Exploration of a ternary deep eutectic solvent of methyltriphenylphosphonium bromide/chalcone/formic acid for the selective recognition of rutin and quercetin in Herba Artemisiae Scopariae

Methyltriphenylphosphonium bromide/chalcone/formic acid, a green ternary deep eutectic solvent, was applied as a functional monomer and dummy template simultaneously in the synthesis of a new molecularly imprinted polymer. Ternary deep eutectic solvent based molecularly imprinted polymers are used as a solid‐phase extraction sorbent in the separation and purification of rutin and quercetin from Herba Artemisiae Scopariae combined with high‐performance liquid chromatography. Fourier transform infrared spectroscopy and field‐emission scanning electron microscopy were applied to characterize the deep eutectic solvent based molecularly imprinted polymers synthesized using different molar ratios of chalcone. The static and competitive adsorption tests were performed to examine the recognition ability of the molecularly imprinted polymers to rutin and quercetin. The ternary deep eutectic solvent consisting of formic acid/chalcone/methyltriphenylphosphonium bromide (1:0.05:0.5) had the best molecular recognition effect. After optimization of the washing solvents (methanol/water, 1:9) and eluting solvents (acetonitrile/acetic acid, 9:1), a reliable analytical method was developed for strong recognition towards rutin and quercetin in Herba Artemisiae Scopariae with satisfactory extraction recoveries (rutin: 92.48%, quercetin: 94.23%). Overall, the chalcone ternary deep eutectic solvent‐based molecularly imprinted polymer coupled with solid‐phase extraction is an effective method for the selective purification of multiple bioactive compounds in complex samples.     

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

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.     

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

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.     

One-pot rapid synthesis of 4H-1-benzopyran derivatives in a deep eutectic solvent

A method for introducing a biologically active heterocycle, 2-methylquinoline into the 4-position of a 2-amino-4H-1-benzopyran skeleton is described. Choline chloride/glucose (1:1 molar ratio) was used as both the solvent and catalyst in the reaction of a salicylaldehyde, methylquinoline, and cyanoacetate to obtain 2-amino-4H-1-benzopyran derivatives in 48%–80% yields after short reaction times. The effects of the deep eutectic solvent type, substrate molar ratio, cosolvent, temperature, and reaction time were examined. The method has the advantages of simple steps, environmental friendliness, mild conditions, and wide substrate applicability. This is the first attempt to synthesize methylquinoline derivatives of 4H-1-benzopyran.     

Microwave-Assisted One-Pot Lipid Extraction and Glycolipid Production from Oleaginous Yeast Saitozyma podzolica in Sugar Alcohol-Based Media

Glycolipids are non-ionic surfactants occurring in numerous products of daily life. Due to their surface-activity, emulsifying properties, and foaming abilities, they can be applied in food, cosmetics, and pharmaceuticals. Enzymatic synthesis of glycolipids based on carbohydrates and free fatty acids or esters is often catalyzed using certain acyltransferases in reaction media of low water activity, e.g., organic solvents or notably Deep Eutectic Systems (DESs). Existing reports describing integrated processes for glycolipid production from renewables use many reaction steps, therefore this study aims at simplifying the procedure. By using microwave dielectric heating, DESs preparation was first accelerated considerably. A comparative study revealed a preparation time on average 16-fold faster than the conventional heating method in an incubator. Furthermore, lipids from robust oleaginous yeast biomass were successfully extracted up to 70% without using the pre-treatment method for cell disruption, limiting logically the energy input necessary for such process. Acidified DESs consisting of either xylitol or sorbitol and choline chloride mediated the one-pot process, allowing subsequent conversion of the lipids into mono-acylated palmitate, oleate, linoleate, and stearate sugar alcohol esters. Thus, we show strong evidence that addition of immobilized Candida antarctica Lipase B (Novozym 435^®), in acidified DES mixture, enables a simplified and fast glycolipid synthesis using directly oleaginous yeast biomass.     

Preparation of choline chloride–urea deep eutectic solvent‐modified magnetic nanoparticles for synthesis of various 2‐amino‐4H‐pyran derivatives in water solution

A novel hybrid magnetic nanocatalyst was synthesized by covalent coating of Fe₃O₄ magnetic nanoparticles with choline chloride–urea deep eutectic solvent using 3‐iodopropyltrimethoxysilane as a linker. The structure of this new catalyst was fully characterized via elemental analysis, transmission and scanning electron microscopies, X‐ray diffraction and Fourier transform infrared spectroscopy. It was employed in the synthesis of various 2‐amino‐4H ‐pyran derivatives in water solution via an easy and green procedure. The desired products were obtained in high yields via a three‐component reaction between aromatic aldehyde, enolizable carbonyl and malononitrile at room temperature. The employed nanocatalyst was easily recovered using a magnetic field and reused four times (in subsequent runs) with less than 8% decrease in its catalytic activity.     

How a Transition‐Metal(II) Chloride Interacts with a Eutectic AlCl3‐Based Ionic Liquid: Insights into the Speciation of the Electrolyte and Electrodeposition of Magnetic Materials

Electrostatic interactions are characteristic of ionic liquids (ILs) and play a pivotal role in determining the formation of species when solutes are dissolved in them. The formation of new species/complexes has been investigated for certain ILs. However, such investigations have not yet focused on eutectic liquids, which are a promising class of ILs. These liquids (or liquid coordination complexes, LCCs) are rather new and are composed of cationic and anionic chloro complexes of metals. To date, these liquids have been employed as electrolytes to deposit metals and as solvents for catalysis. The present study deals with a liquid that is prepared by mixing a 1.2:1 mol ratio of AlCl₃ and 1‐butylpyrrolidine. An attempt has been made to understand the interactions of FeCl₂ with the organic molecule using spectroscopy. It was found that dissolved Fe(II) species interact mainly with the IL anion and such interactions can lead to changes in the cation of the electrolyte. Furthermore, the viability of depositing thick magnetic films of Fe and Fe–Al has been explored.     

Embedded palladium nanoparticles on metal–organic framework/covalently sulfonated magnetic SBA-15 mesoporous silica composite: As a highly proficient nanocatalyst for Suzuki–Miyaura coupling reaction in amino acid-based natural deep eutectic solvent

In this project, the main aim is the design and present a novel and unique heterogeneous nanocatalyst based on a metal–organic framework/covalently sulfonated magnetic SBA-15 mesoporous silica composite with the emphasis on promoting clean and green synthetic transformations and increasing the catalytic properties. In more detail, initially, SBA-15 containing magnetic nanoparticles was functionalized by a 1,3-propane sultone ligand. In the next step, the functionalized mesoporous substrate was used as a scaffold for the growth and synthesis of the zeolite imidazolate framework-8 (ZIF-8) crystals. The obtained composite was further applied as a suitable support for the immobilization of Pd nanoparticles via a post-modification procedure and the generation of heterogeneous catalysts. The prepared Fe₃O₄@SBA-15-SO₃H@ZIF-8@Pd was incorporated as a heterogeneous and green catalyst in the Suzuki coupling reaction in the natural deep eutectic solvent with efficient recyclability.     

Rapid extraction of bioactive compounds from gardenia fruit using new and recyclable deep eutectic solvents

The utilization of deep eutectic solvent as an alternative and environmentally friendly option has gained significant attention. This study first proposed a series of benzylammonium chloride based-deep eutectic systems for the extraction of bioactive compounds from Gardenia jasminoides Ellis. Through the implementation of response surface methodology, the optimal solvent was determined to be dodecyldimethylbenzylammonium chloride–levulinic acid (1:3, mol/mol) with 35% (v/v) water, specifically tailored to extract geniposide, genipin-1-β-d -gentiobioside, crocin-1, and crocin-2 from gardenia fruits with the ratio of solid to liquid of 1:20 at 86°C for 16 min. Their total extraction yields could reach 70.6 mg/g, outperforming those obtained by other solvents and corresponding techniques. Furthermore, the eutectic system was retrieved after first-cycle extraction, and then applied in the subsequent extraction progress, yielding a consistent extraction efficiency of 97.1%. As compared to previous traditional methods, a quick, high-yielding, and green extraction procedure was achieved through simple heating settings that did not constrain the instrument. Therefore, dodecyldimethylbenzylammonium chloride–levulinic acid could serve as a sustainable and reusable solvent for efficient extraction of natural bioactive compounds from plant-based raw materials. The application of deep eutectic solvents has demonstrated their potential as designable solvents with stronger extraction capabilities than traditional organic solvents.