Lipase-catalyzed Reaction Research Articles

Evaluation of deep eutectic solvents as new media for Candida antarctica B lipase catalyzed reactions

This study aimed at analyzing the advantages and limitations of several deep eutectic solvents (DESs) as ‘green solvents’ for biotransformation using immobilized Candida antarctica lipase B as catalyst. The transesterification of vinyl laurate was chosen as model reaction and the influence of substrate polarity was assessed using alcohols of various chain lengths. Results showed that grinding of immobilized lipase was essential parameters for good lipase activity. Moreover, in our model reaction some hydrogen-bond donor component from the DES can compete with the alcoholysis reaction. Indeed, side reactions were observed with DES based on dicarboxylic acid or ethylene glycol, leading to some limitations of their use. However, the results showed that other DESs such as choline chloride:urea and choline chloride:glycerol could exhibit high activity and selectivity making them promising solvents for lipase-catalyzed reactions. Finally, the best DES's specific activity – and stability up to five days incubation time – were analyzed and compared with conventional organic solvents. Experiments revealed that iCALB is less influenced by the chain length of alcohol in DES than organic solvents and it is preserves its activity with minimally destructive to protein structure.

ChemInform Abstract: Enantioselective Synthesis of δ‐Lactones with Lipase‐Catalyzed Resolution and Mitsunobu Reaction.

AbstractDerivative (R)‐(I) can easily be converted into lactone (S)‐(IV) by means of Mitsunobu reaction.

Synthesis of esterified solid fat from fractionated rapeseed oil and palm stearin modeling by response surface methodology

The main purpose of the study was to produce esterified solid fat (ESF) from fractionated rapeseed oil and palm stearin through lipase-catalyzed reaction. The response surface methodology (RSM) was applied for optimization of three reaction factors such as substrate mole ratio, enzyme percent, and reaction time. The design was adequate and reproducible due to satisfactory levels of coefficient of determination (R2, 0.98) for both cases and coefficient variation (CV, 4.06 for SFC at 10 °C and 7.95 for SFC at 30 °C, respectively). The substrate mole ratio was the significant term for affecting the response of SFC (P<0.05) rather than reaction time and enzyme percent. Based on ridge analysis, the production of ESF with SFC 51.48 ±0.94 % at 10 ºC would be predicted by the combinations of optimized 24.07 h reaction time, 10.66 % enzyme and 1: 1.52 substrate mole ratios. On the other hand, the SFC of 21.44±0.83 at 30 ºC would be predicted by the combinations of optimized 24.37 h reaction time, 10.23 % enzyme and 1: 1.5 substrate mole ratios. The ESF contained mainly of palmitic (45.1%), oleic (40.8%), linoleic (5.6%) and stearic (4.5%) acids, respectively. The total sterol and tocopherol contents of ESF were 243.27 mg/100g and 19.26 mg/100 g, respectively. Therefore, these results in this study suggested that RSM can be used to optimize the lipase-catalyzed synthesis of ESF with suitable physical characteristics. DOI: http://dx.doi.org/10.3329/jbau.v9i2.11040 J. Bangladesh Agril. Univ. 9(2): 273–282, 2011

Regioselective Enzymatic Acylation of Aureolic Acids to Obtain Novel Analogues with Improved Antitumor Activity

A variety of aureolic acids was efficiently obtained by lipase-catalyzed regioselective acylation reactions of mithramycin and its analogues mithramycin SK and mithramycin SDK. The acylation took place in the aglycone moiety or in the B sugar unit, depending on the substrate, lipase and acyl donor considered. Most of the novel acylated derivatives showed antitumor activity at double digit nanomolar concentrations, in some cases significantly improving the activity of the parent drugs.

Lipase-catalyzed synthesis of poly(e-caprolactone) in supercritical carbon dioxide

Abstract In this study, the synthesis of poly(e-caprolactone) by lipase-catalyzed reactions in supercritical carbon dioxide was performed in a batch reactor in order to evaluate the influence of the operating conditions on polymer chain size and on polydispersity index. Firstly, a fractional 2 4−1 factorial design was performed to evaluate the effect of temperature, concentration of enzyme, water content and agitation. Then, a full 2 3 experimental design was carried out to evaluate the effects of pressure, enzyme concentration and water content. The best result was a polymer chain size of 7419.6 g/gmol, obtained in a reaction conducted at 145 bar, 65 °C, 200 rpm, 10 wt% enzyme concentration and at the lowest water content.

Lipase Catalyzed Kinetic Resolution of rac-2-(3-Methoxy-4-methylphenyl) propan-1-ol and rac-2-(3-Hydroxy-4-methylphenyl)propyl propanoate for S-(+)-Xanthorrhizol

E-mail: c2496@kist.re.krReceived November 1, 2011, Accepted November 23, 2011Xanthorrhizol is a bisabolane type of natural sesquiterpene, the major component of essential oils of Curcumaxanthorrhiza. 2-(3-Methoxy-4-methylphenyl)propan-1-ol and 2-(3-hydroxy-4-methyl phenyl)propan-1-olcould be essential building block for enantioselective synthesis of xanthorrhizol. Enantioselective ( c = 53%, E= 80 ± 3) for R-(+)-2-(3-hydroxy-4-methylphenyl) propan-1-ol and (c = 58%, E = 27 ± 1) for R-(+)-2-(3-methoxy-4-methylphenyl) propan-1-ol resolution processes were developed via lipase-catalyzed reaction. Wefound lipase Aspergillus oryzae (AOL) and Porcine pancreas (PPL) are selective to transesterification andhydrolysis in organic and aqueous phase. Modified demethylated substrate is appropriate for enantioselectivehydrolysis reaction without any additives. Enantiopure chiral alcohol was crystallized from ethyl acetate/n-hexane co-solvent system. Gram scale resolved chiral intermediate will facilitate the synthesis of theunnatural S-(+)-xanthorrhizol, the corresponding isomer of the natural one.Key Words : Lipase, Sesquiterpene, Xanthorrhizol, Transesterification, HydrolysisIntroductionR-(−)-Xanthorrhizol is a bisabolane type of natural ses-quiterpene containing a stereogenic centre at the benzylicposition. R-(−)-Enantiomer was isolated from the naturalsources, as constituent of rhizomes of Curcuma xanthorrhiza,

Synthesis of thiol functionalized poly(meth)acrylates through enzymatic catalysis and a subsequent one pot reaction process

The synthesis and modification of thiol functionalized poly(meth)acrylates using a straightforward reaction concept that consists of an enzymatically catalyzed monomer synthesis, free radical polymerization and post-polymerization modification is presented. The well-known enzymatic transacylation of methyl acrylate and methyl methacrylate that runs under mild and environmentally friendly conditions was used to synthesize thiol protected acrylic and methacrylic monomers. Upon free radical polymerization and subsequent removal of protection groups, polymers with pendant thiol groups are obtained, which, in turn, can react in situ with Michael acceptors to form thiol-ene reaction products. The exceptional advantage of the proposed method is that upon removal of the enzyme from the monomer mixture, the polymerization, deprotection of thiols and subsequent Thio-Michael-type addition reaction can be conducted in one pot without purification of the intermediate products. Furthermore, the different reactivities of acetyl and benzoyl protection groups in lipase catalyzed reactions are discussed.

Synthesis of glycerolipidyl derivatives of permethylated β-cyclodextrin as potential nanovectors

This work reports the chemo-enzymatic synthesis of a new family of amphiphilic cyclodextrins for Nano Drug Delivery. Monoamino-permethylated β-CD 1 was used as the polar head of amphiphilic structures. Three derivatives of glycerol were grafted onto cyclodextrin with or without a spacer arm. The two free hydroxyl groups were submitted to lipase-catalyzed reaction in mild conditions, leading to mono- or diesterified compounds. The reactivity of the hydroxyl groups was discussed and the compounds were fully characterized by NMR and mass spectrometry. The surfactive properties of bicatenar compounds 8, 9, 12 and 14 were evaluated and low CAC were determined, suggesting very promising assembly properties of these compounds in aqueous media.

Homopolymerization and copolymerization of a dilactone, 13,26-dihexyl-1,14-dioxa-cyclohexacosane-2,15-dione: Synthesis of bio-based polyesters and copolyesters consisting of 12-hydroxystearate sequences

A dilactone, 13,26-dihexyl-1,14-dioxacyclohexacosane-2,15-dione (12-HSAD), was synthesized by lipase-catalyzed reaction of 12-hydroxystearic acid (12-HSA) in high yield. It was subjected to the ring-opening polymerization with various catalysts to obtain poly(12-hydroxystearate) (PHS). The polymerization system of 12-HSAD showed an interesting polymerization behavior because of its large ring system. The polymers produced by this polymerization were directly reacted with L-lactide to obtain a diblock copolymer of poly(L-lactide)-block-poly-(12-hydroxystearate) (PLLA-b-PHS). Characterization of the resultant copolymers was also performed. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Enantioselective Synthesis of δ-Lactones with Lipase-Catalyzed Resolution and Mitsunobu Reaction

Both enantiomers of a series of δ-lactones (e.g., δ-decalactone, δ-dodelactone, and δ-hexadecalactone) were synthesized stereoselectively by Novozym 435–catalyzed resolution. Furthermore, only (S)-enantiomers of δ-lactones were synthesized with a combination of Novozym 435–catalyzed resolution and Mitsunobu reaction.

Synthesis of C2-symmetric chiral crown ethers by lipase-catalyzed reactions

Kinetic resolution of a racemic mixture of C 2-symmetric 18-crown-6 diols ( rac- 1a) and 15-crown-5 diol ( rac- 1c) was achieved by lipase-catalyzed acetylation. The enantiomeric excess of the chiral crown diols (95% ee and 82% ee) was determined by 1H NMR spectroscopy, using ( R)-(+)-1-(1-naphthyl)ethylammonium hydrochloride as a shift reagent. The C 2-symmetric chiral 15-crown-5 diol (>95% ee) was also obtained by kinetic resolution of the racemic diacetate ( rac- 2c) using lipase-catalyzed solvolysis.

Lipase‐catalysed production of triacylglycerols enriched in pinolenic acid at the sn‐2 position from pine nut oil

The purpose of this study was to produce triacylglycerols (TAGs) enriched in pinolenic acid (PLA) at the sn-2 position using the principle of acyl migration, from the pine nut oil containing PLA esterified exclusively at the sn-3 position. Two types of lipase-catalysed reactions, i.e. redistribution and reesterification of fatty acids, were successively performed using seven commercially available lipases as biocatalysts. Of the lipases tested, Novozym 435 and Lipozyme TL IM were effective biocatalysts for positioning PLA at the sn-2 location. These biocatalysts were selected for further evaluation of the effects of reaction parameters, such as temperature and water content on the migration of PLA residues to the sn-2 position and TAG content. For both lipases, a significant decrease in TAG content was observed after the lipase-catalysed redistribution of fatty acids for both lipases. The reduced TAG content could be enhanced up to approx. 92%, through lipase-catalysed re-esterification of the hydrolysed fatty acids under vacuum. TAG enriched in PLA at the sn-2 position was synthesised from pine nut oil via lipase-catalysed redistribution and re-esterification of fatty acid residues using Lipozyme TL IM and Novozym 435 as biocatalysts.

Multivariate Optimization in the Biosynthesis of a Triethanolamine (TEA)-Based Esterquat Cationic Surfactant Using an Artificial Neural Network

An Artificial Neural Network (ANN) based on the Quick Propagation (QP) algorithm was used in conjunction with an experimental design to optimize the lipase-catalyzed reaction conditions for the preparation of a triethanolamine (TEA)-based esterquat cationic surfactant. Using the best performing ANN, the optimum conditions predicted were an enzyme amount of 4.77 w/w%, reaction time of 24 h, reaction temperature of 61.9 °C, substrate (oleic acid: triethanolamine) molar ratio of 1:1 mole and agitation speed of 480 r.p.m. The relative deviation percentage under these conditions was less than 4%. The optimized method was successfully applied to the synthesis of the TEA-based esterquat cationic surfactant at a 2,000 mL scale. This method represents a more flexible and convenient means for optimizing enzymatic reaction using ANN than has been previously reported by conventional methods.

Lipase-catalyzed synthesis and characterization of myristoyl maltose ester

Myristoyl maltose ester was synthesized by lipase-catalyzed reaction of maltose and myristic acid. Influence of different reaction parameters, such as molecular sieve concentration, molar ratio of acid/sugar, enzyme concentration, reaction time, and reaction temperature, was studied. Under the optimum conditions of 20 g/L molecular sieve, 14% (w/w) lipase from Novozym 435, and acid/sugar molar ratio of 5:1 at 60 °C for 60 h, the highest conversion (90%) was achieved. The as-prepared maltose ester was confirmed by Fourier-transform infrared spectra (FTIR), liquid chromatograph–mass spectrum (LC–MS), and scanning electron microscopy (SEM).

Lipase-catalyzed syntheses of sugar esters in non-aqueous media

The lipase-catalyzed reaction is useful to obtain sugar esters with chemically defined structures and will contribute to the synthesis of sugar-based compounds by a chemo-enzymatic pathway. The synthesis of sugar esters in nonaqueous media has been attempted for a quarter century. To facilitate the reactions, they have been performed either in an organic solvent with/without a polar adjuvant or in an ionic liquid, or by using a hydrophobic sugar derivative. In this review, the following points are discussed: (1) various synthetic methods of sugar esters; (2) role of the solvents or adjuvants; and (3) improvement in the productivity.

Diacylglycerol synthesis by lipase-catalyzed partial hydrolysis of palm oil under microwave irradiation and continuous flow conditions

Abstract Diacylglycerols (DAG) are commonly used in different purity levels for food, medicine and cosmetic industries. Several approaches are found over the literature on DAG production under lipase-catalyzed reactions among which are highlighted: glycerol sterification, vegetable oils’ glycerolysis and selective hydrolysis. Results obtained palm oil partial hydrolysis catalyzed by PS Amano IM under microwave irradiation show that DAG can be produced through short-term reactions and moderated yields (5 min, 30%). The DAG production using packed bed reactors under conventional heating and continuous flow conditions is more efficient allowing us to produce 128 g in 24 h with flow rate as a key feature.

Biocatalytic synthesis of new copolymers from 3-hydroxybutyric acid and a carbohydrate lactone

Abstract Lipase-catalyzed reaction of 3-hydroxybutyric acid with d -glucono-δ-lactone at 5:1 molar ratio and 80 °C yielded a mixture of moderate molecular weight linear and cyclic oligomers. The most efficient biocatalyst, Candida antarctica B lipase (Novozyme 435), allowed the synthesis of new oligomeric compounds with ring-opened gluconolactone units included in the oligomeric chain, without previous derivatization of the sugar, or activation of the acid monomer. The reaction medium nature had an important influence on the product composition. Although the main copolymer amount was synthesized in tert-butanol/dimethylsulfoxide medium, the highest polymerization degrees, up to 9 for the copolymer, and 10 for the 3-hydroxybutyric acid homopolymer co-product, were achieved in solventless conditions.

Crystallization, Physicochemical Properties, and Oxidative Stability of the Interesterified Hard Fat from Rice Bran Oil, Fully Hydrogenated Soybean Oil, and Coconut Oil through Lipase-Catalyzed Reaction

Interesterified hard fat (IEHF) was produced from fully hydrogenated soybean oil (FHSBO) and rice bran oil (RBO) with different molar ratio (RBO/FHSBO = 1:1, 1:2, and 1:3). For interesterification, Lipozyme TL IM (10% of total substrates) was used as a biocatalyst. Further, coconut oil (CO; 40 wt.% on total weight of RBO and FHSBO) was also added in all reactants for providing medium chain fatty acid. After interesterification, the obtained IEHF and physical blend (before interesterification) with same molar ratio were carried out for comparing the physical properties, (i.e., solid fat content, melting and crystallization behavior, and polymorphic forms). From DSC results at 25 °C, solid fat content of the IEHF with different molar ratio (RBO/FHSBO = 1:1, 1:2, and 1:3) were 33.9%, 58.8%, and 72.1%, respectively, whereas physical blends at same molar ratio showed 66.2%, 71.6%, and 74.8%. Besides, short spacing β crystal polymorphic form was observed in the physical blend while only β′ crystal form was observed in IEHF, in which β′ polymorphic form is a desirable for the production of shortenings and margarines. In Rancimat test for oxidative stability, IEHF showed significantly lower induction time than the physical blend. When the catechin (200, 400, and 800 ppm) was added to the IEHF, induction time was significantly increased to 21.4, 34.1, and 44.3 h, respectively. In this study, IEHF from this study may have a potential functionality for the shortenings and margarines.

Application of a Burkholderia cepacia lipase-immobilized silica monolith to batch and continuous biodiesel production with a stoichiometric mixture of methanol and crude Jatropha oil

BackgroundThe enzymatic production of biodiesel through alcoholysis of triglycerides has become more attractive because it shows potential in overcoming the drawbacks of chemical processes. In this study, we investigate the production of biodiesel from crude, non-edible Jatropha oil and methanol to characterize Burkholderia cepacia lipase immobilized in an n-butyl-substituted hydrophobic silica monolith. We also evaluate the performance of a lipase-immobilized silica monolith bioreactor in the continuous production of biodiesel.ResultsThe Jatropha oil used contained 18% free fatty acids, which is problematic in a base-catalyzed process. In the lipase-catalyzed reaction, the presence of free fatty acids made the reaction mixture homogeneous and allowed bioconversion to proceed to 90% biodiesel yield after a 12 hour reaction time. The optimal molar ratio of methanol to oil was 3.3 to 3.5 parts methanol to one part oil, with water content of 0.6% (w/w). Further experiments revealed that B. cepacia lipase immobilized in hydrophobic silicates was sufficiently tolerant to methanol, and glycerol adsorbed on the support disturbed the reaction to some extent in the present reaction system. The continuous production of biodiesel was performed at steady state using a lipase-immobilized silica monolith bioreactor loaded with 1.67 g of lipase. The yield of 95% was reached at a flow rate of 0.6 mL/h, although the performance of the continuous bioreactor was somewhat below that predicted from the batch reactor. The bioreactor was operated successfully for almost 50 days with 80% retention of the initial yield.ConclusionsThe presence of free fatty acids originally contained in Jatropha oil improved the reaction efficiency of the biodiesel production. A combination of B. cepacia lipase and its immobilization support, n-butyl-substituted silica monolith, was effective in the production of biodiesel. This procedure is easily applicable to the design of a continuous flow-through bioreactor system.

ChemInform Abstract: Design of Lipase-Catalyzed Asymmetric Reactions in Organic Solvents and Their Application to the Synthesis of Optically Active Medicines

New strategy of lipase-catalyzed asymmetric reactions is described. Chiral 2-O-substituted glycerols, 2-substituted 1, 3-propanediols and 1, 4-diols were obtained in high optical yields by the asymmetric transesterification using activated esters as acyl donors. Facile process for the kinetic resolution of racemic alcohols was developed by the lipase-catalyzed esterification with acid anhydride. And chiral 1, 4-dihydropyridines and barbiturates were obtained in high optical yields by the lipase-catalyzed hydrolysis of their acyloxymethyl groups. Chiral medicines were synthesized from optically active compounds obtained by these lipase-catalayzed asymmetric reactions.