Enantioseparation of the esters of α-N-acetyl amino acids by lipase in ionic liquid

Malhotra, Sanjay V.; Zhao, Hua

doi:10.1002/chir.20132

Cited by 19 publications

(17 citation statements)

References 22 publications

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“…[8][9][10]12,15 Lipases tolerate nonnatural environments surprisingly well, and have been well established as promising catalysts for biotransformations in organic solvents 2 or ILs. [14][15][16][17] On the other hand, acyl transfer reactions catalyzed by lipases with vinyl acetate as acyl donor have become a standard and popular technique for the kinetic resolution of racemic alcohols. However, the lipase has to be chosen carefully because the released by-product of this reaction, acetaldehyde, may cause a dramatic loss in the activity possibly due to the Schiff's base formation of lysine residues in the lipase structure.…”

Section: Resultsmentioning

confidence: 99%

“…The observed activities were similar to those achieved in traditional organic solvents, but the stability of the enzyme was markedly enhanced. Following this pioneering work, the potential application of lipase, [14][15][16][17] protease, 18,19 esterase, 20,21 amidase, 22 epoxide hydrolase, 23 peroxidase, 24 alcohol dehydrogenase, 25 or hydroxynitrile lyase 26,27 in IL-containing systems was explored, and many enzymes were demonstrated to be active in ILs, showing comparable or even higher activity, selectivity, and stability than in organic solvents. For example, the replacement of typical organic solvents by ILs in the lipase-catalyzed asymmetric acylation of amines with carboxylic acids has led to increased reaction rate and higher enantioselectivity.…”

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confidence: 99%

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Efficient kinetic resolution of (R,S)‐1‐trimethylsilylethanol via lipase‐mediated enantioselective acylation in ionic liquids

Lou

Zong

2006

Chirality

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Efficient enantioselective acylation of (R,S)-1-trimethylsilylethanol {(R,S)-1-TMSE} with vinyl acetate catalyzed by immobilized lipase from Candida antarctica B (i.e., Novozym 435) was successfully conducted in ionic liquids (ILs). A remarkable enhancement in the initial rate and the enantioselectivity of the acylation was observed by using ILs as the reaction media when compared to the organic solvents tested. Also, the activity, enantioselectivity, and thermostability of Novozym 435 increased with increasing hydrophobicity of ILs. Of the six ILs examined, the IL C4MIm.PF6 gave the fastest initial rate and the highest enantioselectivity, and was consequently chosen as the favorable medium for the reaction. The optimal molar ratio of vinyl acetate to (R,S)-1-TMSE, water activity, and reaction temperature range were 4:1, 0.75, and 40 -50 degrees C, respectively, under which the initial rate and the enantioselectivity (E value) were 27.6 mM/h and 149, respectively. After a reaction time of 6 h, the ee of the remaining (S)-1-TMSE reached 97.1% at the substrate conversion of 50.7%. Additionally, Novozym 435 was effectively recycled and reused in C4MIm.PF6 for five consecutive runs without substantial lose in activity and enantioselectivity. The preparative scale kinetic resolution of (R,S)-1-TMSE in C4MIm.PF6 is shown to be very promising and useful for the industrial production of enantiopure (S)-1-TMSE.

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Section: Resultsmentioning

confidence: 99%

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confidence: 99%

Efficient kinetic resolution of (R,S)‐1‐trimethylsilylethanol via lipase‐mediated enantioselective acylation in ionic liquids

Lou

Zong

2006

Chirality

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“…The enantioselectivity of BCL increased from 10~40 to > 200 after coating the lipase with 1-butyl-2,3-dimethylimidazolium (BMMIM) (poly(oxyethylene)alkyl sulfate) [52]. The enantioselectivity of porcine pancreatic lipase (PPL) in the hydrolysis of methyl or ethyl esters of N-acetyl amino acids increased up to 10-fold in 15% N-ethylpyridinium (CF 3 COO) as compared to acetonitrile: from E = 2.3 to E = 23 for threonine methyl ester [53].…”

Section: Ionic Liquids As Non-aqueous Solventsmentioning

confidence: 99%

Toward advanced ionic liquids. Polar, enzyme-friendly solvents for biocatalysis

Gorke

Srienc

Kazlauskas

2010

Biotechnol Bioproc E

253

159

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Ionic liquids, also called molten salts, are mixtures of cations and anions that melt below 100 o C. Typical ionic liquids are dialkylimidazolium cations with weakly coordinating anions such as (MeOSO 3 ) or (PF 6 ). Advanced ionic liquids such as choline citrate have biodegradable, less expensive, and less toxic anions and cations. Deep eutectic solvents are also included in the advanced ionic liquids. Deep eutectic solvents are mixtures of salts such as choline chloride and uncharged hydrogen bond donors such as urea, oxalic acid, or glycerol. For example, a mixture of choline chloride and urea in 1:2 molar ratio liquefies to form a deep eutectic solvent. Their properties are similar to those of ionic liquids. Water-miscible ionic liquids as cosolvents with water enhance the solubility of substrates or products. Although traditional water-miscible organic solvents also enhance solubility, they often inactivate enzymes, while ionic liquids do not. The enhanced solubility of substrates can increase the rate of reaction and often increases the regioor enantioselectivity. Ionic liquids can also be solvents for non-aqueous reactions. In these cases, they are especially suited to dissolve polar substrates. Polar organic solvent alternatives inactivate enzymes, but ionic liquids do not even when they have similar polarities. Besides their solubility properties, ionic liquids and deep eutectic solvents may be greener than organic solvents because ionic liquids are nonvolatile, and can be made from nontoxic components. This review covers selected examples of enzyme catalyzed reaction in ionic liquids that demonstrate their advantages and unique properties, and point out opportunities for new applications. Most examples involve hydrolases, but oxidoreductases and even whole cell reactions have been reported in ionic liquids. © KSBB hÉóïçêÇëW=áçåáÅ=äáèìáÇëI=ÇÉÉé=ÉìíÉÅíáÅ=ëçäîÉåíëI=ÜóÇêçä~ëÉëI=çñáÇçêÉÇìÅí~ëÉëI=éçäóãÉêáò~íáçå= = = = = IONIC LIQUIDS AND DEEP EUTECTIC SOLVENTSIonic liquids, also called molten salts, are mixtures of cations and anions that melt below 100 o C. The low melting point stems from a mismatch in the size of the anion and cation that prevents crystallization. Changing the structures of the anions or cations can tune the polarities and other properties. Even though they are salts, their polarities are only moderate, similar to ethanol. Ionic liquids have negligible vapor pressure. Ionic liquids are viscous, typically 0.1 Pas or more, which is similar to glycerol or honey.The first ionic liquid -ethylammonium nitrate (mp 12 o C) -was reported in 1914 [1], but attracted limited use. The first generation of widely studied ionic liquids used the dialkylimmidazolium and related cations reported in 1982 [2], Fig. 1. Varying the cation structure varied the properties of the ionic liquid. The anions were chloroaluminate or other metal halide anions, which react with water and thus are not suited for biotransformations. The second generation of ionic liquids, discovered a decade later [3], replaced the water r...

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“…This reaction has also been investigated as a useful path to the resolution of racemates of the amino acids, and work in this area was reviewed by Miyazawa. 23 More recently, Malhotra and Zhao 24 have researched the enantioseparation of the esters of a-amino acids by lipase in an ionic liquid.…”

Section: -11mentioning

confidence: 99%

Following the lipase catalyzed enantioselective hydrolysis of amino acid esters with capillary electrophoresis using contactless conductivity detection

Schuchert‐Shi

Hauser

2009

Chirality

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The progress of the enzymatic hydrolysis of racemic mixtures of the enantiomers of the methyl esters of serine and threonine was monitored. This was possible in a reaction vessel of 1.5 mL by direct sampling of volumes in the nanoliter-range directly into an electrophoresis capillary. Contactless conductivity detection was used for quantification as the analytes are not accessible by UV-detection in capillary electrophoresis. Porcine pancreatic lipase and wheat germ lipase both showed a preference for the L-enantiomers of both amino acid esters. The selectivity of the porcine lipase between the two L-esters of the two amino acids was also studied and it was found that the production of L-threonine had priority over L-serine. Chirality 22:331-335, 2010. V V C 2009 Wiley-Liss, Inc.

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Enantioseparation of the esters of α-N-acetyl amino acids by lipase in ionic liquid

Cited by 19 publications

References 22 publications

Efficient kinetic resolution of (R,S)‐1‐trimethylsilylethanol via lipase‐mediated enantioselective acylation in ionic liquids

Efficient kinetic resolution of (R,S)‐1‐trimethylsilylethanol via lipase‐mediated enantioselective acylation in ionic liquids

Toward advanced ionic liquids. Polar, enzyme-friendly solvents for biocatalysis

Following the lipase catalyzed enantioselective hydrolysis of amino acid esters with capillary electrophoresis using contactless conductivity detection

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