• Title/Summary/Keyword: enzymatic esterification

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Ketoprofen Resolution by Enzymatic Esterification and Hydrolysis of the Ester Product

  • Wu, Jin Chuan;Low, Hou Ran;Leng, Yujun;Chow, Yvonne;Li, Ruijiang;Talukder, MMR;Choi, Won-Jae
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.3
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    • pp.211-214
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    • 2006
  • Immobilized Candida antarctica lipase was used to catalyze the separation of ketoprofen into its components by means of esterification followed by the enzymatic hydrolysis of the ester product. In this study, ketoprofen underwent esterification to ethanol in the presence of isooctane. When the reaction was complete, 58.3% of the ketoprofen had been transformed into an ester. The ketoprofen remaining in solution after the reaction was complete consisted primarily of its S-enantiomer (83.0%), while the 59.4% of the ketoprofen component of the ester consisted of its R-enantiomer. We then subjected the ester product to enzymatic hydrolysis in the presence of the same enzyme and produced a ketoprofen product rich in the R-enantiomer; 77% of this product consisted of the R-enantiomer when 50% of the ester had been hydrolyzed, and 90% of it consisted of the R-enantiomer when 30% of the ester had been hydrolyzed. By contrast, the R-enantiomer levels only reached approximately 42 and 65%, respectively, when 50 and 30% of the racemic ester was hydrolyzed under the same conditions.

On-line Conversion Estimation for Solvent-free Enzymatic Esterification System with Water Activity Control

  • Lee, Sun-Bok;Keehoon Won
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.7 no.2
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    • pp.76-84
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    • 2002
  • On-line conversion estimation of enzymatic esterification reactions in solvent-free media was investigated. In principle, conversion to ester can be determined from the amount of water produced by the reaction, because water is formed as a by-product in a stoichiometric manner. In this study, we estimated the water production rate only from some measurements of relative humidity and water balances without using any analytical methods. In order to test the performance of the on-line conversion estimation, the lipase-catalyzed esterification of n-capric acid and n-decal alcohol in solvent-free media was performed whilst controlling water activity at various values. The reaction conversions estimated on-line were similar to those determined by offline gas chromatographic analysis. However, when the water activity was controlled at higher values, discrepancies between the estimated conversion values and the measured values became significant. The deviation was found to be due to the inaccurate measurement of the water content in the reaction medium during the initial stages of the reaction. Using a digital filter, we were able to improve the accuracy of the on-line conversion estimation method considerably. Despite the simplicity of this method, the on-line estimated conversions were in good agreement with the off-line measured values.

On-off Dewatering Control for Lipase-catalyzed Synthesis of n-Butyl Oleate in n-Hexane by Tubular Type Pervaporation System

  • Kwon, Seok-Joon;Rhee, Joon-Shick
    • Journal of Microbiology and Biotechnology
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    • v.8 no.2
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    • pp.165-170
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    • 1998
  • Lipase-catalyzed esterification of n-butyl oleate was carried out in n-hexane as a model reaction. The optimal activity of Candida rugosa lipase was shown in a water activity ($a_w$) range of 0.52 to 0.65 at $30^{\circ}C$. The water produced from the esterification was removed by a tubular type pervaporation system. The rate of ester formed from the enzymatic esterification was allowed to be the same as the rate of water removal by maintaining an optimal $a_w$ of the reaction system using an on-off dewatering control device. The reaction rate and yield with a$a_w$ control were increased two folds higher than the respective values for the uncontrolled reaction.

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Enzymatic Synthesis of Glycosyl Acrylate and Methacrylate (배당화 아크릴레이트와 메타크릴레이트의 효소적 합성)

  • Park, Dae-Won;Kim, Hae-Sung
    • Journal of the Korean Applied Science and Technology
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    • v.21 no.1
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    • pp.37-44
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    • 2004
  • Glycosyl acrylate and methacrylate were synthesized by lipase-catalyzed esterification of vinyl acrylate and vinyl methacrylate with ${\beta}$-methyl glucoside in t-butanol as a reaction medium. At the optimum conditions of initial concentration of 150g/l ${\beta}$-methyl glucoside, molar ratio of 1 : 3, 5%(w/v) lipase(Novozym 435) and $50^{\circ}C$, we attained up to 100% conversion for enzymatic glycosylation of vinyl acrylate and vinyl methacrylate by supersaturated solvent process. The polymerizable glycosyl acrylates and methacrylate are expected to have biomedical application as hydrophilic monomers and hydration modifiers to be used for biocdmpatible hydrogel.

Intramolecular Esterification by Lipase Powder in Microaqueous Cycohexane (미소 수용 Cyclohexange 중에서 분말 Lipase에 의한 분자내 에스테르화반응)

  • 이민규;감삼규
    • Journal of Life Science
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    • v.5 no.4
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    • pp.155-161
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    • 1995
  • The effects of substrate concentration, enzyme concentration, reaction temperature, and water content were investigated in intramolecular esterification. This study used cyclohexane as organic solvent, power lipase as enzyme, and benzyl alcohol and octanoic acid as substrate. The initial reaction rate was found to be proportional to enzyme concentration; followed Michaelis-Menten equation for octanoic acid; and was inhibited by benzyl alcohol . The observed initial reaction rate first increased, then decreased with increasing reaction temperature, giving rise to the maximum rate at 20$\circ$. The drop in the reaction rate at higher temperature was to partition equilibrium change of substrate between organic solvent and hydration layer of enzyme molecule in addition to the deactivation by enzyme denaturation. Water layer surrounding enzyme molecule seemed to activate in organic solvent and the realistic reaction was done in the water layer. In the enzymatic reaction in organic solvent, the initial reaction rate was influenced by partition quilibrium of substrate, so the optimum condition of substrate concentration, enzyme concentration, reaction temperature, and water content would give a good design tool.

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Sorbitan acrylate의 Novozyme 435를 이용한 효소적 합성에 관한 연구

  • Im, Geun-Gil;Kim, In-Hong;Lee, Gwang-Yeon;Gang, Chun-Hyeong;Park, Don-Hui
    • 한국생물공학회:학술대회논문집
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    • 2002.04a
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    • pp.562-565
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    • 2002
  • The esterification reaction of previously obtained l,4-sorbitan with acrylic acid using Novozym 435 was carried out in t-butanol as solvent. Immobilized lipase Novozym 435 showed high enzymatic activity at $50^{\circ}C$ in t-butanol and optimum contents of Novozym 435 added in the esterification reaction was 3%(w/v). The maximum conversion rate was 55.8% when initial concentration was 50g/L and conversion rate of this reaction was 63.5% when the molar ratio of l,4-sorbitan to acrylic acid was 1:3.

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Kinetics for Selective Synthesis of Enzymatic Long Chain Alkyl Monoglycerid (효소반응에 의한 장쇄 알킬모노글리세리드의 선택적 합성에 있어 동력학적 고찰)

  • Kim, S.C.;Kim, H.S.;Joe, K.H.;Nam, K.D.
    • Journal of the Korean Applied Science and Technology
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    • v.10 no.1
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    • pp.67-74
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    • 1993
  • 1, 2-Isopropylidene glycerol produced by ketalyzation of glycerol with aceton was esterified with long chain fatty acids in the presence of a Mucor miehei lipase to obtain 1, 2-isopropylidene 3-long chain acyl glycerol. To determine optimal conditions for the esterification reaction, esterification was proceeded as a reversible second-order reaction in various parameters that are enzyme/substrate ratio 0.096g/g at reaction temperatures ranged from $25^{\circ}C$ to $70^{\circ}C$. The order of reaction rate of fatty acids were lauric acid, myristic acid, oleic acid, and stearic acid. The range of their activation energies were from 7.8 to 11.4 (kcal/mol) and that of entropies of activation which have negative values were from 42.8 to 52.5(e.u.).

Synthesis of Acetins from Glycerol using Lipase from Wheat Extract

  • Pradima, J;Rajeswari, M Kulkarni;Archna, Narula;Sravanthi, V;Rakshith, R;Nawal, Rabia Nizar
    • Korean Chemical Engineering Research
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    • v.57 no.4
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    • pp.501-506
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    • 2019
  • New technology-driven biocatalysts are revolutionizing the biochemical industries. With maximum utilization of renewable feedstock, biocatalysts have been the basis for a major breakthrough. Lipases are the most widely established catalysts used for hydrolysis, esterification and transesterification reactions. In this research, a biochemical process that combines extraction of lipase enzyme from germinated wheat seeds and its application to valorize glycerol to acetins by esterification is presented. Acetins are among highly rated, value-added products derived from glycerol. The favorable conditions for the enzymatic conversion of glycerol were observed as glycerol to acetic acid molar ratio (1:5), reaction temperature ($40^{\circ}C$) and the amount of enzyme (20% v/v). 65.93% of glycerol conversion was achieved for duration of 15 h with the use of tert-butanol solvent. This method proposes to explore the viability of a biological route to convert glycerol derived from biodiesel industry to acetins with further streamlining.

Enzymatic Biodiesel Synthesis of Waste Oil Contained High Free Fatty Acid (효소 촉매를 이용한 고산가 폐유지 유래 바이오디젤 합성)

  • Jeon, Cheol-Hwan;Lim, Kwang-Mook;Kim, Jae-Kon;Hwang, In-Ha;Na, Byung-Ki
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.4
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    • pp.1048-1056
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    • 2018
  • Non-edible oil sources (i.e., Palm Acid Oil, waste animal fat) usually contain relatively high amount of free fatty acids (FFA) that make them inadequate for direct base catalyzed transesterification reaction. Enzymatic biodiesel synthesis can solve several problems posed by the alkaline-catalyzed transesterification, and has certain advantages over the chemical catalysis of transesterification, as it is less energy intensive, allows easy recovery of glycerol and the transesterification of glycerides with high free fatty acid contents. In this study, we synthesized biodiesel through enzymatic catalyzed process using high free fatty acid containing waste oil in biodiesel reactor (1 ton/day) and optimized the biodiesel production processes.

Candida rugosa Lipase-Catalyzed Production of Optically Pure S-(+)-Ketoprofen (Candida rugosa 리파제를 이용한 광학적으로 순수한 S-(+)-Ketoprofen의 생산)

  • 김민곤;최순자;최원아;김철호;정봉현
    • KSBB Journal
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    • v.14 no.2
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    • pp.225-229
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    • 1999
  • Enzymatic resolution reactions were investigated using Candida rugosa lipase for the production of potically pure S-(+)-Ketoprofen. When the enzymatic hydroysis (and esterification) of recemic ketoprofen esters (and recemic ketoprofen with alcohol) was investigated comparatively, aqueous media was more specific for S-enantiomer than organic media. In the enzymatic hydrolysis of racemic ketoprofen ethyl ester in aqueous media, optimal temperature and pH for enantioselectivity were $37^{\circ}C$ and 4, respectively. The stereoselectivity of the enzyme was enhanced by adding dialcohols such as ethylene glycol and propylene glycol. The enantiomeric ratio obtained in the 40 %(v/v) ethylene glycol was 2-fold higher than that without the additive. By adding $CH_2Cl_2$, $CHCl_3$ and $CCl_4$ (5%,v/v), the enantioselectivity was reversed. A dramatic increase in the stereoselectivity was achieved using lipase purified by anion exchange chromatography. The type A lipase(the first eluted lipase fraction) showed an enantiomeric ratio of >100, whereas the type B lipase(the second eluted lipase fraction) exhibited enantimomer ratio of 9.0 in the hydrolysis of racemic ketoprofen ethyl ester.

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