scholarly journals The Versatile Applications of DES and Their Influence on Oxidoreductase-Mediated Transformations

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2190 ◽  
Author(s):  
Fatima Zohra Ibn Majdoub Hassani ◽  
Saaid Amzazi ◽  
Iván Lavandera
Keyword(s):  
Redox Reactions ◽  
Enantiomeric Excess ◽  
Deep Eutectic Solvents ◽  
Product Yield ◽  
Molar Ratios ◽  
Solvent Properties

In the last decade, new types of solvents called deep eutectic solvents (DES) have been synthesized and commercialized. Among their main advantages, they can be eco-friendly and are easy to synthesize at different molar ratios depending on the desired solvent properties. This review aims to show the different uses of DES in some relevant biocatalytic redox reactions. Here we analyze oxidoreductase-mediated transformations that are performed in the presence of DES and compare them with the ones that avoided those solvents. DES were found to present advantages such as the increase in the product yield and enantiomeric excess in many reactions.

scholarly journals Green Solvents as an Alternative to DMF in ZIF-90 Synthesis

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1573
Author(s):  
Aljaž Škrjanc ◽  
Ciara Byrne ◽  
Nataša Zabukovec Logar
Keyword(s):  
Room Temperature ◽  
Product Yield ◽  
Solvent Exchange ◽  
Green Solvents ◽  
Zeolitic Imidazolate Framework ◽  
Short Treatment ◽  
Molar Ratios ◽  
Primary Particles ◽  
High Product Yield

The use of green solvents as an alternative to dimethylformamide (DMF) in the synthesis of zeolitic imidazolate framework-90 (ZIF-90) was investigated. Two biobased aprotic dipolar solvents CyreneTM and γ-valerolactone (GVL) proved to successfully replace DMF in the synthesis at room temperature with a high product yield. While the CyreneTM—based product shows reduced porosity after activation, the use of GVL resulted in materials with preserved crystallinity and porosity after activation, without prior solvent exchange and a short treatment at 200 °C. The primary particles of 30 nm to 60 nm in all products further form agglomerates of different size and interparticle mesoporosity, depending on the type and molar ratios of solvents used.

scholarly journals MATHEMATICAL MODELING OF THE 3(Н)-QUINAZOLIN-4-ONЕ SYNTHESIS PROCESS

2021 ◽  
pp. 51-57
Keyword(s):  
Mathematical Modeling ◽  
Reaction Rate ◽  
Linear Equations ◽  
Product Yield ◽  
Farm Animals ◽  
Synthesis Process ◽  
Optimal Conditions ◽  
System Of Linear Equations ◽  
Molar Ratios ◽  
The Matrix

The aim is to optimize the conditions for the synthesis of 3(H)-quinazolin-4-one by the method of mathematical modeling to develop a technology for producing the substance of a new domestic drug used in the treatment of farm animals from helminths. In mathematical modeling, the method of a small number of squares was used. Analytical dependences of the product yield on temperature, reaction time, and molar ratios of the starting materials were determined. A system of linear equations has been compiled. The system of linear equations was performed by the matrix method (A, B, C).The average reaction rate was determined. Based on the results obtained, a 3(H)-quinazolin-4-one diagram using the Maple 18 program and an icon diagram of the reaction duration, temperature, and reaction rate are shown. Based on the results of mathematical modeling, a highly efficient technological scheme for obtaining 3(H)-quinazolin-4-one has been developed. Based on this technology, compound 3(H)-quinazolin-4-one was synthesized in quantitative products at the Institute of Plant Chemistry, at a pilot production plant.The results obtained confirmed the found optimal conditions

scholarly journals Delignification of unbleached pulp by ternary deep eutectic solvents

2021 ◽  
Vol 10 (1) ◽  
pp. 666-676
Author(s):  
Veronika Majová ◽  
Michal Jablonský ◽  
Marek Lelovský
Keyword(s):  
Hydrogen Bond ◽  
Lactic Acid ◽  
Lignin Content ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Kappa Number ◽  
Molar Ratios ◽  
The Individual ◽  
Low Solubility ◽  
Unbleached Pulp

Abstract The processing of lignocellulosic materials is very limited because of their low solubility in water and some organic solvents. Fifteen ternary deep eutectic solvents (DESs) were prepared and tested as solvents suitable for delignification of unbleached pulp. The selected ternary DESs are composed of quaternary ammonium salts and amino acids as hydrogen-bond acceptors, and organic acids and polyvalent alcohols as hydrogen bond donors, with molar ratios varying for the individual components. The delignification efficiency is significantly influenced by the degree of penetration of the solvent into the pulp fibre structure. Therefore, the density and viscosity analysis of individual solvents was performed. Unbleached beech pulp with initial kappa number 13.9 was treated with the prepared DESs. The kappa number indicates the residual lignin content or the bleachability of pulp. The efficiency of the solvents ranged from 1.4% to 28.1%. The most suitable for the pretreatment of fibres, based on lignin removal efficiency, were found to be three DESs, in the following order: malonic acid/choline chloride/1,3-propanediol (1:1:3) > choline chloride/acetamide/lactic acid (1:2:3) > choline chloride/urea/lactic acid (1:2:3).

scholarly journals A Global Model for the Estimation of Speeds of Sound in Deep Eutectic Solvents

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1626
Author(s):  
Hamed Peyrovedin ◽  
Reza Haghbakhsh ◽  
Ana Rita C. Duarte ◽  
Sona Raeissi
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Speed Of Sound ◽  
Deep Eutectic Solvents ◽  
Green Solvents ◽  
Speeds Of Sound ◽  
Molar Ratios ◽  
Lack Of Information ◽  
Proposed Model ◽  
Group Contribution Methods

Deep eutectic solvents (DESs) are newly introduced green solvents that have attracted much attention regarding fundamentals and applications. Of the problems along the way of replacing a common solvent by a DES, is the lack of information on the thermophysical properties of DESs. This is even more accentuated by considering the dramatically growing number of DESs, being made by the combination of vast numbers of the constituting substances, and at their various molar ratios. The speed of sound is among the properties that can be used to estimate other important thermodynamic properties. In this work, a global and accurate model is proposed and used to estimate the speed of sound in 39 different DESs. This is the first general speed of sound model for DESs. The model does not require any thermodynamic properties other than the critical properties of the DESs, which are themselves calculated by group contribution methods, and in doing so, make the proposed method entirely independent of any experimental data as input. The results indicated that the average absolute relative deviation percentages (AARD%) of this model for 420 experimental data is only 5.4%. Accordingly, based on the achieved results, the proposed model can be used to predict the speeds of sound of DESs.

scholarly journals Formate as an Auxiliary Substrate for Glucose-Limited Cultivation of Penicillium chrysogenum: Impact on Penicillin G Production and Biomass Yield

2007 ◽  
Vol 73 (15) ◽  
pp. 5020-5025 ◽  
Author(s):  
Diana M. Harris ◽  
Zita A. van der Krogt ◽  
Walter M. van Gulik ◽  
Johannes P. van Dijken ◽  
Jack T. Pronk
Keyword(s):  
Penicillium Chrysogenum ◽  
Product Yield ◽  
Penicillin G ◽  
Carbon Substrate ◽  
Molar Ratios ◽  
Formate Oxidation ◽  
System A ◽  
Glucose Ratio ◽  
Biomass Yields ◽  
Substrate Feeding

ABSTRACT Production of β-lactams by the filamentous fungus Penicillium chrysogenum requires a substantial input of ATP. During glucose-limited growth, this ATP is derived from glucose dissimilation, which reduces the product yield on glucose. The present study has investigated whether penicillin G yields on glucose can be enhanced by cofeeding of an auxiliary substrate that acts as an energy source but not as a carbon substrate. As a model system, a high-producing industrial strain of P. chrysogenum was grown in chemostat cultures on mixed substrates containing different molar ratios of formate and glucose. Up to a formate-to-glucose ratio of 4.5 mol·mol−1, an increasing rate of formate oxidation via a cytosolic NAD+-dependent formate dehydrogenase increasingly replaced the dissimilatory flow of glucose. This resulted in increased biomass yields on glucose. Since at these formate-to-glucose ratios the specific penicillin G production rate remained constant, the volumetric productivity increased. Metabolic modeling studies indicated that formate transport in P. chrysogenum does not require an input of free energy. At formate-to-glucose ratios above 4.5 mol·mol−1, the residual formate concentrations in the cultures increased, probably due to kinetic constraints in the formate-oxidizing system. The accumulation of formate coincided with a loss of the coupling between formate oxidation and the production of biomass and penicillin G. These results demonstrate that, in principle, mixed-substrate feeding can be used to increase the yield on a carbon source of assimilatory products such as β-lactams.

scholarly journals Flow synthesis of phenylserine using threonine aldolase immobilized on Eupergit support

2013 ◽  
Vol 9 ◽  
pp. 2168-2179 ◽  
Author(s):  
Jagdish D Tibhe ◽  
Hui Fu ◽  
Timothy Noël ◽  
Qi Wang ◽  
Jan Meuldijk ◽  
...  
Keyword(s):  
Residence Time ◽  
Enzyme Stability ◽  
Thermotoga Maritima ◽  
Enantiomeric Excess ◽  
Product Yield ◽  
Packed Bed ◽  
Product Inhibition ◽  
Stable Operation ◽  
Flow Synthesis ◽  
Threonine Aldolase

Threonine aldolase (TA) from Thermotoga maritima was immobilized on an Eupergit support by both a direct and an indirect method. The incubation time for the direct immobilization method was optimized for the highest amount of enzyme on the support. By introducing the immobilized TA in a packed-bed microreactor, a flow synthesis of phenylserine was developed, and the effects of temperature and residence time were studied in particular. Calculations of the Damköhler number revealed that no mass transfer limitations are given in the micro-interstices of the packed bed. The yield does not exceed 40% and can be rationalized by the natural equilibrium as well as product inhibition which was experimentally proven. The flow synthesis with the immobilized enzyme was compared with the corresponding transformation conducted with the free enzyme. The product yield was further improved by operating under slug flow conditions which is related to the very short residence time distribution. In all cases 20% diastereomeric excess (de) and 99% enantiomeric excess (ee) were observed. A continuous run of the reactant solution was carried out for 10 hours in order to check enzyme stability at higher temperature. Stable operation was achieved at 20 minute residence time. Finally, the productivity of the reactor was calculated, extrapolated to parallel run units, and compared with data collected previously.

scholarly journals Solubility and Stability of Some Pharmaceuticals in Natural Deep Eutectic Solvents-Based Formulations

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2645
Author(s):  
Natali Rianika Mustafa ◽  
Vincent Simon Spelbos ◽  
Geert-Jan Witkamp ◽  
Robert Verpoorte ◽  
Young Hae Choi
Keyword(s):  
Amino Acids ◽  
Chloral Hydrate ◽  
Tube Feeding ◽  
Deep Eutectic Solvents ◽  
Water Soluble ◽  
Molar Ratios ◽  
Natural Deep Eutectic Solvents ◽  
Potential Applications ◽  
Poorly Soluble ◽  
Poorly Water Soluble

Some medicines are poorly soluble in water. For tube feeding and parenteral administration, liquid formulations are required. The discovery of natural deep eutectic solvents (NADES) opened the way to potential applications for liquid drug formulations. NADES consists of a mixture of two or more simple natural products such as sugars, amino acids, organic acids, choline/betaine, and poly-alcohols in certain molar ratios. A series of NADES with a water content of 0–30% (w/w) was screened for the ability to solubilize (in a stable way) some poorly water-soluble pharmaceuticals at a concentration of 5 mg/mL. The results showed that NADES selectively dissolved the tested drugs. Some mixtures of choline-based NADES, acid-neutral or sugars-based NADES could dissolve chloral hydrate (dissociated in water), ranitidine·HCl (polymorphism), and methylphenidate (water insoluble), at a concentration of up to 250 mg/mL, the highest concentration tested. Whereas a mixture of lactic-acid–propyleneglycol could dissolve spironolacton and trimethoprim at a concentration up to 50 and 100 mg/mL, respectively. The results showed that NADES are promising solvents for formulation of poorly water-soluble medicines for the development of parenteral and tube feeding administration of non-water-soluble medicines. The chemical stability and bioavailability of these drug in NADES needs further studies.

scholarly journals Exploratory study on internal recycling of crude glycerol for biodiesel production: Catalyst replacement

2016 ◽  
Vol 22 (4) ◽  
pp. 445-452 ◽  
Author(s):  
Joana Dias ◽  
Pedro Leite ◽  
Maria Alvim-Ferraz ◽  
Manuel Almeida
Keyword(s):  
Crude Glycerol ◽  
Catalyst Concentration ◽  
Product Yield ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Minor Effect ◽  
Molar Ratios ◽  
Reaction Conversion ◽  
A Minor ◽  
Catalyst Distribution

The present study evaluated the recycling of crude glycerol as source of catalyst for biodiesel production. For that purpose, two sets of experiments were conducted. In the first set (A), biodiesel was synthesized by conventional methanolysis of sunflower oil using NaOH as catalyst at 65?C during 1 h and varying catalyst concentration (0.4 - 1.2 wt.%) or methanol to oil molar ratio (6:1-12:1). The second set (B) was performed by replicating the conditions of set A and considering the use of crude glycerol as source of catalyst. The evaluation of excess methanol and catalyst distribution in the crude products was performed. For both sets of experiments, product yield and quality (viscosity and purity) were determined. Methanol was predominantly in the glycerol phase (54 - 68%), with negligible effect of variation in catalyst concentration and higher percentages found when higher methanol to oil molar ratios were used, due to a higher polarity of this phase. In most cases, catalyst was predominantly in the crude glycerol (53 wt.% in average) and no clear relation was found between catalyst distribution and the different reaction conditions studied. The results from set A showed a clear influence of catalyst concentration in biodiesel conversion and a minor effect of methanol to oil molar ratio. The best conditions were 6:1 methanol to oil molar ratio and 0.6 wt.% of catalyst leading to a product yield of 95.1 wt.%, a purity of 99.3% and a viscosity of 4.59 mm2s-1. The second set of experiments showed different trends and variability compared to the first one and the results indicated that catalyst might be altered during glycerol storage. It was found an effect of methanol to oil molar ratio in reaction conversion with the highest purity (96.9 wt.%) being obtained when the highest molar ratio was used (12:1) possibly due to the reduced mass transfer limitations. Overall, the results clearly show the potential of using crude glycerol as source of catalyst, avoiding the use of new catalyst and allowing a more sustainable biodiesel production.

scholarly journals Solubility Enhancement of Betamethasone, Meloxicam and Piroxicam by Use of Choline-Based Deep Eutectic Solvents

2020 ◽  
Vol 27 (1) ◽  
pp. 86-101
Author(s):  
Salva Golgoun ◽  
Masumeh Mokhtarpour ◽  
Hemayat Shekaari
Keyword(s):  
Choline Chloride ◽  
Aqueous Solubility ◽  
Weight Fraction ◽  
Deep Eutectic Solvents ◽  
Molar Ratios ◽  
New Class ◽  
Different Temperatures ◽  
Calculated Solubility ◽  
Experimental Values ◽  
Good Agreement

Background: The low aqueous solubility of three important drugs (betamethasone (BETA), meloxicam (MEL) and piroxicam (PIR)) have been increased by use of deep eutectic solvents (DESs) based choline chloride/urea (ChCl/U), choline chloride/ethylene glycol (ChCl/EG) and choline chloride/glycerol (ChCl/G) as new class of solvents at T = (298.15 to 313.15) K. Methods: DESs were prepared by combination of the ChCl/EG, U and G with the molar ratios: 1:2. The solubility of drugs in the aqueous DESs solutions was measured at different temperatures with shake flask method. Results: The solubility of the investigated drugs increased with increasing the weight fraction of DESs. The solubility data were correlated by e-NRTL and Wilson models. Also, the thermodynamic functions, Gibbs energy, enthalpy, and entropy of dissolution were calculated. Conclusion: At the same composition of co-solvents and temperature, the BETA, PIR and MEL solubility was highest in (ChCl/U + water), (ChCl/U + water) and (ChCl/EG + water) respectively. The calculated solubility based on these models was in good agreement with the experimental values. In addition, the results show that, the main contribution for drugs solubility in the aqueous DES solutions is the enthalpy.

scholarly journals Significant Increase in the Solubility of Celecoxib in Presence of Some Deep Eutectic Solvents as Novel Sustainable Solvents and the Thermodynamic Analysis of These Systems

2020 ◽  
Vol 26 (4) ◽  
pp. 423-433
Author(s):  
Hemayat Shekaari ◽  
Masomeh Mokhtarpour ◽  
Fereshteh Mokhtarpour ◽  
Saeid Faraji ◽  
Fleming Martinez ◽  
...  
Keyword(s):  
Choline Chloride ◽  
Aqueous Solubility ◽  
Weight Fraction ◽  
Deep Eutectic Solvents ◽  
Solubility Data ◽  
Driving Mechanism ◽  
Solvent Mixtures ◽  
Molar Ratios ◽  
Different Temperatures ◽  
B Vitamin

Background: Deep eutectic solvents (DESs) exist a wide variety of potential and existing applications. Based on the fact that the choline chloride (ChCl) is a complex B vitamin and widely used as food additive, the choline-based DESs are generically regarded as being harmless and non-toxic. In this regard, the low aqueous solubility of celecoxib (CLX) have been increased by use of DESs as neoteric class of solvents at T = (298.15 to 313.15) K. Methods: DESs were prepared by combination of the ChCl/EG, U and G with the molar ratios: 1:2 and ChCl/MA with 1:1. The shake flask method was used to measure the solubility of CLX in the aqueous DESs solutions at different temperatures. Results: The solubility of the CLX increased with increasing the weight fraction of DESs. The observed solubility data was subjected to evaluate the relative performance of a number of models including Apelblat, Yalkowsky and Jouyban–Acree models for their correlation efficacy. Moreover, the apparent dissolution enthalpy, entropy and Gibbs free energy were obtained from the experimental solubility values. Conclusion: It was found that the solubility data was satisfactorily fitted using the mentioned models at different temperatures. The dissolution process of CLX in the studied solvent mixtures within investigated temperature range was endothermic, and the driving mechanism is the positive entropy.

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