Subcritical Water Enhanced with Deep Eutectic Solvent for Extracting Polysaccharides from Lentinus edodes and Their Antioxidant Activities

Ultrasonic-Assisted Extraction of Polysaccharides from Schizochytrium limacinum Meal Using Eutectic Solvents: Structural Characterization and Antioxidant Activity

To address the underutilization of Schizochytrium limacinum meal, polysaccharides from Schizochytrium limacinum meal (SLMPs) were prepared via ultrasonic-assisted eutectic-solvent-based extraction. Although polysaccharides exhibit promising application potential, the structural ambiguity of SLMPs necessitates systematic investigation to elucidate their structure-activity relationships, thereby providing a scientific foundation for their subsequent development and utilization. Using response-surface methodology (RSM), the optimized extraction conditions were determined as follows: ultrasonic temperature of 52 °C, ultrasonic duration of 31 min, ultrasonic power of 57 W, water content of 29%, and a material-to-liquid ratio of 1:36 g/mL. Under these conditions, the maximum polysaccharide yield reached 9.25%, demonstrating a significant advantage over the conventional water extraction method (4.18% yield). Following purification, the antioxidant activity and structural characteristics of SLMPs were analyzed. The molecular weight, monosaccharide composition, reducing groups, and higher-order conformation were systematically correlated with antioxidant activity. Fourier-transform infrared spectroscopy (FTIR), monosaccharide composition analysis, and 1H nuclear magnetic resonance (NMR) spectroscopy revealed characteristic polysaccharide functional groups (C-O, O-H, and C=O). Monosaccharides such as glucose (Glc), galactose (Gal), and arabinose (Ara) were found to enhance antioxidant activity. High-performance gel permeation chromatography (HPGPC) indicated a molecular weight of 20.7 kDa for SLMPs, with low-molecular-weight fractions exhibiting superior antioxidant activity. Scanning electron microscopy (SEM) further demonstrated that ultrasonically extracted polysaccharides possess porous structures capable of chelating redox-active functional groups. These findings suggest that ultrasonic-assisted eutectic-solvent-based extraction is an efficient method for polysaccharide extraction while preserving antioxidant properties.

Pioneering polysaccharide extraction with deep eutectic solvents: A review on impacts to extraction yield, physicochemical properties and bioactivities

Deep eutectic solvents (DES) have emerged as promising solvents for polysaccharide extraction from various sources. The DES which is produced by combining hydrogen bond donors and acceptors offers sustainability, low toxicity, a wide range of solubility and tailored properties. This review examines DES features and their effectiveness as extraction media for polysaccharides, highlighting the mechanisms behind their enhanced extraction efficiency compared to classical solvents. Additionally, we discuss the mechanism behind the DES affecting the physicochemical and structural properties of the extracted polysaccharides. The review also explores the antioxidant, antihyperglycemic, antihyperlipidemic and immunomodulatory properties of DES-extracted polysaccharides compared to classical solvents which emphasize structural changes in the polymer complex. This review intends to shed insight into the prospects of green extraction technologies by providing information on the benefits of DES and its potential to modify polysaccharide characteristics and enhance their biological activities, which is covered in depth for the first time here.

Unveiling techniques and exploring the potential of Myconutraceticals: Analyzing current applications and future prospects

The escalating demand for natural, nutritionally rich food products underscores the significance of exploring the fungal kingdom, comprising yeast, lichens, molds, and mushrooms, as an abundant reservoir of nutritionalcompounds, secondary metabolites and bioactive components. This paper delves into the nutritional profiles of lichen, yeast, and mushrooms, emphasizing their role as prominent sources of myco-nutraceuticals and functional foods. The growing popularity of eco-friendly extraction techniques for mycochemicals is noted, alongside the exploration of established methods for qualitative and quantitative mycochemical analysis. Notably, studies have affirmed that the incorporation of mushroom and yeast extracts, and their derived compounds, enhances the nutritional profile of meals without compromising desirable dietary attributes. The biological health-promoting properties inherent in extracts and chemicals are also discussed. Anticipated trends the incorporation of myconutrients into functional foods and dietary supplements are highlighted. Finally, challenges hindering the optimal utilization of myconutraceuticals are scrutinized.

Polysaccharides from sea buckthorn - Ultrasound-assisted enzymatic extraction, purification, structural characterization, and antioxidant activity analysis

This study employed a sophisticated approach consisting of ultrasound-assisted enzyme treatment to extract polysaccharides from sea buckthorn (SBP). The SBP extraction parameters were optimized, the following optimal parameters were identified: solid-liquid ratio of 1:32 g/mL, ultrasound duration of 26 min, ultrasound temperature of 52 °C, and composite enzyme concentration of 6000 U/100 mL, and the maximum extraction yield of SBP was 24.07 ± 0.15 %. The separation and purification of SBP resulted in the isolation of three fractions of polysaccharides (SBPR-1, SBPR-2, SBPR-3). The composition and structural characteristics of the SBPRs were identified. Furthermore, the SBPRs exhibited the characteristic absorption peaks of polysaccharides. Notably, the surface microstructures of the SBPRs showed significant variations. Moreover, all SBPRs demonstrated commendable thermal stability and in vitro antioxidant activity. This study serves as a reference for the development and application of natural antioxidants and provides a theoretical foundation for the environmentally friendly and effective extraction of SBP.

Deep eutectic solvent extraction and biological activity of polysaccharides from Tenebrio molitor

This study aimed to extract polysaccharides from Tenebrio molitor using ultrasound-assisted deep eutectic solvent (DESs) and to evaluate their structural features, as well as their antimicrobial, antioxidant, and α-amylase inhibitory activities. Various DESs were tested for polysaccharides extraction, and the process was optimized using response surface methodology (RSM). A preliminary structural analysis of the polysaccharides was conducted using infrared spectrum. The DESs were characterized by measuring their pH, viscosity, conductivity, refractive index, and density. The optimal extraction agent and parameters were determined. Significant differences in pH, viscosity, and conductivity were observed among DESs, whereas differences in refractive index and density were not significant. Choline chloride-lactic acid was identified as the optimal extraction agent. The optimal extraction parameters were a DES molar ratio of 1:2.1, a water content of 27 %, an extraction temperature of 70 °C, and an extraction time of 44 min, resulting in polysaccharides yield of 18.62 %. The extracted polysaccharides exhibited strong inhibitory effects against Salmonella, along with antioxidant activity and α-amylase inhibitory activities. The study demonstrated that polysaccharides from Tenebrio molitor can be efficiently extracted using DESs, showcasing significant biological activities, including antibacterial, antioxidant, and α-amylase inhibitory properties. These findings highlight the potential applications of Tenebrio molitor polysaccharides as valuable biological resources.

Isolation, Purification, and Characterization of Lentinus edodes Polysaccharides Extracted With Subcritical Water Enhanced With Deep Eutectic Solvent

The Lentinus edodes polysaccharide (LEP) was extracted with a new subcritical water extraction (SWE) enhanced with deep eutectic solvent (DES) method and then purified with a DEAE-52 cellulose column and a Sephadex G-100 column. Two purified polysaccharides (LEP1 and LEP2) were obtained, and their structure, antioxidant activity, and immunomodulatory activity were analyzed. LEP1 and LEP2 were composed of mannose, glucose, and galactose with a molar ratio of 1:12.97:7.84 and 1:51.18:5.29, respectively. The molecular weights were 9.878 × 104 and 1.976 × 104 Da, respectively. Interestingly, both LEP1 and LEP2 were mainly composed of →4)-β-d-Glcp-(1→, →6)-β-d-Glcp-(1→ and →6)-α-d-Galp-(1→ with different molar ratio. Besides, both LEP1 and LEP2 had strong DPPH free radical scavenging activity and Fe2+ chelating capacity. Moreover, they could reduce the level of reactive oxygen species (ROS) and regulate the activities of malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD) in HepG2 cells, demonstrating strong antioxidant activity. Furthermore, both LEP1 and LEP2 could improve the phagocytic capacity, nitric oxide (NO) release, and the content of interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α) in RAW264.7 cells, exhibiting significant immunostimulatory activity. It was worth noting that LEP2 exhibited stronger biological activities than LEP1. Therefore, the SWE enhanced with DES is an ideal method for extracting polysaccharides, which can be further applied to extract other polysaccharides.

Recent advances in pressurized hot water extraction/modification of polysaccharides: Structure, physicochemical properties, bioactivities, and applications

Pressurized hot water, as a green and efficient physical treatment technology, has been widely utilized for the extraction and modification of polysaccharides, with the objective of enhancing the physicochemical properties and biological activities of polysaccharides applied in food systems. This article reviews the recent advances regarding the effects of pressurized hot water treatment (extraction and modification) on polysaccharide extraction rates, structure, physicochemical properties, and bioactivities. The potential modes and mechanisms of polysaccharides subjected to pressurized hot water treatment and the relevant applications of these treated polysaccharides are also thoroughly discussed. Finally, the challenges that it may encounter in commercial applications are analyzed, and the future trends in this field are envisioned. This article will be of great value for the scientific elucidation of polysaccharides treated with pressurized hot water and their potential food applications.

Integration of glutathione disulfide-mediated extraction and capillary electrophoresis for determination of Cd(II) and Pb(II) in edible oils

A novel method is introduced for extracting and enriching Cd(II) and Pb(II) from edible oils using glutathione disulfide (GSSG) as both an extractant and a phase-separation agent. The ions in the oils were initially extracted into an aqueous solution containing GSSG. After mixing the solution with acetonitrile at the appropriate volume ratio, a new phase formed, resulting in enrichment of the analytes. The experimental conditions were optimized using response surface methodology with a central composite design. Under optimal conditions, the method offered a combined enrichment factor of >660, with combined extraction efficiencies of 84.31% and 83.35% for Cd(II) and Pb(II), respectively. Finally, the method was conjugated to capillary electrophoresis to determine Cd(II) and Pb(II) in edible oil samples, with detection limits of 0.45 and 1.24 ppb, respectively. In comparison to traditional approaches, the GSSG-based method demonstrates rapidity, efficiency, and recyclability in extracting heavy metal ions from complex matrices.

Deep eutectic solvent: Synthesis, classification, properties and application in macromolecular substances

Deep eutectic solvent (DES) is a kind of solvent prepared by mixing hydrogen bond donors and hydrogen bond acceptors, and have become a hot topic in ecological civilization construction due to its low toxicity and sustainability. Its excellent properties such as low volatility, thermal stability and biodegradability make it stand out among many organic solvents and widely used in fields including medicine, chemical industry and agriculture, with broad development prospects. In recent years, the application of DES in the food field has mostly focused on the extraction of small molecular substances, and there are few summaries on the application of DES in macromolecular substances. In this review, we introduced the synthesis, classification and properties of DES, and summarized the application of DES in the food industry for macromolecular substances, including the extraction of macromolecular substances such as chitosan and pectin, as well as the preparation of related macromolecular substrate films. At the same time, we analyzed the characteristics of DES and its advantages and limitations in application, and provided prospects for future development.

Deep eutectic solvents as sustainable extraction media for extraction of polysaccharides from natural sources: Status, challenges and prospects

Deep eutectic solvents (DES) emerge as promising alternatives to conventional solvents, offering outstanding extraction capabilities, low toxicity, eco-friendliness, straightforward synthesis procedures, broad applicability, and impressive recyclability. DES are synthesized by combining two or more components through various synthesis procedures, such as heat-assisted mixing/stirring, grinding, freeze drying, and evaporation. Polysaccharides, as abundant natural materials, are highly valued for their biocompatibility, biodegradability, and sustainability. These versatile biopolymers can be derived from various natural sources such as plants, algae, animals, or microorganisms using diverse extraction techniques. This review explores the synthesis procedures of DES, their physicochemical properties, characterization analysis, and their application in polysaccharide extraction. The extraction optimization strategies, parameters affecting DES-based polysaccharide extraction, and separation mechanisms are comprehensively discussed. Additionally, this review provides insights into recently developed molecular guides for DES screening and the utilization of artificial neural networks for optimizing DES-based extraction processes. DES serve as excellent extraction media for polysaccharides from different sources, preserving their functional features. They are utilized both as extraction solvents and as supporting media to enhance the extraction abilities of other solvents. Continued research aims to improve DES-based extraction methods and achieve selective, energy-efficient processes to meet the demands of this expanding field.

Ultrasound-assisted deep eutectic solvents extraction of polysaccharides from Loquat leaf: Process optimization and bioactivity study

Loquat leaves are the by-product of loquat fruit production. Polysaccharides are one of the main active ingredients in loquat leaves. In this study, polysaccharides were extracted from loquat leaves by ultrasonic-assisted deep eutectic solvents (DESs) extraction method. Further, the extracted crude loquat leaf polysaccharides (CLLP) were purified and separated via S-8 resin and DEAE-52 cellulose column chromatography, respectively. Additionally, the effects of polysaccharides on activity of sperm in boar semen preserved in medium at 17 °C, were evaluated preliminarily. DES, composed of choline chloride/ethylene glycol (1:6, molar ratio), was proved to be the suitable solvent for LLP extraction. The optimized extraction conditions were water content 44 %, liquid-solid ratio 1:29 (g/g), extraction temperature 61 °C and extraction time 98 min. Under these conditions, the LLP yield was 57.82 ± 1.50 mg/g. A homogeneous polysaccharide (LLP1-2, Mw: 2.17 × 104 Da) was isolated from CLLP. Its total sugar, uronic acid and protein contents were 76.31 ± 1.25 %, 14.19 ± 0.67 % and 3.28 ± 0.42 %, respectively. Further, 800 μg/mL LLP1-2 could effectively enhance the antioxidant activity of sperm. This study laid a foundation for DESs and column chromatography in the field of polysaccharide extraction and separation, proving that LLP can be used as a natural antioxidant for sperm preservation.

Extraction of Lentinus Edodes Polysaccharides with Ultrasound Enhanced with Deep Eutectic Solvent and Their Structural Characterization and Antioxidant Activity

Ultrasound extraction (UE) enhanced with deep eutectic solvent (DES) was used to extract Lentinus edodes polysaccharides. Box-Behnken design (BBD) was applied to investigate the influences of water content (10-90 %), solid-liquid solvent (1 : 10-1 : 50 g/mL), time (4-12 min), temperature (40-80 °C) and ultrasonic power (100-500 W) on the yield of Lentinus edodes polysaccharides. The optimal extraction conditions were ultrasonic power of 300 W, extraction time of 8 min, water content of 80 %, a solid-liquid ratio of 1 : 30 g/mL and a temperature of 60 °C, respectively. The highest extraction yield of Lentinus edodes polysaccharide was 10.17 % under optimal conditions. The results of FT-IR, SEM, and monosaccharide composition confirmed that the extracts possessed the characteristics of polysaccharides. In addition, the polysaccharides obtained with the UE enhanced with DES method exhibited higher antioxidant activities than the polysaccharides extracted with the UE method and HWE method. This extraction method can further expand the production efficiency and structural diversity of Lentinus edodes polysaccharides and meet the supply and demand relationship. It can be foreseen that this method can be applied to the extraction of more active substances.

Exploring the Phytochemical Compositions, Antioxidant Activity, and Nutritional Potentials of Edible and Medicinal Mushrooms

Mushrooms are a valuable source of food and medicine that have been used for centuries in various cultures. They contain a variety of phytochemicals, such as terpenoids and polysaccharides, that exhibit diverse biological activities, such as antioxidant, anti-inflammatory, anticancer, antimicrobial, immunomodulatory, and antidiabetic effects. However, mushroom's phytochemical composition and bioactivity vary depending on their species, cultivation conditions, processing methods, and extraction techniques. Therefore, using reliable analytical methods and standardized protocols is important for systematically evaluating the quality and quantity of mushroom phytochemicals and their therapeutic potential. This review provides a bibliometric analysis of the recent literature on biological activities, highlights trends in the field, and highlights the countries and journals with the highest contribution. It also discusses the nutritional value of the total content of phenolic and other phytochemicals in some species of mushrooms.

Extraction and Biological Activity of Lignanoids from Magnolia officinalis Rehder & E.H.Wilson Residual Waste Biomass Using Deep Eutectic Solvents

Lignanoids are an active ingredient exerting powerful antioxidant and anti-inflammatory effects in the treatment of many diseases. In order to improve the efficiency of the resource utilization of traditional Chinese medicine waste, Magnolia officinalis Rehder & E.H.Wilson residue (MOR) waste biomass was used as raw material in this study, and a series of deep eutectic solvents (ChUre, ChAce, ChPro, ChCit, ChOxa, ChMal, ChLac, ChLev, ChGly and ChEG) were selected to evaluate the extraction efficiency of lignanoids from MORs. The results showed that the best conditions for lignanoid extraction were a liquid-solid ratio of 40.50 mL/g, an HBD-HBA ratio of 2.06, a water percentage of 29.3%, an extract temperature of 337.65 K, and a time of 107 min. Under these conditions, the maximum lignanoid amount was 39.18 mg/g. In addition, the kinetics of the extraction process were investigated by mathematic modeling. In our antioxidant activity study, high antioxidant activity of the lignanoid extract was shown in scavenging four different types of free radicals (DPPH, ·OH, ABTS, and superoxide anions). At a concentration of 3 mg/mL, the total antioxidant capacity of the lignanoid extract was 1.795 U/mL, which was equal to 0.12 mg/mL of Vc solution. Furthermore, the antibacterial activity study found that the lignanoid extract exhibited good antibacterial effects against six tested pathogens. Among them, Staphylococcus aureus exerted the strongest antibacterial activity. Eventually, the correlation of the lignanoid extract with the biological activity and physicochemical properties of DESs is described using a heatmap, along with the evaluation of the in vitro hypoglycemic, in vitro hypolipidemic, immunomodulatory, and anti-inflammatory activity of the lignanoid extract. These findings can provide a theoretical foundation for the extraction of high-value components from waste biomass by deep eutectic solvents, as well as highlighting its specific significance in natural product development and utilization.

Combination of a Deep Eutectic Solvent and Macroporous Resin for Green Recovery of Iridoids, Chlorogenic Acid, and Flavonoids from Eucommia ulmoides Leaves

To increase the effectiveness of using typical biomass waste as a resource, iridoids, chlorogenic acid, and flavonoids from the waste biomass of Eucommia ulmoides leaves (EULs) were extracted by deep eutectic solvents (DESs) in conjunction with macroporous resin. To optimize the extract conditions, the experiment of response surface was employed with the single-factor of DES composition molar ratio, liquid-solid ratio, water percentage, extraction temperature, and extraction time. The findings demonstrated that the theoretical simulated extraction yield of chlorogenic acid (CGA), geniposidic acid (GPA), aucubin (AU), geniposide (GP), rutin (RU), and isoquercetin (IQU) were 42.8, 137.2, 156.7, 5.4, 13.5, and 12.8 mg/g, respectively, under optimal conditions (hydrogen bond donor-hydrogen bond acceptor molar ratio of 1.96, liquid-solid ratio of 28.89 mL/g, water percentage of 38.44%, temperature of 317.36 K, and time of 55.59 min). Then, 12 resins were evaluated for their adsorption and desorption capabilities for the target components, and the HPD950 resin was found to operate at its optimum. Additionally, the HPD950 resin demonstrated significant sustainability and considerable potential in the recyclability test. Finally, the hypoglycemic in vitro, hypolipidemic in vitro, immunomodulatory, and anti-inflammatory effects of EUL extract were evaluated, and the correlation analysis of six active components with biological activity and physicochemical characteristics of DESs by heatmap were discussed. The findings of this study can offer a theoretical foundation for the extraction of valuable components by DESs from waste biomass, as well as specific utility benefits for the creation and development of natural products.

Polysaccharides from Radix Peucedani: Extraction, Structural Characterization and Antioxidant Activity

In this study, an ultrasound-assisted green extraction method was applied for the extraction of polysaccharides from Radix Peucedani based on deep eutectic solvents (DESs), and the result showed that a DES system composed of betaine and 1,2-propylene glycol with a molar ratio of 1:2 possessed the optimal extraction efficiency for polysaccharides. Single-factor and Box-Behnken designs were used to determine the optimum extraction conditions for the maximum yields of polysaccharides from Radix Peucedani by using DESs. The maximum yields of polysaccharides attained 11.372% within a DES water content of 19%, an extraction time of 36 min, an extraction temperature of 54 °C, a solid-liquid ratio of 1:30 and an ultrasonic irradiation power of 420 W. The physicochemical properties of polysaccharides were analyzed using ICS and FT-IR, and the structure morphology was observed by SEM. The polysaccharides extracted from Radix Peucedani exhibited general antioxidant activities in vitro including DPPH, Hydroxyl and ABTS+ radical-scavenging activity. The antioxidant mechanism of Radix Peucedani polysaccharides was investigated using network pharmacology and molecular docking methods. The result showed that the high binding activity of glucose and IL1B, galactose and CASP3 was recognized as a potential mechanism for the antioxidant effects of Radix Peucedani polysaccharides.

Exploring carbohydrate extraction from biomass using deep eutectic solvents: Factors and mechanisms

Deep eutectic solvents (DESs) are increasingly being recognized as sustainable and promising solvents because of their unique properties: low melting point, low cost, and biocompatibility. Some DESs possess high viscosity, remarkable stability, and minimal toxicity, enhancing their appeal for diverse applications. Notably, they hold promise in biomass pretreatment, a crucial step in biomass conversion, although their potential in algal biomass carbohydrates extraction remains largely unexplored. Understanding the correlation between DESs' properties and their behavior in carbohydrate extraction, alongside cellulose degradation mechanisms, remains a gap. This review provides an overview of the use of DESs in extracting carbohydrates from lignocellulosic and algal biomass, explores the factors that influence the behavior of DESs in carbohydrate extraction, and sheds light on the mechanism of cellulose degradation by DESs. Additionally, the review discusses potential future developments and applications of DESs, particularly extracting carbohydrates from algal biomass.

Advance in Morchella sp. polysaccharides: Isolation, structural characterization and structure-activity relationship: A review

Morchella sp. is a kind of precious medicinal and edible fungus with a unique flavor and is rich in various amino acids and organic germanium needed by the human body. Most notably, Morchella sp. polysaccharides have attracted widespread attention due to their significant bioactivity in recent years. At present, extensive studies have been carried out on the extraction methods, structural characterization and activity evaluation of Morchella sp. polysaccharides, which provides a good theoretical basis for its further development and application. However, the systematic summary of the related research of Morchella sp. polysaccharides has not been reported yet. Therefore, this review mainly focused on the isolation and purification methods, structural characterization, biological activities and structure-activity relationship of Morchella sp. polysaccharides. This work will help to have a better in-depth understanding of Morchella sp. polysaccharides and provide a scientific basis and direct reference for more scientific and rational applications.

Study on Process Optimization and Antioxidant Activity of Polysaccharide from Bletilla striata Extracted via Deep Eutectic Solvents

Taking the extraction yield of Bletilla striata polysaccharide (BSP) as the index and taking the type of deep eutectic solvents (DESs), extraction time, extraction temperature, DES water content, and solid-liquid ratio as the investigation factors, single-factor and Box-Behnken response surface tests were carried out to optimize the extraction process of BSP. Thus, the antioxidant activity of BSP on DPPH radicals, ABTS radicals and ferric reducing antioxidant power were determined. The results showed that the most suitable deep eutectic solvent was DES-2, namely choline chloride-urea. The optimal extraction conditions for BSP were an extraction time of 47 min, extraction temperature of 78 °C, water content of 35%, and solid-liquid ratio of 1:25. Under this optimized condition, the extraction yield of BSP was able to reach (558.90 ± 8.83) mg/g, and recycling studies indicated the good cycle stability of the DES. Antioxidant results showed that BSP had superior antioxidant activity and had a dose-response relationship with drug concentration. Compared with Bletilla striata polysaccharide obtained via conventional hot water extraction (BSP-W), the extraction yield of BSP obtained through this method (BSP-2) increased by 36.77%, the scavenging activity of DPPH radicals increased by 24.99%, the scavenging activity of ABTS radicals increased by 41.16%, and the ferric reducing antioxidant power increased by 49.19%. Therefore, DESs as new green reagents and BSP extracted with DESs not only had a high yield but also had strong antioxidant activity.

Density-oriented deep eutectic solvent-based system for the selective separation of polysaccharides from Astragalus membranaceus var. Mongholicus under ultrasound-assisted conditions

The water extraction and ethanol precipitation method is an extraction method based on the solubility characteristics of polysaccharides that offers wide applicability in the extraction and separation of plant polysaccharides. However, this method leads to large amounts of proteins, nucleic acids, pigments, and other impurities in the polysaccharides products, which makes downstream purification complicated and time-consuming. In this study, a green, high-density natural deep eutectic solvents was used for the high-purity extraction and separation of polysaccharides from Astragalus membranaceus (Fisch) Bge. var. Mongholicus (Bge.) Hsiao roots under ultrasound-assisted conditions. In this study, 16 different natural deep eutectic solvents were designed to screen the best solvent for extracting Astragalus polysaccharides (APSs). Based on the yield and recovery of APSs, a natural deep eutectic solvents composed of choline chloride and oxalic acid with a molar ratio of 1:2 was selected. The related factors affecting polysaccharides extraction and solvent precipitation were investigated. To improve the operating methodology, single-factor trials, a Plackett-Burman design, and a Box-Behnken design were used. The optimal extraction process conditions were obtained as follows: water content of 55%, liquid-solid ratio of 24 mL/g, ultrasonic irradiation time of 54 min, ultrasonic irradiation temperature of 50 °C, ultrasonic irradiation power of 480 W, ethanol precipitation time of 24 h, and ethanol concentration of 75%. Under optimal extraction conditions, the recovery of APSs was 61.4 ± 0.6 mg/g. Considering the special matrix characteristics of A. membranaceus var. Mongholicus roots, physical-technology-based ultrasonic waves promote penetration, and the mass transfer function also solves the bottleneck of high-viscosity deep eutectic solvents in the extraction stage. In comparison with the conventional method, the proposed method based on deep eutectic solvents isolation can significantly increase APSs recovery, which is beneficial to simplifying the process of polysaccharides purification by using solvent properties to separate extracts and reduce impurities in APSs.

N,N-dimethyl chitosan oligosaccharide (DMCOS) promotes antifungal activity by causing mitochondrial damage

By modifying chitosan oligosaccharide (COS) with the Eschweiler-Clarke reaction, the chitosan oligosaccharide derivative DMCOS was synthesized. FT-IR, 1D and 2D NMR spectra, MALDI-ToF MS, and elemental analysis were applied to analyze the structure of DMCOS, which revealed that the primary amines were converted into tertiary amines after methylation. DMCOS displayed less thermal stability than COS. In comparison to COS, it was discovered that DMCOS possessed more potent antimicrobial activity against four bacterial strains (Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) and three yeast strains (Candida albicans, Candida tropicalis, and Candida parapsilosis). The antioxidant studies indicated that DMCOS had less antioxidant activity than COS. Consequently, ROS level elevated in C. albicans cells following treatment with DMCOS, which decreased mitochondrial membrane potential. It was recalled that DMCOS may kill C. albicans by causing mitochondrial damage. In addition, DMCOS was demonstrated to be non-cytotoxic.