Addition Of Deep Eutectic Solvent Research Articles

Assessing the effect of deep eutectic solvents on α-chymotrypsin thermal stability and activity.

Optimizing the liquid reaction phase holds significant potential for enhancing the efficiency of biocatalytic pro- cesses since it determines reaction equilibrium and kinetics. This study investigates the influence of the addition of deep eutectic solvents on the stability and activity of α-chymotrypsin, a proteolytic enzyme with industrial rele- vance. Deep eutectic solvents, composed of choline chloride or betaine mixed with glycerol or sorbitol, were added in the reaction phase at various concentrations. Experimental techniques, including kinetic and fluorometry, were employed to assess the α-chymotrypsin activity, thermal stability, and unfolding reversibility. Atomistic molecular dynamics simulations were also conducted to assess the interactions and provide molecular-level insights between α-chymotrypsin and the solvent. The results showed that among all studied mixtures, adding choline chloride + sorbitol improved thermal stability up to 18 °C and reaction kinetic efficiency up to two-fold upon adding choline chloride + glycerol. Notably, the choline chloride + sorbitol system exhibited the most substantial stabilization effect, attributed to the surface preferential accumulation of sorbitol, as corroborated by the computational anal- yses. This work highlights the potential of tailoring liquid reaction phase of α-chymotrypsin catalyzed reaction using neoteric solventsto enhance α-chymotrypsin performance and stability in industrial applications.

Three-dimensional cross-linked network deep eutectic gel polymer electrolyte with the self-healing ability enable by hydrogen bonds and dynamic disulfide bonds

Solid polymer electrolytes (SPEs) are effective solutions for the development of high-performance and flexible lithium metal batteries (LMBs). However, the key problems of SPEs including low ionic conductivity and inability to repair damage have hindered their industrialization process. In this work, a three-dimensional (3D) cross-linked network gel polymer electrolyte (CNGPE) is designed. The addition of deep eutectic solvent (DES) improves the ionic conductivity of CNGPE. The hydrogen bonds and dynamic disulfide bonds in the 3D cross-linked network endow CNGPE rapid self-healing ability at ambient temperature. In addition, the addition of lithium difluoro(oxalato)borate (LiDFOB) and lithium nitrate (LiNO3) helps to form a stable solid electrolyte interface (SEI). Due to the ingenious design, the Li/CNGPE/Li symmetrical cell exhibits excellent interface stability and no short circuit occurs for more than 800 h. The assembled LiFePO4/CNGPE/Li cell exhibits a discharge specific capacity of 126 mAh g−1 after 960 cycles at 0.5C. This work has shown that the self-healing gel polymer electrolyte containing DES provides an effective and feasible method for the development of high-performance LMBs.

A countercurrent chromatography solvent system based on deep eutectic solvents for separation of cis- and trans-crocetin from Gardenia jasminoides Ellis.

Due to the structural similarity and large difference in concentration, the separation of trans- and cis-crocetin has been challenging, and the cis-crocetin is usually neglected. In this work, a countercurrent chromatography method was developed for the quick separation of trans-crocetin and cis-crocetin from the hydrolytic extract of Gardenia jasminoides Ellis. High purity of trans-crocetin (>95%) and cis-crocetin (>91%) were prepared simultaneously for the first time through a novel biphasic system based on deep eutectic solvents, n-heptane/n-butyl alcohol/13mmol/L Na2 CO3 in water/acetamide-benzyltrimethylammonium chloride (4:1, mol/mol) (4:7:9:1, v/v). The addition of deep eutectic solvent significantly improved the separation efficiency. The two targets can be easily recovered from the separation system through simple acidification and precipitation. It has potential for preparative separations on a large scale.

Structural Characteristics and Skin Permeabilities of Bicelles Dispersed in Hydrated Deep Eutectic Solvents

The structural properties of bicelles dispersed in hydrated deep eutectic solvents (DESs) was investigated by small-angle X-ray scattering, transmittance electron microscopy, and dynamic light scattering experimentations. Subsequently, we evaluated their skin permeabilities. The results showed that bicelles can be stably dispersed in hydrated DESs and the addition of DESs can improve the skin penetration of bicelles. However, further addition of DES induced the formation of the aggregates, resulting in the decrease of its skin permeability.

Medium engineering of phenylethanoid transfructosylation catalysed by yeast β-fructofuranosidase.

Tyrosol and hydroxytyrosol, by-products of olive oil production, are valuable substrates for enzymatic transglycosylation that can provide products with pharmaceutical potential. Phenylethanoid fructosides are produced from sucrose and phenylethanoids by the catalytic action of β-fructofuranosidases. This work dealt with the potential of the most abundant β-fructofuranosidase, baker's yeast invertase, for this bioconversion. The effects of sucrose and phenylethanoid concentrations were investigated with a focus on the selectivity of phenylethanoid transfructosylation and fructoside yields. For this purpose, initial rate and progress curve experiments were carried out for the initial (hydroxy)tyrosol and sucrose concentrations of 0.072-0.3M and 1-2M, respectively. Reaction courses exhibited either a maximum or plateau of fructoside yield in the range of about 10-18%. The addition of deep eutectic solvents was applied in the concentration range from 5 to 70% (v/v) to investigate the possibility of shifting the reaction equilibrium towards fructoside synthesis.

Continuous, stable, and safe organometallic reactions in flow at room temperature assisted by deep eutectic solvents

<h2>Summary</h2> This work demonstrates the first continuous, stable, and safe operation of organometallic reactions in flow under ambient conditions with high moisture tolerance and clogging resistance. The addition of deep eutectic solvents (DESs), such as glyceline (choline chloride/glycerol) and reline (choline chloride/urea), overcomes the previous limitations associated with the need for cryogenic conditions (long residence times and high energy requirements) and clogging. The immiscibility of the different solvents leads to a segmented flow where the reactive organic substrates are dispersed in a continuous DES-containing carrier phase. This system provides intimate contact between solvents, favoring the dissolution of lithium species (by-product) into the DES phase, avoiding the clogging under a wide range of conditions. In addition, the microfluidic scale provides excellent heat management (recirculation flow patterns) and a high surface area/volume ratio, enabling safe operation. The benefits of DESs were studied with a selection of two organolithiums and two organomagnesium reagents, and different imine/ketone substrates.

Characterization of w/o-type Microemulsions Containing l-Menthol-based Deep Eutectic Solvents for Use in Transdermal Drug Delivery

Abstract We investigated the structural properties of microemulsions (MEs) dispersed in oil base including hydrophobic deep eutectic solvents (DESs) and their skin permeabilities. The results showed that the addition of DESs can improve the skin penetration of monodispersed MEs by disturbing the lipid structures in the stratum corneum. Further addition of DESs caused the structural transition of MEs from a sphere to a cylinder and a bicontinuous system and decreased reduced skin penetration.

Stereoselective separation of dimethenamid by cyclodextrin electrokinetic chromatography using deep eutectic solvents

An Electrokinetic Chromatography (EKC) method was developed in this work enabling for the first time the separation of the four stereoisomers of the acetamide herbicide dimethenamid. A screening of different anionic cyclodextrins (CDs) revealed that the use of a single CD system did not allow the separation of the four dimethenamid stereoisomers while dual systems improved the chiral separation. The combination of 15 mM (2-carboxyethyl)-β-CD (CE-β-CD) with 10 mM methyl-γ-CD (M-γ-CD) originated the partial separation of dimethenamid stereoisomers. To obtain the baseline separation between all consecutive peaks, the effect of the addition of ionic liquids and deep eutectic solvents to the CDs dual system was investigated. While ionic liquids did not improve the chiral separation obtained with the CDs dual system, the addition of deep eutectic solvents showed generally beneficial effects on the separation in terms of resolution. The influence of the nature of the deep eutectic solvent was studied and the effects of the ready-made deep eutectic solvent and its components on the separation were compared. Choline chloride-D-fructose (ChCl-D-fructose) when added to the CDs dual system under optimized conditions (15 mM CE-β-CD, 10 mM M-γ-CD, 1.5 % ChCl-D-fructose (2:1) in a 100 mM borate buffer (pH 9.0), a separation voltage of 25 kV and a temperature of 20 ˚C) enabled separating the four stereoisomers of dimethenamid in 21 min with resolutions between consecutive peaks of 6.0, 2.1 and 1.5. The analytical characteristics of the developed method were evaluated and considered adequate to achieve the stereoselective analysis of dimethenamid-P in commercial agrochemical formulations. Results demonstrated the potential of the method to control the quality of these formulations and to determine the stereoisomeric purity of dimethenamid-P in these products.

Enhancing biodiesel production via liquid Yarrowia lipolytica lipase 2 in deep eutectic solvents

With the rapid development of effective overexpression of enzymes, the process of liquid lipase catalysis of biodiesel can be concerned in a commercial viewpoint. The main bottleneck is to achieve high yield of biodiesel under a high water content. In this research, firstly, liquid Yarrowia lipolytica Lipase 2 was used to catalyze synthesis of biodiesel and 91.8% yield was obtained in the optimized reaction conditions after 24 h of reaction at 40 °C, water content 30 wt% (water/oil, w/w) and 1500 U/g oil of lipase dosage. To further improve the biodiesel yield, a deep eutectic solvent based on choline chloride and glucose was synthesized and optimized in terms of addition amount and water content, and the highest biodiesel yield of 98.5% was then achieved. The dynamics of each component during the reaction process were totally investigated, and found it was the addition of deep eutectic solvent that led to a deeper completion of the transesterification reaction. It also improved the reusability of the enzyme with a maximum biodiesel yield of 99.6% at the second reuse batch. This study demonstrates that deep eutectic solvent addition strategy has great potential for the commercialization of liquid lipase-catalyzed biodiesel production.

Effect of the addition of deep eutectic solvent to the anthracene separation

Anthracene (AN) is an important fine chemical feedstock, mainly derived from the anthracene oil fraction of high-temperature coal tar. The traditional solvent crystallization method used to obtain anthracene involves large amounts of solvents. A method with a high separation capacity and a high selectivity needs to be developed urgently. To this end, the composition of crude AN oil and the solubility of its main components in xylene were determined, and phenanthrene in crude AN oil was extracted with xylene. Pure deep eutectic solvents (DESs) and DESs–organic solvent mixture were then applied to separate anthracene and carbazole, respectively. Based on the distribution coefficient, selectivity, and purity of the AN product, the influence of organic solvent type, the molar ratio of DESs to organic solvent, and DESs type on the separation efficiency were investigated. Finally, the separation mechanism was investigated with density functional theory calculations and UV–visible spectroscopy. The results show that the phenanthrene content decreased from 25.5% to 2.6% and most of other condensed aromatics in crude AN were removed after washing twice with xylene. DESs–organic solvent mixtures had better performance than pure DESs for the separation of anthracene and carbazole, and under optimal condition, the 97.5% purity of AN is acquired in a single separation step with a tetraethyl ammonium chloride–glycerol DESs–DMF mixture. The more complicated interactions between phenanthrene and xylene than between anthracene / carbazole and xylene favored the removal of phenanthrene. The hydrogen bond with the minimum bond energy (-17.6 kJ/mol) between DESs and carbazole is also stronger than that with the maximum bond energy (-16.8 kJ/mol) between DESs and anthracene. Adding DESs to organic solvent can enhance the interactions between carbazole and the solvent, but had no significantly influence on interactions between anthracene and the solvent, thereby facilitating the separation of anthracene and carbazole.

Improving Whole-Cell Biocatalysis by Addition of Deep Eutectic Solvents and Natural Deep Eutectic Solvents

Being considered greener alternatives to ionic liquids (IL), deep eutectic solvents (DES) and natural deep eutectic solvents (NADES) have currently attracted broad interests from academics and industry. In this study, the transformation of isoeugenol to vanillin catalyzed by Lysinibacillus fusiformis CGMCC1347 cells was taken as the model reaction to examine the impacts of 24 DESs and 21 NADESs as cosolvents on whole-cell biocatalysis. Both types of cosolvents showed the ability of improving the production yields up to 142% and 132% of the ones obtained in (NA)DES-free aqueous systems, respectively. The data obtained by confocal laser scanning microscopy and flow cytometry tests and measurements of OD260 and OD280 agreed well with the bioconversion data, suggesting that addition of these cosolvents may be beneficial to whole-cell biocatalysis in enhancing the cellular membrane permeability. Interaction of DES with bacterial cell wall was discussed. The cells immobilized in PVA-alginate beads granted an augmented production yield in the presence of DES and NADES, up to 181% of the one obtained in a pure water system, and their catalytic activity was well maintained after being used for at least 13 cycles.