Synthesis and Properties of Hydrophilic and Hydrophobic Deep Eutectic Solvents via Heating-Stirring and Ultrasound
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ABSTRACT:
SUBMITTER: Martin M
PROVIDER: S-EPMC11243031 | biostudies-literature | 2024 Jun
REPOSITORIES: biostudies-literature
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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: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:The solubility of CO2 in hydrophobic deep eutectic solvents (DESs) has been measured for the first time. Six different hydrophobic DESs are studied in the temperature range from 298 to 323 K and at CO2 pressures up to 2 MPa. The results are evaluated by comparing the solubility data with existing hydrophilic DESs and currently applied physical solvents and fluorinated ionic liquids. The DESs are prepared by mixing decanoic acid with a quaternary ammonium salt with different halide anions and alkyl chain lengths. The measured CO2 solubilities are similar to those found in renowned fluorinated ILs, while the heats of CO2 absorption are in the range of nonpolar solvents. The presented DESs show good potential to be used as CO2 capture agents.
| S-EPMC6028150 | biostudies-literature
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:In this study, a high-efficiency and non-pollution extraction procedure, ultrasound-assisted technique with deep eutectic solvents (DESs), was applied for extraction of polysaccharides from Morchella importuna (MIP-D). The results exhibited that the system of DES was: mole ratio between choline chloride and oxalic acid of 2:1, water content of 90% (v/v), and the optimal extraction parameters were as follows: extraction time of 31.2 min, extraction temperature of 62.1°C, and the liquid-solid ratio of 32.5:1 (v/w). Under these extraction parameters, the extraction yield of MIP-D was 4.5 times higher than hot water extraction (HWE) method and had higher carbohydrate (85.27%) and sulfate contents (34.16%). Moreover, high-performance liquid chromatography (HPLC) and Fourier-transform IR (FTIR) spectrum analysis indicated that MIP-D was comprised of glucosamine, galactose, glucose, and mannose, with molar ratios of 0.39:1.88:3.82:3.91, which contained the pyranose ring skeleton. High-performance gel permeation chromatography (HPGPC) analysis revealed that MIP-D showed three fractions with molecular weights of 2.6 × 106, 7.3 × 104, and 3.7 × 103 Da, which were lower than those of polysaccharides extracted by HWE. In-vitro tests proved that MIP-D possessed excellent antioxidant and inhibited α-amylase and α-glucosidase inhibitory activities. Therefore, DESs (choline chloride-oxalic acid) as a high-efficiency and non-pollution solvent alternative can be applied to the separation of bioactive polysaccharides from Morchella importuna (M. importuna).
| S-EPMC9218490 | biostudies-literature
Project description:The impact of the composition of natural deep eutectic solvents (NADES) and extraction conditions on the simultaneous extraction of hydrophilic ascorbic acid (AA), phlorotannins (TPhC), and lipophilic fucoxanthin (FX) from Fucus vesiculosus was investigated for the first time. In biological tests, the NADES extracts showed the promising ability to scavenge DPPH radicals. A positive correlation was observed between DPPH scavenging activity and AA, TPhC, and FX contents. We calculate the synergistic effect of antioxidants extracted by NADES from F. vesiculosus based on the mixture effect (ME). The addition of 30% water to the NADES and the prolongation of sonication time from 20 min up to 60 min were favorable for the ME. The ME for extracts with the NADES was increased by two folds (ME > 2). In contrast, conventional extraction by maceration with steering at 60 °C does not lead to the synergistic effect (ME = 1). It is notable that the NADES provides high stability and preserves the antioxidant activity of the extracts from F. vesiculosus during storage.
| S-EPMC8304060 | biostudies-literature
Project description:Triterpenic acids (TTAs), known for their promising biological properties, can be found in different biomass sources and related by-products, such as Eucalyptus globulus bark, and have been extracted using organic volatile solvents such as dichloromethane. Recently, deep eutectic solvents (DES) have been identified as promising alternatives for the extraction of value-added compounds from biomass. In the present work, several hydrophobic DES were tested for the extraction of TTAs from E. globulus bark. Initial solubility studies revealed that DES based on menthol and thymol as the most promising solvents for these compounds given the highest solubilities obtained for ursolic acid (UA) at temperatures ranging from room temperature up to 90 °C. Accordingly, an eutectic mixture of menthol:thymol (1:2) was confirmed as the best candidate for the TTAs extraction from E. globulus outer bark, leading to extraction yields (weight of TTA per weight of biomass) at room temperature of 1.8 wt% for ursolic acid, 0.84 wt% for oleanolic acid and 0.30 wt% for betulinic acid. These values are significantly higher than those obtained with conventional organic solvents under similar conditions. The results obtained using these DES are promising for the recovery of TTAs for nutraceutical and pharmacological applications, while reinforcing the potential of DES as promising solvents to be applied in biorefinery processes.
| S-EPMC6983165 | biostudies-literature
Project description:Redox biocatalysis is an essential pillar of the chemical industry. Yet, the enzymes' nature restricts most reactions to aqueous conditions, where the limited substrate solubility leads to unsustainable diluted biotranformations. Non-aqueous media represent a strategic solution to conduct intensified biocatalytic routes. Deep eutectic solvents (DESs) are designable solvents that can be customized to meet specific application needs. Within the large design space of combining DES components (and ratios), hydrophobic DESs hold the potential to be both enzyme-compatible - keeping the enzymes' hydration -, and solubilizers for hydrophobic reactants. We explored two hydrophobic DESs, lidocaine/oleic acid, and lidocaine/decanoic acid, as reaction media for carbonyl reduction catalyzed by horse liver alcohol dehydrogenase, focusing on the effect of water contents and on maximizing substrate loadings. Enzymes remained highly active and stable in the DESs with 20 wt % buffer, whereas the reaction performance in DESs outperformed the pure buffer system with hydrophobic substrates (e. g., cinnamaldehyde to form the industrially relevant cinnamyl alcohol), with a 3-fold specific activity. Notably, the cinnamaldehyde reduction was for the first time performed at 800 mM (~100 g L-1) with full conversion, which opens up new avenues to industrial applications of hydrophobic DESs for enzyme catalysis.
| S-EPMC11911972 | biostudies-literature
Project description:Deep eutectic solvents (DESs) are eutectic mixtures of salts and hydrogen bond donors with melting points low enough to be used as solvents. DESs have proved to be a good alternative to traditional organic solvents and ionic liquids (ILs) in many biocatalytic processes. Apart from the benign characteristics similar to those of ILs (e.g., low volatility, low inflammability and low melting point), DESs have their unique merits of easy preparation and low cost owing to their renewable and available raw materials. To better apply such solvents in green and sustainable chemistry, this review firstly describes some basic properties, mainly the toxicity and biodegradability of DESs. Secondly, it presents several valuable applications of DES as solvent/co-solvent in biocatalytic reactions, such as lipase-catalyzed transesterification and ester hydrolysis reactions. The roles, serving as extractive reagent for an enzymatic product and pretreatment solvent of enzymatic biomass hydrolysis, are also discussed. Further understanding how DESs affect biocatalytic reaction will facilitate the design of novel solvents and contribute to the discovery of new reactions in these solvents.
| S-EPMC5522511 | biostudies-other
Project description:Environmentally friendly and biodegradable reaction media are an important part of a sustainable glycolipid production in the transition to green chemistry. Deep eutectic solvents (DESs) are an ecofriendly alternative to organic solvents. So far, only hydrophilic DESs were considered for enzymatic glycolipid synthesis. In this study, a hydrophobic DES consisting of (-)-menthol and decanoic acid is presented for the first time as an alternative to hydrophilic DES. The yields in the newly introduced hydrophobic DES are significantly higher than in hydrophilic DESs. Different reaction parameters were investigated to optimize the synthesis further. Twenty milligrams per milliliter iCalB and 0.5 M glucose resulted in the highest initial reaction velocity for the esterification reaction, while the highest initial reaction velocity was achieved with 1.5 M glucose in the transesterification reaction. The enzyme was proven to be reusable for at least five cycles without significant loss of activity.
| S-EPMC7352255 | biostudies-literature