfonic acid confined acidic ionic liquid: A powerful and water-tolerant catalyst for solvent-free esterifications
-
Incorporating a hydrophobic Bronsted acid ionic liquid (HBAIL) inside the nanospaces of SBA-15-Pr-SO3H led to a hydrophobic super Bronsted acid catalyst, which showed excellent catalytic performance in direct esterification of alcohols and carboxylic acids at ambient temperature under solvent-free conditions. The Royal Society of Chemistry 2012.
- Karimi, Babak,Vafaeezadeh, Majid
-
supporting information; experimental part
p. 3327 - 3329
(2012/04/23)
-
- Ultrasound-assisted synthesis of aliphatic acid esters at room temperature
-
This work describes the ultrasound-assisted synthesis of saturated aliphatic esters from synthetic aliphatic acids and either methanol or ethanol. The products were isolated in good yields after short reaction times under mild conditions.
- Hobuss, Cristiane B.,Venzke, Dalila,Pacheco, Bruna S.,Souza, Alexander O.,Santos, Marco A.Z.,Moura, Sidnei,Quina, Frank H.,Fiametti, Karina G.,Vladimir Oliveira,Pereira, Claudio M.P.
-
experimental part
p. 387 - 389
(2012/04/23)
-
- Antimicrobial evaluation of 4-methylsulfanyl benzylidene/3-hydroxy benzylidene hydrazides and QSAR studies
-
A series of 4-methylsulfanyl benzylidene/3-hydroxy benzylidene hydrazides (1-20) was synthesized and tested for in vitro antimicrobial activity against S. aureus, B. subtilis, E. coli, C. albicans and A. niger. The results of antimicrobial studies indicated that 3-phenylacrylic acid-(3-hydroxybenzylidene) -hydrazide, 16, was the most effective as it showed both bactericidal and fungicidal properties and other compounds possessed bacteriostatic/fungistatic activity. The multi-target QSAR model demonstrated that the topological parameter, Balaban topological index (J) is effective in describing the antimicrobial activity of synthesized substituted hydrazides. Springer Science+Business Media, LLC 2010.
- Kumar, Davinder,Narang, Rakesh,Judge, Vikramjeet,Kumar, Devinder,Narasimhan, Balasubramanian
-
experimental part
p. 382 - 394
(2012/08/27)
-
- P-Sulfonic acid calix[n]arenes as homogeneous and recyclable organocatalysts for esterification reactions
-
Esterification yields were significantly improved using calix[n]arenes catalysts under simple conditions. p-Sulfonic acid calix[4]arene and p-sulfonic acid calix[6]arene were powerful organocatalysts in several esterification reactions, which showed activity comparable or even superior to other well-established acids catalysts, such as, sulfuric acid, p-toluenesulfonic acid, and p-hydroxybezenesulfonic acid described in the literature.
- Fernandes, Sergio Antonio,Natalino, Ricardo,Gazolla, Poliana Aparecida Rodrigues,Da Silva, Márcio José,Jham, Gulab Newandram
-
experimental part
p. 1630 - 1633
(2012/04/17)
-
- Transesterification to biodiesel with superhydrophobic porous solid base catalysts
-
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.
- Liu, Fujian,Li, Wei,Sun, Qi,Zhu, Longfeng,Meng, Xiangju,Guo, Yi-Hang,Xiao, Feng-Shou
-
scheme or table
p. 1059 - 1062
(2012/04/11)
-
- Lipase-catalyzed transformations using poly(ethylene glycol) as solvent
-
Candida antarctica lipase catalyzes a number of elementary reactions like alcoholysis, ammoniolysis and aminolysis in poly(ethylene glycol) (PEG) media. Reaction rates were comparable to or better than those observed in conventional organic reaction media and ionic liquids. It is envisaged that PEGs could have added benefits for performing biotransformations with highly polar substrates, which are sparingly soluble in common organic solvents.
- Kidwai, Mazaahir,Poddar, Roona,Bhardwaj, Saurav
-
experimental part
p. 113 - 118
(2011/12/15)
-
- Synthesis, antimicrobial evaluation and QSAR studies of 3-ethoxy-4-hydroxybenzylidene/4-nitrobenzylidene hydrazides
-
A series of 3-ethoxy-4-hydroxybenzylidene/4-nitrobenzylidene hydrazides (1-20) was synthesized and tested for in vitro antimicrobial activity. The results of antimicrobial studies indicated that the compounds having dinitro, methoxy, hydroxy and nitro substituents on phenyl ring of the aromatic acids were most active ones. The QSAR investigation indicated the importance of the topological parameter, third order molecular connectivity index ( 3χ) in describing the antimicrobial activity of synthesized hydrazides.
- Kumar, Davinder,Kapoor, Archana,Thangadurai, Ananda,Kumar, Pradeep,Narasimhan, Balasubramanian
-
experimental part
p. 1293 - 1296
(2012/01/07)
-
- Novel H3PW12O40: Catalysed esterification reactions of fatty acids at room temperature for biodiesel production
-
The catalytic activity of Bronsted acids on fatty acid (FA) esterification at room temperature has been investigated. Noticeably, the H 3PW12O40 heteropolyacid (HPW) showed a very high activity than other catalysts herein evaluated, i.e. p-toluene sulfonic acid and sulfuric acid. High yields in ethyl esters (ca. 90%) were reached after a 4 h reaction at 25 °C on a HPW catalysed reactions. Despite the fact that HPW catalyst was used in a homogeneous phase, it could be efficiently recovered and reused through out a simple recycling protocol, without any activity loss. The effects of alcohol and the FA nature on yield reaction were also investigated.
- De Godoi Silva, Vinicius Wilker,Laier, Leticia Oliveira,Silva, Marcio Jose Da
-
experimental part
p. 207 - 211
(2010/08/03)
-
- Benzylidene/2-chlorobenzylidene hydrazides: Synthesis, antimicrobial activity, QSAR studies and antiviral evaluation
-
A series of benzylidene hydrazides (1-20) was synthesized and tested, in vitro, for antibacterial, antifungal and antiviral activities. The microbial screening results indicated that compounds having chloro and nitro substituents were the most active ones. The antiviral evaluation depicted that compounds 9 and 19 were active against Vesicular stomatitis virus (VSV) in HeLa cell cultures. QSAR investigations indicated that the multi-target QSAR model was effective in describing the antimicrobial (antibacterial and antifungal) activity over the one-target QSAR models. Further the mt-QSAR model indicated that the topological parameters, second order molecular connectivity index (2χ) and third order Kier's alpha shape index (κα3) are effective in describing the antimicrobial activity of synthesized hydrazides.
- Kumar, Davinder,Judge, Vikramjeet,Narang, Rakesh,Sangwan, Sonia,De Clercq, Erik,Balzarini, Jan,Narasimhan, Balasubramanian
-
experimental part
p. 2806 - 2816
(2010/08/20)
-
- Direct syntheses of sulfonated mesoporous SiO2-TiO 2-SO3H materials as solid acid catalysts
-
A facile one-step approach for a mesoporous solid acid catalyst SiO 2-TiO2-SO3H network was developed by the simple chelation of a benzene disulfonate compound to the Ti ion. The resulting catalyst showed excellent catalytic performance for esterification.
- Ryoo, Hyang Im,Hong, Lan Young,Jung, Sang Hee,Kim, Dong-Pyo
-
supporting information; experimental part
p. 6419 - 6421
(2010/09/06)
-
- Esterification of free fatty acids to biodiesel over heteropolyacids immobilized on mesoporous silica
-
Tungstophosphoric acid (PW), molybdophosphoric acid (PMo) and tungstosilicic acid (SiW) immobilized on SBA-15 were used, as catalysts, in the esterification of palmitic acid with methanol, at 60 °C. Catalysts were characterized by N2 adsorption, FTIR, X-ray diffraction, ICP-AES and TEM. All catalysts exhibited high catalytic activity in palmitic acid esterification with methanol. It was observed that the catalytic activity decreases in the follow series: PW1-SBA-15 > SiW-SBA-15 > PMo-SBA-15. A series of PW immobilized on SBA-15 with different PW loadings from 2.7 wt% to 8.3 wt% were prepared. It was observed high catalytic activity with low amount of tungstophosphoric acid immobilized on SBA-15. In order to optimize the reaction conditions, the effect of different parameters, such as catalyst loading, carbon length of the alcohol and temperature, molar ratio of fatty acid to methanol in the presence of PW3-SBA-15 were studied. PW3-SBA-15 catalyst can be separated from reaction system for re-use. It was observed a small leaching of the PW from SBA-15 to liquid phase. PW3-SBA-15 catalyst was also used in the esterification of stearic and oleic acid with methanol. High catalytic activity was observed.
- Tropecêlo,Casimiro,Fonseca,Ramos,Vital,Castanheiro
-
experimental part
p. 183 - 189
(2012/01/02)
-
- METHOD OF MAKING ALKYL ESTERS
-
Methods of making alkyl esters are described herein. The methods are capable of using raw, unprocessed, low-cost feedstocks and waste grease. Generally, the method involves converting a glyceride source to a fatty acid composition and esterifying the fatty acid composition to make alkyl esters. In an embodiment, a method of making alkyl esters comprises providing a glyceride source. The method further comprises converting the glyceride source to a fatty acid composition comprising free fatty acids and less than about 1% glyceride by mass. Moreover, the method comprises esterifying the fatty acid composition in the presence of a solid acid catalyst at a temperature ranging firm about 70° C. to about 120° C. to produce alkyl esters, such that at least 85% of the free fatty acids are converted to alkyl esters. The method also incorporates the use of packed bed reactors for glyceride conversion and/or fatty acid esterification to make alkyl esters.
- -
-
Page/Page column 4-5
(2008/06/13)
-
- Selective esterification of aliphatic carboxylic acids in the presence of aromatic carboxylic acids over monoammonium salt of 12-tungstophosphoric acid
-
Monoammonium salt of 12-tungstophosphoric acid [(NH4)H 2PW12O40] was found to be a practical and useful heterogeneous catalyst for an efficient and selective esterification of aliphatic carboxylic acids with alcohols in the presence of aromatic carboxylic acids. The heteropoly acid-based heterogeneous catalyst has the advantages of a simple workup procedure, water insolubility, and good activity. Copyright Taylor & Francis LLC.
- Giri,Prabhavathi Devi,Gangadhar,Narasimha Rao,Lingaiah,Sai Prasad,Prasad
-
-
- Process for producing fatty acid alkyl ester composition
-
An object of the present invention is to solve a problem of separation and recovery of catalysts present in an alkali metal catalytic method currently often used, a problem of excess consumption of a catalyst by a free fatty acid in a raw material, and other problems, and to solve a problem of the presence of a large excess amount of alcohol in a conventional supercritical methanol method, and to provide a method for producing a fatty acid alkyl ester composition in a reaction system containing water and free fatty acid present. The present invention has attained the above-mentioned object by provided a method for producing a fatty acid alkyl ester composition using fats and oils containing a fatty acid glyceride and/or fatty acid, wherein alcohol and/or water is allowed to co-exist with the above-mentioned fats and oils and the reaction is conducted under conditions of a temperature of 100° C. to 370° C. and a pressure of 1 to 100 MPa.
- -
-
Page/Page column 7-8
(2008/06/13)
-
- Efficient esterification of carboxylic acids and phosphonic acids with trialkyl orthoacetate in ionic liquid
-
An operationally simple, inexpensive, efficient, and environmentally friendly esterification of various carboxylic acids, phosphonic acids, and phosphinic acids with triethyl orthoacetate or trimethyl orthoacetate under neutral conditions in a typical room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate, was successfully carried out to provide the corresponding ethyl esters or methyl esters in high yields.
- Yoshino, Tomonori,Imori, Satomi,Togo, Hideo
-
p. 1309 - 1317
(2007/10/03)
-
- Conversion of a carboxylesterase into a triacylglycerol lipase by a random mutation
-
A true convert: The carboxylesterase enzyme R.34 (see picture) can be converted into a triacylglycerol lipase without modification of the shape, size, or hydrophobicity of the substrate binding site. The substitution of Asn33 by Asp results in a salt bridge between the Asp33 and Arg49, which causes a distortion of the enzyme structure that makes the catalytic site more accessible to larger substrates but also more labile. (Figure Presented).
- Reyes-Duarte, Dolores,Polaina, Julio,Lopez-Cortes, Nieves,Alcalde, Miguel,Plou, Francisco J.,Elborough, Kieran,Ballesteros, Antonio,Timmis, Kenneth N.,Golyshin, Peter N.,Ferrer, Manuel
-
p. 7553 - 7557
(2007/10/03)
-
- PROCESS FOR EXTRACTION AND CATALYTIC ESTERIFICATION OF FATTY ACIDS FOUND IN SEWAGE SCUM
-
The innovation proposed herein describes the process of a fatty acids esterification presents in the sewage scum namely the surface phase of sewage rich in fatty matter, being that this fatty acids are extracted from the scum and esterified by acid catalysts and reagents like as methanol or ethanol.
- -
-
-
- Environmentally friendly esterification of carboxylic acids with triethyl orthoacetate in ionic liquid
-
An operationally simple, inexpensive, efficient, and environmentally friendly esterification of carboxylic acids with triethyl orthoacetate under neutral conditions in a typical room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate, was carried out to provide the corresponding ethyl esters in high yields.
- Yoshino, Tomonori,Togo, Hideo
-
p. 1604 - 1606
(2007/10/03)
-
- Enzymatic reaction in supercritical fluid carbon dioxide using dry-ice
-
New enzymatic reactions in supercritical fluid carbon dioxide catalyzed by lipases (PPL, Lipase MY, Candida cylindracea Lipase), and Proteases (subtilisin Carlsberg, subtilisin 8397, immobilized papain) with high efficiency and yields in a simple high pressure reactor using readily available dry-ice have been developed.
- Yu, Hui-Ming
-
p. 647 - 650
(2007/10/03)
-
- Mild hydrolysis or alcoholysis of amides. Ti(IV) catalyzed conversion of primary carboxamides to carboxylic acids or esters
-
Reaction of primary amides (e.g., 1a or 6-13) or O-methylhydroxamates (1b and 1c) with a catalytic amount of TiCI4 and one equivalent of aqueous HCI converts these compounds in good yields to carboxylic esters (when an alcohol is used as solvent) or to carboxylic acids (when 9:1 dioxane:H2O is used as solvent). These conversions are chemoselective for primary amides: mono- and dialkyl amides are not affected by the reaction conditions. The hydrolysis conditions described do not compromise the stereochemical integrity of an adjacent chiral center. This is exemplified by the hydrolysis of naproxen amide (34) to naproxen (33) without detectable racemization as determined by chiral HPLC.
- Fisher,Caroon,Stabler,Lundberg,Zaidi,Sorensen,Sparacino,Muchowski
-
p. 142 - 145
(2007/10/02)
-
- SYNTHESIS OF MONOESTERS AS SURFACTANTS AND DRUGS FROM D-GLUCOSE
-
We have synthesized a series of monoesters from D-glucose corresponding to the structures 3-O-acyl, 6-O-acyl-1,2-O-isopropylidene-α-D-glucofuranose and 3-acyl-D-glucose, following the sequence of reactions : D-glucose -> diacetone glucose -> acylation -> partial or total deprotection.These compounds were prepared as either potential non-ionic surfactants (fatty acid esters and perfluoroalkylated ester) or antitumour drugs (n-butyric esters).Results concerning surface activity, toxicity and antitumour effects are reported.A novel method for obtaining partially deprotected 6-O-acyl esters from their corresponding 3-O-acyl isomers is reported.Deprotection conditions have been studied and a higher selectivity in partial deprotection has been achieved.We have given particular attention to the choice of solvents and reagents in order not to limit the extent to which the products might be applied.
- Goueth, Pierre Y.,Gogalis, Pascalis,Bikanga, Raphael,Gode, Paul,Postel, Denis,et al.
-
p. 249 - 272
(2007/10/02)
-
- Electrogenerated Acid as an Efficient Catalyst for the Protection and Deprotection of Alcohols with Dihydropyran and Transesterification of Glyceride
-
Protection of alcohols with 3,4-dihydro-2H-pyran and hydrolysis of the resulting tetrahydropyranyl ethers are cleanly performed by using an electrogenerated acid (EG acid) as a catalyst.Transesterification of glyceride was also achieved with EG acid.
- Torii, Sigeru,Inokuchi, Tsutomu,Kondo, Kazumi,Ito, Hiroshi
-
p. 1347 - 1348
(2007/10/02)
-
- Effect of Metal Ions in Organic Synthesis. XI - Hydrolysis and Alcoholysis of Some Acylhydrazines and N-Acyl-N'-arenesulphonylhydrazines in the Presence of Copper(II) Chloride
-
Die Hydrolyse und Alkoholyse einiger Acylhydrazine und N-Acyl-N'-arensulfonylhydrazine in Gegenwart von Kupfer(II)-chlorid * 2 H2O wurden untersucht.Das Mesitylensulfonylhydrazid und die 2,4,6-Triisopropylbenzensulfonylhydrazid-Derivate sind reaktiver als die entsprechenden Hydrazine oder Tosylhydrazid-Derivate.Die entsprechenden Carbonsaeuren und Ester erhaelt man in guten Ausbeuten und unter sehr milden Bedingungen.Die vorliegende Methode ist einfach und bequem im Vergleich zu anderen Methoden.Die Reaktion verlaeuft wahrscheinlich ueber Kupferkomplexe der Acylhydrazine.
- Attanasi, Orazio,Serra-Zanetti, Franco
-
p. 901 - 907
(2007/10/02)
-