Natural Deep Eutectic Solvents Research Articles

Acidic deep eutectic solvent as a greener medium for highly efficient extraction of anthocyanins from blackberry fruit: Optimization, stability and purification with two-aqueous phase method

Natural deep eutectic solvents (NADESs) are a sustainable and green solution for the recovery of food ingredients such as pigments. In this work, the extraction conditions to obtain the maximum anthocyanins from blackberry fruit were investigated using NADES composed of choline chloride-acetic acid (CHAC) as the green solvent. The central composite design was used conseidering molar ratio, water content, solvent ratio and extraction time as independent variables and total anthocyanin content (TAC), cyanidin-3-glucoside, cyanidin-3-rutinoside, pelargonidin-3-glucoside and cyanidin chloride as responses. The results showed that the independent variables significantly affected the responses. The optimum conditions for CHAC were 1:3.5 M, 40 %, 30 g and 15 min for molar ratio, water content, solvent ratio and extraction time, respectively. Under these conditions, the experimental responses were 131.54 ± 7.89 mg CGE/100 g, 1208.08 ± 13.76 mg/kg, 163.43 ± 1.72 mg/kg, 53.78 ± 1.37 mg/kg and 91.98 ± 0.62 mg/kg for TAC, cyanidin-3-glucoside, cyanidin-3-rutinoside, pelargonidin-3-glucoside and cyanidin chloride, respectively. The pH, viscosity and electric conductivity of CHAC were determined as 1.24 ± 0.03, 1.21 ± 0.17 and 7.50 ± 0.55 mPa and 4675.33 ± 57.74 µS.cm−1, respectively. After storing the NADES extract for 28 days in the dark, cyanidin-3-glucoside, cyanidin-3-rutinoside, pelargonidin-3-glucoside and cyanidin chloride remained 71.57 ± 0.64 %, 75.00 ± 0.26 %, 33.42 ± 0.41 % and 71.45 ± 0.21 %, respectively. Over the 28-day exposure of the NADES extract to light, the cyanidin-3-glucoside, cyanidin-3-rutinoside, pelargonidin-3-glucoside and cyanidin chloride remained 19.09 ± 0.10 %, 34.89 ± 2.28, 13.28 ± 0.25 and 30.97 ± 1.10, respectively. The application of the aqueous two-phase system resulted in the preliminary purification of the NADES extract, providing the highest purity in the top phase for cyanidin-3-glucoside (68.85 ± 1.05 %). The findings revealed that CHAC is a promising green medium for the industrial extraction of anthocyanins, and the aqueous two-phase is suitable for the purification of the anthocyanin-rich extract obtained with NADES.

Phytochemical Characterization and Bioactivity of Extracts from Different Fruit Parts of Opuntia leucotricha DC.: A Comparison between a Conventional Organic Solvent and Green Natural Deep Eutectic Solvents

The objective of this study was to analyze the chemical profile of extracts from different fruit parts of the perennial arborescent cactus Opuntia leucotricha by applying ultra-high-performance liquid chromatography–high-resolution mass spectrometry (UHPLC-HRMS) and to evaluate their biological properties (antioxidant and enzyme inhibitory capacities). Extracts were obtained from the fruit pulp (without or with seeds), seeds, and peel by ultrasound-assisted extraction (UAE) using the conventional solvent methanol 50% and two Natural Deep Eutectic Solvents (NADESs) (glycerol:urea, 1:1 and citric acid:sorbitol, 1:2). A total of 33 compounds were identified, including phenolics, fatty acids, and others. Phenolic acids were the most abundant class of phenolics identified in all fruit parts, with the highest concentration observed in the methanol extracts from peel (593.02 µg/gDW), followed by seed-containing pulp (69.03 µg/gDW), pulp (57.83 µg/gDW), and seeds (39.97 µg/gDW). The second most effective extractant was NADES 1 (glycerol:urea, 1:1), which was also successful in extracting compounds with antioxidant capacity. Overall, the extracts demonstrated considerable enzyme inhibitory activities, with the greatest effects observed against α-amylase and α-glucosidase. The results indicate that O. leucotricha fruits could be a promising source of bioactive compounds, and NADES a viable alternative to organic solvents for their industrial exploitation.

NADES systems comprising choline chloride and polyphenols: Physicochemical characterization, antioxidant and antimicrobial activities

Natural Deep Eutectic Solvents (NADES) represent a new group of green and environmentally friendly solvents that comply with all the principles of green chemistry. NADES are formed via hydrogen bonding by combining hydrogen bond donors (HBD) and hydrogen bond acceptors (HBA). In this paper, we presented ten NADES systems based on choline chloride and different polyphenols. The basic physicochemical and biological properties were evaluated (stability, density, viscosity, FTIR, ORAC, antibacterial activity). It was shown that all the systems had a high densities and high dynamic viscosities. The densities ranged from 1.096 – 1.221 mg/mL for ChCl – resveratrol and ChCl – rutin, respectfully. The dynamic viscosities ranged from 0.247 – 1.662 Pa S for ChCl – gallic acid and ChCl – chlorogenic acid, respectfully. The viscosity could be lowered by increasing the molar ratio of choline chloride. Four NADES systems, comprising catechin, rosmarinic acid, gallic acid and chlorogenic acid could be diluted with water without affecting the stability of those systems. This finding could increase the usability of those systems. The FT-IR analysis of the selected systems showed that the peaks are widened and slightly shifted, without formation of new peaks, which proves the formation of hydrogen bonds between the NADES constituents. All tested systems showed high ORAC value (426.94 – 874.96 Trolox eq/mL) and antibacterial activity (0.625 – 2.5 % NADES).

A Natural deep eutectic solvent as an effective material for dual debridement and antibiofilm effects in chronic wound treatment

In chronic wound treatment, the debridement of devitalized tissue and the eradication of the biofilm must balance aggressiveness with care to protect regenerating tissues. In this study, urea, a potent chaotropic molecule, was modulated through the formation of a Natural Deep Eutectic Solvent (NADES) with betaine to develop a new debriding material (BU) suitable for application into injured dermal tissues. To evaluate BU’s debriding capacity, along with its antibiofilm effect and biocompatibility, pre-clinical to clinical methods were employed. In vitro determinations using artificial and clinical slough samples indicate that BU has a high debriding capacity. Additionally, BU’s de-structuring effects lead to a strong antibiofilm capability, demonstrated by a reduced bacterial load compared to the antiseptic PHMB-Betaine or medical honey, evaluated in artificial slough and ex vivo human skin. Furthermore, BU’s efficacy was evaluated in a murine model of diabetic wound, demonstrating significant effects on debriding and antibiofilm capacity, similar to those observed in PHMB-Betaine and medical honey-treated animals. Finally, BU was clinically evaluated in leg ulcers, showing superiority in reduction of bacterial load and wound area compared to honey, with no adverse effects. Thus, BU represents a simple and non-biocidal option that could contributes to chronic wound care.

Supramolecular solvents based on hydrophobic natural deep eutectic solvents and primary amines for preconcentration and determination of enrofloxacin in milk

In this work, coacervation in primary amines solutions with hydrophobic natural deep eutectic solvents based on terpenoids and carboxylic acids was demonstrated for the first time. A liquid-phase microextraction approach was developed based on supramolecular solvent formation with primary amine acting as amphiphile and hydrophobic deep eutectic solvent making up mixed vesicles and serving as coacervation agent. Such supramolecular solvents could be used to separate wide range of substances from different aqueous media, such as food products, biological liquids and wastewaters. It is important that both hydrophobic and ionic interactions with supramolecular aggregates take place ensuring synergetic effect and better extraction ability, which is significant in separating relatively polar analytes. Different primary amines and deep eutectic solvents were investigated for liquid-phase microextraction of proof-of-concept amphoteric analyte (enrofloxacin, widely used veterinary fluoroquinolone antibiotic) and its determination by high-performance liquid chromatography with fluorescence detection using Shimadzu LC-20 Prominence chromatograph and RF-20A fluorescence detector. It was found that the supramolecular solvent based on 1-nonylamine, formed after addition of a deep eutectic solvent based on menthol and hexanoic acid (molar ratio of 1:1), provided maximum extraction recovery (85 %) and maximum enrichment factor (34). To characterize the extraction system, the composition of the phases was investigated, and cryo-transmission electron microscopy images were obtained. Vesicular aggregates were observed in the supramolecular solvent. The extraction mechanism was proposed in terms of formation of mixed aggregates to capture the analyte. Limit of detection was found to be 7 μg kg-1, while linear range of 20 to 250 μg kg-1 was established. Relative standard deviation values were lower than 7 %. Relative bias did not exceed 12 %.

Electro-depolymerization of Kraft lignin with deep eutectic solvents

AbstractThe paper production industry annually produces approximately 50 million tons of lignin, an intermediate product. While lignin has the potential for producing valuable chemicals and energy materials, an effective method for its conversion is yet to be developed. This study aims to establish a sustainable and environmentally friendly approach for electrochemically synthesizing valuable compounds from lignin with using natural deep eutectic solvents as electrolytes. The study used cyclic voltammetry (CV) for the electrochemical depolymerization of Kraft lignin, examining the effects of different scan numbers on depolymerization and the resulting lignin derivatives. Observed changes in the depolymerization peak current of lignin were reported as the number of scans increased. Choline chloride: Lactic acid (CC:LA), Choline chloride: Ethylene glycol (CC:EG), and Lactic acid:1,2-propanediol (LA:PR) were used as green electrolytes. Syringaldehyde was found to be the major compound obtained by this method. As a result of statistical analysis performed using The Grey Relations Analysis method, it was determined that the conditions that utilized Kraft lignin with the highest added value involved performing five cycles of CV scans with the CC:LA electrolyte. CV scans in DES environments increased the yield of lignin-derived phenolic compounds.

Comparison, optimization and antioxidant activity of ultrasound-assisted natural deep eutectic solvents extraction and traditional method: A greener route for extraction of flavonoid from Moringa oleifera Lam. leaves

To develop an environmentally sustainable and efficient extraction method for flavonoids from Moringa oleifera Lam. (M. oleifera) leaves, natural deep eutectic solvents (NADES) with ultrasound-assisted extraction was utilized in this study. After optimization of extraction parameters of NADES, including ultrasonic power, ultrasonic time, and liquid–solid ratio, the extraction yield of ultrasound-assisted NADES (UAN) composed of betaine and urea (Bet-Urea) reached 54.69 ± 0.19 mg RE/g DW, which made a 1.7-fold increase compared to traditional ultrasound-assisted traditional solvent (UATS). UPLC-Q Exactive/MS analysis revealed that M. oleifera leaves flavonoids (MOLF) was mainly composed of Quercetin 3-β-D-glucoside, Rutin, Kaempferol-3-O-glucoside, Vitexin and Quercetin. Furthermore, the COSMO-RS model was employed to verify the optimal compatibility of solubility and activity coefficient between Bet-Urea and the five primary flavonoids in MOLF. In vitro antioxidant assays verified that MOLF extracted by UAN exhibited superior antioxidant activity compared to MOLF extracted by UATS. Overall, the devised process not only augmented the extraction yield of MOLF but also effectively preserved the bioactive compounds, thus promoting the utilization of green extraction solvents in the food industry.

Efficient phosphorus recovery from waste activated sludge: Pretreatment with natural deep eutectic solvent and recovery as vivianite

Recycling phosphorus from waste activated sludge (WAS) is an effective method to address the nonrenewable nature of phosphorus and mitigate environmental pollution. To overcome the challenge of low phosphorus recovery from WAS due to insufficient disintegration, a method using a citric acid-based natural deep eutectic solvent (CA-NADES) assisted with low-temperature pretreatment was proposed to efficiently release and recover phosphorus. The results of 31P nuclear magnetic resonance (NMR) confirmed that low-temperature pretreatment promoted the conversion of organic phosphorus (OP) to inorganic phosphorus (IP) and enhanced the effect of CA-NADES. Changes in the three-dimensional excitation-emission matrix (3D-EEM) and flow cytometry (FCM) indicated that the method of CA-NADES with low-temperature thermal simultaneously release IP and OP by disintegrating sludge flocs, dissolving extracellular polymeric substances (EPS) structure, and cracking cells. When 5 % (v/v) of CA-NADES was added and thermally treated at 60 °C for 30 min, 43 % of total phosphorus (TP) was released from the sludge. The concentrations of proteins and polysaccharides reached 826 and 331 mg/L, respectively, which were 6.30 and 14.43 times higher than those of raw sludge. The dewatering and settling of the sludge were also improved. Metals were either enriched in the solid phase or released into the liquid phase in small quantities (most efficiencies of less than 10 %) for subsequent clean recovery. The released phosphorus was successfully recovered as vivianite with a rate of 90 %. This study develops an efficient, green, and sustainable method for phosphorus recovery from sludge using NADES and provides new insights into the high-value conversion of sludge.

Antibacterial and antioxidant activities of Chlorella vulgaris and Scenedesmus incrassatulus using natural deep eutectic solvent under microwave assisted by ultrasound

Microalgae are increasingly recognized as promising sources of natural bioactive compounds. However, traditional extraction methods using volatile organic solvents (VOCs) pose environmental risks. This study explores renewable deep eutectic solvents (DES) as sustainable alternatives for extracting bioactive compounds from microalgae biomass, focusing on Chlorella vulgaris and Scenedesmus incrassatulus. Four DES systems, comprising choline chloride (ChCl) and glycerol, citric acid, urea, and glucose, were compared with three conventional solvents (ethanol, methanol, and water). Extraction efficiency was assessed based on total phenolic content (TPC), flavonoid content, and tannin content, followed by antioxidant activity evaluation using DPPH, CAT, and FRAP assays. Additionally, antibacterial activity of the DES extracts was determined against Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 29213), and Bacillus subtilis (ATCC 3366) using disc diffusion and microplate dilution methods to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Results reveal that DES, particularly choline chloride: citric acid, outperform conventional solvents in terms of polyphenol extraction efficiency, antioxidant activity, and antibacterial activity against both Gram-negative and Gram-positive bacteria. For instance, the citric acid-based DES (SIDES2) showed a TPC of 4.98 mg/g, while the conventional solvent ethanol exhibited a TPC of 3.27 mg/g. Additionally, SIDES2 exhibiting the highest DPPH scavenging activity of 75 %, compared to 60 % for ethanol. Furthermore, SIDES2 showed an MIC of 0.5 mg/ml against Staphylococcus aureus. This study underscores the potential of DES for sustainable extraction of natural antioxidants from microalgae biomass, contributing to the development of environmentally friendly extraction processes in various industries.

Solubility enhancement of metronidazole using natural deep eutectic solvents: Physicochemical and thermodynamic studies

This research aimed to explore the utility of natural deep eutectic solvents (NADES) as the co-solvents for slightly water-soluble metronidazole (MNZ). After testing 70 wt% (percentage by weight) aqueous mixtures of seven NADESs, it was found that MNZ had the highest solubility in water solutions of NADES composed of choline chloride (ChCl) and citric acid (CA). The solubility of MNZ (expressed as 103 mol fraction) increased with the concentration of ChCl:CA NADES (from 6.7743 to 26.8518 at 298.5 K, for 30 and 70 wt% NADES-water mixtures, respectively), and it was more effective when compared to aqueous solutions of individual NADES components with wt.% corresponding to these in the NADES-water mixtures. The study also found a preferable mixing of MNZ with aqueous solutions of NADES reflected by negative values of standard molar enthalpy change of mixing (approx. − 4.2 kJ·mol−1), compared with positive values in the case of MNZ mixing with water or ChCl aqueous solutions (approx. 7.3 kJ·mol−1). Comparative research conducted on the volume and acoustics of MNZ in water and aqueous solutions of ChCl, CA, and ChCl:CA NADES also confirmed stronger interactions between the drug and NADES and CA. The dominant interactions between MNZ and co-solvent were hydrophilic-hydrophobic and hydrophobic-hydrophobic. This effect increased in the following strength order: ChCl < NADES<CA. In conclusion, the obtained NADES seems to be a promising co-solvent which provides solid grounds for further research to evaluate the full potential in pharmaceutical design of MNZ liquid formulations.

Green and efficient extraction process of flavonoids from sea buckthorn fruits by natural deep eutectic solvents aided with ultrasound

In recent years, with the advantages of environment friendly, natural deep eutectic solvents (NADES) have been gradually applied for the extracting bioactive compounds from natural products. In this study, NADES-12 (betaine-lactic acid, n/n, 1:2) was selected for the first time to extract flavonoids from sea buckthorn fruit after screening of 23 NADES. The optimal technical conditions of NADES combined with ultrasonic assisted extraction (UAE) were determined by single factor test and response surface optimization test. The results showed that the optimal process for the extraction of antioxidant components by NADES-12 was 37 min extraction time, 40 °C extraction temperature, 17 % (v/v) water content, 40 mL mg−1 liquid–solid ratio, 160 W ultrasonic power, and a maximum extraction rate of 5.248 mg g−1, and the extraction yield is 2.4 and 3.1 times that of 60 % ethanol and water. The sea buckthorn extract by NADES has antioxidant activity. The study proposes a green and efficient method for the extraction of bioactive components from sea buckthorn fruit and provides a valuable basis for the exploitation of other natural plants.

Systematic study on date palm seeds (Phoenixdactylifera L.) extraction optimisation using natural deep eutectic solvents and ultrasound technique

Natural deep eutectic solvents (NADES) are emerging, environment-friendly solvents that have garnered attention for their application in extracting phenolic compounds. This study investigated the effects of four synthetic NADES on polyphenols extracted from date seeds (DS) using choline chloride (ChCl) as a hydrogen-bond acceptor and lactic acid (La), citric acid (Citri), glycerol (Gly), and fructose (Fruc) as hydrogen-bond donors, in comparison with DS extracts extracted by conventional solvents (water, 70% methanol, and 70% ethanol). The antioxidant activity (DPPH), total phenolic content (TPC) and 6 phenolic compounds were determined using HPLC. The results showed that the ChCl–La and ChCl–Citri systems exhibited a high extraction efficiency regarding TPC, and DPPH in the DS extracts extracted by NADES compare to those DS extracts extracted with conventional solvents (p ˂ 0.001). HPLC results demonstrated that DS extracted by ChCl–La contained all measured phenolic compounds. Also gallic acid and catechin were the major compounds identified in the DS extracts. In addition DS extracted by ChCl–Citri and ChCl–Gly had the highest concentration of catechin. In conclusion, combining NADES is a promising and environment-friendly alternative to the conventional solvent extraction of phenolic compounds from DS.

Enhanced Preparative-Scale Extraction from Graševina Grape Pomace Using Ultrasound-Assisted Extraction and Natural Deep Eutectic Solvents

This research paper presents an advanced exploration into the utilization of ultrasound-assisted extraction (UAE) combined with natural deep eutectic solvents (NADESs) to achieve higher concentrations of polyphenols from Graševina grape pomace. Focusing on optimizing extraction parameters to maximize the yield of polyphenols, this study evaluates their potential industrial applications, particularly within the food and cosmetics sectors. The effectiveness of betaine/glucose (BGlc) NADESs in producing stable, ready-to-use extracts with enhanced bioavailability and eco-friendly attributes is underscored. The integration of UAE with BGlc NADESs has shown significant scalability and applicability for industrial use, as evidenced by the extracts’ collagenase-inhibitory effects, determined using a ninhydrin-based colorimetric assay showing the significant inhibition of gelatine degradation and scratch tests on cultured skin cells, demonstrating enhanced cell migration and wound healing, indicating their potential in anti-aging cosmetic products. Additionally, the results from PAMPA tests demonstrated that NADES extraction significantly enhances the intestinal absorption of polyphenols from grape pomace extracts compared to conventional solvents, highlighting the potential of NADESs to improve the bioavailability of these compounds and offering promising implications for their application in the food industry. Furthermore, the research highlights the practicality of directly incorporating these extracts into products, such as anti-aging creams and functional foods, supporting sustainability initiatives within the cosmetic and food industries. This work aims to provide a comprehensive guide to green extraction techniques on a preparative scale, showcasing the versatility and innovative applications of NADES-extracted compounds across various industries, thereby paving the way for the development of eco-conscious and effective products.

Advanced and Potential Methods for Extraction of Bioactive Compounds from Avocado Peel—A Review

Extraction techniques are continuously developed by the scientific community. Meanwhile, avocado peel is a by-product of avocado processing and a source of bioactive compounds. The purpose of this review was to summarize the use of advanced techniques for extracting bioactive compounds from avocado peel to help understand which techniques have and have not been applied to avocado peel. Three primary databases were used to collect the information, including Google Scholar, Scopus, and Web of Science, by using the keywords “avocado”, “peel”, and “extraction”. Additional keywords related to the extraction technique were also used, including “Microwave-Assisted Extraction”, “Ultrasound-Assisted Extraction”, “Enzyme-Assisted Extraction”, “Pressurized Liquid Extraction”, “Supercritical Fluid Extraction”, “Natural Deep Eutectic Solvents”, “Three-phase partitioning (TPP)”, “Pulsed-Electric Field”, “High Voltage Electric Discharge Plasma”, “Centrifugal Partition Extraction”, and “Surfactant-Mediated Extraction”. The results show that microwave-assisted extraction, ultrasound-assisted extraction, enzyme-assisted extraction, pressurized liquid extraction, supercritical fluid extraction, TPP, and natural deep eutectic solvent extraction have been used to retrieve bioactive compounds from avocado peel. Other techniques have not yet been applied for the extraction of bioactive compounds from avocado peel. This article is the first review discussing the advanced extraction technique for retrieving bioactive compounds from avocado peel. This article creates a paradigm for future studies.

Investigating the synergistic effects of apple vinegar and deep eutectic solvent as natural antibiotics: an experimental and COSMO-RS analysis

ABSTRACT The present investigation examines the antimicrobial and antifungal characteristics of natural deep eutectic solvents (NADES) and apple vinegar in relation to a diverse array of bacterial and fungal strains. The clinical bacterial strains, including gram-negative and gram-positive, and the fungal pathogen Candida albicans, were subjected to solid medium diffusion to determine the inhibitory effects of these compounds. The results show that NADES has superior antimicrobial and antifungal action compared to apple vinegar. The observed inhibitory zones for apple vinegar and NADES varied in length from 16.5 to 24.2 and 16 to 52.5 mm, respectively. The results obtained indicate that no synergy is observed for this mixture (50% AV + 50% NADES). The range of values for bactericidal concentrations (MBC) and minimal inhibitory concentrations (MIC) was 0.0125 to 0.2 and 0.0125 to 0.4 µl/ml, respectively. Antibacterial and antifungal chemicals may be found in apple vinegar and NADES, with NADES offering environmentally safe substitutes for traditional antibiotics. Additional investigation is suggested to refine these compounds for a wide range of bacteria, which could create antimicrobial solutions that are both highly effective and specifically targeted, thereby offering extensive potential in medicine and the environment.

Enhanced Curcumin Delivery and Stability through Natural Deep Eutectic Solvent-Based Niosomes

Curcumin, a highly sought-after medicinal compound with diverse health benefits, encounters limitations regarding its oral bioavailability and aqueous solubility. To overcome these challenges, curcumin can be encapsulated within niosomal formulations, allowing controlled drug release and improving encapsulation efficacy. In this study, incorporating a natural deep eutectic solvent (NADES) with curcumin-loaded niosomes was investigated to enhance the bioavailability of curcumin. Initially, NADESs were synthesized using betaine as a hydrogen bond acceptor and a range of hydrogen bond donors. Among the different combinations tested, the NADES formed with betaine and glucose, fructose, or xylose exhibited the highest solubility of 6.16 ± 0.61 mg/g, 6.03 ± 0.25 mg/g and 5.57 ± 0.14 mg/g, respectively. Subsequently, these NADESs with the ideal combination were utilized to incorporate with curcumin niosomes denoted by the formulation abbreviations BG, BF, and BX. These formulations were prepared at varying masses, including 25 mg (BG1, BF1, and BX1), 50 mg (BG2, BF2, and BX2), 75 mg (BG3, BF3, and BX3), and 100 mg (BG4, BF4, and BX4). Optical microscopy results revealed that curcumin-loaded niosomes with NADES displayed a spherical morphology. The entrapment efficiency of eutectic-based curcumin niosomes ranged from 82.20 ± 0.46 % (BX1) to 97.61 ± 0.67 % (BG4), significantly outperforming blank niosomes, which achieved a mere 74.27 ± 0.20 %. The zeta potential measurements reveal distinct differences where the blank curcumin niosomes exhibit a relatively modest value of −17.57 ± 0.90 mV, whereas the eutectic-based niosomes display markedly elevated zeta potentials, spanning from −45.50 ± 2.55 mV to −53.70 ± 1.63 mV. Raman spectroscopy studies were performed to examine the interactions between the NADES and curcumin in the niosome, providing insights into the molecular interactions and potential improvements in drug delivery where BG4 achieved the optimum intensity ratio (I2930/I2850) at 0.3106. Stability investigations were conducted to evaluate the enduring stability of the NADES-niosome formulation, affirming its capacity to preserve its electrostatic coherence and underscoring its resilience across varying temperature conditions under 28 days. Moreover, comprehensive experiments were conducted to assess the photochemical stability, revealing that BG4 boasts the lengthiest half-life, reaching an impressive 158.56 days. The antioxidant assay results indicate that niosomes incorporating NADES exhibit lower IC50 values. Furthermore, in vitro studies coupled with Korsmeyer-Peppas and Peppas-Sahlin’s model fitting were performed to evaluate curcumin’s release profile and dissolution behavior from the NADES-niosome system. Overall, this study explores the potential of incorporating NADES with curcumin-loaded niosomes to enhance the bioavailability of curcumin. The comprehensive analysis and characterization techniques provide valuable insights into the formulation’s stability, efficiency, and drug release behavior, paving the way for potential advancements in curcumin delivery systems.

Biopolymeric sensor based on natural deep eutectic solvents for monitoring meat spoilage

Ensuring food safety by monitoring freshness is crucial, particularly for high-protein meat products susceptible to spoilage. Smart packaging with pH-sensitive indicators, using natural pigments such as anthocyanin, provides a cost-effective and non-invasive solution. In this work, a novel colorimetric pH sensor based on biopolymer and natural deep eutectic solvents (NADES) is proposed. The NADES composed by Betaine: Glycerol: Water (BGH) was used for the anthocyanin extraction from Brassica oleracea (Purple Cabbage, PC), using the ultrasonic “one-step” method and BGH extraction efficiency was compared with water. Then, the BGH extract was mixed with different concentrations of xanthan gum (XG) 5, 10, 15 and 20%. The biopolymeric materials were characterized in terms of structure, mechanical properties, stability and pH response. The combination containing 10 % of xanthan gum (PC-BGH-XG10) presented suitable features to be used as a sensor. Thus, PC-BGH-XG10 was applied for real-time monitoring of meat spoilage. Interestingly colour changes were visible to the naked eye and they were successfully correlated with microbiological assays. To the best of our knowledge, this is the first integration of NADES and xanthan gum in the development of a colorimetric pH sensor. The proposed approach represents a green strategy for in-situ control of packaged foods intended for final consumption.

Natural deep eutectic solvent for the simultaneous derivatization and microextraction of isoniazid from human plasma

BackgroundPersonalized medicine is a rapidly revolving field that offers new opportunities for tailoring disease treatment to individual patients. The main idea behind this approach is to carefully select safe and effective medications and treatment plant based on each patient's unique pharmacokinetic profile. Isoniazid is a first-line anti-tuberculosis drug that has interindividual variability in its metabolic processing, leading to significant differences in plasma concentrations among patients receiving equivalent doses. This variability necessitates the creation of individualized treatment regimens as part of personalized medicine to achieve more effective therapy. ResultsIn this work, a deep eutectic solvent-based liquid-liquid microextraction approach for the separation and determination of isoniazid in human plasma by high-performance liquid chromatography with UV-Vis detection was developed for the first time. A new natural deep eutectic solvent based on thymol as a hydrogen bond donor and 4-methoxybenzaldehyde as a hydrogen bond acceptor was proposed as the extraction solvent. The developed microextraction procedure assumed two simultaneous processes during the mixing of the sample and extraction solvent: the derivatization of the polar analyte in the presence of 4-methoxybenzaldehyde (component of the natural deep eutectic solvent) with the formation of a hydrophobic Schiff base (1); mass transfer of the Schiff base from the sample phase to the extraction solvent phase (2). Under optimal conditions, the limits of detection and quantification were 20 and 60 μg L-1, respectively. The RSD value was < 10 %, the extraction recovery was 95 %. SignificanceIn this work, the possibility of isoniazid derivatization in the natural deep eutectic solvent phase with the formation of the Schiff base was presented for the first time. The approach provided the separation and preconcentration of polar isoniazid without the use of expensive derivatization agents and solid-phase extraction cartridges. The formation of the Schiff base was confirmed by mass spectrometry.

Natural deep eutectic solvents-based concurrent approach for qualitative and quantitative enhancement of Rosa damascena essential oil and recovery of phenolics from distilled rose petals

In pursuit of adopting environment friendly methodologies to amplify essential oil (EO) yield of industrially important aromatic plants, enrichment of bioactive content in distillation waste, and to establish the recovery process for the enriched product; this study employed natural deep eutectic solvents (NADESs) as cosolvent in the conventional hydro distillation method using Rosa damascena Mill L (Damask rose) petals as biomass. R. damascena is one of the most important species of Rosaceae family known for producing high-valued rose EO [often termed as “liquid gold”] but with very low yield. Herein, nine NADESs were used as cosolvent along with conventional hydro distillation method which led to 1.7 times EO yield enhancement (retention of EO quality as per ISO guidelines) using choline chloride: glycerol as cosolvent. Further, to sustainably utilize the residue (otherwise waste) left after hydro distillation, hydrolate (aqueous part left in the flask) and spent (dried solid waste) were analyzed with UHPLC to determine targeted phenolics content. All the samples (EO, dried hydrolate, and spent) were also evaluated for in-vitro antioxidant activity using DPPH-radical scavenging activity, which revealed that hydrolate obtained by using NADES-5 showed the highest activity (IC50 0.85 µg/mL) [Ascorbic acid IC50 5.40 µg/mL]. Hence, the present study provides a green protocol for enhancing rose EO yield with phenolics-enriched antioxidant byproducts.

Natural eutectic solvents and graphene integrated within emulsion liquid membrane system for sodium removal from crude biodiesel

This study reports a new technique for sodium ion removal from biodiesel using a green emulsion liquid membrane (GELM) system based on natural deep eutectic solvents (NADESs) and graphene. The DES consists of choline chloride with glycerol and lactic acid, and tetramethylammonium chloride with glycerol and lactic acid. COSMO-RS software was used to compute the intermolecular interaction of sodium with hydrogen bond acceptors and donors of the NADES. The simulation shows that NADES was the most effective stripping phase for sodium ion removal, which follows the experimental results. The investigation on the stability of ELM and sodium (830 ppm of initially) extraction efficiency showed that the GELM-NADES technique can achieves a sodium ion extraction efficiency of 99.6 % (3.17 ppm) with high stability at a homogenization speed of 8000 rpm, homogenization time of 3 min, HBA: HBD molar ratio of 1:4, 3 wt% of span 80, 10 minutes of extraction time, 400 rpm stirring speed and 0.5 treatment ratio. The presence of graphene (0.3 g) in the system further enhanced the efficiency and shortened the required extraction time from 6 to 4 min to meet the ASTM D6752 standards. The transport mechanism of sodium ions into the ELM phases adheres to the first-order kinetics model and film theory mechanisms. The overall mass transfer coefficient KO, mass transfer coefficient of the external phase in agitated reactor KM, and interfacial reaction rate constant KF of 5.188×10−9,1.373×10−7,and 5.392×10−9 m/s, respectively. ELM system with NADES and graphene can provide a cleaner route for biodiesel downstream processing.