Recent progress on deep eutectic solvents in biocatalysis.
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ABSTRACT:
SUBMITTER: Xu P
PROVIDER: S-EPMC5522511 | biostudies-other | 2017
REPOSITORIES: biostudies-other
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Project description:As functional liquid media, natural deep eutectic solvent (NADES) species can dissolve natural or synthetic chemicals of low water solubility. Moreover, the special properties of NADES, such as biodegradability and biocompatibility, suggest that they are alternative candidates for concepts and applications involving some organic solvents and ionic liquids. Owing to the growing comprehension of the eutectic mechanisms and the advancing interest in the natural eutectic phenomenon, many NADES applications have been developed in the past several years. However, unlike organic solvents, the basic structural unit of NADES media primarily depends on the intermolecular interactions among their components. This makes NADES matrices readily influenced by various factors, such as water content, temperature, and component ratio and, thus, extends the metabolomic challenge of natural products (NPs). To enhance the understanding of the importance of NADES in biological systems, this review focuses on NADES properties and applications in NP research. The present thorough chronological and statistical analysis of existing report adds to the recognition of the distinctiveness of (NA)DES, involves a discussion of NADES-related observations in NP research, and reportes applications of these eutectic mixtures. The work identifies potential areas for future studies of (NA)DES by evaluating relevant applications, including their use as extraction and chromatographic media as well as their biomedical relevance. The chemical diversity of natural metabolites that generate or participate in NADES formation highlights the growing insight that biosynthetically primordial metabolites (PRIMs) are as essential to the biological function and bioactivity of unrefined natural products as the biosynthetically more highly evolutionary metabolites (HEVOs) that can be isolated from crude mixtures.
| S-EPMC5913660 | biostudies-literature
Project description:Abstract This article provides an overview of a deep eutectic mixture based on the application of lithium nitrate (V) and acetamide as an electrolyte in a carbon‐based electrochemical capacitor. This type of electrolyte is intended to be applied in devices designed for operation under critical conditions (e. g., extreme temperatures). In contrast to water‐ and common organic‐based formulations, the proposed electrolyte ensures good device performance at 100 °C. To describe the chemistry of the proposed mixture, infrared and Raman spectroscopy, differential scanning calorimetry, and gas chromatography with mass spectrometry were used. Electrochemical analysis includes the verification of system ageing, self‐discharge monitoring, leakage current measuring, and fundamental testing related to determining the specific capacitance or maximum voltage. Additionally, comprehensive analysis of the lithium nitrate salt and organic solvent addition to the operating system was carried out, including the replacement of lithium ions with sodium or potassium. Extreme electrolyte: There is a great need for new electrolytes for use in electrochemical capacitors that will allow operation in extreme environmental conditions. Here, a deep eutectic solvent based on lithium nitrate and acetamide was applied at 100 °C. This solvent‐free mixture ensures stability and long cyclability of the system under such severe conditions.
| S-EPMC8596588 | biostudies-literature
Project description:Glycolipids are considered an alternative to petrochemically based surfactants because they are non-toxic, biodegradable, and less harmful to the environment while having comparable surface-active properties. They can be produced chemically or enzymatically in organic solvents or in deep eutectic solvents (DES) from renewable resources. DES are non-flammable, non-volatile, biodegradable, and almost non-toxic. Unlike organic solvents, sugars are easily soluble in hydrophilic DES. However, DES are highly viscous systems and restricted mass transfer is likely to be a major limiting factor for their application. Limiting factors for glycolipid synthesis in DES are not generally well understood. Therefore, the influence of external mass transfer, fatty acid concentration, and distribution on initial reaction velocity in two hydrophilic DES (choline:urea and choline:glucose) was investigated. At agitation speeds of and higher than 60 rpm, the viscosity of both DES did not limit external mass transfer. Fatty acid concentration of 0.5 M resulted in highest initial reaction velocity while higher concentrations had negative effects. Fatty acid accessibility was identified as a limiting factor for glycolipid synthesis in hydrophilic DES. Mean droplet sizes of fatty acid-DES emulsions can be significantly decreased by ultrasonic pretreatment resulting in significantly increased initial reaction velocity and yield (from 0.15 ± 0.03 μmol glucose monodecanoate/g DES to 0.57 ± 0.03 μmol/g) in the choline: urea DES. The study clearly indicates that fatty acid accessibility is a limiting factor in enzymatic glycolipid synthesis in DES. Furthermore, it was shown that physical pretreatment of fatty acid-DES emulsions is mandatory to improve the availability of fatty acids.
| S-EPMC7214929 | biostudies-literature
Project description:Stabilization of reactive intermediates is an enabling concept in biomass fractionation and depolymerization. Deep eutectic solvents (DES) are intriguing green reaction media for biomass processing; however undesired lignin condensation is a typical drawback for most acid-based DES fractionation processes. Here we describe ternary DES systems composed of choline chloride and oxalic acid, additionally incorporating ethylene glycol (or other diols) that provide the desired 'stabilization' function for efficient lignocellulose fractionation, preserving the quality of all lignocellulose constituents. The obtained ethylene-glycol protected lignin displays high β-O-4 content (up to 53 per 100 aromatic units) and can be readily depolymerized to distinct monophenolic products. The cellulose residues, free from condensed lignin particles, deliver up to 95.9 ± 2.12% glucose yield upon enzymatic digestion. The DES can be recovered with high yield and purity and re-used with good efficiency. Notably, we have shown that the reactivity of the β-O-4 linkage in model compounds can be steered towards either cleavage or stabilization, depending on DES composition, demonstrating the advantage of the modular DES composition.
| S-EPMC8440657 | biostudies-literature
Project description:Hydrophobic deep eutectic solvents (DESs) have recently gained much attention as water-immiscible solvents for a wide range of applications. However, very few studies exist in which the hydrophobicity of these DESs is quantified. In this work, the interfacial properties of hydrophobic DESs with water were computed at various temperatures using molecular dynamics simulations. The considered DESs were tetrabutylammonium chloride-decanoic acid (TBAC-dec) with a molar ratio of 1:2, thymol-decanoic acid (Thy-dec) with a molar ratio of 1:2, and dl-menthol-decanoic acid (Men-dec) with a molar ratio of 2:1. The following properties were investigated in detail: interfacial tensions, water-in-DES solubilities (and salt-in-water solubilities for TBAC-dec/water), density profiles, and the number densities of hydrogen bonds. Different ionic charge scaling factors were used for TBAC-dec. Thy-dec and Men-dec showed a high level of hydrophobicity with negligible computed water-in-DES solubilities. For charge scaling factors of 0.7 and 1 for the thymol and decanoic acid components of Thy-dec, the computed interfacial tensions of the DESs are in the following order: TBAC-dec (ca. 4 mN m-1) < Thy-dec (20 mN m-1) < Men-dec (26 mN m-1). The two sets of charge scaling factors for Thy-dec did not lead to different density profiles but resulted in considerable differences in the DES/water interfacial tensions due to different numbers of decanoic acid-water hydrogen bonds at the interfaces. Large peaks were observed for the density profiles of (the hydroxyl oxygen of) decanoic acid at the interfaces of all DES/water mixtures, indicating a preferential alignment of the oxygen atoms of decanoic acid toward the aqueous phase.
| S-EPMC8591605 | biostudies-literature
Project description:Deep eutectic solvents are a new class of green solvents that are being explored as an alternative for used nuclear fuel and critical material recycling. However, there is a paucity of knowledge regarding metal behavior in them. This paper explores the underlying chemistry of rare-earth elements in choline chloride-based deep eutectic solvents by using a multi-technique spectroscopic methodology. Results show that speciation is highly dependent on the choice of the hydrogen-bond donor. Collected EXAFS data showed Ln3+ coordination with ethylene glycol and urea in their respective solvents and coordination with chloride in the lactic acid system. Generalized coordination environments were determined to be [LnL4-5], [LnL7-10], and [LnL5-6] in the ethylene glycol, urea, and lactic acid systems, respectively. Collected UV/vis spectra for Nd3+ and Er3+ showed variations with changing solvents, showing that Ln-Cl interactions do not dominate in these systems. Luminescence studies were consistent, showing varying emission spectra with varying solvent systems. The shortest luminescent lifetimes were observed in the choline chloride-ethylene glycol deep eutectic solvent, suggesting coordination through O-H groups. Combining all collected data allowed Eu3+ coordination geometries to be assigned.
| S-EPMC8756809 | biostudies-literature
Project description:The encapsulation ?-carotene in whey protein concentrate (WPC) capsules through the emulsion electrospraying technique was studied, using deep eutectic solvents (DES) as solvents. These novel solvents are characterized by negligible volatility, a liquid state far below 0 °C, a broad range of polarity, high solubilization power strength for a wide range of compounds, especially poorly water-soluble compounds, high extraction ability, and high stabilization ability for some natural products. Four DES formulations were used, based on mixtures of choline chloride with water, propanediol, glucose, glycerol, or butanediol. ?-Carotene was successfully encapsulated in a solubilized form within WPC capsules; as a DES formulation with choline chloride and butanediol, the formulation produced capsules with the highest carotenoid loading capacity. SEM micrographs demonstrated that round and smooth capsules with sizes around 2 µm were obtained. ATR-FTIR results showed the presence of DES in the WPC capsules, which indirectly anticipated the presence of ?-carotene in the WPC capsules. Stability against photo-oxidation studies confirmed the expected presence of the bioactive and revealed that solubilized ?-carotene loaded WPC capsules presented excellent photo-oxidation stability compared with free ?-carotene. The capsules developed here clearly show the significant potential of the combination of DES and electrospraying for the encapsulation and stabilization of highly insoluble bioactive compounds.
| S-EPMC7070406 | biostudies-literature
Project description:In this work, 502 experimental data for CO2 solubilities and 132 for Henry's constants of CO2 in DESs were comprehensively summarized from literatures and used for further verification and development of COSMO-RS. Large systematic deviations of 62. 2, 59.6, 63.0, and 59.1% for the logarithmic CO2 solubilities in the DESs (1:2, 1:3, 1:4, 1:5), respectively, were observed for the prediction with the original COSMO-RS, while the predicted Henry's constants of CO2 in the DESs (1:1.5, 1:2, 1:3, 1:4, 1:5) at temperatures ranging of 293.15-333.15 K are more accurate than the predicted CO2 solubility with the original COSMO-RS. To improve the performance of COSMO-RS, 502 data points of CO2 solubility in the DESs (1:2, 1:3, 1:4, 1:5) were used for correcting COSMO-RS with a temperature-pressure dependent parameter, and the CO2 solubility in the DES (1:6) was predicted to further verify the performance of the corrected model. The results indicate that the corrected COSMO-RS can significantly improve the model performance with the ARDs decreasing down to 6.5, 4.8, 6.5, and 4.5% for the DESs (1:2, 1:3, 1:4, and 1:5), respectively, and the corrected COSMO-RS with the universal parameters can be used to predict the CO2 solubility in DESs with different mole ratios, for example, for the DES (1:6), the corrected COSMO-RS significantly improves the prediction with an ARD of 10.3% that is much lower than 78.2% provided by the original COSMO-RS. Additionally, the result from COSMO-RS shows that the ?-profiles can reflect the strength of molecular interactions between an HBA (or HBD) and CO2, determining the CO2 solubility, and the dominant interactions for CO2 capture in DESs are the H-bond and Van der Waals force, followed by the misfit based on the analysis of the predicted excess enthalpies.
| S-EPMC7031488 | biostudies-literature
Project description:The aim of this work was to prepare sugar alcohol-based deep eutectic solvents (DES) and test them as starch plasticizers. Thermoplastic starch (TPS) films were obtained via a simple and convenient thermocompression method. Influence of starch/DES premixtures conditioning (preheating, storage time) on TPS properties was investigated. TPS/sorbitol (S)-based DES exhibited similar tensile strength (TS) (8.6 MPa) but twice higher elongation at the break (?) (33%) when compared with TPS plasticized only with S. Extra treatment, i.e., heating or prolonged storage time, facilitated starch/DES plasticizing. Starch with selected DES was also extruded and the influence of preconditioning and extrusion rotational speed were subsequently studied on thermocompressed films. Extrusion at 100 rpm led to films with TS up to ca. 10 MPa and ? up to 52%. Some differences in film samples morphology obtained via two processing methods were observed. X-ray diffractograms revealed that extruded samples exhibited a V-type peak at 18.2°, with intensity depending on plasticizer total molecular size. Applied techniques (mechanical tests, XRD, Dynamic Mechanical Analysis (DMA), FTIR-Attenuated Total Reflection (ATR), and moisture sorption) indicated that S-based DES forms stronger interactions with starch than glycerol (G) only used as conventional plasticizer, thus leading to better mechanical properties and inhibited tendency to starch recrystallization (studied up to one year).
| S-EPMC6780061 | biostudies-literature
Project description:Daidzein, which is scarce in nature, has gained significant attention due to its superior biological activity and bioavailability compared with daidzin. So far, it has been widely used in the medicine and health care products industries. The enzymatic approach for the preparation of daidzein has prevailed, benefitted by its high efficiency and eco-friendly nature. Our present research aimed at providing a preparation method of daidzein by enzymatic hydrolysis of daidzin in a new "green" reaction medium-deep eutectic solvents (DESs). Herein, the DESs were screened via evaluating enzyme activity, enzyme stability and the substrate solubility, and the DES (ChCl/EG 2:1, 30 vol %) was believed to be the most appropriate co-solvent to improve the bioconversion efficiency. Based on the yield of daidzein, response surface methodology (RSM) was employed to model and optimize the reaction parameters. Under these optimum process conditions, the maximum yield of 97.53% was achieved and the purity of daidzein crude product reached more than 70%, which is more efficient than conversions in DESs-free buffer. Importantly, it has been shown that DESs medium could be reused for six batches of the process with a final conversion of above 50%. The results indicated that this procedure could be considered a mild, environmentally friendly, highly efficient approach to the economical production of daidzein, with a simple operation process and without any harmful reagents being involved.
| S-EPMC6155624 | biostudies-literature