Characterization and antioxidant activity of the oligo-maltose fraction from Polygonum Cillinerve

Effects of electron beam irradiation on microbial load, physicochemical properties, sensory quality, stability of active components, and antioxidant activity of Platycodon grandiflorum (Jacq.) A. DC

Platycodon grandiflorum (Jacq.) A. DC. (PG) is an edible and medicinal plant. This study aimed to investigate the potential of electron beam (EB) irradiation for preserving PG. EB irradiation at doses of 2-8 kGy were applied to PG, and the effects on microbial content, sensory qualities, chemical qualities, and EB penetration were examined. Results showed that irradiation with 6 kGy effectively maintained the microbiological quality of PG when packing thickness was ≤6.3 cm during a 360-day storage period. The physicochemical properties, color, active ingredient contents, and antioxidant capacities of PG remained unaffected. However, total flavonoid and platycodin D (PD) content exhibited a non-dose-dependent alteration. The use of electronic nose analysis successfully differentiated the odor of EB irradiated PG samples from non-irradiated ones. Fingerprint analysis also indicated no significant impact of EB irradiation on PG quality. These findings suggest that EB treatment could be a valuable approach for extending the shelf life of PG.

Extraction of American ginseng polysaccharide by ultrasound-assisted deep eutectic solvents-based three-phase partitioning: Process optimization, structural characterization, and anti-ulcerative colitis study

Three-phase partitioning (TPP) is promising for isolating bioactive polysaccharides, but t-butanol's environmental impact limits its application. Deep eutectic solvents can serve as a green and recyclable alternative to t-butanol. This study introduces an ultrasonic-assisted DES three-phase partitioning (UA-TPP-DES) system to extract and purify American ginseng polysaccharides (AGPs). The optimized DES-4, composed of lauric acid and nonanoic acid (molar ratio = 1:1), achieved a 35.28 % extraction yield under specific conditions and can be recycled five times with minimal yield loss. AGP-DES-4 has a broad molecular weight distribution (2.48-174.64 kDa) and mainly consists of mannose, glucose, galactose, and arabinose. In vivo Drosophila models show that AGP-DES-4 improves UC fly survival and enhances intestinal barrier function by regulating the proliferation and differentiation of intestinal epithelial cells (IECs) and intestinal stem cells (ISCs). Our results highlight the effectiveness of the AGP-DES-4 extraction method and its potential therapeutic value for treating UC.

Evaluating the Root Extract of Reynoutria ciliinervis (Nakai) Moldenke: An Analysis of Active Constituents, Antioxidant Potential, and Investigation of Hepatoprotective Effects in Rats

Reynoutria ciliinervis (Nakai) Moldenke (R. ciliinervis) root, a traditional Chinese medicine, was found to exhibit remarkable pharmacological properties through a series of comprehensive investigations. Our study commenced with a qualitative phytochemical analysis that identified 12 bioactive compounds within the plant. Subsequently, utilizing ultraviolet-visible spectrophotometry, the methanol extract emerged as the optimal solvent extract, which was abundant in diverse classes of compounds such as carbohydrates, phenolics, steroids, alkaloids, phenolic acids, and tannins. In vitro antioxidant assays underscored the exceptional free radical scavenging, metal ion chelation, hydrogen peroxide scavenging, singlet oxygen quenching, and β-carotene bleaching capabilities of the methanol extract, significantly outperforming other solvent extracts. Further ultra high-performance liquid chromatography-electrospray ionization-quadrupole time of flight-mass spectrometry analysis revealed the presence of 45 compounds, predominantly anthraquinones and phenolics, in the methanol extract. The extract demonstrated robust stability under various conditions, including high temperatures, varying pH levels, and simulated gastrointestinal digestion as well as efficacy in inhibiting the oxidation in edible oils. Acute toxicity tests in mice confirmed the safety of the methanol extract and provided a valuable dosage reference for future studies. Importantly, high-dose methanol extract exhibited a significant pre-protective effect against D-galactosamine-induced liver injury in rats, as evidenced by reduced alanine aminotransferase, aspartate aminotransferase, γ-glutamyl transpeptidase, malondialdehyde levels, and elevated catalase and albumin levels. These findings suggest a potential role for the methanol extract of R. ciliinervis root in treating oxidative stress-related disorders, highlighting the plant's immense medicinal potential. Our research offers a thorough evaluation of the bioactive components, antioxidant properties, stability, and liver-protecting effects of the methanol extract, setting the stage for deeper investigation and potential clinical applications.

Polygonum cuspidatum polysaccharide: A review of its extraction and purification, structure analysis, and biological activity

ETHNOPHARMACOLOGICAL RELEVANCE

Polygonum cuspidatum Sieb. et Zucc. is mainly distributed in Shanxi, Gansu, and Sichuan province of China. It is also found in Korea and Japan. Its dried roots and rhizomes are used as medicinal herbs and have been used to treat hyperglycemia and various inflammatory disorders.

AIM OF THE REVIEW

This paper aims to provide an up-to-date review of the developments in the studies involving the extraction and purification, structure analysis, pharmacological effects, and potential applications of polysaccharides obtained from Polygonum cuspidatum. Additionally, the possible future research directions of this plant are discussed.

MATERIALS AND METHODS

This article used "Polygonum cuspidatum polysaccharide (PCP)" and "Polygonum cuspidatum" as the keywords and gathered relevant data on Polygonum cuspidatum using electronic databases (Elsevier, PubMed, ACS, CNKI, Google Scholar, Baidu Scholar, Web of Science), relevant books, and classic literature about Chinese herb.

RESULTS

Excluding irrelevant and repetitive documents, 278 documents were finally included, of which 88 were in Chinese and 190 were in English. The CiteSpace software was used to visualize the trends and keywords in this research field. We concluded that the main extraction methods for Polygonum cuspidatum polysaccharide are water extraction and alcohol precipitation, microwave-assisted extraction, ultrasound-assisted extraction, and microjet extraction. High-performance liquid chromatography and column chromatography are also commonly used in the separation and purification of PCP. PCP has antitumor, immunomodulatory, hypoglycemic, and antioxidant effects. This paper provides an updated and deeper understanding of PCP, serving as a theoretical foundation for the further optimization of polysaccharide structures and the development of PCP as a novel functional material for clinical application.

Polygonum ciliinerve (Nakai) Ohwi: a review of its botany, traditional uses, phytochemistry, pharmacology, pharmacokinetics and toxicology

Polygonum ciliinerve (Nakai) Ohwi is a perennial twining vine plant from the Polygonaceae family, which is a Chinese herbal medicine with great value for development and utilization. The purpose of this paper is to provide a systematic review of the botany, traditional uses, phytochemistry, pharmacology, pharmacokinetics, and toxicology of Polygonum ciliinerve (Nakai) Ohwi, as well as an outlook on the future research directions and development prospects of the plant. Data on Polygonum ciliinerve (Nakai) Ohwi were obtained from different databases, including China National Knowledge Infrastructure, Baidu Academic, Wanfang Database, Google Academic, PubMed, Web of Science, SpringerLink, Wiley; books; standards; and Ph.D. and MSc theses. So far, 86 compounds have been identified from Polygonum ciliinerve (Nakai) Ohwi, including anthraquinones, stilbenes, flavonoids, tannins, chromogenic ketones, organic acids and esters, lignans, isobenzofurans, alkaloids, naphthols, and others. Studies have found that Polygonum ciliinerve (Nakai) Ohwi has a wide range of pharmacological effects, including antiviral, antibacterial, anti-inflammatory and analgesic, antitumor, immunomodulatory, hypoglycemic, and antioxidant effects. Clinically, Polygonum ciliinerve (Nakai) Ohwi is very effective in the treatment of gastritis and chronic gastritis. Based on its traditional use, chemical composition, and pharmacological activity, Polygonum ciliinerve (Nakai) Ohwi is a promising source of natural medicine in drug development.

The genus Polygonum: An updated comprehensive review of its ethnomedicinal, phytochemical, pharmacological activities, toxicology, and phytopharmaceutical formulation

Polygonum is a plant genus that includes annual and perennial species and is found at various temperatures, from northern temperate regions to tropical and subtropical areas. The genus Polygonum has been used for centuries for various disorders, including hypertension, intestinal and stomach pain, dysuria, jaundice, toothaches, skin allergies, hemorrhoids, cardiac disorders, kidney stones, hemostasis, hyperglycemia, and others. Various databases, including Google Scholar, Scifinder, ScienceDirect, PubMed, Scopus, ResearchGate, and Web of Science, were utilized to collect pertinent scientific literature data. According to bibliographic studies, the Polygonum genus possesses various compounds from different families, including phenolic acids (gallic acid, caffeic acid, quinic acid, p-coumaric acid, ferulic acid, protocatechuic acid, chlorogenic acid, and many other compounds), flavonoids (quercetin, catechin, epicatechin, quercitrin, kaempferol, myricetin, etc.), tannins, stilbenes (polydatin and resveratrol), terpenes (α-pinene, β-caryophyllene and β-caryophyllene oxide, bisabolene, β-farnesene, etc.), fatty acids (decanoic acid, lauric acid, linoleic acid, oleic acid, palmitic acid, stearic acid, dodecanoic acid), polysaccharides, and others. Various chemical and biological activities (in vitro and in vivo), such as antioxidant, antimicrobial, anticancer, antitumor, anti-inflammatory, antidiabetic, antiparasitic, hepatoprotective, neuropharmacological, gastroprotective, diuretic, antipyretic, and others, have been described in several biological studies involving this species. An updated summary of Polygonum species and their ethnomedicinal, phytochemical, toxicological, pharmacological, and phytopharmaceutical formulations is necessary. Considering the numerous potentialities of the Polygonum species and their wide-ranging use, it is extremely essential to provide knowledge by compiling the accessible literature to identify the topics of intense investigation and the main gaps to better design future studies. The objective of this review is to give readers a better understanding, greater comprehension, and in-depth knowledge of the genus Polygonum's traditional applications, phytochemistry, pharmacology, toxicological features, and galenic formulation. Several species of this genus have been detailed in this review, including those that were frequently used in traditional medicine (P. minus, P. aviculare, P. hydropiper, P. cuspidatum, and P. multiflorum) and many of the genus' therapeutic species, like P. equisetiforme, which do not get enough attention.

Does the Symbiotic Relationship Between Hydra Viridissima and Photoautotrophic Alga Provide an Evolutionary Advantage in Protecting DNA against Damage by the Cytotoxic or Genotoxic Mode of Action of Environmental Stressors?

The aim of this paper was to evaluate whether symbiotic cooperation between green hydra (Hydra viridissima) and photoautotrophic alga gives higher resistance of the preservation of DNA integrity compared to brown hydra (Hydra oligactis). Norflurazon concentrations were 0.061 or 0.61 mg/L and UV-B light 254 nm, 0.023mWcm- 2 applied separately or simultaneously. By alkaline comet assay primary DNA damage was assessed and cytotoxicity by fluorescent staining. Norflurazon at 0.61 mg L- 1 significantly increased DNA damage in brown hydras compared to the control (6.17 ± 0.6 μm, 5.2 ± 1.7% vs. 2.9 ± 0.2 μm, 1.2 ± 0.2%). Cytotoxicity was significantly elevated, being higher in brown hydras (25.7 ± 3.5% vs. 8.2 ± 0.2%). UV-B irradiation induced significant DNA damage in brown hydras (13.5 ± 1.0 μm, 4.1 ± 1.0%). Simultaneous exposure to UV-B and norflurazon led to a synergistic DNA damaging. The frequency of cytotoxicity and hedgehog nucleoids was more pronounced in brown (78.3 ± 9.4%; 56.4 ± 6.0%) than in green hydras (34.7 ± 2.5%; 24.2 ± 0.6%). Evolutionary established symbiotic cooperation proved to provide resistance against cyto/genotoxicity.

Polygonum cillinerve polysaccharide inhibits transmissible gastroenteritis virus by regulating microRNA-181

Transmissible gastroenteritis virus (TGEV) is an important pathogen capable of altering the expression profile of cellular miRNA. In this study, the potential of Polygonum cillinerve polysaccharide (PCP) to treat TGEV-infected piglets was evaluated through in vivo experiments. High-throughput sequencing technology was employed to identify 9 up-regulated and 17 down-regulated miRNAs during PCP-mediated inhibition of TGEV infection in PK15 cells. Additionally, miR-181 was found to be associated with target genes of key proteins in the apoptosis pathway. PK15 cells were treated with various concentrations of PCP following transfection with miR-181 mimic or inhibitor. Real-time PCR assessed the impact on TGEV replication, while electron microscopy (TEM) and Hoechst fluorescence staining evaluated cellular functionality. Western blot analysis was utilized to assess the expression of key signaling factors-cytochrome C (cyt C), caspase 9, and P53-in the apoptotic signaling pathway. The results showed that compared with the control group, 250 μg/mL PCP significantly inhibited TGEV gRNA replication and gene N expression (P < 0.01). Microscopic examination revealed uniform cell morphology and fewer floating cells in PCP-treated groups (250 and 125 μg/mL). TEM analysis showed no typical virus structure in the 250 μg/mL PCP group, and apoptosis staining indicated a significant reduction in apoptotic cells at this concentration. Furthermore, PCP may inhibit TGEV-induced apoptosis via the Caspase-dependent mitochondrial pathway following miR-181 transfection. These findings provide a theoretical basis for further exploration into the mechanism of PCP's anti-TGEV properties.

Structural Characterization and Anticomplement Activity of an Acidic Heteropolysaccharide from Lysimachia christinae Hance

A novel acidic heteropolysaccharide (LCP-90-1) was isolated and purified from a traditional "heat-clearing" Chinese medicine, Lysimachia christinae Hance. LCP-90-1 (Mw, 20.65 kDa) was composed of Man, Rha, GlcA, Glc, Gal, and Ara, with relative molar ratios of 1.00: 3.00: 11.62: 1.31: 1.64: 5.24. The backbone consisted of 1,4-α-D-GlcpA, 1,4-α-D-Glcp, 1,4-β-L-Rhap, and 1,3,5-α-L-Araf, with three branches of β-D-Galp-(1 → 4)-β-L-Rhap-(1→, α-L-Araf-(1→ and α-D-Manp-(1→ attached to the C-5 position of 1,3,5-α-L-Araf. LCP-90-1 exhibited potent anticomplement activity (CH50: 135.01 ± 0.68 µg/mL) in vitro, which was significantly enhanced with increased glucuronic acid (GlcA) content in its degradation production (LCP-90-1-A, CH50: 28.26 ± 0.39 µg/mL). However, both LCP-90-1 and LCP90-1-A were inactivated after reduction or complete acid hydrolysis. These observations indicated the important role of GlcA in LCP-90-1 and associated derivatives with respect to anticomplement activity. Similarly, compared with LCP-90-1, the antioxidant activity of LCP-90-1-A was also enhanced. Thus, polysaccharides with a high content of GlcA might be important and effective substances of L. christinae.

Glycyrrhiza polysaccharides inhibits PRRSV replication

Glycyrrhiza polysaccharide (GCP) is a natural plant active polysaccharide extracted from traditional Chinese medicine licorice. In this research, we studied the antiviral activity of glycyrrhiza polysaccharide against porcine reproductive and respiratory syndrome virus (PRRSV), a virus of the Arteriviridae family, with a high rate of variation and has caused huge economic losses to the pig industry in various countries since its discovery. Our results show that GCP can inhibit PRRSV replication in a dose-dependent manner. Furthermore, GCP could inhibit the mRNA expression of receptor genes CD163 and NF-κB p65 and promote the mRNA expression of the SLA-7 gene. Because of these results, GCP can be used as a candidate drug to prevent and treat PRRS.

Preparation and structural characterization of acid-extracted polysaccharide from Grifola frondosa and antitumor activity on S180 tumor-bearing mice

In this study, an acid-extracted polysaccharide (GFP-A) was extracted from the fruiting bodies of G. frondosa with 1 % hydrochloric acid solution. Our study aimed to imitate the processes of digestion, absorption and antitumor activities of polysaccharides from G. frondosa under the acid environment of stomach in the body. The preliminary structural analysis resulted that GFP-A (about 1.10 × 10⁶ Da) was a neutral polysaccharide composed of xylose, mannose, glucose (molar ratio: 0.12:1.00:6.98) with α-type glycosidic linkages. Additionally, antitumor activities on S180 tumor-bearing mice showed that GFP-A could effectively inhibit the growth of S180 tumor cells by protecting immune organs (thymus and spleen), activating immune cells (NK cells, lymphocytes and macrophages), upregulating the secretion of serum cytokines (TNF-α, IL-2 and IFN-γ) in vivo. H & E staining and cell cycle determination further demonstrated that GFP-A could induce S180 tumor cells apoptosis via arresting them in G₁ phase. These results demonstrated that GFP-A could provide a theoretical basis for treatment of cancer.

Immunoenhancement and antioxidative damage effects of Polygonum Cillinerve polysaccharide on RAW264.7 cells

OBJECTIVES

The effects of Polygonum Cillinerve polysaccharide (PCP) on the immune and antioxidant activity were studied.

METHODS

The effects of PCP on cell proliferation, phagocytic activity, cell uptake, the secretion of NO, iNOS, IL-6, IL-12, CAT and POD, intracellular ROS, cell apoptosis and antioxidative mechanism were measured by MTT, ELISA, fluorescence staining, flow cytometry and western blot.

KEY FINDINGS

The results showed that PCP had no toxic effect at 31.25-1.95 µg/ml, could improve the uptake of neutral red and fluorescein isothiocyanate-labelled ovalbumin and promote the release of nitric oxide and nitric oxide synthase. Moreover, PCP also could promote the secretion of IL-6 and IL-12. The damage of RAW264.7 cells induced by hydrogen peroxide was significantly alleviated by PCP at 15.63-0.975 µg/ml. The mechanism of antioxidative damage might be that PCP inhibited the upstream p38 and the phosphorylation of JNK and ERK proteins, and down-regulated caspase 3 and up-regulated the protein expressions of cytochrome C and Bcl-2, finally PCP improved the antioxidative capacity and protected the oxidative damage of cells.

CONCLUSIONS

These results indicated that PCP had the better immunopotentiation and antioxidative damage activity.

Structure features, selenylation modification, and improved anti-tumor activity of a polysaccharide from Eriobotrya japonica

A homogeneous polysaccharide, EJP90-1, was isolated from the leaves of E. japonica by hot water extraction in this study. EJP90-1 (7702 Da) was a heteropolysaccharide mainly consisting of →5)-linked-α-L-Araf-(1→, →4)-linked-β-D-Manp-(1→, →2,4)-linked-α-L-Rhap-(1→, →4)-linked-α-D-Xylp-(1→, →4)-linked-β-D-Galp-(1→, →2)-linked-β-D-Galp-(1→, →6)-linked-β-D-Glcp-(1→, α-D-Glcp-(4→, and t-linked-α-L-Araf. EJP90-1 was found to show moderate anti-tumor activity at the cellular level. In order to improve the anti-tumor activity and the potential applications of EJP90-1, a typical sodium selenite-nitric acid (Na₂SeO₃-HNO₃) modification on EJP90-1 was carried out. X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrometer (EDS) analysis confirmed that Se was successfully introduced into the polymer chain of EJP90-1. The subsequent in vitro cytotoxicity evaluation showed the selenylation modification derivative (EJP90-1-Se) possessed significant antiproliferative activity against cancer cells (HepG2 and A549 cells) through inducing cell apoptosis. The anti-tumor activity of EJP90-1-Se was further confirmed by zebrafish models, which inhibited the proliferation and migration of HepG2 cells and the angiogenesis.

An enzymatic membrane reactor for oligodextran production: Effects of enzyme immobilization strategies on dextranase activity

An enzymatic membrane reactor (EMR) with immobilized dextranase provides an excellent opportunity for tailoring the molecular weight (Mw) of oligodextran to significantly improve product quality. However, a highly efficient EMR for oligodextran production is still lacking and the effect of enzyme immobilization strategy on dextranase hydrolysis behavior has not been studied yet. In this work, a functional layer of polydopamine (PDA) or nanoparticles made of tannic acid (TA) and hydrolysable 3-amino-propyltriethoxysilane (APTES) was first coated on commercial membranes. Then cross-linked dextranase or non-cross-linked dextranase was loaded onto the modified membranes using incubation mode or fouling-induced mode. The fouling-induced mode was a promising enzyme immobilization strategy on the membrane surface due to its higher enzyme loading and activity. Moreover, unlike the non-cross-linked dextranase that exhibited a normal endo-hydrolysis pattern, we surprisingly found that the cross-linked dextranase loaded on the PDA modified surface exerted an exo-hydrolysis pattern, possibly due to mass transfer limitations. Such alteration of hydrolysis pattern has rarely been reported before. Based on the hydrolysis behavior of the immobilized dextranase in different EMRs, we propose potential applications for the oligodextran products. This study presents a unique perspective on the relation between the enzyme immobilization process and the immobilized enzyme hydrolysis behavior, and thus opens up a variety of possibilities for the design of a high-performance EMR.

The inhibitory effect Polygonum Cillinerve polysaccharide on transmissible gastroenteritis virus of swine

Transmissible gastroenteritis virus of swine (TGEV) is one kind of the main pathogens causing viral diarrhea in pig. In this study, the inhibitory effect of Polygonum Cillinerve polysaccharide (PCP) on TGEV was studied. Firstly, MTT method was used to measure the cell viability of PCP. Then Hoechst 33258 fluorescence staining, Annexin V-FITC/PI fluorescence staining, real-time PCR and western blot were used to explore the effect of PCP on inhibiting TGEV. The results showed that PCP could significantly reduce the apoptosis rate induced by TGEV, reduce the expression of ROS, reduce TGEV replication, increase the expression levels of Bcl-2 and Bax genes, increase the expression of Bcl-2 protein, decreased the expression of Cyto c protein, and reduce the amount of cleaved caspase 3. Therefore, PCP had the better inhibitory effect on TGEV, which provided a certain theoretical basis for the prevention and treatment of TGEV.

Purification, Physicochemical Properties, and Antioxidant Activities of Two Low-Molecular-Weight Polysaccharides from Ganoderma leucocontextum Fruiting Bodies

Two low-molecular-weight polysaccharides (GLP-1 and GLP-2) were purified from Ganoderma leucocontextum fruiting bodies, and their physicochemical properties and antioxidant activities were investigated and compared in this study. The results showed that GLP-1 and GLP-2 were mainly composed of mannose, glucose, galactose, xylose, and arabinose, with weight-average molecular weights of 6.31 and 14.07 kDa, respectively. Additionally, GLP-1 and GLP-2 had a similar chain conformation, crystal structure, and molecular surface morphology. Moreover, GLP-1 exhibited stronger antioxidant activities than GLP-2 in five different assays: 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), hydroxyl radical, superoxide anion radical, ferric reducing antioxidant power (FRAP), and oxygen radical antioxidant capacity (ORAC). The main linkage types of GLP-1 were found to be →4)-α-D-Glcp-(1→, →4)-β-D-Glcp-(1→, →3)-β-D-Glcp-(1→, →6)-β-D-Galp-(1→, →6)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, and Glcp-(1→ by methylation analysis and nuclear magnetic resonance (NMR) spectroscopy. In addition, GLP-1 could protect NIH3T3 cells against tert-butyl hydroperoxide (tBHP)-induced oxidative damage by increasing catalase (CAT) and glutathione peroxidase (GSH-Px) activities, elevating the glutathione/oxidized glutathione (GSH/GSSG) ratio, and decreasing the malondialdehyde (MDA) level. These findings indicated that GLP-1 could be explored as a potential antioxidant agent for application in functional foods.

Preparation and antioxidant activities of polysaccharides obtained from abalone viscera by combination of enzymolysis and multiple separation methods

Abalone viscera were byproducts of the abalone processing and usually discarded as wastes. In this study, we tried to obtain functional polysaccharides from abalone viscera by a combination of enzymatic hydrolysis, membrane separation, anion exchange chromatography, and gel filtration techniques. Abalone viscera underwent successive hydrolyzation with alcalase and flavourzyme. Each enzymolysis was followed by deproteinization via membrane separation. The final yield of crude abalone viscera polysaccharide (CAVP) was 19.72%; the polysaccharide content of CAVP was 51.75%. Furthermore, three fractions of polysaccharides (AVP1, AVP2, and AVP3) were isolated from the CAVP by anion exchange chromatography and gel filtration. The molecular weights of each AVP were 14.99 kDa, 58.48 kDa, and 39.63 kDa, with a carbohydrate content of 62.75, 23.09, and 44.67%, respectively. These AVPs showed excellent antioxidant activities in vitro. Our results provide a scientific basis for the further utilization of polysaccharides from abalone viscera. PRACTICAL APPLICATION: This study demonstrated an eco-friendly approach for industrial production of high purity animal-derived polysaccharides without any environmental pollution caused by the viscera waste of abalone and promoting the comprehensive utilization of abalone resources.

Synthesis, characterization, and the antioxidant activity of the acetylated chitosan derivatives containing sulfonium salts

In this study, a new class of chitosan derivatives possessing sulfonium salts was synthesized, and characterized by FT-IR, ¹H NMR, ¹³C NMR, and elemental analyses. IR spectra, ¹H NMR and ¹³C NMR of the structural units of these polymers validated the designed chitosan derivatives were successfully synthesized. In addition, the antioxidant potential of chitosan and chitosan derivatives was assessed in vitro, screened by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, hydroxyl radical scavenging, and superoxide radical scavenging, respectively. Results revealed that designed chitosan derivatives could effectively scavenge DPPH radical, hydroxyl radical, and superoxide radical with inhibition rate of more than 90% at 1.6 mg/mL, higher than chitosan. Moreover, in the cytotoxicity assay, no cytotoxicity was observed for the L929 cells with chitosan and its derivatives at all the testing concentrations. These results indicated that the acetylated chitosan derivatives containing sulfonium salts may be a promising natural antioxidant for the pharmaceutics, food, cosmetics and agriculture management.

Solubility, Antioxidation, and Oral Bioavailability Improvement of Mangiferin Microparticles Prepared Using the Supercritical Antisolvent Method

In view of the poor water solubility and low oral bioavailability of mangiferin (MG), in this study, the supercritical antisolvent (SAS) technology was used to prepare mangiferin microparticles (MG MPs) with N,N-dimethylformamide (DMF) as solvent and carbon dioxide as antisolvent, so as to improve its water solubility, antioxidant capacity and oral bioavailability. Four factors affecting the solubility of the MG MPs were investigated by orthogonal design (OAD), including precipitation pressure, precipitation temperature, MG concentration and feeding speed, and the optimal preparation conditions were determined by range and variance analysis (ANOVA). Under the optimal conditions, the spherical MG MPs with an average diameter of 532.8 nm was obtained, and the yield of the powder was about 95.3%. Scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), X-Ray Diffractometry (XRD), differential scanning calorimetry (DSC), and thermal gravimetric (TG) were used to analyze the characteristics of the MG MPs. The results obtained showed that the chemical structure of the MG did not change before and after supercritical crystallization, but its particle size and crystallinity decreased significantly. The MG MPs had a higher solubility, and was about 4.26, 2.1 and 2.5 times than that of free MG in water, artificial gastric juice (AGJ) and artificial intestinal juice (AIJ), respectively. The dissolution rate of the MG MPs were also obviously higher than that of free MG. Furthermore, the bioavailability of the MG MPs in vivo was about 2.07 times higher than that of the free MG, and its antioxidant capacity was also much higher than that of free MG, which was close to vitamin C.

Synthesis, Characterization, and the Antioxidant Activity of Carboxymethyl Chitosan Derivatives Containing Thiourea Salts

A new class of chitosan derivatives possessing thiourea salts were synthesized to improve the solubility and the antioxidant activity of chitosan. Firstly, chitosan was modified to carboxymethyl chitosan, combining carboxymethyl chitosan with thiourea salts that have different structures to form new chitosan derivatives. The chitosan and chitosan derivatives were characterized by FT-IR, ¹³C NMR, TGA, and elemental analyses. The new peaks of thiourea salts could be clearly observed at about 1240 cm^-1 in the IR spectra, and the peak of C=S was clearly observed at around 180 ppm in the ¹³C NMR. IR spectra and ¹³C NMR of the structural units of these polymers validated the chitosan derivatives possessing thiourea salts were successfully synthesized. Their antioxidant properties were tested, including DPPH-radical scavenging ability, superoxide-radical scavenging ability, and hydroxyl-radical scavenging ability. Our results suggested the increase of thiourea salt groups in chitosan derivatives promotes the scavenging effect. The scavenging activity of 4TMCMCS, TMCMCS. 4,4DCMCS, and 4ACMCS against DPPH-radical and superoxide-radical were more than 90% at 1.6 mg/mL, respectively. In the cytotoxicity assay, no cytotoxicity was observed for the L929 cells with chitosan and its derivatives at all testing concentrations. These results demonstrated that the combination of chitosan and thiourea salt groups improved the antioxidant activity of chitosan, and the antioxidants or free radical scavengers based on natural polymers and thiourea salts showed potential applications.