Extraction, purification, separation, structure, derivatization and activities of polysaccharide from Chinese date

Advances in Eucommia ulmoides polysaccharides: extraction, purification, structure, bioactivities and applications

Eucommia ulmoides (EU) is a precious tree species native to China originating during the ice age. This species has important economic value and comprehensive development potential, particularly in medicinal applications. The medicinal parts of EU are its bark (Eucommiae cortex) and leaves (Eucommiae folium) which have been successively used as a traditional Chinese medicine to treat diseases since the first century BC. During the last 2 decades, as natural polysaccharides have become of increasing interest in pharmacology, biomedicine, cosmetic and food applications, more and more scholars have begun to study polysaccharides derived from EU as well. EU polysaccharides have been found to have a variety of biological functions both in vivo and in vitro, including immunomodulatory, antioxidant, anti-inflammatory, anticomplementary, antifatigue, and hepatoprotective activities. This review aims to summarize these recent advances in extraction, purification, structural characteristics, pharmacological activities and applications in different fields of EU bark and leaf polysaccharides. It was found that both Eucommiae folium polysaccharides and Eucommiae cortex polysaccharides were suitable for medicinal use. Eucommiae folium may potentially be used to substitute for Eucommiae cortex in terms of immunomodulation and antioxidant activities. This study serves as a valuable reference for improving the comprehensive utilization of EU polysaccharides and further promoting the application of EU polysaccharides.

Polysaccharides from Platycodon grandiflorum: A review of their extraction, structures, modifications, and bioactivities

Platycodon grandiflorum (P. grandiflorum) has long been used as a food and traditional herbal medicine. As a food, P. grandiflorum is often transformed into pickles for consumption, and as a traditional Chinese medicine, P. grandiflorum clears the lung, nourishes the pharynx, dispels phlegm, and discharges pus. Polysaccharides are among the main active components of P. grandiflorum. Recent literature has described the preparation, identification, and pharmacological activity of these polysaccharides. Studies have shown that these polysaccharides exhibit a variety of significant biological effects in vitro and in vivo, such as immune stimulation and antioxidant, anti-liver injury, anti-apoptosis and antitumour effects. However, there is no systematic summary of the related research articles on P. grandiflorum polysaccharide, which undoubtedly brings some difficulties to the future research. The purpose of this review is to comprehensively describe research progress on the extraction, purification, structural characterization, modification, and biological activity of P. grandiflorum polysaccharides. The shortcomings of recent research are summarized, further research on their biological activity is proposed to provide new reference value for the application of P. grandiflorum polysaccharides in drugs and health products in the future.

Research progress and future development potential of Flammulina velutipes polysaccharides in the preparation process, structure analysis, biology, and pharmacology: A review

In recent years, Flammulina velutipes (F. velutipes) has attracted consequential attention in various research fields due to its rich composition of proteins, vitamins, amino acids, polysaccharides, and polyphenols. F. velutipes polysaccharides (FVPs) are considered as key bioactive components of F. velutipes, demonstrating multiple physiological activities, including immunomodulatory, anti-inflammatory, and antibacterial properties. Moreover, they offer health benefits such as antioxidant and anti-aging properties, which have exceptionally valuable clinical applications. Polysaccharides derived from different sources exhibit a wide range of biomedical functions and distinct biological activities. The varied biological functions of polysaccharides, coupled with their extensive application in functional foods and clinical applications, have prompted a heightened focus on polysaccharide research. Additionally, the extraction, deproteinization, and purification of FVPs are fundamental to investigate the structure and biological activities of polysaccharides. Therefore, this review provides a comprehensive and systematic overview of the extraction, deproteinization, purification, characterization, and structural elucidation of FVPs. Furthermore, the biological activities and mechanisms of FVPs have been further explored through in vivo and in vitro experiments. This review aims to provide a theoretical foundation and guide future research and development of FVPs.

β-Glucans obtained from fungus for wound healing: A review

The cell surface of fungus contains a large number of β-glucans, which exhibit various biological activities such as immunomodulatory, anti-inflammatory, and antioxidation. Fungal β-glucans with highly branched structure show great potential as wound healing reagents, because they can stimulate the expression of many immune- and inflammatory-related factors beneficial to wound healing. Recently, the wound healing ability of many fungal β-glucans have been investigated in animals and clinical trials. Studies have proved that fungal β-glucans can promote fibroblasts proliferation, collagen deposition, angiogenesis, and macrophage infiltration during the wound healing process. However, the development of fungal β-glucans as wound healing reagents is not systematically reviewed till now. This review discusses the wound healing studies of β-glucans obtained from different fungal species. The structure characteristics, extraction methods, and biological functions of fungal β-glucans with wound healing ability are summarized. Researches about fungal β-glucan-containing biomaterials and structurally modified β-glucans for wound healing are also involved.

Recent trends in extraction, purification, structural characterization, and biological activities evaluation of Perilla frutescens (L.) Britton polysaccharide

Perilla frutescens (L.) Britton is an annual herb plant of the Perilla genus in the Labiatae family, which is commonly utilized as an edible and medicinal resource. Polysaccharides are among the major components and essential bioactive compounds of P. frutescens, which exhibit a multitude of biological activities, including antioxidant, antitumor, anti-fatigue, immunoregulation, hepatoprotective, anti-inflammatory, and lipid-lowering effects. As a natural carbohydrate, P. frutescens polysaccharide has the potential to be utilized in the development of drugs and functional materials. In this paper, we provide an overview of progress made on the extraction, purification, structural characterization, and bioactivity of polysaccharides from different parts of P. frutescens. The challenges and opportunities for research are discussed, along with the potential development prospects and future areas of focus in the study of P. frutescens polysaccharides.

Effect of Lactiplantibacillus plantarum fermentation on the physicochemical, antioxidant activity and immunomodulatory ability of polysaccharides from Lvjian okra

Okra polysaccharides exhibits a range of biological activities. To date, its processing using microbial fermentation has not been explored. This study investigated the fermentation of okra juice with various lactic acid bacteria, followed by the extraction and characterization of crude polysaccharides (termed OPS-F), in contrast to their non-fermented counterpart (OPS). Changes in physicochemical properties, antioxidant activity and immunomodulatory ability were noted. The results demonstrated that OPS-F had a 7.42-12.53 % increase in total polysaccharides content compared to OPS. However, high-performance size-exclusion chromatography indicated a reduction in the molecular weight of OPS-F (7.9-9.5 × 105 Da) relative to OPS (1.66 × 106 Da). Compared to OPS, OPS-F had reduced levels of mannose, glucose, glucuronic acid and arabinose, but increased rhamnose, galacturonic acid and galactose, exhibiting enhanced solubility and lower apparent viscosity. Fourier transform infrared spectroscopy and nuclear magnetic resonance analysis showed minimal changes in polysaccharide structure post-fermentation. Moreover, despite a decrease in antioxidant activity post-fermentation, OPS-F exhibited superior immunomodulatory potential. In conclusion, fermenting okra juice with lactic acid bacteria alters the physicochemical properties of crude polysaccharides and enhances their immunomodulatory activity, offering a promising approach for developing new functional food resources.

Application of chromatography in purification and structural analysis of natural polysaccharides: A review

Polysaccharides are widely distributed in natural sources from monocytic microorganisms to higher animals, and are found in a variety of biological activities in recent decades. Natural polysaccharides have the characteristics of large molecular weight, diverse composition, and complex structure, so their purification and structural analysis are difficult issues in research. Chromatography as a powerful separation technique, plays an irreplaceable role in the separation and structural analysis of natural polysaccharides, especially in the purification of polysaccharides, the separation of hydrolysates, and the analysis of monosaccharide composition. The separation mechanisms and application of different chromatographic methods in the studies of polysaccharides were summarized in this review. Moreover, the advantages and drawbacks of various chromatography methods were discussed as well.

Comparison in structural, physicochemical and functional properties of sweet potato stems and leaves polysaccharide conjugates from different technologies

In order to better understand the influences of extraction techniques on the yield, characteristics, and bioactivities of polysaccharide conjugates, hot reflux extraction (HRE), ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE), complex enzymolysis extraction (CEE), ultra-high pressure extraction (UPE), ultrasonic complex enzymes extraction (UEE) were used to extract sweet potato stems leaves polysaccharide conjugates (SPSPCs), and their physicochemical characteristics, functional properties, antioxidant and hypoglycemic activities were compared. Results showed that compared with HRE conjugate (HR-SPSPC), the yield, content of uronic acid (UAC), total phenol (TPC), total flavonoid (TFC) and sulfate group (SGC), water solubility (WS), percentage of glucuronic acid (GlcA), galacuronic acid (GalA) and galactose (Gal), antioxidant and hypoglycemia activities of UEE polysaccharide conjugates (UE-SPSPC) significant increased, while its molecular weight (Mw), degree of esterification (DE), content of protein (PC) and percentage of glucose (Glc) declined, but monosaccharides and amino acid types, and glycosyl linkages were not much different. Indeed, UE-SPSPC possessed the highest antioxidant activities and hypolipidemic activities among six SPSPCs, which might be due to the high UAC, TPC, TFC, SGC, GlcA, GalA and WS, low Mw, DE and Glc of UE-SPSPC. The results reveal that UEE is an effective extraction and modification technology of polysaccharide conjugates.

Chemical Modification of Polysaccharides: A Review of Synthetic Approaches, Biological Activity and the Structure-Activity Relationship

Natural polysaccharides are macromolecular substances with great potential owing to their wide biological activity and low toxicity. However, not all polysaccharides have significant pharmacodynamic activity; hence, appropriate chemical modification methods can be selected according to the unique structural characteristics of polysaccharides to assist in enhancing and promoting the presentation of their biological activities. This review summarizes research progress on modified polysaccharides, including common chemical modification methods, the change in biological activity following modification, and the factors affecting the biological activity of chemically modified polysaccharides. At the same time, the difficulties and challenges associated with the structural modification of natural polysaccharides are also outlined in this review. Thus, research on polysaccharide structure modification is critical for improving the development and utilization of sugar products.

Isolation, structural properties, and bioactivities of polysaccharides from Althaea officinalis Linn.: A review

Althaea officinalis Linn. (AO) is a widely distributed herbaceous plant with a long history of medicinal and food functions in Europe and Western Asia. Althaea officinalis polysaccharide (AOP), as one of the main components and a crucial bioactive substance of AO, has a variety of pharmacological activities, including antitussive, antioxidant, antibacterial, anticancer, wound healing, immunomodulatory, and infertility therapy effects. Many polysaccharides have been successfully obtained in the last five decades from AO. However, there is currently no review available concerning AOP. Considering the importance of AOP for biological study and drug discovery, the present review aims to systematically summarize the recent major studies on extraction and purification methods of polysaccharides from different AO parts (seeds, roots, leaves and flowers), as well as the characterization of their chemical structure, biological activity, structure-activity relationship, and the application of AOP in different fields. Meanwhile, the shortcomings of AOP research are further discussed in detail, and new valuable insights for future AOP research as therapeutic agents and functional foods are proposed.

Isolation, structural features, rheological properties and bioactivities of polysaccharides from Lignosus rhinocerotis: A review

L. rhinocerotis, an edible and medicinal mushroom, has long been utilized as folk medicine and nutritional food in Southeast Asia and southern China. Polysaccharides are the main bioactive substances of L. rhinocerotis sclerotia, and they have attracted extensive attention of researchers both at home and abroad. In the past few decades, various methods have been applied to extract polysaccharides from L. rhinocerotis (LRPs) and the structural features of LRPs are closely related to the used methods of extraction and purification. Many studies have confirmed that LRPs possess various remarkable bioactivities, including immunomodulatory, prebiotic, antioxidant, anti-inflammatory and anti-tumor activities and intestinal mucosa protective effect. As a natural polysaccharide, LRP has the potential to be a drug and functional material. This paper systematically reviews the recent studies on structural characteristics, modification, rheological properties and bioactivities of LRPs, and provides a theoretical basis for an in-depth study of the structure-activity relationship, and utilization of LRPs as therapeutic agents and functional foods. Additionally, the further research and development of LRPs are also prospected.

Pd nanoparticles stabilized by bitter gourd polysaccharide with peroxidase properties for H2O2 detection

The development of nanozymes using noble metal nanoparticles to replace natural peroxidase in bio-related detection has been gain great interest. Noble metal nanoparticles with small size have large specific surface area. However, small noble metal nanoparticles tend to aggregate without stabilizer. In this paper, small Pd nanoparticles (3-6 nm) stabilized by bitter gourd polysaccharide (Pd_n-BGP NPs) were prepared by using bitter gourd polysaccharide as reducing agent and stabilizing agent. Pd₂₅-BGP NPs had peroxidase-like catalytic property. And the catalytic kinetics of Pd₂₅-BGP NPs towards substrates conformed to the Michaelis-Menten equation. Furthermore, a method was established to detect H₂O₂ using Pd₂₅-BGP NPs. The linear range and detection limit of this method was 20-320 μM and 2.04 μM, respectively. Finally, Pd₂₅-BGP NPs had good biocompatibility when the concentration was less than 80 μg/mL. The prepared Pd nanoparticles with high stability showed their good prospect in H₂O₂ detection.

Structural characterization and anti-inflammatory activity of a novel polysaccharide PKP2-1 from Polygonatum kingianum

Introduction

This study aimed to investigate the structure characterization and antiinflammatory activity of a novel polysaccharide, PKP2-1, from the rhizomes of Polygonatum kingianum Coll. and Hemsl.

Methods

We isolated a novel polysaccharide, PKP2-1, from the rhizomes of Polygonatum kingianum Coll. and Hemsl. for the first time, which was then successively purified through hot-water extraction, 80% alcohol precipitation, anion exchange and gel permeation chromatography. The in vitro anti-inflammatory activity of PKP2-1 in MH7A cells was assessed using a CCK-8 kit assay.

Results

Monosaccharide composition assay revealed that PKP2-1 was mainly composed of glucose, galactose, mannose, and glucuronic acid at an approximate molar ratio of 6:2:2:1. It had a molecular weight of approximately 17.34 kDa. Structural investigation revealed that the backbone of PKP2-1 consisted of (→2, 3)-α-D-Galp(4→, →2)-α-D-Manp(3→, →2)-β-D-Glcp(4→) and α-D-Glcp(3→) residues with side chains (→2)-β-D-Glcp(4→, →1)-α-D-Galp(4→) and α-D-Glcp(3→) branches located at O-3 position of (→2, 3)-α-D-Galp(4→). The in vitro anti-inflammatory activity of PKP2-1 in MH7A cells revealed that PKP2-1 could reduce the expression of IL-11β and IL-6, increase the expression of IL-10 and induce apoptosis of synovial fibroblasts.

Conclusion

The PKP2-1 could inhibit MH7A cell growth and potentially be exploited as an anti-inflammatory agent.

Extraction, Characterization, and Antioxidant Activity of Polysaccharides from Ajwa Seed and Flesh

The date palm has been cultivated in dry and hot areas of the planet for much of human history. In the Kingdom of Saudi Arabia, dates are the main crop used as a source of food. Among several species of date fruits, the Ajwa AL-Madinah date is unique, growing only in Al-Madinah geographical region. The Ajwa date is used in traditional medicine due to its abundant active components and therapeutic properties. This study investigates the structural properties and the antioxidant effects of water-soluble polysaccharides extracted from Ajwa flesh and seed. The polysaccharides were isolated by two techniques including hot water and ultrasonic extraction. After isolation and partial purification, the physicochemical properties of four samples of polysaccharides extracted from flesh and seed were studied by several techniques including FTIR, solid-state NMR, elemental analysis, and mass spectrometry. Several radical scavenging experiments were combined to study the antioxidant activity of the polysaccharide compounds. FTIR and NMR results showed a structure typical of heterogeneous polysaccharides. Mass spectrometry revealed that the polysaccharide samples were composed mainly of mannose, glucose, galactose, xylose, arabinose, galacturonic acid, and fucose. In addition, the physicochemical properties and composition of polysaccharides extracted from flesh and seed were compared. The extracted polysaccharides showed antioxidant activity, with 2, 2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, Fe chelating ability, hydroxyl free radical scavenging ability, and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging. These results highlight their potential to be a useful nutritional element or supplemental medication.

Anti-cholinesterase, anti-inflammatory and antioxidant properties of Combretum micranthum G. Don: Potential implications in neurodegenerative disease

Background

Brain damage is a severe and common pathology that leads to life-threatening diseases. Despite development in the research, the medical evidence of the effectiveness of potential neuroprotective medicines is insufficient. As a result, there is an immense and urgent demand for promising medication. For millennia, herbal remedies were a fundamental aspect of medical treatments. Combretum micranthum (CM), a plant of the family Combretaceae in sub-Saharan Africa, has been utilized in folklore medicine to cure diverse human ailments. In order to develop a neuroprotective phytomedicine, the current research was undertaken to explore the antioxidant, anti-inflammatory, anticholinesterase and neuroprotective potential of CM extract.

Methods

Colorimetric methods were used to determine CM antioxidant activity, in-vitro protein denaturation and membrane destabilization assays were used to evaluate its anti-inflammatory capacity, anticholinesterase activity was carried out using Ellman's method, and neuroprotective potential was assessed on brain homogenate stressed with ferric chloride and ascorbic acid (FeCl₂-AA) by assessing the lipoperoxidation biomarker malondialdehyde (MDA).

Results

In Ferric Reducing Antioxidant Power (IC₅₀ = 27.15 ± 0.06 µg/mL) and Total Antioxidant Capacity (IC₅₀ = 31.13 ± 0.02 µg/mL), CM extract demonstrated strong antioxidant activity. Anti-inflammatory effect were improved in heat-induced Egg albumin and BSA denaturation (IC ₅₀ = 46.35 ± 1.53 and 23.94 ± 1.10 µg/mL) as well as heat and hypotonia induced membrane destabilization (IC ₅₀ = 20.96 ± 0.11 and 16.75 ± 0.94 µg/mL).CM extract showed strong anticholinesterase activity (IC ₅₀ = 59.85 ± 0.91 µg/mL). In an ex-vivo neuroprotective model, CM extract showed substantial inhibition (p < 0.001) of oxidative damage caused by FeCl₂-AA in brain tissue.

Conclusion

C. micranthum may be a good candidate for its probable neuroprotective potential. Its neuroprotective benefits might be attributed to its antioxidant, anti-inflammatory and anticholinesterase effects.

Recent progress of Lycium barbarum polysaccharides on intestinal microbiota, microbial metabolites and health: a review

Intestinal microbiota is symbiotically associated with host health, learning about the characteristics of microbiota and the factors that modulate it could assist in developing strategies to promote human health and prevent diseases. Polysaccharides from Lycium barbarum (LBPs) are found beneficial for enhancing the activity of gut microbiota, as a potential prebiotic, which not only participates in improving body immunity, obesity, hyperlipidemia and systemic inflammation induced by oxidative stress, but also plays a magnificent role in regulating intestinal microenvironment and improving host health and target intestinal effects via its biological activities, as well as gut microbiota and metabolites. To highlight the internal relationship between intestinal microbiota and LBPs, this review focuses on the latest advances in LBPs on the intestinal microbiota, metabolites, immune regulation, intestinal barrier protection, microbiota-gut-brain axis and host health. Moreover, the preparation, structure, bioactivity and modification of LBPs were also discussed. This review may offer new perspective on LBPs improving health of gut and host via intestinal microbiota, and provide useful guidelines for the application of LBPs in the food industry.

A novel acidic polysaccharide from blackened jujube: Structural features and antitumor activity in vitro

Liver cancer is one of the most common cancers, with increasing trends in incidence and mortality. A novel acidic polysaccharide (BJP-2) obtained from blackened jujube was extracted by hot water followed by chromatographic purification employing DEAE-cellulose 52 and Sephadex G-100 column. And then BJP-2 was identified by SEC-MALLS-RI, GC-MS, methylation and NMR for the following characteristics: molecular weight of 6.42 × 104 Da, monosaccharide composition of glucuronic acid (GalA), arabinose (Ara), galactose (Gal), rhamnose (Rha), xylose (Xyl), glucuronic acid (GlcA), glucose (Glc), fucose (Fuc) and mannose (Man) with the percentage of 39.78, 31.93, 16.86, 6.43, 1.86, 1.28, 1.02, 0.61, and 0.23%, as well as the main chain of → 5)-α-L-Araf (1 → 4)-β-D-Gal(1 → , T-α-L-Araf (1 → 4)-β-D-Gal(1 → , and → 4)-α-L-6MeGalAp(1 → . The effect of BJP-2 on the apoptosis of HepG2 cells and its anti-tumor mechanism were further explored. The analysis by MTT and flow cytometry showed that BJP-2 suppressed cell proliferation by inducing apoptosis in a concentration-dependent manner. Cell scratching and Transwell revealed that BJP-2 was able to block the invasion and metastasis of tumor cells. Western blot results demonstrated that BJP-2 exhibited antitumor activity through a mitochondria-dependent pathway, as evidenced by overexpression of Bax, Cleaved Caspase-3/Caspase-3 and Cleaved Caspase-9/Caspase-9 and downregulation of Bcl-2. Therefore, BJP-2 has broad research prospects as a tumor preventive or therapeutic agent.

Research Progress on the Extraction, Structure, and Bioactivities of Polysaccharides from Coriolus versicolor

Coriolus is the dried fruiting body of Coriolus versicolor (L. ex Fr.) Quel. C. versicolor (CV) is a worldwide-distributed fungus, which is common and widely used in primitive forests in the northern hemisphere. Polysaccharide, as the main active ingredient in CV, has a variety of biological activities, such as promoting immune function, antivirus, antitumor, anti-diabetes, and so on. However, Coriolus versicolor polysaccharide (CVP) faces the problems of a single extraction method, lack of research on separation and purification, and the research on structural characterization is limited to the primary structure. Furthermore, the existing research results have not been systematically reviewed. Therefore, this paper summarizes the research status of CVP in terms of extraction technology, separation and purification, structural characterization, and pharmacological activity in recent years, in order to provide a theoretical basis for in-depth research, development, and utilization of CVP.

Microalgae-derived polysaccharides: Potential building blocks for biomedical applications

In recent years, the increasing concern about human health well-being has strongly boosted the search for natural alternatives that can be used in different fields, especially in biomedicine. This has put microalgae-based products in evidence since they contain many bioactive compounds, of which polysaccharides are attractive due to the diverse physicochemical properties and new or improved biological roles they play. Polysaccharides from microalgae, specially exopolysaccharides, are critically important for market purposes because they can be used as anti-inflammatory, immunomodulatory, anti-glycemic, antitumor, antioxidant, anticoagulant, antilipidemic, antiviral, antibacterial, and antifungal agents. Therefore, to obtain higher productivity and competitiveness of these naturally available compounds, the cultivation parameters and the extraction/purification processes must be better optimized in order to bring perspectives for the exploitation of products in commercial and clinical practice. In this sense, the objective of the present review is to elucidate the potential biomedical applications of microalgae-derived polysaccharides. A closer look is taken at the main polysaccharides produced by microalgae, methods of extraction, purification and structural determination, biological activities and their applications, and current status.

Preparation, characterization and immunoregulatory activity of derivatives of polysaccharide from Atractylodes lancea (Thunb.) DC

A polysaccharide (ALP-1) extracted from Atractylodes lancea (Thunb.) DC. was carboxymethylated (C-ALP-1), phosphorylated (P-ALP-1) and acetylated (A-ALP-1) to improve its physicochemical properties and bioactivities. The solubility of all derivatives was increased, and the solubility of A-ALP-1 increased to 137.5 mg/mL, which was much higher than the solubility of ALP-1 (15.0 mg/mL). The results of HPSEC-MALLS-RID showed that the molecular weight of polysaccharides was slightly increased after the modification, and the root mean square radius of rotation (Rz) and morphology of polysaccharides in solution were also changed. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) results confirmed that the surface morphology of ALP-1 changed dramatically and the crystallinity decreased after structural modification. From thermal analysis results, the T₅₀ of ALP-1, C-ALP-1, P-ALP-1 and A-ALP-1 were 281.34, 292.14, 333.75 and 298.70 °C, which showed that derivatives had stronger thermal stability than ALP-1. The immunomodulatory activity studies displayed that P-ALP-1 showed the best ability to stimulate RAW264.7 macrophages to release NO, and A-ALP-1 showed the best capacity to stimulate TNF-α and IL-6 releasing. These results indicated that chemical modification could enhance the solubility, the thermal stability and immunomodulatory activity of polysaccharides, which is beneficial for the development and utilization of natural polysaccharides.

Isolation, Structural Analysis and Anti-Inflammatory Activity of a Polysaccharide from Ilex cornuta Fruits

In the present study, a polysaccharide from Ilex cornuta fruits (LCFP-3) was obtained by hot water extraction, Diethyaminoethyl cellulose-52 (DEAE-52) chromatography column and Sephadex G-100 gel column purification. Its structural characteristics were further explored using high performance anion exchange chromatography (HPAEC), gas chromatography and mass spectrometry (GC/MS), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. Monosaccharide composition analysis revealed LCFP-3 contained mainly Galactose (31.92 %), Arabinose (25.87 %) and Galacturonic acid (23.35 %) while small percentage of Rhamnose, Glucose, Mannose and Xylose. Chemical composition analysis showed that the total sugar content of LCFP-3 was 90.31 % and the protein content was 0.246 %. Gel permeation chromatography (GPC) analysis showed that its average molecular weight was 41.199 kDa. Structural analysis showed that LCFP-3 may be composed of residues, T-α-Arap, T-α-Rhap, 1,3-α-Arap, 1,4-α-Arap, T-β-Galp, 1,4-α-GalpA(OMe), 1,4-β-Glcp, 1,3-β-Galp, 1,3,6-β-Manp, 1,6-β-Galp, 1,3,4-β-GalpA, 1,4,6-β-Manp, 1,3,6-β-Glcp, 1,2,3,4-α-Xylp. The anti-inflammatory activity of LCFP-3 was evaluated using lipopolysaccharide (LPS)-induced RAW246.7 macrophages. The results showed that 1-200 μg/mL LCFP-3 could dose-dependently protect against LPS-induced toxicity and 1 μg/mL LCFP-3 could significantly inhibit LPS-induced NO production. Therefore, LCFP-3 exerted an anti-inflammatory activity and has great potential as a functional ingredient.

High-performance free-standing microbial fuel cell anode derived from Chinese date for enhanced electron transfer rates

Traditional anode materials have disadvantages like low specific surface area and poor electrical conductivity. Herein, carbonized Chinese dates (CCD) were synthesized as microbial fuel cells (MFC) anodes. The obtained materials exhibited excellent biocompatibility with fast start-up (within one day) and charge transfer (R_ct 4.0 Ω). Their porous structure allows efficient ion transport and microbial community succession, favorable for long-term operation. The biomass analysis shows that CCD anodes can load higher weight of biomass. High-throughput sequencing (16S rRNA) discovered that CCD anode can enrich Geobacter spp., with highest abundance of 73.4%, much higher than carbon felt (CF, 39.2%). Benefit from these properties, the MFC with CCD anodes possess a maximum power density of 12.17 W m^-3 (1.62 times of commercial carbon felt). In all, the CCD anode exhibits high performance with low cost and easy fabrication, certificating it a promising candidate for an ideal MFC anode material.

Relationship Between the Structure and Immune Activity of Components From the Active Polysaccharides APS-II of Astragali Radix by Enzymolysis of Endo α-1,4-Glucanase

Astragali Radix polysaccharides (APSs) have a wide range of biological activities. Our preliminary experiment showed that APS-Ⅱ (10 kDa) was the main immunologically active component of APSs. However, the characteristic structure related to activity of APS-Ⅱ needs further verification and clarification. In this study, APS-II was degraded by endo α-1,4-glucosidase. The degraded products with different degrees of polymerization [1–3 (P1), 3–6 (P2), 7–14 (P3), and 10–18 (P4)] were obtained using a polyacrylamide gel chromatography column. The structural features of the different products were characterized by HPGPC, monosaccharide composition, Fourier transform infrared spectrum, GC–MS, nuclear magnetic resonance, and UPLC-ESI-QTOF-MS analysis. Specific immune and non-specific immune cell tests were used to identify the most immunogenic fractions of the products. The backbone of P4 was speculated to be α-D-1,4-linked glucans and rich in C2 (25.34%) and C6 (34.54%) branches. Immune screening experiments indicated that the activity of P4 was better than that of APS-II and the other three components. In this research, the relationship between the structure of APS-Ⅱ and the immune activity from the degradation level of polysaccharides was studied, laying a foundation for the quality control and product development of APSs.

Structure–immunomodulatory activity relationships of dietary polysaccharides

Polysaccharides are usually composed of more than ten monosaccharide units, which are connected by linear or branched glycosidic bonds. The immunomodulatory effect of natural polysaccharides is one of the most important bioactive function. In this review, molecular weight, monosaccharide (including galactose, mannose, rhamnogalacturonan-I arabinogalactan and uronic acid), functional groups (namely sulfate, selenium, and acetyl groups), types of glycoside bond connection (including β-1,3-D-glucosyl, α-1,4-D-glucosyl, β-1,4-D-glucosyl, α-1,6-D-glucosyl, β-1,4-D-mannosyl, and β-1,4-D-Xylopyranosyl), conformation and the branching degrees are systematically identified as their contribution to the immunostimulatory activity of polysaccharides. At present, studies on the structure-activity relationships of polysaccharides are limited due to their low purity and high heterogeneity. However, it is an important step in providing useful guidance for dietary supplements with polysaccharides. The chemical structures and the process of immune responses induced are necessary to be discussed. Polysaccharides may bind with the cell surface receptors to modulate immune responses. This review mainly discusses the structure-activity relationship of dietary polysaccharides.

•

Structure - activity relationships of polysaccharides with immune-enhancing effect are proposed.

•

Polysaccharides with the higher molecular weight are helpful to improve immunity.

•

Higer galactose, mannose, rhamnogalacturonan-I, arabinogalacta,n and uronic acid contents have immunoregulation.