Biphasic extraction of different polysaccharides from Radix Sophorae Tonkinensis by microwave-assisted aqueous two-phase extraction: Process optimization, structural characterization and mechanism exploration

Ultrasound-assisted ethanol/K2HPO4 aqueous two-phase extraction of polysaccharides from Plantago asiatica L. seeds: Process optimization, physicochemical properties, and antioxidant activity

INTRODUCTION

The seeds of Plantago asiatica L., a folk herb, are rich in polysaccharides that possess antioxidant, antidiabetic, and anti-inflammatory properties. Polysaccharides with lower molecular weights generally exhibit higher biological activity, so a method to efficiently extract low-molecular-weight polysaccharides from P. asiatica L. seeds (PLPs) is needed.

OBJECTIVES

The aim was to establish an efficient method for extracting polysaccharides from P. asiatica L. seeds while preserving their activity.

MATERIALS AND METHODS

Response surface methodology was applied to determine the optimal polysaccharide extraction conditions. Subsequently, the extracted polysaccharides were characterized to determine their monosaccharide composition, physicochemical properties, and molecular weight. Their antioxidant activity was evaluated by measuring their ability to scavenge DPPH and ABTS free radicals.

RESULTS

An extraction yield of 9.17% was achieved under an ethanol concentration of 18.0% (w/w), a K2HPO4 concentration of 27.8% (w/w), a solvent-to-material ratio of 30:1 (mL/g), an ultrasound power of 203 W, and an extraction time of 39 min. Structural analyses indicated that this method might cause physicochemical changes in the conformation of PLPs and induce the degradation of PLP side chains but not the backbone. The antioxidant assay results showed that the DPPH and ABTS radical scavenging rates of PLPs were 48.3% and 49.2%, respectively, while in the control group the radical scavenging rates were 35.5% and 37.1%, respectively.

CONCLUSION

The established method for extracting polysaccharides from P. asiatica L. seeds is efficient and reliable. The polysaccharides could be used as an important resource with antioxidant activity.

The traditional use, structure, and immunostimulatory activity of bioactive polysaccharides from traditional Chinese root medicines: A review

As research on traditional Chinese medicine (TCM) has expanded, our understanding of the role it can have in controlling the immune system has increased. Polysaccharides from medicinal plants exhibit numerous beneficial therapeutic properties, presumably owing to their modulation of innate immunity and macrophage function. Numerous studies have demonstrated the multiple ways whereby certain polysaccharides can affect the immune system. In addition to stimulating immune cells, such as T cells, B lymphocytes, macrophages, and natural killer cells, polysaccharides stimulate complements and increase cytokine secretion. The biological functions of polysaccharides are directly correlated with their structures. This paper summarizes the sources, TCM uses, extraction and purification methods, structural characterization, in vitro and in vivo immune activities, and underlying molecular mechanisms of TCM root polysaccharides. Moreover, the structure-activity relationships of TCM root polysaccharides are emphasized and discussed. This review can provide a scientific basis for the research and industrial utilization of TCM root polysaccharides.

The Separation, Purification, Structure Identification, and Antioxidant Activity of Elaeagnus umbellata Polysaccharides

In order to investigate the antioxidant activity of Elaeagnus umbellata polysaccharides, the physicochemical characteristics of purified Elaeagnus umbellata polysaccharides (EUP, consisting of two fractions, EUP1 and EUP2) were investigated using UV spectrophotometry, high-performance liquid chromatography (HPLC), high-performance gel permeation chromatography (HPGPC), and Fourier transform infrared spectroscopy (FT-IR). This revealed that EUP1 and EUP2 were acidic polysaccharides with an average molecular weight (MW) of 63 and 38 kDa, respectively. EUP1 mainly consisted of L-rhamnose and D-galactose in a molar ratio of 2.05:1, and EUP2 consisted of D-mannose, L-rhamnose, D-galactose, and D-arabinose in a molar ratio of 2.06:1:2.78:1. Furthermore, EUP exhibited considerable antioxidant potential for scavenging hydroxyl, superoxide anion, DPPH, and ABTS radicals. Therefore, EUP can be developed as a potential antioxidant for the functional food or pharmaceutical field.

Optimization of ultrasound-assisted aqueous two-phase extraction of polysaccharides from seabuckthorn fruits using response methodology, physicochemical characterization and bioactivities

BACKGROUND

Seabuckthorn fruits contains many active subtances, among them, the seabuckthorn polysaccharide is one of the main active ingredients, and exhibits diverse bioactivities. The extraction of polysaccharides from seabuckthorn fruits is the most important step for their wide applications. Ultrasound-assisted aqueous two-phase extraction (UA-ATPE) is a promising green method for extracting polysaccharides. Additionally, physicochemical characterization and antioxidant activities can evaluate the potential functions and applications in the food and medicine industries.

RESULTS

Based on the single-factor experiments, 20.70% (w/w) ammonium sulfate ((NH₄ )₂ SO₄ ) and 27.56% (w/w) ethanol were determined as the suitable composition for aqueous two-phase. The optimum conditions of UA-ATPE obtained by response surface methodology were as follows: ultrasonic power (390 W), extraction time (41 min), liquid-to-material ratio (72: 1 mL/g), and the total yield of the polysaccharides reached 34.14 ± 0.10%, The molecular weights of the purified upper-phase seabuckthorn polysaccharide (PUSP) and the purified lower-phase seabuckthorn polysaccharide (PLSP) were 65 525 and 26 776 Da, respectively. PUSP and PLSP contained the same six monosaccharides (galacturonic acid, rhamnose, xylose, mannose, glucose and galactose), but with different molar ratios. Furthermore, PUSP and PLSP displayed certain viscoelastic property, had no triple helical structure, possessed different thermal stability, surface morphology and conformation in aqueous solution. PUSP and PLSP displayed strong antioxidant properties by the assays of scavenging ability of ABTS⁺ ·, the protection of DNA damage and erythrocyte hemolysis.

CONCLUSION

UA-ATPE significantly increased the yield of seabuckthorn polysaccharides. PUSP and PLSP were different in many aspects, such as molar ratio, surface shape and antioxidant activities. Seabuckthornpolysaccharides possess great potential in medicine and functional foods. © 2022 Society of Chemical Industry.

Enzyme and microwave co-assisted extraction, structural characterization and antioxidant activity of polysaccharides from Purple-heart Radish

A novel method of simultaneous extraction and separation of diverse polysaccharides from Purple-heart Radish was developed by integrating EAE with MAATPE. The effects of different enzymes, the ATPS composition, extraction temperature, time etc. were investigated by single-factor experiments and RSM. Under the optimum conditions, the extraction yields of PTP, PBP and total polysaccharides were 9.107 ± 0.391%, 32.506 ± 0.046% and 41.613 ± 0.437%, respectively. By means of HPGPC and PMP-HPLC, Mw of PTP and Mw of PBP were 15935 Da and 27962 Da, respectively. PTP and PBP were mainly composed of mannose, glucuronic acid, aminogalactose, glucose, galactose and arabinose. Moreover, both polysaccharides exhibited stronger antioxidant activities for scavenging multiple radicals and anti-lipid peroxidation. Compared to the conventional extraction methods, EAE-MAATPE achieved higher extraction efficiency due to the synergistic effect between EAE and MAATPE leading to rupture and enzymolysis of cell. Thus, EAE-MAATPE provided an efficient alternative to simultaneous extraction of different polysaccharides from natural products.

Aqueous Two-Phase Extraction, Antioxidant and Renal Protective Effects of Polysaccharides from Spores of Cordyceps cicadae

The aim of this study was to investigate the aqueous two-phase extraction (ATPE), in vitro antioxidant, and in vivo renal protective effects of polysaccharides from spores of Cordyceps cicadae (CCSPs). The optimal ATPE parameters were as follows: an extraction temperature of 61 °C, an ammonium sulfate concentration of 18%, an ethanol concentration of 40%, a liquid-to-material ratio of 33 mL/g, and an extraction time of 60 min. Under these parameters, the CCSPs yield was 6.96 ± 0.11% (n = 3), which was consistent with the predicted yield (6.92%). Among the three purified polysaccharide fractions, CCSP-2 displayed stronger scavenging activities against DPPH radicals and hydroxyl radicals, reducing power and ferrous-ion-chelating ability to a greater extent than CCSP-1 and CCSP-3. CCSP-2 exhibited its protective effect in lipopolysaccharide (LPS)-induced septic acute kidney injury (AKI) mice by significantly alleviating renal edema; reducing 24 h urine protein, blood urea nitrogen (BUN), and serum creatinine (SCr); inhibiting the release of serum proinflammatory cytokines; boosting the activities of antioxidant enzymes; and reducing the levels of oxidative damage products. These results suggest that CCSP-2 exerted its protective effect against LPS-induced septic AKI in mice through anti-inflammatory and antioxidant pathways.

Optimization of an ultrasonic-assisted aqueous two-phase extraction method for four flavonoids from Lysionotus pauciflorus

An effective approach to extracting four flavonoids (lysioside C, nevadensin-7-sambubioside, ikarisoside B, and nevadensin) from Lysionotus pauciflorus using ultrasonic-assisted aqueous two-phase extraction (UAATPE) technology was studied. Ethanol/K₂HPO₄ system was selected and the influence of several important parameters, including composition of the aqueous two-phase system (ATPS), extraction temperature and time, particle size, and solvent to material ratio, were investigated by single factor experimentss. Then three key parameters (ethanol concentration, solvent to material ratio and extraction temperature) were further optimized by response surface methodology (RSM). The optimal process was that 1 g 120 mesh herb powders were extracted with 45 g ATPS (made of 30% ethanol/18% K₂HPO₄) in 43 °C for 30 min, and yields of four flavonoids could reach 2.56, 2.06, 3.62, and 6.28 mg/g, respectively. Compared with ultrasonic-assisted extraction (UAE) in three conventional solvents (water, ethanol and 60% ethanol), the UAATPE displayed comparatively higher extraction capability. Therefore, UAATPE in ethanol/K₂HPO₄ system could be an alternative technology for integrated extraction of the flavonoids from L. pauciflorus.

Three-liquid-phase salting-out extraction of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)-rich oils from Euphausia superba

The TLPSOES parameters were optimized by response surface methodology using Box-Behnken design, which were 16.5% w/w of ammonium citrate, 17.5% w/w of ethanol, and 46% w/w of n-hexane at 70 min of stirring time. Under optimized conditions the extraction efficiency attained was 90.91 ± 0.97% of EPA, 90.02 ± 1.04% of DHA, and 91.85 ± 1.11% of KO in the top n-hexane phase. The highest extraction efficiency of proteins and flavonoids, i.e. 88.34 ± 1.35% and 79.67 ± 1.13%, was recorded in the solid interface and ethanol phase, respectively. The KO extracted by TLPSOES system consisted of lowest fluoride level compared to the conventional method and whole wet krill biomass. The TLPSOES is a potential candidate for nutraceutical industry of KO extraction from wet krill biomass.

Ultrasonic-Assisted Aqueous Two-Phase Extraction and Properties of Water-Soluble Polysaccharides from Malus hupehensis

Malus hupehensis (M. hupehensis), an edible and medicinal plant with significant antioxidant and hypoglycemic activity, has been applied to new resource foods. However, the structural characterization and biological effects of its polysaccharides (MHP) are less known. The optimum extraction parameters to achieve the highest extraction efficiency (47.63%), the yield (1.68%) and purity of MHP (89.6%) by ultrasonic-assisted aqueous two-phase system (ATPS) were obtained under the liquid-to-solid ratio of 23 g/mL, ultrasonic power of 65 W, and ultrasonic time of 33 min. According to the analysis results, MHP was composed of Man, GlcA, Rha, GalA, Glc, Gal, Xyl, Ara, and Fuc, in which Ara and Gal were the main components, and the content of GlcA was the lowest. In in vitro activity analysis, MHP showed a significant antioxidant capacity, and an inhibition activity of α-glucosidase and the advanced glycation end products (AGEs) formation in the BSA/Glc reaction model. MHP interacted with α-glucosidase and changed the internal microenvironment of the enzyme, and inhibited the AGEs formation, which provides more evidence for the antihyperglycemic mechanism of MHP. The results suggest that ATPS is an efficient and environmentally friendly solvent system, and M. hupehensis has broad application prospects in functional foods, healthcare products, and pharmaceuticals.

An Efficient Synthesis of Novel Dextran-Arsenite Nanoparticles intended for Potential Antitumor Drug Material

The functionalization of polysaccharides with synthetic nanopolymers has attracted great attention owing to the applications of this method in many industrial fields. This work aimed to investigate the effect of arsenic trioxide on the functionalization of dextran. Dextran-arsenite nanoparticle formation was induced by microwave with sulfuric acid as a catalyst. Various analytical techniques were used to verify the structure of the nanopolymers. Besides, various reaction conditions, such as dextran concentration, arsenic trioxide concentration and pH, were investigated to determine their impact on particle size. The results indicated that the product was an arsenite-based nanomaterial retaining the basic configuration of dextran and that the product size was positively correlated with pH but negatively correlated with arsenic trioxide concentration. Moreover, the inhibitory effects of the dextran-arsenite nanoparticles on the growth of the human colorectal cancer cell line HCT-116 and human hepatoma carcinoma cell lines Huh-7 and SMMC-7721 were studied. The results showed that the product could inhibit the proliferation of these three tumor cell lines in a dose-dependent manner. Therefore, the product could be a new type of functional nanomaterial for further study on the synthesis, biological activity and development of polysaccharide drugs.

Sequential extraction and enrichment of pesticide residues in Longan fruit by ultrasonic-assisted aqueous two-phase extraction linked to vortex-assisted dispersive liquid-liquid microextraction prior to high performance liquid chromatography analysis

A simple, green and efficient method for extraction, purification and enrichment of pesticide residues of triazoles and pyrethroids in Longan fruit was developed by ultrasonic-assisted aqueous two-phase extraction (UAATPE) coupled to vortex-assisted dispersive liquid-liquid microextraction (VADLLME). Using an aqueous two-phase system (ATPS) of ethanol/K₂HPO₄ as extraction solvent, the composition of the ATPS, extraction temperature and time were investigated, respectively. Then VADLLME process also was optimized by investigating type and volume of extracting and dispersive solvents, vortex-assisted time and salt addition. The optimum conditions were as follows: the ATPS composition of ethanol concentration 30.0% (w/w) and K₂HPO₄ concentration 25% (w/w), extraction temperature 70 °C and extraction time 15 min for UAATPE; 1-dodecanol 200 μL as extraction solvent, ethanol 1.25 mL as dispersive solvent, vortex-assisted time 1.5 min and addition of NaCl 4% (w/v) for VADLLME. Ethanol as extraction solvent and dispersive solvent could directly connect UAATPE with VADLLME without extra steps. By means of HPLC-DAD detection, nine pesticides had good linearity ranged from 0.0200 to 13.59 μg/mL (R² ≥ 0.9957). LODs and LOQs were in the range of 0.005576-0.01740 μg/mL and 0.01859-0.05010 μg/mL, respectively. UAATPE-VADLLME coupled to HPLC was successfully applied to simultaneous determination of multiple pesticides in Longan fruit, and mean recoveries and RSDs were between 76.95% and 98.63%, 1.2% and 9.8%, respectively. Furthermore, myclobutanil, fenpropathrin and deltamethrin were detected in pericarp and pulp of Longan samples from different districts, respectively.