Effects of physicochemical properties of ionic liquids on butyl acetate synthesis using Candida antarctica lipase B

Kim, Ho Shin; Koo, Yoon‐Mo

doi:10.1007/s11814-012-0043-y

Cited by 8 publications

(6 citation statements)

References 44 publications

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“…Our experimental results showed that the type of imidazolium cations influences the enzyme activity of CALB and their initial reaction rate increases in the following order: S2, ESI †). 24 Since the observed trend in the reaction rate does not correlate with the length of the cation chain or other properties of cations, we hypothesized that cations affected the conformation and dynamics of CALB and consequently the size of the catalytic cavity. Size of the catalytic cavity plays an important role in the regulation of substrate's influx and product's egress and enzyme activity can be hindered if the cavity entrance becomes smaller than the size of substrates.…”

Section: Resultsmentioning

confidence: 99%

“…23 Our previous experimental observations showed that the CALB activity and the initial reaction rate did not correlate with the cation's alkyl side chain length nor with the relevant IL solvent parameters such as density, viscosity and hydrophobicity. 24 Thus, the effect of cations on the activity and stability of enzymes in ILs is still unclear and remains to be understood. Here, we aim to address the effect of cations on the structure and function of the CALB enzyme by correlating the structural changes of the CALB with its activity in four different ILs with various cations and the same weakly coordinating anion trifluoromethanesulfonate [TfO] À .…”

Section: Introductionmentioning

confidence: 99%

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The effect of imidazolium cations on the structure and activity of the Candida antarctica Lipase B enzyme in ionic liquids

Kim

Eom

Koo

et al. 2016

Phys. Chem. Chem. Phys.

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In order to understand how cations affect the structural changes and enzyme activity of Lipase B from Candida antarctica, we performed all-atom molecular dynamics simulations of CALB in four types of ionic liquids (ILs) with varying sizes of imidazolium cations and correlated these results with the experimentally determined CALB activity. The imidazolium cations under study differ in the alkyl tail length in the following order: [Emim](+) < [Bmim](+) < [Hmim](+) < [Omim](+). We observed that the best enzyme activity and structural stability of CALB are obtained in [Bmim][TfO] and [Hmim][TfO]. In contrast, in [Emim][TfO], bonding of [TfO](-) to LYS-290 disrupts the interactions between LYS-290 and ILE-285, which leads to a closed catalytic gate conformation with low accessibility of substrates to the catalytic triad. In [Omim][TfO], strong hydrophobic interactions between [Omim](+) and LEU-278 result in a significant loss of the secondary structure of the α-10 helix and cause the exposure of the catalytic triad to ILs, which affects the stability of the catalytic triad and consequently deteriorates the enzyme activity. Overall, our study indicates that a high ion coordination number ([Emim][TfO]) or the presence of a long hydrophobic tail ([Omim][TfO]) can facilitate ion-protein interactions that cause structural distortions and a decrease in CALB enzyme activity in ILs.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The effect of imidazolium cations on the structure and activity of the Candida antarctica Lipase B enzyme in ionic liquids

Kim

Eom

Koo

et al. 2016

Phys. Chem. Chem. Phys.

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“…The highest reaction rate (273.9 mmol·L −1 h −1 ) was obtained in treatment 22 (45 °C, 3:1 alcohol:acid, amount of biocatalyst 10%, added water 0.5%), whereas the lowest activity was in treatment 21, with a reaction rate of 44.5 mmol·L −1 h −1 (45 °C, 3:1 alcohol:acid, amount of biocatalyst 1%, added water 0.5%). In general, half of the treatments presented good reaction rates, over 200 mmol·L −1 h −1 , which represents almost 70% of conversion in 1 h. These were better results than those obtained using CALB for the butyl acetate synthesis in ionic liquids [23].…”

Section: Resultsmentioning

confidence: 99%

Combined Effects of Ultrasound and Immobilization Protocol on Butyl Acetate Synthesis Catalyzed by CALB

et al. 2014

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It is well established that the performance of lipase B from Candida antarctica (CALB) as catalyst for esterification reactions may be improved by the use of ultrasound technology or by its immobilization on styrene-divinylbenzene beads (MCI-CALB). The present research evaluated the synthesis of butyl acetate using MCI-CALB under ultrasonic energy, comparing the results against those obtained using the commercial preparation, Novozym 435. The optimal conditions were determined using response surface methodology (RSM) evaluating the following parameters: reaction temperature, substrate molar ratio, amount of biocatalyst, and added water. The optimal conditions for butyl acetate synthesis catalyzed by MCI-CALB were: temperature, 48.8 °C; substrate molar ratio, 3.46:1 alcohol:acid; amount of biocatalyst, 7.5%; and added water 0.28%, both as OPEN ACCESSMolecules 2014, 19 9563 substrate mass. Under these conditions, 90% of conversion was reached in 1.5 h. In terms of operational stability, MCI-CALB was reused in seven cycles while keeping 70% of its initial activity under ultrasonic energy. The support pore size and resistance are key points for the enzyme activity and stability under mechanical stirring. The use of ultrasound improved both activity and stability because of better homogeneity and reduced mechanical stress to the immobilized system.

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“…In addition, the viscosity of ionic liquids affects the reaction rate by limiting mass transfer and the size of anionic portion of the ionic liquids majorly influences the enzyme in solubleness. Imidazolium-based ionic liquids ([Bmim][TfO]) with moderate physicochemical properties have been reported to accelerate mass transfer and dissolve large amounts of enzyme 37 . During the butyl acetate biosynthesis with Candida antarctica lipase B in [Bmim][TfO], the initial reaction and conversion rate were approximately 1.4 and 1.1 times higher, respectively, in [Bmim][TfO] than in a conventional solvent (e.g., tert-butanol).…”

Section: Asian Journal Of Chemistry Asian Journal Of Chemistrymentioning

confidence: 99%

Recent Advances in Engineering of Media for Enzymatic Catalysis with Lipase

Li¹,

Wang²,

Shen³

et al. 2014

Asian J. Chem.

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Most lipases display good solubility and catalytic activity in non-aqueous media. In many types of non-aqueous media, such as ionic liquids, supercritical fluids, fluorous solvents etc., substrates and products are soluble and are therefore able to diffuse during reactions, which might often be beneficial to the lipase activity. Lipases often exhibit higher activity and stability in non-aqueous media than in aqueous environments. In addition, after reactions are carried out in novel media, a simple separation procedure might be included with the reaction process to facilitate improved purification of the products without using chromatographic separation or liquid-liquid extraction. This review focuses on novel medium for lipase catalysis, such as fluorous solvents, ionic liquids, supercritical fluids, etc. Some future perspectives and challenges facing in the media for enzymatic synthesis with lipase are also proposed.

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Effects of physicochemical properties of ionic liquids on butyl acetate synthesis using Candida antarctica lipase B

Cited by 8 publications

References 44 publications

The effect of imidazolium cations on the structure and activity of the Candida antarctica Lipase B enzyme in ionic liquids

The effect of imidazolium cations on the structure and activity of the Candida antarctica Lipase B enzyme in ionic liquids

Combined Effects of Ultrasound and Immobilization Protocol on Butyl Acetate Synthesis Catalyzed by CALB

Recent Advances in Engineering of Media for Enzymatic Catalysis with Lipase

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