Natural Deep Eutectic Solvents Research Articles

Chemical Composition and Insecticidal Potential of Essential Oil from Murraya koenigii (L.) Obtained by Natural Deep Eutectic Solvents.

Aphis craccivora Koch and Planococcus lilacinus Cockerell are phloem feeders and act as vectors for transmitting plant viruses to agricultural and horticultural crops thereby damaging them. The persistent and widespread use of synthetic, wide-spectrum pesticides has resulted in resistance development that is detrimental to the environment, human health, and natural enemies of pests. The present investigation uses various extraction mediums to examine the insecticidal efficacy of essential oils (EOs) isolated from Murraya koenigii (L.) leaves. Increase in yield was observed in the EO extracted using NADES-AHD [0.16% (obtained with hydro-distillation)] to 0.30% [obtained with N-1 (glycerol:lactic acid)]. EO obtained with water was found more effective against A. craccivora (LD50 = 0.89 µL/insect) and followed by N-1 (glycerol:lactic acid), and N-3 (choline chloride:citric acid) (LD50 = 1.29-1.38 µL/insect). Similarly, EO isolated by water and N-4 (choline chloride:oxalic acid) was effective against P. lilacinus (LD50 = 2.63-3.06 µL/insect). Additionally, the EO prepared by water substantially reduced glutathione S-transferase (GST) and acetylcholinesterase (AChE) in target pests, suggesting that these enzymes may be the EOs' site of action. NADES-AHD has enhanced the EO yield as compared to the conventional method. The EO obtained with water showed promising toxicity against target pests and target site of action. Therefore, based on field and greenhouse bio-efficacy experiments, EOs/biopesticides/botanicals can be proposed for controlling the spread of mealy bugs and aphids.

Electrochemical DNA Sensor Based on Poly(proflavine) Deposited from Natural Deep Eutectic Solvents for DNA Damage Detection and Antioxidant Influence Assessment

Electrochemical DNA sensors for DNA damage detection based on electroactive polymer poly(proflavine) (PPFL) that was synthesized at screen-printed carbon electrodes (SPCEs) from phosphate buffer (PB) and two natural deep eutectic solvents (NADESs) consisting of citric or malonic acids, D-glucose, and a certain amount of water (NADES1 and NADES2) were developed. Poly(proflavine) coatings obtained from the presented media (PPFLPB, PPFLNADES1, and PPFLNADES2) were electrochemically polymerized via the multiple cycling of the potential or potentiostatic accumulation and used for the discrimination of thermal and oxidative DNA damage. The electrochemical characteristics of the poly(proflavine) coatings and their morphology were assessed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The working conditions for calf thymus DNA implementation and DNA damage detection were estimated for all types of poly(proflavine) coatings. The voltammetric approach made it possible to distinguish native and chemically oxidized DNA while the impedimetric approach allowed for the successful recognition of native, thermally denatured, and chemically oxidized DNA through changes in the charge transfer resistance. The influence of different concentrations of conventional antioxidants and pharmaceutical preparations on oxidative DNA damage was characterized.

Enhanced Nanocellulose Production from Cotton and Textile Waste Using Binary and Ternary Natural Deep Eutectic Solvents

Enhanced Nanocellulose Production from Cotton and Textile Waste Using Binary and Ternary Natural Deep Eutectic Solvents

OPTIMIZATION ULTRASOUND-ASSISTED EXTRACTION USING CHOLINE CHLORIDE-BASED NATURAL DEEP EUTECTIC SOLVENT TO INCREASE PHENOLIC COMPOUNDS AND ANTIOXIDANTS FROM RHODOMYRTUS TOMENTOSA LEAVES

Objective: The main purpose of this study is to give recommendations for the ideal extraction conditions for improving the extraction yield and antioxidant activity of R. tomentosa leaves. Methods: First, the extraction total phenolic yields of five choline chloride-based Natural Deep Eutectic Solvents (NADES) were evaluated. Then, Box Behnken designs of Response Surface Methodology (RSM) were conducted in order to optimize the extraction condition. The extraction variables investigated were extraction time, water content in NADES, and solid-to-liquid ratio. Meanwhile, total phenolic and 2,2′-azinbis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) free radicals scavenging activity were used as responses. Results: NADES with combination of choline chloride and propylene glycol with a molar ratio of 1:1 was found to be the best solvent for extracting phenolic compound. The total phenolic compound obtained was 29.6351 mg GAE/g dried leaves with ABTS scavenging activity about 96.84% under the optimum extraction condition (extraction time of 60 min, 25% water content in NADES, and solid-to-liquid ratio of 0.02 g/ml). Better results were shown compared to extracts with conventional solvents. Conclusion: In sum, the use of choline chloride-based NADES as extraction solvent under optimum condition was proven to be effective in increasing the extraction efficiency of phenolic compounds and antioxidant activity from R. tomentosa leaves.

The response of authors to the comment on “Bibliometric insights into the application of natural deep eutectic solvents in extracting bioactive compounds from fruit wastes” (Int J Environ Sci Technol. 2024 Jul 1)

The response of authors to the comment on “Bibliometric insights into the application of natural deep eutectic solvents in extracting bioactive compounds from fruit wastes” (Int J Environ Sci Technol. 2024 Jul 1)

New Green Biorefinery Strategies to Valorize Bioactive Fractions from Palmaria palmata.

A biorefinery process was developed to isolate phycobiliproteins, sulfated polysaccharides, and phenolic compounds from Palmaria palmata. The extraction process was carried out in three stages using ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) integrated with different natural deep eutectic solvents (NaDESs). In general, PLE provided higher phycobiliprotein contents than UAE in the first step of the process. In fact, the hydrolysis product of the PLE-NaDES extracts achieved a higher antioxidant capacity than that of the UAE-NaDES extracts. Particularly, glycerol:glucose (2:1) with 50% water in combination with PLE was the most suitable NaDES to recover the highest phycobiliprotein, protein, and sulfated polysaccharide contents from Palmaria palmata in the first and second steps of the biorefinery process. Finally, a PLE-NaDES using choline chloride:glycerol (1:2) with 60% water as the NaDES was employed for the recovery of antioxidant and neuroprotective phenolic compounds from the residue of the second step, obtaining a higher total phenolic content than employing PLE with ethanol/water (70:30, v/v) as the extraction solvent. Moreover, a forced stability study revealed that the NaDESs provided a protective effect compared to the water extracts against the degradation of phycobiliproteins, preserving their color over time. This study contributes to the recovery of high-value components from an undervalued biomarine source through a sustainable biorefinery process.

One-pot synthesis of dihydropyrimidinone and polyhydroquinoline derivatives with natural deep eutectic solvents (NADESs): Alternative to toxic organic solvents and environmental eco-friendly

Natural deep eutectic solvents (NADESs) have emerged as a novel class of solvents with properties reminiscent of ionic liquids while offering additional advantages in terms of cost, environmental impact, and synthesis. This article focuses on the applications of NADESs of mannose:urea and glucose:dimethylurea as inexpensive, accessible, and reusable catalysts in the synthesis of dihydropyrimidinone and polyhydroquinoline derivatives. The results demonstrate significant yields for both dihydropyrimidinones (47–99%) and polyhydroquinolines (90–97%) reactions using mannose:urea and glucose:dimethylurea as catalysts. The advantages of NADESs as catalysts include their simple and reproducible preparation, low cost, environmentally benign nature, long-term durability, and tunable properties. This NADESs can also be recovered and reused for four times without a significant loss of activity.

Designing Natural Deep Eutectic Solvents for Extraction of Phenolic Compounds and Antioxidant Application: A Case Study with Diverse Thai Rice Bran Varieties

Designing Natural Deep Eutectic Solvents for Extraction of Phenolic Compounds and Antioxidant Application: A Case Study with Diverse Thai Rice Bran Varieties

Advances in Extracting Bioactive Compounds from Food and Agricultural Waste and By-Products Using Natural Deep Eutectic Solvents: A Circular Economy Perspective

Due to the urgent need for a transition to sustainable, zero-waste green technology, the extraction of bioactives from food and agricultural by-products and waste has garnered increasing interest. Traditional extraction techniques often involve using organic solvents, which are associated with environmental and health risks. Natural deep eutectic solvents (NADESs) have emerged as a promising green alternative, offering advantages such as low toxicity, biodegradability, and the ability to dissolve a wide range of biomolecules. This review provides a comprehensive overview of recent trends in the application of NADESs for extracting bioactive compounds from sustainable sources. The review explains the composition and principles of preparation and highlights various applications of NADESs in extracting different classes of bioactive compounds, emphasizing their potential to revolutionize extraction processes. By summarizing the latest advancements and trends, this review aims to support research and industrial applications of NADESs, promoting more sustainable and efficient extraction methods in the food and agricultural sectors.

Sustainable isolation of ginger (Zingiber officinale) herbal dust bioactive compounds with favorable toxicological profile employing natural deep eutectic solvents (NADES)

The usage of ginger (Zingiber officinale) has increased in recent years due to its positive effect on human health affiliated with its richness in gingerols and shogaols. This study optimized the Ultrasound-assisted extraction (UAE) for better phenolic compounds isolation from ginger herbal dust (GHD), a filter tea industry by-product. The extraction was performed using raw and defatted GHD-previously processed by Supercritical fluid extraction – CO2. An additional advantage was using COSMOtherm software for 71 natural deep eutectic solvents (NADES) screening, to select the optimal one for GHD 6-gingerol recovery. As an optimal NADES, Malic acid:Glucose (MA:Glc) in the 1:1 ratio was determined. The optimal MA: Glc-based extract with a 6-gingerol content of 1.90±0.05 mg/g, an antioxidant activity of 321.28±5.09 μmol TE/g, and a favorable toxicological profile was obtained in 2 min of UAE under the sonication amplitude of 20 %, approving the benefits and the sustainability of the present study.

A paradigm for natural eutectic solvents based on fatty acids: Molecular interactions and toxicological considerations

In this work, we present experimental and molecular modeling results on archetypal hydrophobic natural deep eutectic solvents (NADES) based on fatty acids (octanoic and dodecanoic acid) and menthol, a representative monoterpenoid. Our goal is to provide a multiscale characterization to enhance the understanding of this field by studying these selected archetypical mixtures. We examine their liquid state properties, intermolecular forces, nanoscopic arrangements, toxicity, and environmental impact.The computational study integrates quantum chemistry, molecular dynamics (both all-atom and coarse-grained approaches), and thermodynamic modeling (COSMO-RS approach) to analyze the fluids and their interactions with biological entities, such as proteins and plasma membranes. The experimental characterization focuses on elucidating intermolecular interactions and liquid phase dynamics using NMR spectroscopy, visible and UV Resonance Raman spectroscopy (UVRR). Notably, this is the first report of UVRR data on NADES.Additionally, we simulate the effect of the molecular moieties forming the solvents on biological targets—specifically, protein and cell membrane models –. This in silico analysis aims to rationalize and predict their potential toxicity.Overall, our experimental findings and in silico simulations contribute to a deeper understanding of these novel solvents in terms of their network of interactions. Additionally, they highlight the potential impact on biological targets, providing new data to accurately define the eco-friendliness of type V DES and their suitability as sustainable alternatives to traditional molecular solvents.

Unveiling the high-pressure behavior of thymol+carvone NADES: A combined experimental-computational approach

this study considers the high-pressure behavior of thymol + carvone Natural Deep Eutectic Solvent using a combined experimental and computational approach. Experimentally, PVT (pressure – volume/density - temperature) measurements were conducted to characterize the fluid volumetric behavior as well as compressibility and internal pressure, which are directly related with hydrogen bonding and nanoscopic structuring. Likewise, these measurements provide crucial insights into the thermodynamic properties of the considered fluid under high pressure, which is pivotal for scaling up and process design for high pressure operations. Computationally, the PC-SAFT equation of state was employed to predict phase equilibria and PVT behavior, Machine Learning for density predictions, while Density Functional Theory and Classical Molecular Dynamics simulations were considered for the structural and dynamic characterization. These simulations provides insights into the electronic structure, intermolecular interactions (hydrogen bonding), liquid structuring and they unveil the pressure's impact on microscopic interactions, structural organization, and transport properties. This comprehensive investigation aims to shed light on the behavior under high pressure, facilitating their optimization for applications in chemical processing, energy storage, and materials science.

Optimization of Eugenol Extraction From Piper betle Leaves Using Natural Deep Eutectic Solvents and Ultrasound‐Assisted Extraction

ABSTRACTPiper betle L. (Piperaceae) is a herbal plant used in Thai traditional medicine for its antifungal and antiallergic properties, particularly through topical application. This study aimed to optimize the extraction of Piper betle leaves using natural deep eutectic solvents to enhance the extraction efficiency of eugenol, the active compound in Piper betle leaves. Various types of hydrogen bond donors—including glycolic acid, lactic acid, malic acid, tartaric acid, ascorbic acid, and citric acid—were combined with a hydrogen bond acceptor, choline chloride, to prepare natural deep eutectic solvents. The results indicated that lactic acid was the most effective hydrogen bond donor for eugenol extraction. Subsequently, the choline chloride:lactic acid molar ratios, the natural deep eutectic solvent:water mass ratios, and ultrasonication times were varied. Results showed that the optimal conditions based on one‐factor‐at‐a‐time approach were a choline chloride:lactic acid molar ratio of 1:5, a natural deep eutectic solvent:water mass ratio of 2:1, and an ultrasonication time of 30 min. Under these conditions, the eugenol concentration reached 457.22 ± 21.68 µg/mL, compared to 224.76 ± 6.99 µg/mL when ethanol was used. In conclusion, this study successfully optimized the extraction of eugenol from Piper betle leaves using natural deep eutectic solvents. These findings suggest that natural deep eutectic solvents could be a more effective solvent for the extraction of eugenol.

Solubility and extractability enhancement of the main food flavonoids by using choline chloride-based natural deep eutectic solvents

This study investigates the solubility of ten primary food flavonoids in both conventional solvents and natural deep eutectic solvents (NADES), utilizing five choline chloride-based NADES. These NADES were formulated with lactic acid, ascorbic acid, urea, sorbitol, and 1,2-propanediol as hydrogen bond donors (HBD). Conventional solvents used in the comparison included water, menthol, and ethanol. The flavonoids studied—catechin, daidzein, quercetin, naringenin, luteolin, genistein, kaempferol, apigenin, diosmetin, and chrysin—were analyzed for solubility and extractability via both solvents. Flavonoid solubility was observed to vary based on both the structural characteristics of the flavonoid and the choice of HBD. Notably, catechin demonstrated the highest solubility across all solvent systems, followed by naringenin and quercetin. Among the NADES systems, the blend based on 1,2-propanediol notably enhanced the solubility of quercetin and luteolin to 53.4 mg/mL and 26.9 mg/mL, respectively, surpassing their solubility in conventional solvents. The empirical findings were consistent with theoretical predictions made using the COSMO-RS method, confirming the efficacy of NADES in solubilizing food flavonoids more effectively than conventional solvents.

Isolation and Structural Characterization of Natural Deep Eutectic Solvent Lignin from Brewer's Spent Grains.

Brewer's spent grains (BSG) offer valuable opportunities for valorization beyond its conventional use as animal feed. Among its components, lignin-a natural polymer with inherent antioxidant properties-holds significant industrial potential. This work investigates the use of microwave-assisted extraction combined with acidic natural deep eutectic solvents (NaDESs) for efficient lignin recovery, evaluating three different NaDES formulations. The results indicate that choline chloride-lactic acid (ChCl-LA), a NaDES with superior thermal stability as confirmed via thermogravimetric analysis (TGA), is an ideal solvent for lignin extraction at 150 °C and 15 min, achieving a balance of high yield and quality. ChCl-LA also demonstrated good solubility and cell disruption capabilities, while microwaves significantly reduced processing time and severity. Under optimal conditions, i.e., 150 °C, 15 min, in the presence of ChCl-LA NaDES, the extracted lignin achieved a purity of up to 79% and demonstrated an IC50 (inhibitory concentration 50%) of approximately 0.022 mg/L, indicating a relatively strong antioxidant activity. Fourier transform infrared (FTIR) and 2D-HSQC NMR (heteronuclear single quantum coherence nuclear magnetic resonance) spectroscopy confirmed the successful isolation and preservation of its structural integrity. This study highlights the potential of BSG as a valuable lignocellulosic resource and underscores the effectiveness of acidic NaDESs combined with microwave extraction for lignin recovery.

α-Glucosidase Inhibiting Chromene Derivatives from Ageratum conyzoides L. Essential Oil Extracted via NADES-Assisted Hydrodistillation.

This work employed a green approach utilizing natural deep eutectic solvent (NADES)-assisted hydrodistillation for EO extraction from the aerial part of Ageratum conyzoides. Out of seven eutectic combinations used, glycerol-lactic acid (GLY:LA) (1:1) mixture significantly enhanced the yield from 0.78 mg/g (water as extraction media) to 1.00 mg/g. GC and GC-MS analysis revealed that EOs mainly contain (E)-β-caryophyllene (15.2-25.3%), (E)-β-farnesene (2.7-8.2 %), and notably, precocene-I (8.5-18.0 %) and precocene-II (31.8-51.4 %), which varied significantly across different extraction media. Further column chromatography-based purification of EO led to the isolation of two known chromene derivatives precocene-I (1) and precocene-II (2). Precocene-I exhibited potent anti-diabetic activity (IC50 0.26 mg/mL) compared to the standard drug acarbose. Among the EO samples, USK-N7, which had the highest percentage of precocene-I, showed the highest activity. The present study demonstrated the potential use of this weed plant as an anti-diabetic agent.

In silico study on helicenes in hydrophobic natural deep eutectic solvent

This research explores the behavior of helicenes in Deep Eutectic Solvents (DES) formed by thymol and dodecanoic acid using a combined theoretical approach. COSMOtherm, Density Functional Theory (DFT), and molecular dynamics (MD) simulations were employed to elucidate the interactions between helicenes and the DES components at the molecular level. The behavior of helicenes in water was also studied as a reference system. COSMOtherm calculations provided insights into the thermodynamic properties of the system. DFT simulations allowed for the investigation of the electronic structure and bonding interactions between helicenes and DES molecules. Additionally, MD simulations offered dynamic information on the solvation behavior and conformational preferences of helicenes within the DES media. The combined approach provides a comprehensive understanding of the interactions between helicenes and thymol-dodecanoic acid DES. The research findings will contribute to the development of a theoretical framework for predicting the behavior of other functional molecules in DES environments. This knowledge has potential applications in various fields, including material science, catalysis, and drug delivery.

Sustainable reuse of date palm biomass via extraction of cellulose using natural deep eutectic solvent (NaDES) and microwave-assisted process

In Saudi Arabia, date palm biomass is often considered bulk waste, posing health risks to humans and the environment when incinerated or disposed of in landfills. This study explores the reuse of date palm biomass through cellulose extraction using Natural Deep Eutectic Solvent (NaDES) and Microwave-assisted process as compared with conventional alkali peroxide method. Characterization of the extracted cellulose was conducted using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), x-ray diffractometry (XRD), and fourier-transform infrared spectroscopy (FTIR). Our NaDES-microwave method produced a cellulosic product with a yield of 89 %, double that of conventional non-microwave methods and more rapid cellulosic extraction, indicating its favorable efficiency. Moreover, the incorporation of the microwave process resulted in larger cellulosic crystallite sizes and higher thermal stabilities in the produced samples. The utilization of NaDES and microwave-assisted process for cellulose extraction from date palm biomass not only demonstrates superior efficiency, but also accentuates a significant sustainability advantage by repurposing a prevalent waste stream, thereby mitigating environmental and health risks associated with traditional disposal methods.

Extraction of camptothecin and 10-hydroxycamptothecin from Camptotheca acuminata fruits by natural deep eutectic solvent

A natural deep eutectic solvent-based ultrasound-assisted simultaneous extraction (NADES-UAE) of camptothecin (CPT) and 10-hydroxycamptothecin (10-HCPT) was established. The 1.31 mg of CPT and 1.66 mg of 10-HCPT were obtained from each gram of the fruit powder of Camptotheca acuminata under the optimum conditions with a water content of 20%, a liquid-solid ratio of 12 mL/g and an ultrasound time of 20 min. The recovery efficiencies of CPT and 10-HCPT after AB-8 resin enrichment were 70.5% and 74.8%, respectively. The stronger interaction between NADES3 which was screened from 12 kinds of NADES and target components compared with methanol or water was demonstrated using molecular dynamics simulation. Moreover, the recovered NADES3 could be reused at least 4 times. The present research provided an efficient, environment-friendly, and sustainable method for extracting and recovering CPT and 10-HCPT from the fruits of C. acuminata.

Microextraction of steroidal hormones from urine samples using natural deep eutectic solvents: insights into chemical interactions using molecular dynamics simulations.

Natural deep eutectic solvents (NADES) are gaining significant attention in analytical chemistry due to attractive physico-chemical properties associated with sustainable aspects. They have been successfully evaluated in different fields, and applications in sample preparation have increased in the last years. However, there is a limited knowledge related to chemical interactions and mechanism of intermolecular action with specific analytes. In this regard, for the first time, this study exploited a computational investigation using molecular dynamics (MD) predictions combined with experimental data for the extraction/determination of steroidal hormones (estriol, β-estradiol, and estrone) in urine samples using NADES. The ultrasound-assisted liquid-liquid microextraction (UALLME) approach followed by high-performance liquid chromatography with diode array detection (HPLC-DAD) was employed using menthol:decanoic acid as extraction solvent. Experimental parameters were optimized through multivariate strategies, with the best conditions consisting of 3min of extraction, 150 μL of NADES, and 3mL of sample (tenfold diluted). According to molecular dynamics predictions confirmed by experimental data, a molar ratio that permitted the highest efficiency consisted of menthol:decanoic acid 2:1 v/v. Importantly, computational simulations revealed that van der Waals interactions were the most significant contributor to the interaction energy of analytes-NADES. Using the optimized conditions, limits of detection (LOD) ranged from 3 and 8μg L-1, and precision (n = 3) varied from 8 to 19%. Intraday precision was evaluated at 3 concentrations: low (LOQ according to each analyte), medium (100μg L-1), and high (750μg L-1). Accuracy was successfully assessed through recoveries that ranged from 82 to 98%. In this case, molecular dynamics simulations proved to be an important tool for in-depth investigations of interaction mechanisms of DES with different analytes.