Enzymatic Polymerization of Dihydroquercetin (Taxifolin) in Betaine-Based Deep Eutectic Solvent and Product Characterization

Deep eutectic solvents (DESs) are an alternative to conventional organic solvents in various biocatalytic reactions. Meanwhile, there have been few studies reporting on synthetic reactions in DESs or DES-containing mixtures involving oxidoreductases. In this work, we have studied the effects of several DESs based on betaine as the acceptor of hydrogen bonds on the catalytic activity and stability of laccase from the basidial fungus Trametes hirsuta and performed enzymatic polymerization of the flavonoid dihydroquercetin (DHQ, taxifolin) in a DES–buffer mixture containing 60 vol.% of betaine-glycerol DES (molar ratio 1:2). The use of the laccase redox mediator TEMPO enabled an increased yield of DHQ oligomers (oligoDHQ), with a number average molecular weight of 1800 g mol−1 and a polydispersity index of 1.09. The structure of the synthesized product was studied using different physicochemical methods. NMR spectroscopy showed that oligoDHQ had a linear structure with an average chain length of 6 monomers. A scheme for enzymatic polymerization of DHQ in a DES–buffer mixture was also proposed.

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Design Optimization of Deep Eutectic Solvent Composition and Separation Performance of Cyclohexane and Benzene Mixtures with Extractive Distillation

Processes ◽

10.3390/pr9101706 ◽

2021 ◽

Vol 9 (10) ◽

pp. 1706

Author(s):

Fang Bai ◽

Chao Hua ◽

Yongzhi Bai ◽

Mengying Ma

Keyword(s):

Tetrabutylammonium Bromide ◽

Deep Eutectic Solvent ◽

Ternary Systems ◽

Deep Eutectic Solvents ◽

Extractive Distillation ◽

Molar Concentration ◽

Molar Ratio ◽

Coefficient Of Determination ◽

Separation Performance ◽

Equilibrium Data

Deep eutectic solvents (DESs) have properties that make them suitable candidates to be used as entrainers for extractive distillation. In the previous work, it was proven that DES(1:2) (tetrabutylammonium bromide: levulinic acid, 1:2, molar ratio) can break the cyclohexane-benzene azeotrope. In the present work, the HBA and HBD ratio and molar concentration of DES were optimized to obtain a better constitute and condition of DES to be utilized in cyclohexane and benzene extractive distillation. The physical properties and structure of the prepared DESs were characterized. Vapor–liquid equilibrium data of the ternary system (benzene + cyclohexane + DESs) were also measured at atmospheric pressure. All experimental equilibrium data were correlated with Wilson, nonrandom two-liquid (NRTL), and universal quasichemical (UNIQUAC) activity coefficient models, from which the coefficient of determination (R2) of the three pseudo-ternary systems fitting was calculated. From the obtained results, the best HBA and HBD ratio in the DESs is elucidated as 1:2, the best molar concentration of DES is 0.1, and the NRTL model predicts the experimental data more accurately than the Wilson and UNIQUAC models. From the derived mechanism, the formation of stronger hydrogen bond and π–π bond interactions between DES and benzene is obtained when HBA and HBD ratio in DES is 1:2. In other conditions, the azeotrope cannot be broken, or the efficiency is low. The present work provides an environmentally friendly method to separate aromatic/aliphatic mixtures and act as a guide for further study of DESs in extractive distillation.

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Performance of p-Toluenesulfonic Acid–Based Deep Eutectic Solvent in Denitrogenation: Computational Screening and Experimental Validation

Molecules ◽

10.3390/molecules25215093 ◽

2020 ◽

Vol 25 (21) ◽

pp. 5093 ◽

Cited By ~ 1

Author(s):

Ainul F. Kamarudin ◽

Hanee F. Hizaddin ◽

Lahssen El-blidi ◽

Emad Ali ◽

Mohd A. Hashim ◽

...

Keyword(s):

Deep Eutectic Solvent ◽

Deep Eutectic Solvents ◽

Fuel Oil ◽

Proton Nuclear Magnetic Resonance ◽

Molar Ratio ◽

Nitrogen Compounds ◽

Green Solvents ◽

Computational Screening ◽

Toluenesulfonic Acid ◽

Fuel Oils

Deep eutectic solvents (DESs) are green solvents developed as an alternative to conventional organic solvents and ionic liquids to extract nitrogen compounds from fuel oil. DESs based on p-toluenesulfonic acid (PTSA) are a new solvent class still under investigation for extraction/separation. This study investigated a new DES formed from a combination of tetrabutylphosphonium bromide (TBPBr) and PTSA at a 1:1 molar ratio. Two sets of ternary liquid–liquid equilibrium experiments were performed with different feed concentrations of nitrogen compounds ranging up to 20 mol% in gasoline and diesel model fuel oils. More than 99% of quinoline was extracted from heptane and pentadecane using the DES, leaving the minutest amount of the contaminant. Selectivity was up to 11,000 for the heptane system and up to 24,000 for the pentadecane system at room temperature. The raffinate phase’s proton nuclear magnetic resonance (1H-NMR) spectroscopy and GC analysis identified a significantly small amount of quinoline. The selectivity toward quinoline was significantly high at low solute concentrations. The root-mean-square deviation between experimental data and the non-random two-liquid (NRTL) model was 1.12% and 0.31% with heptane and pentadecane, respectively. The results showed that the TBPBr/PTSADES is considerably efficient in eliminating nitrogen compounds from fuel oil.

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TAXIFOLIN POLYMERIZATION IN DEEP EUTECTIC SOLVENT USING LACCASE-MEDIATOR SYSTEM

BIOTECHNOLOGY: STATE OF THE ART AND PERSPECTIVES ◽

10.37747/2312-640x-2020-18-52-53 ◽

2020 ◽

pp. 52-53

Author(s):

O. Morozova ◽

M. Khlupova ◽

G. Shumakovich ◽

E. Gromova ◽

A. Yaropolov ◽

...

Keyword(s):

Molecular Weight ◽

Atmospheric Oxygen ◽

Oxidative Polymerization ◽

Average Molecular Weight ◽

Deep Eutectic Solvent ◽

Oxidizing Agent ◽

Weight Average Molecular Weight ◽

Trametes Hirsuta ◽

Synthesis Conditions ◽

Mediator System

An oxidative polymerization of flavonoid taxifolin (dihydroquercetin) in betaine-glycerin (B-G, 1: 2) as cosolvent medium has been performed using laccase from basidial fungus Trametes hirsuta as a biocatalyst and TEMPO as a redox mediator. The terminal oxidizing agent was atmospheric oxygen. Under optimal synthesis conditions, dihydroquercetin oligomers (oligo DHQ) with a weight average molecular weight of 1800 g / mol, a polydispersity index of 1.09 and a yield of 57 ± 7% were obtained.

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Effective Extraction of Limonene and Hibaene from Hinoki (Chamaecyparis obtusa) Using Ionic Liquid and Deep Eutectic Solvent

Molecules ◽

10.3390/molecules26144271 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4271

Author(s):

Rina Yasutomi ◽

Riki Anzawa ◽

Masamitsu Urakawa ◽

Toyonobu Usuki

Keyword(s):

Ionic Liquid ◽

Organic Solvent ◽

Essential Oils ◽

Control Method ◽

Deep Eutectic Solvent ◽

Deep Eutectic Solvents ◽

Chamaecyparis Obtusa ◽

Molar Ratio ◽

Gas Chromatography Mass Spectrometry ◽

Selected Ion Monitoring

The essential oils of hinoki (Chamaecyparis obtusa) leaves have anti-bacterial, anti-fungal, and relaxation properties that are likely associated with the major components such as sabinene, α-terpinyl acetate, limonene, elemol, myrcene, and hibaene. The present study describes the use of a cellulose-dissolving ionic liquid (IL) [C2mim][(MeO)(H)PO2] and low-toxicity solvents called betaine-based deep eutectic solvents (DESs) for the efficient extraction of hinoki essential oils. As a control method, organic solvent extraction was performed using either hexane, ethyl acetate (EtOAc), or acetone at 30 °C for 1 h. Both the experimental and control methods were conducted under the same conditions, which relied on partial dissolution of the leaves using the IL and DESs before partitioning the hinoki oils into the organic solvent for analysis. Quantitative analysis was performed using gas chromatography–mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode. The results indicated that extraction using the [C2mim][(MeO)(H)PO2]/acetone bilayer system improved the yields of limonene and hibaene, 1.5- and 1.9-fold, respectively, when compared with the control method. In addition, extraction using betaine/l-lactic acid (molar ratio 1:1) gave the greatest yields for both limonene and hibaene, 1.3-fold and 1.5-fold greater, respectively, than when using an organic solvent. These results demonstrate the effective extraction of essential oils from plant leaves under conditions milder than those needed for the conventional method. The less toxic and environmentally begin DESs for the extraction are also applicable to the food and cosmetic industries.

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Pemanfaatan Hidrofobik Deep Eutectic Solvents dalam Penyisihan Dimetoat, Klorpirifos, dan Profenofos pada Buah Tomat dan Sayur Brokoli

Jurnal Teknik Kimia USU ◽

10.32734/jtk.v9i1.3464 ◽

2020 ◽

Vol 9 (1) ◽

pp. 7-10

Author(s):

Axel Try Iddo Daely ◽

Renita Manurung

Keyword(s):

Lauric Acid ◽

Freezing Point ◽

Deep Eutectic Solvent ◽

Chemical Properties ◽

Deep Eutectic Solvents ◽

Extraction Process ◽

Molar Ratio ◽

Organophosphate Insecticide ◽

Pesticide Removal ◽

New Generation

Organophosphate insecticide is a type of pesticide that is commonly used, where this pesticide can be toxic to environmental organisms even to humans. Hydrophobic Deep Eutectic Solvent (DES) is a new generation nonpolar solvent of ionic liquids because it has better physical properties and chemical properties so that it can be used in the extraction process. DES was synthesized at 50 oC for 15 minutes with a stirring speed of 300 rpm and a molar ratio of Dl-menthol: lauric acid varied from 1: 1, 2: 1, and 3: 1. Pesticide removal is done by mixing 5 ml of DES with 200 ml of aquadest and then Tomatoes and Broccoli vegetables are washed with the solution. DES characteristics are done by analyzing the shape and measuring the freezing point, density and viscosity of DES. The concentration of pesticide residues was analyzed using Gas Chromatography-Mass Spectrometer (GC-MS). The highest elimination of pesticides obtained with DES hydrophobic which has a molar ratio of dl-menthol: lauric acid is 3: 1 where the highest elimination of pesticides in Tomatoe is 44.82% for Dimethoate pesticide, 84.1% for Chlorpyrifos pesticide, and 83.72% for Profenofos pesticide and Broccoli 35.19% for Dimetoat pesticide, 64.64% for Chlorpyrifos pesticide, and 55.28% for Profenofos pesticides.

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Enhanced Furfural Production in Deep Eutectic Solvents Comprising Alkali Metal Halides as Additives

Molecules ◽

10.3390/molecules26237374 ◽

2021 ◽

Vol 26 (23) ◽

pp. 7374

Author(s):

Eduarda S. Morais ◽

Mara G. Freire ◽

Carmen S. R. Freire ◽

Armando J. D. Silvestre

Keyword(s):

Alkali Metal ◽

Lithium Bromide ◽

Deep Eutectic Solvent ◽

Deep Eutectic Solvents ◽

Operating Conditions ◽

Molar Ratio ◽

Metal Halides ◽

Promising Alternative ◽

Operational Conditions ◽

Alkali Metal Halides

The addition of alkali metal halide salts to acidic deep eutectic solvents is here reported as an effective way of boosting xylan conversion into furfural. These salts promote an increase in xylose dehydration due to the cation and anion interactions with the solvent being a promising alternative to the use of harsh operational conditions. Several alkali metal halides were used as additives in the DES composed of cholinium chloride and malic acid ([Ch]Cl:Mal) in a molar ratio of 1:3, with 5 wt.% of water. These mixtures were then used as both solvent and catalyst to produce furfural directly from xylan through microwave-assisted reactions. Preliminary assays were carried out at 150 and 130 °C to gauge the effect of the different salts in furfural yields. A Response Surface Methodology was then applied to optimize the operational conditions. After an optimization of the different operating conditions, a maximum furfural yield of 89.46 ± 0.33% was achieved using 8.19% of lithium bromide in [Ch]Cl:Mal, 1:3; 5 wt.% water, at 157.3 °C and 1.74 min of reaction time. The used deep eutectic solvent and salt were recovered and reused three times, with 79.7% yield in the third cycle, and the furfural and solvent integrity confirmed.

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Structural and Transport Properties of Binary Mixtures of Deep Eutectic Solvent (Ethaline) with Primary Alcohols: A Molecular Dynamics Study

10.26434/chemrxiv.14381996.v1 ◽

2021 ◽

Author(s):

kishant kumar ◽

Anand Bharti ◽

Aditya Sinha

Keyword(s):

Molecular Dynamics ◽

Transport Properties ◽

Binary Mixtures ◽

Choline Chloride ◽

Deep Eutectic Solvent ◽

Deep Eutectic Solvents ◽

Md Simulations ◽

Molar Ratio ◽

Green Solvents ◽

Primary Alcohols

<table><tr><td>Deep eutectic solvents (DESs) are classified as the green solvents which are considered as an alternative to volatile organic solvents. In this work, the thermophysical, structural and transport properties of binary mixtures of DES ethaline (choline chloride (ChCl) + ethylene glycol (etgly) at a molar ratio of 1:2) with primary alcohols (methanol/ethanol) are studied using molecular dynamics (MD) simulations</td></tr></table> <br>

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Synthesis of various 2-benzylbenzoxazole derivatives catalyzed by deep eutectic solvent-supported onto magnetic nanoparticles

Science and Technology Development Journal - Natural Sciences ◽

10.32508/stdjns.v4i3.901 ◽

2020 ◽

Vol 4 (3) ◽

pp. First

Author(s):

The Thai Nguyen ◽

Phuong Hoang Tran

Keyword(s):

Magnetic Nanoparticles ◽

Magnetic Nanoparticle ◽

Fourier Transforms ◽

Condensation Reaction ◽

Deep Eutectic Solvent ◽

Deep Eutectic Solvents ◽

Significant Loss ◽

Molar Ratio ◽

Efficient Catalyst ◽

X Ray

Magnetic nanoparticle supported deep eutectic solvents have been synthesized by preparing and grafting [Urea]4[ZnCl2] deep eutectic solvent onto the surface of silica-coated Fe3O4 magnetic nanoparticles using 3‐ chloropropyltrimethoxysilane as a linker. DES@MNP was fully characterized using scanning and transmission electron microscopies, Fourier transforms infrared, energy-dispersive X-ray spectroscopies, vibrating sample magnetometer X-ray diffraction, and thermogravimetric analysis. In this study, we have developed the synthesis of 2-benzylbenzoxazole via condensation reaction of 2-nitrophenols and acetophenones using a magnetic nanoparticle supported [Urea]4[ZnCl2] deep eutectic solvent as a novel, green and efficient catalyst. In the presence of 1,4-diazabicyclo[2.2.2]-octane, elemental sulfur acted as an excellent reductant in promoting oxidative rearranging coupling in this reaction. The reaction has been conducted via the stirring method and the reaction conditions were surveyed (16 h, 130 °C, acetophenone, 2-nitrophenol, DABCO and sulfur molar ratio of 2:1:1:3, 10 mol% DES@MNP catalyst). Six 2-benzylbenzoxazole derivatives have been synthesized via this method with good yield (86-91%). The structure of the pure product has been confirmed through FT-IR, 1H NMR, 13C NMR, and GC-MS methods. More importantly, DES@MNP has been separated from the reaction mixture by a magnet and reused over five consecutive runs without significant loss of catalytic activity.

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Green Valorization of Olive Leaves to Produce Polyphenol-Enriched Extracts Using an Environmentally Benign Deep Eutectic Solvent

AgriEngineering ◽

10.3390/agriengineering2020014 ◽

2020 ◽

Vol 2 (2) ◽

pp. 226-239 ◽

Cited By ~ 2

Author(s):

Olga Kaltsa ◽

Spyros Grigorakis ◽

Achillia Lakka ◽

Eleni Bozinou ◽

Stavros Lalas ◽

...

Keyword(s):

High Performance ◽

Deep Eutectic Solvent ◽

Deep Eutectic Solvents ◽

Process Variable ◽

Molar Ratio ◽

Olive Leaves ◽

Total Polyphenol ◽

Solid Ratio ◽

Wide Range ◽

Efficient Recovery

Olive leaves (OLL) are considered to be a highly appreciated bioresource of bioactive polyphenolic phytochemicals, embracing several different structures. However, extraction processes based on deep eutectic solvents (DES) are very limited despite the wide range of techniques developed for the efficient recovery of polyphenols. This study had as objective the development of a simple, green, high-performance extraction methodology for OLL polyphenols, using a recently reported effective DES, composed of L-lactic acid and glycine. Initially, a screening was performed to select the most appropriate L-lactic/glycine molar ratio and process optimization was then carried out with response surface methodology. The optimized process variable values were DES/water (78% w/v), liquid-to-solid ratio of 36 mL g−1, and stirring speed of 500 rounds per minute, and the total polyphenol yield amounted to 97.53 ± 3.54 mg gallic acid equivalents per g dry matter. Extraction with DES at 80 °C did not significantly increase the total polyphenol yield, but it did enhance the total flavonoid yield and antioxidant activity. High-performance liquid chromatography analyses revealed that extraction with the DES resulted in extended oleuropein hydrolysis, to the favor of hydroxytyrosol formation. This finding might have a prospect in using properly tuned DES for polyphenol modification with improved bioactivities.

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