Enzymatic ester synthesis in ionic liquids

Lozano, Pedro; Diego, Teresa De; Carrié, Daniel; Vaultier, Michel; Iborra, José L.

doi:10.1016/s1381-1177(02)00128-5

Cited by 116 publications

(39 citation statements)

References 15 publications

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“…Results represented in Figure 5 revealed that more than 80% of the productivity was preserved in eight consecutive semicontinuous biotransformations within the integrated microfluidic system with reused CaLB in the ionic liquid phase, which confirmed previous findings that enzyme could retain its activity in several imidazolium-based ionic liquids [38,39]. The drop in productivity might be attributed to the presence of products in the ionic liquid inlet flow, which resulted in the reversed reaction to form acetic acid.…”

Section: Biotransformation With Reused Enzyme and Ionic Liquidsupporting

confidence: 86%

Integrated lipase-catalyzed isoamyl acetate synthesis in a miniaturized system with enzyme and ionic liquid recycle

Novak

Žnidaršič–Plazl

2013

Green Processing and Synthesis

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Isoamyl acetate synthesis employing aqueous Candida antarctica lipase B (CaLB) solution was performed in a two-phase solvent system comprising hydrophilic ionic liquid 1-butyl-3-methylpyridinium dicyanamide and n-heptane. An X-junction glass microfluidic chip was used to obtain uniform microdroplets of n-heptane within a continuous phase of ionic liquid with dissolved enzyme and reactants, namely, isoamyl alcohol and acetic anhydride. A developed flow pattern resulted in a very large specific interfacial area for the reaction with amphiphilic CaLB and simultaneous extraction of isoamyl acetate in n-heptane. Biotransformation was performed within a continuously operated microfluidic system consisting of an X-junction chip and a silanized tube of a submillimeter diameter, which was further integrated with a microseparator based on a hydrophobic membrane. Efficient separation of n-heptane with product from ionic liquid phase containing enzyme and remaining substrates and products was achieved, enabling reuse of CaLB together with ionic liquid phase. More than 80% of productivity was preserved in each of the eight consecutive biotransformations within the integrated microfluidic system with reused lipase B in the ionic liquid phase. Subsequent ionic liquid regeneration accomplished by vacuum distillation enabled efficient reuse of this solvent in esterification with fresh enzyme.

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Section: Biotransformation With Reused Enzyme and Ionic Liquidsupporting

confidence: 86%

Integrated lipase-catalyzed isoamyl acetate synthesis in a miniaturized system with enzyme and ionic liquid recycle

Novak

Žnidaršič–Plazl

2013

Green Processing and Synthesis

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“…In the case of IL, 12.5% (v/v) 1-propanol was added in order to test a liquid medium identical to that previously used for amino acid ester synthesis (Lozano et al, 2001b(Lozano et al, , 2003. At regular intervals, aliquots of 50 AL were withdrawn from the incubation mixture and the residual activity was measured as described above.…”

Section: Enzyme Stabilitymentioning

confidence: 99%

“…as novel media for enzyme-catalyzed transformations has recently attracted considerable attention, and could be considered an important axis for development of green chemistry in the near future (van Rantwijk et al, 2003). Indeed, some ionic liquids (ILs) have been shown to be excellent nonaqueous media for enzyme-catalyzed reactions, not only because the enzymes display a high level of activity and stereoselectivity for many different chemical transformations, e.g., aliphatic ester synthesis (Lozano et al, 2003), the kinetic resolution of racemic alcohols (Schöfer et al, 2001;Lozano et al, 2004;Noël et al, 2004), carbohydrate ester synthesis (Park and Kazlauskas, 2001), and polymer synthesis (Nara et al, 2003), but also because of their important stabilizing effect on enzymes (up to 2,300-fold increased half-life time with respect to classical organic solvents) (Lozano et al, 2001a,b;Persson and Bornscheuer, 2003).…”

Section: Introductionmentioning

confidence: 99%

Fluorescence and CD spectroscopic analysis of the α‐chymotrypsin stabilization by the ionic liquid, 1‐ethyl‐3‐methylimidazolium bis[(trifluoromethyl)sulfonyl]amide

Diego

Lozano

Gmouh

et al. 2004

Biotech & Bioengineering

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188

139

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The stability of alpha-chymotrypsin in the ionic liquid, 1-ethyl-3-methyl-imidizolium bis[(trifluoromethyl)sulfonyl]amide ([emim][NTf2]), was studied at 30 and 50 degrees C and compared with the stability in other liquid media, such as water, 3 M sorbitol, and 1-propanol. The kinetic analysis of the enzyme stability pointed to the clear denaturative effect of 1-propanol, while both 3M sorbitol and [emim][NTf2] displayed a strong stabilizing power. For the first time, it is shown that enzyme stabilization by ionic liquids seems to be related to the associated structural changes of the protein that can be observed by differential scanning calorimetry (DSC) and fluorescence and circular dichroism (CD). The [emim][NTf2] enhanced both the melting temperature and heat capacity of the enzyme compared to the other media assayed. The fluorescence spectra clearly showed the ability of [emim][NTf2] to compact the native structural conformation of alpha-chymotrypsin, preventing the usual thermal unfolding which occurs in other media. Changes in the secondary structure of this beta/beta protein, as quantified by the CD spectra, pointed to the great enhancement (up 40% with respect to that in water) of beta-strands in the presence of the ionic liquid, which reflects its stabilization power.

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“…In addition, subtilisin Carlsberg has been shown to be active in a Hofmeister series of hydrophilic ionic liquids [42] and both α -chymotrypsin and subtilisin Carlsberg catalyzed the esterifi cation of N -acetylphenylalanine in water miscible 1 -ethyl -3 -methylimidazolium trifl uoromethyl sulfonate ( [EMIM] [Tf] ) with 0.2% water (v/v) at 30 ° C [43] . The transestrifi cation activity half -life of α -chymotrypsin was increased in four different ionic liquids as compared to 1 -propanol as reaction medium at 50 ° C and 2% water (v/v): the largest increase was obtained with the ionic liquid of lowest polarity, methyltrioctylammonium trifl imide and it was 13.5 times higher than that of 1 -propanol [44] .…”

Section: Solvent Engineering 63mentioning

confidence: 94%