Structural elucidation and antioxidant activity a novel Se-polysaccharide from Se-enriched Grifola frondosa

Structure, rheology and antioxidant properties of a polysaccharide from Atractylodes macrocephala in Pan'an

To date, no studies have reported on the structure and properties of the polysaccharides from Atractylodes macrocephala cultivated in Pan'an. In this paper, a polysaccharide designated as RAMP1 was isolated from A. macrocephala in Pan'an for the first time. Its structure was determined as a heteropolysaccharide consisting of fructose and glucose in a molar ratio of 20:1, with a molecular weight of 3494 Da based on chemical and NMR analysis. Scanning electron microscopy analysis revealed that RAMP1 presented a smooth flake structure with irregular curls. Thermal analysis results indicated that RAMP1 had high thermal stability below 165 °C. Rheological studies indicated that both temperature and concentration affected the viscosity of RAMP1. The viscosity of the RAMP1 solution decreased as the shear rate increased, displaying shear - thinning behavior, suggesting that the RAMP1 solution was a non - Newtonian fluid. RAMP1 showed potent dose - dependent antioxidant activity against DPPH, superoxide, ABTS, and hydroxyl radicals, with the strongest inhibition against hydroxyl radicals (83.97 ± 1.62 % at 8 mg/mL). This paper reports for the first time on the structure, rheology, and antioxidant properties of the polysaccharide (RAMP1) from A. macrocephala in Pan'an. These results highlight the potential applications of RAMP1 in the food and biotechnology industries.

Efficient production, structural characterization and bioactivity of an extracellular polysaccharide from Grifola frondosa endophytic Burkholderia sp

Endophytic bacteria Burkholderia sp. (GFB) was firstly identified and isolated from Grifola frondosa. An exopolysaccharide (GFB-MP) of GFB strain was obtained following fermentation optimization, resulting in a maximum yield of 11.36 g/L in 5 L fed-batch fermentation. GFB-MP (MW 432.05 kDa) comprised mainly galactose, glucose, and mannose with a ratio of 39.52:14.22:46.26, indicating a mannose-enriched polysaccharide. Methylation and NMR analysis revealed that GFB-MP consisted of the main chain that was repeat units →4)-α-D-Glcp-(1 → bonded →6)-β-D-Galp-1 → repeat units and three O-6-linked branched chains. Antibacterial activity suggested that GFB-MP can effectively inhibit food pathogen bacteria Listeria and Escherichia coli with inhibition ratios of 73.4 % and 81.6 %, respectively. In addition, GFB-MP exhibited remarkable growth-promoting activity on probiotics with >50 % increments of cell growth. This study demonstrates that GFB-MP has the potential for health-beneficial food. Knowledge of endophyte polysaccharides in G. frondosa is important to understand their physiological activities and symbiotic interactions.

Absorption and transport of polysaccharides from soybean seed coat in the Caco-2 cell model and their interaction with the MUC2 protein

Polysaccharides derived from soybean seed coats exhibit diverse functional properties and significant application potential; however, their intestinal absorption and transport mechanisms remain poorly understood. This study investigates the molecular docking interactions of two soybean seed coat polysaccharides (NMSP and CSSP), extracted using different methods, with the MUC2 protein, and explores their absorption and transport properties using Caco-2 cell models. Molecular dynamics simulations revealed the binding modes and key interaction sites between NMSP, CSSP, and the MUC2 protein. A Caco-2 monolayer model was established to evaluate polysaccharide uptake and transport under varying concentrations, temperatures, and pH conditions. The results demonstrated that the absorption of both polysaccharides was time- and concentration-dependent, while transport analyses revealed that both NMSP and CSSP could traverse the Caco-2 cells, primarily via endocytic pathways. In terms of apparent permeability (Papp) and transport rate, CSSP exhibited moderate absorption, whereas NMSP was classified as poorly absorbed. Moreover, acidic conditions significantly enhanced the transport rates of both polysaccharides. This study provides critical insights into the absorption and transport characteristics of soybean seed coat polysaccharides, offering a theoretical foundation for further exploration of their bioavailability and physiological functions.

Structural characterization of pure xylan from corncob and its effect on xylooligosaccharides yield after enzymatic hydrolysis

The structure of xylan plays a significant role in the degradation rate by xylanase to product xylooligosaccharides (XOS). In this study, xylan was extracted and purified from corncob, yielding two xylan fractions (WUAX-2, WUAX-3) with purities exceeding 90 %. The structures of WUAX-2 and WUAX-3 were characterized and hydrolysis efficiency was studied in relation to their structures. FT-IR results indicated that although xylan fractions had the same types of functional groups, WUAX-3 exhibited a higher level of -OH, CH, and CO groups compared to WUAX-2. NMR, the vibration signal of WUAX-2 and WUAX-3 was β-(1 → 4) -linked D-lignin unit β-D-xylopyran. X-ray diffraction results confirmed that WUAX-2 was a stable single-crystal structure. Meanwhile, the number of side-chains of WUAX-2 in the liquid was smaller than that of WUAX-3. WUAX-2 and WUAX-3 were hydrolyzed by a high-temperature-resistant xylanase (XynA) and yielded primarily xylohexaose (X6), xylotriose (X3), and xylobiose (X2). The XOS yield of WUAX-2 was 4.25 times higher than that of WUAX-3. These results indicate that the fewer xylan side-chains and substituent groups of xylan, the higher the enzymatic hydrolysis efficiency. The findings provide a deep understanding of the effect of xylan structure on the enzymatic behavior.

Antioxidant and hepatic fibrosis-alleviating effects of selenium-modified Bletilla striata polysaccharide

Liver fibrosis is a significant precursor to cirrhosis and liver cancer, yet effective treatments remain elusive. Our previous studies demonstrated that Bletilla striata polysaccharide (BSP) has therapeutic effects, though it performed poorly at medium concentrations. To address this limitation, BSP underwent selenization modification. In this study, selenized BSP (Se-BSP) was structurally characterized, and its in vivo activity in alleviating liver fibrosis was evaluated. The results showed that the molecular weight of Se-BSP increased, its in vitro antioxidant activity improved, and it exhibited enhanced efficacy in alleviating liver fibrosis at medium concentrations (150 mg/kg) compared to BSP. These findings provide a theoretical basis for the potential application of Se-BSP as an anti-liver fibrosis agent.

Purification, structural characterization, and in vitro immunomodulatory activity of a low-molecular-weight polysaccharide from cultivated Chinese cordyceps

Cultivated Chinese cordyceps, an optimal substitute for the endangered wild resource, has recently been produced on a large scale. This work sought to explore the structural features and immunomodulatory activity of a novel low-molecular-weight polysaccharide (CSP1a, 15.7 kDa) isolated from cultivated Chinese cordyceps. CSP1a was prepared with a multi-step process that encompassed hot water extraction, alcohol precipitation, and column chromatographic purification. The monosaccharide composition, infrared spectroscopy, methylation, and nuclear magnetic resonance results revealed that CSP1a was highly branched (with a branching degree of 49.21 %) and primarily constituted of galactose (30.60 %), glucose (12.87 %) and mannose (56.53 %), comprising 13 distinct types of glycosidic linkage fragments. The main chain of CSP1a consisted of different mannose residues, with several exposed β-d-Galf-(1→ residues in various side chains. The results from scanning electron microscopy and Congo red analyses revealed that CSP1a possessed a reticulated porous chain conformation, which enhanced its bioavailability and demonstrated its potential as a carrier. In vitro immunological investigations demonstrated that CSP1a significantly promoted splenic lymphocyte proliferation. Additionally, CSP1a increased RAW264.7 cell proliferation, improved phagocytic capacity, and stimulated the secretion of nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in a dose-dependent manner. Collectively, CSP1a, a novel low-molecular-weight polysaccharide galactoglucomannan with a high branching degree and reticulated porous chain conformation, was isolated for the first time from cultivated Chinese cordyceps and showed promise as a potential immunomodulator or drug carrier. These findings contribute to elucidating the polysaccharide material basis for the immune activity of Chinese cordyceps and promote its industrial development as a functional food product.

A Novel Polysaccharide Purified from Tricholoma matsutake: Structural Characterization and In Vitro Immunological Activity

Tricholoma matsutake, as a rare wild edible mushroom, is popular due to its unique flavor and taste, as well as high nutritional and economic value. Investigating the relationship between the complex structure and in vitro immunological activity of TMP-2a, a novel polysaccharide isolated from T. matsutake, was the aim of this study. The results showed that TMP-2a consisted of six monosaccharides, fucose, glucosamine hydrochloride, galactose, glucose, mannose, and glucuronic acid, with molar ratios of 8.8:0.6:23.4:48.1:15.1:4.0 and a molecular weight of 27,749 Da. Furthermore, TMP-2a was mainly composed of →6)-β-Glcp-(1→ with →3)-β-D-Glcp-(1→ forming the main chain, with a small amount of →2,6)-α-D-Manp-(1→ and →6)-α-D-Galp-(1→ structural units attached, and the branched chain was mainly composed of β-Glcp-(1→ or a small amount of α-L-Fucp-(1→ as a telosaccharide attached at the O-6 position of →3,6)-β-D-Glcp-(1→. TMP-2a enhanced the proliferation and phagocytic activity of mouse macrophage RAW264.7, as well as the secretion of NO and cytokines (TNF-α, IL-6, IL-1β) to a considerable degree, maybe attributable to its glucan structure and the elevated presence of (1→3)-β-D-Glcp glycosidic bonds. This study establishes a basis for the structural identification and comprehensive investigation of the functional activities of T. matsutake polysaccharides while also offering a theoretical framework for the creation of T. matsutake-related food products.

Selenium-Enriched Polysaccharides from Lentinula edodes Mycelium: Biosynthesis, Chemical Characterisation, and Assessment of Antioxidant Properties

Selenium-polysaccharides possess antioxidant properties, making them promising materials for functional foods, pharmaceuticals, and clinical applications. This study examines the incorporation of selenium into polysaccharides via mycelial biosynthesis and its effects on structure and antioxidant activity. Polysaccharides obtained from Lentinula edodes-submerged cultures grown in Se-supplemented and non-supplemented media were analysed for Se content (RP-HPLC/FLD), structure (FT-IR, HPLC, and HPGPC-ELSD), and antioxidant activity (DPPH scavenging, reducing power, and Fe2+ chelation). Two low-molecular-weight Se-heteropolysaccharides (Se-FE-1.1 and Se-FE-1.2) containing ~80 and 125 µg/g Se were isolated, primarily composed of glucose, mannose, and galactose with β-glycosidic linkages. Se incorporation into polysaccharides selectively enhanced their antioxidant activity in the DPPH radical scavenging assay, with minimal effects observed in iron chelation and reducing power assays. Crude Se-polysaccharides displayed the highest antioxidant activity, suggesting an additional contribution from protein components. Our findings demonstrate that Se is effectively incorporated into polysaccharides, altering monosaccharide composition while preserving glycosidic linkages. The selective enhancement of radical scavenging suggests that selenium plays a specific role in antioxidant activity, primarily influencing radical scavenging mechanisms rather than interactions with metal ions. Further research is needed to clarify the mechanisms of selenium incorporation, the nature of its bonding within the polysaccharide molecule, and its impact on biological activity.

Radix Hedysari Polysaccharides modulate the gut-brain axis and improve cognitive impairment in SAMP8 mice

OBJECTIVE

Radix Hedysari Polysaccharides (RHP) are the principal bioactive constituents of the traditional Chinese medicinal herb Radix Hedysari. This study aims to evaluate the neuroprotective effects of RHP in both cellular and animal models of Alzheimer's disease (AD) and to elucidate the underlying molecular mechanisms.

METHODS

HT22 cells subjected to Aβ25-35-induced cytotoxicity were pretreated with RHP, followed by assessments of reactive oxygen species (ROS) generation, mitochondrial superoxide (mSOX) levels, and mitochondrial membrane potential (ΔΨm). Senescence-accelerated mouse-prone 8 (SAMP8) mice were orally administered RHP for 12 weeks. Behavioral assays were conducted to assess cognitive function, while metabolomic and proteomic analyses were performed to examine serum metabolic alterations and hippocampal protein expression profiles. Additionally, neuronal autophagy and gut barrier integrity were evaluated using immunohistochemistry, transmission electron microscopy, and biomarker quantification.

RESULTS

RHP treatment significantly attenuated Aβ25-35-induced oxidative stress in HT22 cells by reducing ROS and mSOX production while preserving ΔΨm. In SAMP8 mice, RHP improved cognitive performance, preserved hippocampal mitochondrial ultrastructure, and enhanced neuronal autophagic activity. Moreover, RHP modulated serum metabolic pathways and alleviated gut barrier dysfunction, suggesting a role in gut-brain axis regulation.

CONCLUSION

RHP ameliorates cognitive impairment in SAMP8 mice, potentially through its modulation of systemic metabolism, mitigation of neuronal mitochondrial damage, and restoration of gut barrier integrity. These findings highlight the therapeutic potential of RHP in AD intervention and warrant further investigation into its mechanistic underpinnings.

Polysaccharides from Exocarpium Citri Grandis: Graded Ethanol Precipitation, Structural Characterization, Inhibition of α-Glucosidase Activity, Anti-Oxidation, and Anti-Glycation Potentials

The endocarp of Exocarpium Citri Grandis (ECG) is abundant in various bioactive components, such as polysaccharides; however, there are few studies on them. Thus, it is highly necessary to carry out further research on the structural characterization and biological activities of ECG polysaccharides (EPs), which are important bioactive substances. In this study, water-extracted EPs were precipitated by ethanol with final concentrations of 50%, 70%, and 90% (v/v), respectively. Three crude polysaccharides (EP50, EP70, and EP90) were fractioned successively. The three polysaccharide fractions were structurally elucidated and were investigated in vitro for their biological activities related to glucose metabolism containing inhibitory effects on α-glucosidase and non-enzymatic glycosylation and their antioxidant capacities. The main results are summarized as follows: (1) Gradient ethanol precipitation and physicochemical properties of EPs: The yields of EP50, EP70, and EP90 were 11.18%, 0.57%, and 0.18%, respectively. The total sugar contents were 40.01%, 52.61%, and 53.46%, and the uronic acid contents were 30.25%, 18.11%, and 8.17%, respectively. In addition, the three fractions had the same composition of monosaccharides, including rhamnose, arabinose, galactose, glucose, xylose, mannose, galacturonic acid, and glucuronic acid, with differences in the content of neutral and acidic monosaccharides. They all may be branched polymers and spherical conformation, and they were acidic polysaccharides containing esterified and non-esterified uronic acids, pyranose-form sugars, and glycosidic linkages of α-configuration and β-configuration, with esterification degrees of 32.25%, 28.82%, and 15.58%, respectively. Meanwhile, EP50, EP70, and EP90 were mainly amorphous, and the molecular conformation in solution was a spherical branching polymer without a triple helix structure. The EPs exhibited excellent thermal stability, with their structures remaining stable below 170 °C. (2) In terms of activity research, the results showed that EPs had a good α-glucosidase inhibitory effect with IC50 values of 1.17 mg/mL, 1.40 mg/mL, and 2.72 mg/mL, respectively, among which EP50 was the best. EP50, EP70, and EP90 displayed antioxidant activity by scavenging DPPH and ABTS radicals as well as oxygen radical absorbance capacity. Among them, EP90 had the strongest antioxidant activity. Furthermore, the EPs showed prominent effects on the inhibitory activity of non-enzymatic glycosylation. In summary, the research on the extraction of polysaccharide from ECG provides a technical reference for the further utilization of ECG resources. This study on antioxidant activity provides theoretical support for their use as a natural antioxidant. As oxidation and glycation are relevant to diabetic complications, the result of this work suggests that EPs may be effective in preventing and treating diabetic complications.

Effects of different crushing methods on the properties and flavor of selenium-enriched sweet potato leaves

In this study, the physical, chemical, structural, and antioxidant characteristics of selenium (Se)-enriched sweet potato leaves (SSPL) powder produced through shear breaking and superfine grinding were examined. The superfine grinding SSPL powder had a brighter color, smaller particle size, and spherical shape. The superfine grinding SSPL powder showed improved dispersibility and solubility but reduced liquidity. Superfine grinding destroyed the crystalline area and decreased the thermal stability, while Se application did not significantly change the ordered structure. Correlation analysis showed that superfine grinding could improve crude fiber, crude lipid, total flavonoids, total polyphenol, and significantly enhance the antioxidant activities compared to shear breaking. Se enrichment can enhance the content of the crude protein and the DPPH• scavenging activity and reducing power. The flavor characteristic was not altered with the different crushing methods and Se concentrations. SSPL powder could serve as a potential resource for a new solid beverage.

TCP80-1, a new levan-neoseries fructan from Tupistra chinensis Baker rhizomes alleviates ulcerative colitis induced by dextran sulfate sodium in Drosophila melanogaster model

Ulcerative colitis (UC) is a recurrent inflammation of the gastrointestinal tract, for which available treatment drugs are severely limited. Natural polysaccharides show potential for UC prevention. Herein, we extracted TCP80-1, a polysaccharide with significant anti-ulcerative colitis (UC) activity, from Tupistra chinensis Baker for the first time. Structure analysis revealed that TCP80-1 (3190 Da) was a levan-neoseries fructan containing → 6)-α-D-Glcp-(1→, →1)-β-D-Fruf-(2→, →1,6)-β-D-Fruf-(2→, →6)-β-D-Fruf-(2→ and β-D-Fruf-(2→ residues as backbone, with →6)-β-D-Fruf-(2→, and β-D-Fruf-(2→ as side chains substituted at C-6. The protective effect of TCP80-1 on UC was further evaluated using a UC Drosophila melanogaster model. The results demonstrated that TCP80-1 could alleviate the UC symptoms by reducing colonic atrophy, enhancing intestinal barrier, and promoting the proliferation and differentiation of intestinal stem cells (ISCs) into intestinal epithelial cells (IECs). Our findings provide important structural information about TCP80-1 and establish the foundation for the future progression and utilization of T. chinensis polysaccharide within the realm of UC therapy.

In vitro antioxidant activity of the polysaccharide from Auricularia auricula and its structural characterisation

A new polysaccharide (AAP) was extracted from Auricularia auricula by water extraction and alcohol precipitation. The antioxidant activity in vitro showed that AAP had a good scavenging effect on ABTS free radicals. Then AAP was purified by DEAE-52 ion exchange chromatography to obtain the purified component pAAP. The structure analysis showed that the molecular weight (Mw) of pAAP was 96.768 kDa, which was composed of rhamnose (Rha), arabinose (Ara), fucose (Fuc), xylose (Xyl), mannose (Man), glucose (Glu) and galactose (Gal), with the ratio of 0.1:0.157:0.33:2.797:2.881:2.988:0.587, and contained α-pyranose configuration and β-pyranose configuration. Field emission scanning electron microscopy and atomic force microscopy revealed the special conformation of pAAP in the ring and chain shape.

Impacts of kappa-selenocarrageenan on the muscle quality of pork: Novel insights into myofibrillar protein and lipid oxidation

Excessive oxidation of protein and lipids in pork leads to quality degradation and loss of nutrients. Kappa-selenocarrageenan (Se-K) can not only be used as a selenium enhancer but also as an antioxidant. To explore potential antioxidants that could be applied to pork, the effect of Se-K on myofibrillar protein (MP) and lipid oxidation was investigated. The results demonstrated that Se-K could scavenge hydroxyl radicals, DPPH radicals, and ABTS radicals. It was found that Se-K inhibited the formation of carbonyls and decreased the loss of sulfhydryl groups of MP. Se-K also inhibited cross-linking, aggregation, unfolding, and structural transformation of MP and repressed the increase in surface hydrophobicity. Additionally, Se-K enhanced the emulsibility, textural properties, and water-holding capacity of MP. We also found that Se-K delayed the increase in acid value, peroxide value, and thiobarbituric acid reactive substances value. Furthermore, Se-K inhibited the degradation of unsaturated fatty acids, especially linoleic acid. Overall, Se-K was effective in inhibiting MP and lipid oxidation and could be a potential antioxidant for pork.

The synergistic gelation of novel Bletilla striata polysaccharide with hyaluronic acid: Characterization, rheology

Bletilla striata polysaccharide (BSP) has attracted considerable interest due to its diverse biological activities. In this research, a novel low-molecular-weight water-soluble polysaccharide (BSP-182) was isolated and purified from Bletilla striata tubers, and its structure was characterized. The findings indicated that BSP-182 is predominantly composed of β-1,4-linked glucose (Glc) and β-1,4-linked mannose (Man) in a molar ratio of approximately 7.8:2.2. Additionally, hyaluronic acid (HA)/BSP-182 hydrogels were synthesized, and their physicochemical properties and structure were examined. Rheological analysis revealed that HA and BSP-182 form hydrogels via hydrogen bonding, with concentration-dependent enhancements in rheological properties, textural attributes, and thermal stability. The hydrogels displayed significant shear-thinning behavior and viscoelasticity, which are beneficial for food processing and texture modification, especially in the development of easy-to-swallow foods. This research offers valuable insights for the development of innovative BSP-based hydrogels for dysphagia management.

Structural characterization and anti-hyperuricemic effect of a mannogalactan from Armillariella tabescens mycelium

Hyperuricemia and its complications caused by purine metabolism disorder continue to occur, which require effective drug treatment with fewer side effects. This study explored the positive effects of a natural homogeneous polysaccharide (AT-W) from the mycelium of Armillariella tabescens in a mouse hyperuricemia model. Structural characterization showed that the average molecular weight of AT-W is 25.6 kDa, and it is composed of mannose, galactose, arabinose, and fucose, with molar percentages of 11.46:70.9:4.96:12.67. The main backbone of AT-W is composed of partially 3-O-methylated →6)-α-Galp-(1→, and the branches are mainly composed of α-Manp-(1→, →3)-α-Fucp-(1→. In vivo bioactivity evaluation showed AT-W could not only reduce serum uric acid levels by inhibiting the activity of xanthine oxidase, upregulating the expression of ABCG2 and OAT1, and downregulating the expression of URAT1 but also have a significant protective effect on renal damage caused by hyperuricemia. These findings indicate that AT-W has therapeutic potential for hyperuricemia diseases.

Influence of Qingzhuan Tea Polysaccharides on F- Adsorption: Molecular Structure, Binding Behavior, and In Vitro and In Vivo Digestion and Metabolism

The high level of fluoride in Qingzhuan tea (QZT) poses a potential health risk to consumers. This study aims to explore the binding behavior of purified Qingzhuan tea polysaccharides (pTPS) and fluoride ions (F-), as well as their regulatory role in the digestion and metabolism of fluoride. The sugar content of pTPS was 94.64 ± 3.01%, with a molecular weight of 7.373 × 104 Da and high homogeneity. The effects of different proportions and environmental conditions on the adsorption of F- by pTPS were investigated. The influence of the complexation of pTPS and F- on the digestion and metabolism of fluoride was explored using an in vitro gastrointestinal digestion model and C57BL/6 mice. The structural alterations of pTPS were observed during simulated gastrointestinal digestion. Furthermore, pTPS were found to reduce serum fluoride levels and inhibit accumulation in major organs and tissues, especially the heart, liver, kidneys, muscles, and femur. This study investigated the binding pattern between fluorine and pTPS and its influence on the digestion and absorption of fluorine, providing a promising potential for pTPS as a bioadsorbent of fluorine to alleviate the toxicity of fluorine in QZT, which laid a theoretical foundation for the safety of consumption of QZT.

A novel antidepressant homogeneous polysaccharide YLP-1 from Millettia pulchra ameliorates tryptophan metabolism and SCFAs through modulating gut microbiota

The root of Millettia pulchra (YLS) has been traditionally used as a folk medicine for the treatment of depression and insomnia in the Zhuang nationality of China, and its polysaccharides have potential antidepressant effect. In this study, a novel homogeneous polysaccharide (YLP-1) was purified from the crude polysaccharides of YLS, and it is mainly composed of glucose, arabinose and mannose with molar ratio of 87.25%, 10.77%, and 1.98%, respectively. YLP-1 is a novel α-glucan with the backbone of 1,4-Glcp and branched at C6 of 1,4,6-Glcp to combine 1,4-Manp and 1,5-Araf. The microstructure of YLP-1 displayed a uniform ellipsoidal-like chain morphology and dispersed uniformly in solution. YLP-1 effectively ameliorated depression-like ethological behaviors and restored the decreased catecholamine levels in chronic variable stress (CVS)-induced depression rats. Additionally, it significantly improved the disturbance of gut microbiota induced by CVS stimuli, particularly affecting bacteria that produce short-chain fatty acids (SCFAs), such as bacteria species Lactobacillus spp.. In vitro fermentation study further confirmed that YLP-1 intake could promote SCFAs production by Lactobacillus spp. YLP-1 also mitigated the disruption of tryptophan metabolites in urine and serum. These findings provide evidences for the further development of YLP-1 as a macromolecular antidepressant drug.

Biofortification of Mushrooms: A Promising Approach

Mushrooms exhibit a broad spectrum of pharmacological activities and are widely used for medical purposes and in nutrition. Numerous bioactive metabolites are responsible for these activities. Their distribution and biological effects differ depending on the fungal species and their chemical composition. Biofortification is a sustainable process that aims to improve the nutritional profile of food crops, as most of them are low in key nutrients. This review aims to delve into the process of fungal biofortification and review the most commonly used elements and species. Through biofortification, it is possible to combat hidden hunger, which affects as many as 2 billion people worldwide. "Hidden hunger" is a phenomenon in which the organism lacks the minerals and vitamins needed for development, growth, and good overall health. Mushrooms are increasingly being considered for biofortification due to their ability to accumulate various elements (both micro- and macroelements).

Degradation of Natural Undaria pinnatifida into Unsaturated Guluronic Acid Oligosaccharides by a Single Alginate Lyase

Here, we report on a bifunctional alginate lyase (Vnalg7) expressed in Pichia pastoris, which can degrade natural Undaria pinnatifida into unsaturated guluronic acid di- and trisaccharide without pretreatment. The enzyme activity of Vnalg7 (3620.00 U/mL-culture) was 15.81-fold higher than that of the original alg (228.90 U/mL-culture), following engineering modification. The degradation rate reached 52.75%, and reducing sugar reached 30.30 mg/mL after combining Vnalg7 (200.00 U/mL-culture) and 14% (w/v) U. pinnatifida for 6 h. Analysis of the action mode indicated that Vnalg7 could degrade many substrates to produce a variety of unsaturated alginate oligosaccharides (AOSs), and the minimal substrate was tetrasaccharide. Site-directed mutagenesis showed that Glu238, Glu241, Glu312, Arg236, His307, Lys414, and Tyr418 are essential catalytic sites, while Glu334, Glu344, and Asp311 play auxiliary roles. Mechanism analysis revealed the enzymatic degradation pattern of Vnalg7, which mainly recognizes and attacks the third glycosidic linkage from the reducing end of oligosaccharide substrate. Our findings provide a novel alginate lyase tool and a sustainable and commercial production strategy for value-added biomolecules using seaweeds.

Novel glucomannan-like polysaccharide from Lycium barbarum L. ameliorates renal fibrosis via blocking macrophage-to-myofibroblasts transition

The macrophage to myofibroblasts transition (MMT) has been reported as a newly key target in renal fibrosis. Lycium barbarum L. is a traditional Chinese medicine for improving renal function, in which its polysaccharides (LBPs) are the mainly active components. However, whether the role of LBPs in treating renal fibrosis is related to MMT process remain unclear. The purpose of this study was to explore the relationship between the regulating effect on MMT process and the anti-fibrotic effect of LBPs. Initially, small molecular weight LBPs fractions (LBP-S) were firstly isolated via Sephadex G-100 column. Then, the potent inhibitory effect of LBP-S on MMT process was revealed on bone marrow-derived macrophages (BMDM) model induced by TGF-β. Subsequently, the chemical structure of LBP-S was elucidated through monosaccharide, methylation and NMR spectrum analysis. In vivo biodistribution characteristics studies demonstrated that LBP-S exhibited effectively accumulation in kidney via intraperitoneal administration. Finally, LBP-S showed a satisfactory anti-renal fibrotic effect on unilateral ureteral obstruction operation (UUO) mice, which was significantly reduced following macrophage depletion. Overall, our findings indicated that LPB-S could alleviate renal fibrosis through regulating MMT process and providing new candidate agents for chronic kidney disease (CKD) related fibrosis treatment.

The carrier function and inhibition effect on benign prostatic hyperplasia of a glucan from Epimedium brevicornu Maxim

Epimedium, a traditional Chinese medicine commonly used as a dietary supplement, contains polysaccharides and flavonoids as its main bioactive ingredients. In this study, a neutral homogeneous polysaccharide (EPSN-1) was isolated from Epimedium brevicornu Maxim. EPSN-1 was identified as a glucan with a backbone of →4)-α-D-Glcp-(1→, branched units comprised α-D-Glcp-(1→6)-α-D-Glcp-(1→, β-D-Glcp-(1→6)-β-D-Glcp-(1→ and α-D-Glcp-(1→ connected to the C6 position of backbone. The conformation of EPSN-1 in aqueous solution indicated its potential to form nanoparticles. This paper aims to investigate the carrier and pharmacodynamic activity of EPSN-1. The findings demonstrated that, on the one hand, EPSN-1, as a functional ingredient, may load Icariin (ICA) through non-covalent interactions, improving its biopharmaceutical properties such as solubility and stability, thereby improving its intestinal absorption. Additionally, as an effective ingredient, EPSN-1 could help maintain the balance of the intestinal environment by increasing the abundance of Parabacteroides, Lachnospiraceae UGG-001, Anaeroplasma, and Eubacterium xylanophilum group, while decreasing the abundance of Allobaculum, Blautia, and Adlercreutzia. Overall, this dual action of EPSN-1 sheds light on the potential applications of natural polysaccharides, highlighting their dual role as carriers and contributors to biological activity.

Extraction, Purification, Sulfated Modification, and Biological Activities of Dandelion Root Polysaccharides

In this study, polysaccharides were extracted at a rate of 87.5% ± 1.5% from native dandelion roots, and the dandelion root polysaccharides (DRPs) were then chemically modified to obtain sulfated polysaccharides (SDRPs) with a degree of substitution of 1.49 ± 0.07. The effects of modification conditions, physicochemical characterizations, structural characteristics, antioxidant properties, hypoglycemic activity, and proliferative effects on probiotics of DRP derivatives were further investigated. Results showed that the optimum conditions for sulfation of DRPs included esterification reagents (concentrated sulfuric acid: n-butanol) ratio of 3:1, a reaction temperature of 0 °C, a reaction time of 1.5 h, and the involvement of 0.154 g of ammonium sulfate. The DRPs and SDRPs were composed of six monosaccharides, including mannose, glucosamine, rhamnose, glucose, galactose, and arabinose. Based on infrared spectra, the peaks of the characteristic absorption bands of S=O and C-O-S appeared at 1263 cm-1 and 836 cm-1. Compared with DRPs, SDRPs had a significantly lower relative molecular mass and a three-stranded helical structure. NMR analysis showed that sulfated modification mainly occurred on the hydroxyl group at C6. SDRPs underwent a chemical shift to higher field strength, with their characteristic signal peaking in the region of 1.00-1.62 ppm. Scanning electron microscopy (SEM) analysis indicated that the surface morphology of SDRPs was significantly changed. The structure of SDRPs was finer and more fragmented than DRPs. Compared with DRPs, SDRPs showed better free radical scavenging ability, higher Fe2+chelating ability, and stronger inhibition of α-glucosidase and α-amylase. In addition, SDRPs had an excellent promotional effect on the growth of Lactobacillus plantarum 10665 and Lactobacillus acidophilus. Therefore, this study could provide a theoretical basis for the development and utilization of DRPs.

Preparation, characterization and evaluation of microwave-assisted synthesized selenylation Codonopsis pilosula polysaccharides

In this work, the selenylation Codonopsis pilosula polysaccharide (Se-CPPS) were synthesized using an optimized microwave-assisted method. Then, physicochemical properties, including molecular weight, particle size, valence state of selenium, antioxidant capacity, release mechanism of selenium under gastrointestinal conditions, as well as their effects on HT-29 cell viability were comprehensively investigated. The results demonstrated that Se-CPPS with the highest selenium content (21.71 mg/g) was synthesized using 0.8% nitric acid concentration under microwave conditions of 90 min at 70 °C. FTIR and XPS analysis revealed that Se was bound to the polysaccharide chain in the form of O-Se-O and O-H···Se, with a valence state of either 0 or +4. In vitro investigations on antioxidant activity and selenium release capacity indicated that selenization not only enhanced the antioxidant activity of CPPS but also endowed Se-CPPS with robust selenium release capability in simulated gastric digestion. The effects of Se-CPPS on HT-29 cells was further investigated by CCK-8 method. The results showed that the selenide modification effectively reduced the toxicity of Na2SeO3 and enhanced the viability of CPPS. The findings of this study offer valuable methodological guidance for the synthesis of Se-polysaccharides with superior functional properties.

The relationship between polysaccharide structure and its antioxidant activity needs to be systematically elucidated

Polysaccharides have a wide range of applications due to their excellent antioxidant activity. However, the low purity and unclear structure of polysaccharides have led some researchers to be skeptical about the antioxidant activity of polysaccharides. The current reports on the structure-activity relationship of polysaccharides are sporadic, so there is an urgent need to systematically summarize the antioxidant effects of polysaccharides with clear structures and the relationships between the structures to provide a scientific basis for the development and application of polysaccharides. This paper will systematically elucidate the structure-activity relationship of antioxidant polysaccharides, including the molecular weight, monosaccharide composition, glycosidic linkage, degree of branching, advanced conformation and chemical modification. For the first time, the antioxidant activity of polysaccharides is related to their chemical structure through histogram and radar map, and further studies using principal component analysis and cluster analysis. We critically discussed how the source, chemical structure and chemically modified groups of polysaccharides significantly contribute to their antioxidant activity and summarized the current research status and shortcomings of the structure-activity relationship of antioxidant polysaccharides. This review provides a theoretical basis and new perspective for further research on the structure-activity relationship of antioxidant polysaccharides and the development of natural antioxidants.

Selenosugar, selenopolysaccharide, and putative selenoflavonoid in plants

Selenium (Se) is a naturally occurring essential micronutrient that is required for human health. Selenium supports cellular antioxidant defense and possesses bioeffects such as anti-inflammation, anti-cancer, anti-diabetic, and cardiovascular and liver protective effects arising from Se-enhanced cellular antioxidant activity. Past studies on Se have focused on elucidating Se speciation in foods, biofortification strategies to produce Se-enriched foods to address Se deficiency in the population, and the biochemical activities of Se in health. The bioavailability and toxicity of Se are closely correlated to its chemical forms and may exhibit varying effects on body physiology. Selenium exists in inorganic and organic forms, in which inorganic Se such as sodium selenite and sodium selenate is more widely available. However, it is a challenge for safe and effective supplementation considering inorganic Se low bioavailability and high cytotoxicity. Organic Se, by contrast, exhibits higher bioavailability and lower toxicity and has a more diverse composition and structure. Organic Se exists as selenoamino acids and selenoproteins, but recent research has provided evidence that it also exists as selenosugars, selenopolysaccharides, and possibly as selenoflavonoids. Different food categories contain various Se compounds, and their Se profiles vary significantly. Therefore, it is necessary to delineate Se speciation in foods to understand their impact on health. This comprehensive review documents our knowledge of the recent uncovering of the existence of selenosugars and selenopolysaccharides and the putative evidence for selenoflavonoids. The bioavailability and bioactivities of these food-derived organic Se compounds are highlighted, in addition to their composition, structural features, and structure-activity relationships.

Structural characterization, molecular dynamic simulation, and conformational visualization of a water-soluble glucan with high molecular weight from Gastrodia elata Blume

Polysaccharides have been widely used in the development of natural drugs and health food. However, polysaccharide characterization lags due to inherently complicated features and the limitations of existing detection approaches. We aimed to provide new insight into the fine structure and conformational visualization of polysaccharides from Gastrodia elata Blume, a medicinal and edible plant. A water-soluble polysaccharide (GEP2-6) with the high molecular weight of 2.7 × 106 Da was first obtained, and its purity reached 99.2 %. Chemical and spectroscopic analyses jointly revealed that GEP2-6 was a glucan linked by α-(1 → 4) and α-(1 → 6) glycosidic bonds. After enzymolysis, the local structure of GEP2-6 included α-1,4-Glcp, α-1,6-Glcp, α-1,4,6-Glcp, and α-1-Glcp at a molar ratio of 31.27∶1.32∶1.08∶0.93. The glycosidic linkage pattern of repeating units was further simulated by a glycan database and spatial examination software. The good dissolution performance was interpreted by dynamics simulation and practical molecular characteristics. Spherical flexible chains and the porous stable conformation were corroborated using atomic force microscopy. In addition, GEP2-6 could effectively scavenge DPPH and hydroxyl radicals as a promising natural antioxidant. These efforts will contribute to the expansion of clinical applications of this G. elata polysaccharide and the structural elucidation for macromolecular polysaccharides combined with traditional and modern analysis techniques.

Structures, physical properties and antibacterial activity of silver nanoparticles of Lactiplantibacillus plantarum exopolysaccharide

Lactic acid bacteria (LAB) exopolysaccharide (EPS) has good water absorption, high viscosity, good stability, so it was widely used in probiotics fields. In this study, EPS-producing LAB strain Lactiplantibacillus plantarum HDL-03 was isolated and identified. Moreover, the HDL-03 EPS was used as a stabilizer and mixed with AgNO3 to synthesize a novel nanoparticle AgNPs whose structure and properties were explored. The monosaccharide composition and molecular weight indicated that HDL-03 EPS was a heteropolysaccharide composed of mannose and glucose. Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) spectroscopy analysis and methylation results jointly proved it was a heteropolysaccharide containing 1,3-Manp and 1,6-Glcp. The X-Ray diffraction (XRD) results showed that this EPS has an amorphous structure, while the synthesized AgNPs have crystalline properties. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results indicated EPS had a smooth and dense sheet structure, while the surface of AgNPs became rougher and large holes appeared after synthesis. Zeta particle size analysis suggested that the particle size of AgNPs increased by 36.63 nm compared to HDL-03 EPS. FT-IR analysis exhibited that the position of the characteristic peaks of AgNPs changed. The OH moving from a wavelength of 3388.49 cm-1 to a wavelength of 3316.79 cm-1 and telescopic vibration peak changed from 1356.07 cm-1 to 1344.22 cm-1. A plate inhibition test revealed the effect of different concentrations of EPS and AgNO3 synthesized AgNPs on the diameter of inhibition circle produced by the indicator bacteria Escherichia coli and Staphylococcus aureus. Furthermore, AgNPs were applied to the indicator bacteria, which the minimum inhibitory concentration (MIC), time-inhibitory curve, and changes in extracellular conductivity, nucleic acids, proteins, ATP, and lactate dehydrogenase (LDH) levels were determined. The AgNPs inhibited the growth of E. coli and S. aureus and exhibited outstanding antimicrobial properties. With the increase of treatment time, the degree of cell membrane damage increased, the permeability enhanced, and the intracellular substances leaked. These results indicate that HDL-03 EPS has good potential for applications in the production of food packaging, antimicrobials, catheters, textiles and coatings.

Impact of internal metal ions in tea polysaccharides on antioxidant potential and suppression of cancer cell growth

Four kinds of tea polysaccharides (MBTPS, MGTPS, ZBTPS, ZGTPS) were extracted from Maofeng black tea, Maofeng green tea,Ziyan black tea and Ziyan green tea, and then four tea polysaccharides (RMBTPS, RMGTPS, RZBTPS, RZGTPS) after metal removal were prepared. The physicochemical properties, antioxidant activity and inhibitory activity on cancer cell proliferation of the above polysaccharides were studied. The composition analysis shows that these tea polysaccharides were glycoproteins complexes, composed of a variety of monosaccharides, and the removal of metal ions did not lead to fundamental changes in the composition of polysaccharides. In vitro activity, after removing metal ions, the ABTS free radicals scavenging ability and reducing power of tea polysaccharides were decreased, and the inhibitory effect on proliferation of H22 cells weakened. There was a great correlation between metal elements Al and Ni and biological activity. The results showed that the metal ions in tea polysaccharides, especially Al and Ni, had positive effects on biological activity.

Grifola frondosa polysaccharides: A review on structure/activity, biosynthesis and engineering strategies

Polysaccharides are the main polymers in edible fungi Grifola frondosa, playing a crucial role in the physiology and representing the healthy benefits for humans. Recent efforts have well elucidated the fine structures and biological functions of G. frondosa polysaccharides. The recently-rapid developments and increasing availability in fungal genomes also accelerated the better understanding of key genes and pathways involved in biosynthesis of G. frondosa polysaccharides. Herein, we provide a brief overview of G. frondosa polysaccharides and their activities, and comprehensively outline the complex process, genes and proteins corresponding to G. frondosa polysaccharide biosynthesis. The regulation strategies including strain improvement, process optimization and genetic engineering were also summarized for maximum production of G. frondosa polysaccharides. Some remaining unanswered questions in describing the fine synthesis machinery were also pointed out to open up new avenues for answering the structure-activity relationship and improving polysaccharide biosynthesis in G. frondosa. The review hopefully presents a reasonable full picture of activities, biosynthesis, and production regulation of polysaccharide in G. frondosa.

Immune regulation and inflammation inhibition of Arctium lappa L. polysaccharides by TLR4/NF-κB signaling pathway in cells

Arctium lappa L. polysaccharides (ALP) are important active ingredients of burdocks with various bioactivities. In the present study, a crude polysaccharide was extracted from A. lappa L. roots and purified using DEAE-52 and Sephacryl™ S-400 columns to reach 99 % purity. This neutral polysaccharide contained fructose, glucose, galactose and arabinose in a ratio of 0.675:0.265:0.023:0.016 and had a Mw of 4256 Da. The immunomodulatory activity and intestinal inflammation inhibitory effects of ALP were investigated in in vitro models, including lipopolysaccharide-induced macrophage RAW264.7 and interleukin (IL)-1β-induced colon Caco-2 cells. The results revealed that ALP possessed both antioxidant and anti-inflammatory effects by decreasing nuclear factor-E2-related factor 2 mRNA expression and reactive oxygen species. Furthermore, ALP was found to have inhibitory effects on pro-inflammatory cytokines, including IL-8, IL-6, IL-1β, and tumor necrosis factor-α, as well as inflammatory cytokines, such as intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and monocyte chemoattractant protein-1 by down-regulating the Toll-like receptor 4 (TLR4)/NF-κB (nuclear factor-kappa B signaling) pathway. It indicated that A. lappa L. was an ideal source of bioactive polysaccharides having potential to be developed as functional foods or nutraceuticals to improve immune system and prevent/treat intestinal inflammation.

Physicochemical characterization, digestion profile and gut microbiota regulation activity of intracellular polysaccharides from Chlorella zofingiensis

A number of studies have shown that the polysaccharides from microalgae exhibit diverse biological activities, however, little is known about their digestibility and impact on human gut microbiota. In this study, a simulating digestion and fermentation system were established to investigate the digestibility and fermentation of intracellular polysaccharides from Chlorella zofingiensis (CZIP-S3). The results indicated that CZIP-S3 is a macromolecular polysaccharide composed of mannose, glucose, galactose and rhamnose, consisting of a main chain and two branched repeating units. CZIP-S3 could not be digested in the upper gastrointestinal tract. However, CZIP-S3 could be metabolized into smaller molecules by the gut microbiota. The pH values continuously decrease during fermentation, whereas, the amount of short-chain fatty acids steadily increase. Furthermore, CZIP-S3 could modulate the composition of gut microbiota, via lowering the ratio of Firmicutes/Bacteroidetes and increasing the relative abundance of Bacteroides, Bifidobacterium and Akkermansia. The data suggested that CZIP-S3 could potentially be used as an ingredient for functional foods or prebiotics to improve human health by promoting the relative abundances of beneficial bacteria.

Structural characterization and in vitro anti-colon cancer activity of a homogeneous polysaccharide from Agaricus bisporus

Colon cancer is the third most prevalent cancer and the second most deadly cancer in the world. Anti-colon cancer activity of Agaricus bisporus polysaccharides has not been studied. In this paper, Agaricus bisporus polysaccharides were sequentially extracted by room temperature water, hot water, high pressure hot water, dilute alkaline solution and concentrated alkaline solution. A homogeneous polysaccharide (WAAP-1) was obtained using DEAE Cellulose-52 column. Physicochemical properties, structural characterization and anti-colon cancer activity of WAAP-1 were investigated. The results showed that WAAP-1 was a neutral polysaccharide with molecular weight of 10.1 kDa. The monosaccharide composition was glucose, mannose and galactose with a molar ratio of 84.95:8.97:4.50. The main chain was mainly composed of (1,4)-α-D-Glcp and (1,6)-β-D-Manp. In vitro anti-colon cancer results showed that WAAP-1 could significantly inhibit proliferation of colon cancer cell HT-29. It promoted apoptosis and inhibited epithelial mesenchymal transition of HT-29 by up-regulating the expression of Caspase-3, Bax and E-cadherin proteins and down-regulating the expression of Bcl-2 and Vimentin proteins. The results provided new potential possibilities for the development of novel functional foods or antitumor drugs.

Selenium Modification of Natural Products and Its Research Progress

The selenization of natural products refers to the chemical modification method of artificially introducing selenium atoms into natural products to interact with the functional groups in the target molecule to form selenides. Nowadays, even though scientists in fields involving organic selenium compounds have achieved numerous results due to their continuous investment, few comprehensive and systematic summaries relating to their research results can be found. The present paper summarizes the selenization modification methods of several kinds of important natural products, such as polysaccharides, proteins/polypeptides, polyphenols, lipids, and cyclic compounds, as well as the basic principles or mechanisms of the selenizing methods. On this basis, this paper explored the future development trend of the research field relating to selenized natural products, and it is hoped to provide some suggestions for directional selenization modification and the application of natural active ingredients.

Antioxidant and Immunomodulatory Activities of Polysaccharides from Fermented Wheat Products of Grifola frondosa: In Vitro Methods

Despite the well-known health benefits of Grifola frondosa, there is a lack of understanding regarding the potential antioxidant and immunomodulatory properties of different varieties when fermented with wheat grains. We aimed to explore the potential of G. frondosa-fermented wheat flour as a functional food. Three varieties of G. frondosa (GFA, GFB, and GFC) were fermented with wheat grains for solid-state fermentation. Polysaccharides were extracted and analyzed for total sugar content, monosaccharide composition, Mw profile, antioxidant activity, cytotoxicity, and immunomodulatory properties. Results were evaluated using HPLC, DPPH assay, MTS assay, Griess reagent, and ELISA method. Our study found variations in three different varieties of G. frondosa-fermented wheat polysaccharides. Glucose was the predominant monosaccharide, followed by galactose and mannose. Each variety had a different molecular weight distribution, with GFA-wheat mainly present in fraction II, GFB-wheat in fraction I, and GFC-wheat in fraction III. At a concentration of 1.25 mg/mL, GFA-wheat and GFB-wheat polysaccharides increased DPPH scavenging ability by 76.8% and 58.7%, respectively. The polysaccharides showed no apparent toxic effect and enhanced the production of NO, IL-6, and TNF-α in RAW 246.7 macrophages. GFB-wheat polysaccharides demonstrated remarkable immunomodulatory properties at a concentration of 5 μg/mL. Our study provides a theoretical basis for using G. frondosa in wheat staple agricultural products to improve human health.

Synthesis of Se polysaccharide catalyzed by sulfonic acid functionalized ionic liquids: Synergism effect of anion/cation

The rational design and construction of controllable selenylation strategy are important for the study on the structure-activity relationship of Se polysaccharides. Herein, selenized Artemisia sphaerocephala polysaccharides (SePASs) were synthesized by using sulfonic acid functionalized ionic liquids (SFILs) as catalysts in order to study the regulation of the cation/anion constitute on the selenylation efficiency and Se polysaccharide structure. Impressively, SFILs could promote the efficient substitution of seleno-group on the polysaccharide backbone through the synergistic catalysis by cation/anions (Se content up to 5582.7 μg/g). Further, reaction mechanism and potential dissolution effect was supported by DFT calculation and polarized light microscopy. ¹³C NMR and FT-IR spectra analysis of SePASs exhibited that selenite existed in polysaccharides and the substitution position occured at C-6. SEC-MALLS, monosaccharide composition results revealed that strong acidity of SFILs lead to the driving forces toward low molecular mass polysaccharide fragments and synergistic effect of anion/cations in SFILs (-SO₃H group of cations as proton donor, anions as nucleophile) showed regulation on average molecular mass. In addition, the strong attractions between the seleno-groups generated agglomeration of polysaccharide chain, which was proved by applying AFM analysis. Therefore, this work provided a new insight for manipulate Se content and M_W of Se polysaccharides.

Extraction, Rheological, and Physicochemical Properties of Water-Soluble Polysaccharides with Antioxidant Capacity from Penthorum chinense Pursh

This study aimed to isolate polysaccharides from Penthorum chinense Pursh and evaluate their rheological characteristics, physicochemical properties, and antioxidant activity. The optimal conditions for the maximal extraction yield of Penthorum chinense Pursh polysaccharides (4.05 ± 0.12%) were determined by employing a single-factor test and response surface methodology which included an extraction time of 3 h, a liquid-solid ratio of 20 mL/g, and three separate extraction times. The rheological experiments showcased that the P. chinense polysaccharides exhibited typical shear-thinning behavior, with their apparent viscosity being influenced by various parameters such as concentration, pH, temperature, salt content, and freeze-thaw. The purified polysaccharides (PCP-100), having an average molecular weight of 1.46 × 10⁶ Da, mainly consisted of glucose (18.99%), arabinose (22.87%), galactose (26.72%), and galacturonic acid (21.89%). Furthermore, the PCP-100 exhibited high thermal stability and displayed an irregular sheet-like morphology. Its superior reducing power and free radical scavenging ability implied its significant antioxidant activity in vitro. Collectively, these findings provide important insights for the future application of P. chinense polysaccharides in the food industry.

Structure characterization and biological activities evaluation of two hetero-polysaccharides from Lepista nuda: Cell antioxidant, anticancer and immune-modulatory activities

Polysaccharides LNP-1 and LNP-2 were extracted and purified from Lepista nuda, and their structural characteristics and biological activities were evaluated. The molecular weights of LNP-1 and LNP-2 were determined to be 16,263 Da and 17,730 Da, respectively. The monosaccharide composition analysis showed that LNP-1 and LNP-2 were composed of fucose, mannose, glucose, and galactose in a molar ratio of 1.00:2.42:1.09:4.04 and 1.00:2.39:1.61:4.23, respectively. The structure analysis revealed that these two polysaccharides were mainly composed of T-Fuc, T-Man, T-Glc, 1,6-Glc 1,6-Gal, and 1,2,6-Man, 1,2,6-Gal. Additionally, LNP-2 contained an additional 1,4-Glc glycosidic linkage in comparison to LNP-1. Both LNP-1 and LNP-2 exhibited anti-proliferation effects on A375 cells, but not on HepG2 cells. Furthermore, LNP-2 showed better cellular antioxidant activity (CAA) than LNP-1. RT-PCR results indicated that LNP-1 and LNP-2 could induce macrophages to secrete immune-modulatory factors NO, IL-6, and TNF-α by regulating their mRNA expression. Overall, this study provides a theoretical basis for the further development of the structure-function relationship of polysaccharides from L. nuda.

Structural Characterization and In Vitro Antioxidant, Hypoglycemic and Hypolipemic Activities of a Natural Polysaccharide from Liupao Tea

This study extracted and purified a natural polysaccharide (TPS-5) that has a molecular weight of 48.289 kDa from Liupao tea, a typical dark tea with many benefits to human health. TPS-5 was characterized as a pectin-type acidic polysaccharide. It has a backbone composed of → 2,4)- α- L-Rhap-(1) → 4)- α- D-GalAp-(1) →, with a branch composed of → 5)- α- L-Ara-(1 → 5,3)- α- L-Ara-(1 → 3)- β- D-Gal-(1 → 3,6)- β- D-Galp-(1) →. The in vitro biological activity evaluation illustrated that TPS-5 has free radical scavenging, ferric-ion-reducing, digestive enzyme inhibitory, and bile-salt-binding abilities. These results suggest that TPS-5 from Liupao tea has potential applications in functional foods or medicinal products.

Structural characterization and immunomodulatory activity of a novel polysaccharide from Panax notoginseng

Introduction: Polysaccharides are important components of Panax notoginseng that contribute to its immunomodulatory ability. This study aimed to isolate polysaccharides from notoginseng and investigate the structural feature and potential immunomodulatory activity. Methods: The polysaccharide was isolated from notoginseng by anion exchange and gel permeation chromatography. Its preliminary structure was characterized by Fourier transform infrared (FT-IR) spectroscopy, gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy. The immunoregulatory function was further investigated in cyclophosphamide induced immunosuppressive mice, murine splenocytes and macrophages. Results: A novel homogeneous polysaccharide (PNPB1) was isolated from notoginseng with the molecular weight of 9.3 × 10⁵ Da. Monosaccharide composition analysis indicated that PNPB1 consisted of Glc (88.2%), Gal (9.0%), Ara (2.4%) and trace GlcA, with the major backbone of (1→4)-linked α-Glcp, (1→6)-linked β-Glcp, and (1, 4→6)-linked β-Glcp. The polysaccharide was found to significantly enhance murine body weight, improve their thymus and spleen indices and increase the white blood cells (WBC). PNPB1 significantly enhanced splenic lymphocyte proliferation, NO and cytokine (TNF-α, IL-2, IL-10 and IFN-γ) production, as well as the phagocytosis and TLR2 expression of peritoneal macrophages, indicating potent immunoenhancement effect. Discussion: These findings provide a theoretical basis for elucidating the structure and immune activity of notoginseng polysaccharides.

Physicochemical characterization, rheological properties, and hypolipidemic and antioxidant activities of compound polysaccharides in Chinese herbal medicines by fractional precipitation

This study aimed to investigate the effects of different compound polysaccharides (CPs) extracted from Folium nelumbinis, Fructus crataegi, Fagopyrum tataricum, Lycium barbarum, Semen cassiae, and Poria cocos (w/w, 2:4:2:1:1.5:1) by gradient ethanol precipitation on the physicochemical properties and biological activities. Three CPs (CP50, CP70, and CP80) were obtained and comprised rhamnose, arabinose, xylose, mannose, glucose, and galactose in different proportions. The CPs contained different amounts of total sugar, uronic acid, and proteins. These also exhibited different physical properties, including particle size, molecular weight, microstructure, and apparent viscosity. Scavenging abilities of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), 1,1'-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and superoxide radicals of CP80 were more potent compared to those of the other two CPs. Furthermore, CP80 significantly increased serum levels of high-density lipoprotein cholesterol (HDL-C) and lipoprotein lipase (LPL), and hepatic lipase (HL) activity in the liver, while decreasing the serum levels of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C), along with LPS activity. Therefore, CP80 may serve as a natural novel lipid regulator in the field of medicinal and functional food.

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.

A Se-enriched Grifola frondosa polysaccharide induces macrophage activation by TLR4-mediated MAPK signaling pathway

Se-polysaccharide (Se-GFP-22) from Se-enriched Grifola frondosa has double and cooperative activities of polysaccharide and Se. To delineate the underlying mechanism and signaling cascade involved in immune-stimulatory property of Se-GFP-22, the production of cellular mediators and key proteins in signaling pathway was examined. Results showed that Se-GFP-22 exhibited no cytotoxic and had a high capacity to promote macrophage phagocytosis, up-regulate interleukin-2 (IL-2), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and nitric oxide (NO) productions, as well as the relative messenger RNA (mRNA) expressions. In Se-GFP-22-induced macrophages, intracellular superoxide dismutase (SOD) activity was significantly increased to protect cells from oxidative injury. However, Se-GFP-22 induced macrophage activation was suppressed when the toll-like receptor 4 (TLR4) signaling pathway was blocked by a specific TLR4 inhibitor. According to the western blot analysis and the use of specific inhibitors against the mitogen-activated protein kinases (MAPK) signaling pathway, we speculated that Se-GFP-22 activated RAW264.7 macrophages through the TLR4-mediated MAPK signaling pathway. This study provides a molecular basis for the potential of Se-GFP-22 as a novel immune-stimulatory agent.

A new polysaccharide from Hawk tea: Structural characterization and immunomodulatory activity associated with regulating gut microbiota

In this study, a novel 28.6 kDa acidic polysaccharide (HTP-1), containing → 4)-GalpA-(1→, →2)-Rhap-(1 → and → 3,6)-Galp-(1 → residues as the backbone, analogous to pectin, was isolated from mature Hawk tea leaves. HTP-1 exhibited significant immunoregulatory activities on CTX-induced immunosuppressed mice in a dose-depend manner by alleviating jejunum injury and improving the levels of immune organ indexes, cytokines and immunoglobulins. Moreover, HTP-1 supplementation boosted the content of SCFAs, altered the intestinalmicrobiota composition, and raised the abundances of beneficial bacteria Muribaculaceae, Lactobacillaceae, Bacteroidaceae, Prevotellaceae and Ruminococcaceae, which showed a strong positive correlation with most immune indicators. The current findings suggested that the immunomodulatory action of HTP-1 might rely on the regulation of the gut microbiota, and these results may also serve as a foundation for the future exploitation of HTP-1 as functional foods.

Characterization and Comparison of Bioactive Polysaccharides from Grifola frondosa by HPSEC-MALLS-RID and Saccharide Mapping Based on HPAEC-PAD

Grifola frondosa polysaccharides (GFPs) from different regions in China were characterized and compared using HPSEC-MALLS-RID and saccharide mapping based on HPAEC-PAD analysis for achieving and improving its quality control. The results showed that HPSEC chromatograms and molecular weight distributions of GFPs were similar. The average contents of each polysaccharide fraction (Peaks 1, 2, and 3) showed that Peak 3 was the main component and much higher than the other two polysaccharide fractions, which also contained protein. The result of saccharide mapping showed that α-1,4-glycosidic, β-1,4-glycosidic and few β-1,3-glycosidic linkages were existed in GFPs. The similarity result showed that HPAEC-PAD fingerprints of the oligosaccharide fragments after hydrolysis by endoglycosidase were certainly different, especially α-amylase with a mean similar index of only 0.781 ± 0.207. The result of hierarchical cluster analysis (HCA) showed that different batches of GFPs from China can be divided into different clusters. Furthermore, immune-enhancing activity based on RAW 264.7 cells showed significant differences among different GFPs. Based on grey relational analysis (GRA), the fractions of Peak 3 were regarded as the major contributors to its immuno-enhancing activity in GFPs. Overall, the implications from these results were found to be stable, comprehensive, and valid for improving the quality control of GFPs.

Highly Efficient Biotransformation and Production of Selenium Nanoparticles and Polysaccharides Using Potential Probiotic Bacillus subtilis T5

Selenium is an essential microelement required for human health. The biotransformation of selenium nanoparticles has attracted increasing attention in recent years. However, little of the literature has investigated the comprehensive evaluation of the strains for practical application and the effect on the functional properties in the existence of Se. The present study showed the selenite reduction strain Bacillus subtilis T5 (up to 200 mM), which could produce high yields of selenium polysaccharides and selenium nanoparticles in an economical and feasible manner. Biosynthesized selenium nanoparticles by B. subtilis T5 were characterized systematically using UV-vis spectroscopy, FTIR, Zeta Potential, DLS, and SEM techniques. The biosynthesized SeNPs exhibited high stability with small particle sizes. B. subtilis T5 also possessed a tolerance to acidic pH and bile salts, high aggregation, negative hemolytic, and superior antioxidant activity, which showed excellent probiotic potential and can be recommended as a potential candidate for the selenium biopharmaceuticals industry. Remarkably, B. subtilis T5 showed that the activity of α-amylase was enhanced with selenite treatment to 8.12 U/mL, 2.72-fold more than the control. The genus Bacillus was first reported to produce both selenium polysaccharides with extremely high Se-content (2.302 g/kg) and significantly enhance the activity to promote α-amylase with selenium treatment. Overall, B. subtilis T5 showed potential as a bio-factory for the biosynthesized SeNPs and organ selenium (selenium polysaccharide), providing an appealing perspective for the biopharmaceutical industry.

Optimisation of the production of a selenium-enriched polysaccharide from Cordyceps cicadae S1 and its structure and antioxidant activity

The fermentation medium of a newly identified Cordyceps cicadae S1 was optimized by response surface methodology, with the optimal medium containing sucrose (80 g/L), yeast powder (60 g/L), KH₂PO₄ (5 g/L), MgSO₄·7H₂O (1 g/L) and Na₂SeO₃ (0. 1 g/L). Under these conditions, the extracellular polysaccharide yield was 8.09 g/L. A novel selenium-enriched polysaccharide (PACI-1) was isolated from Cordyceps cicadae, purified and identified as a homofructose polysaccharide with a low average molecular weight of 9.95 × 10³ Da. The fine structure of PACI-1 was analyzed using NMR, CD, and AFM. Additionally, the in vitro antioxidant results showed that the PACI-1 had stronger antioxidant capacity than natural polysaccharides. These results provided a candidate strain for producing selenium polysaccharide and a new polysaccharide from C. cicadae, which showed good antioxidant activity.

Antioxidant activity and cytotoxicity of exopolysaccharide from mushroom Hericium coralloides in submerged fermentation

Mushrooms of the genus Hericium spp. represent a series of delicious edible mushrooms with medicinal value. Here, for the first time, the species native to Iran, the mushroom Hericium coralloides, was collected in Mazandaran province, identified, and registered with the NCBI under accession number MW136052. The production of exopolysaccharides (EPS) in submerged culture was optimized using the response surface method. Among the physicochemical and culture medium conditions tested, rotation speed and concentration of maltose and peptone of soybean significantly affected the production of EPS. The proposed model predicts maximum EPS production (0.13 g/L) at 50 g/L maltose, 3 g/L soy peptone, and 1 g/L yeast extract, pH = 6.5, 200 rpm, inoculum at 5% v/v, and 22 °C. The molecular weight of the EPS chains was 413 and 1578 Da. EPS has antioxidant action (EC50 = 6.59 mg/mL) and cytotoxic activity against cancer cells. The viability of AGS and MKN-45 cancer cell lines declined to 20 and 30% after 48 h of the EPS treatment. H. coralloides EPS could be considered a natural dietary anti-cancer supplement. Further studies are necessary to understand the mechanism of the H. coralloides EPS activity on the cell cycle of cancer cells and to prove its action in vivo.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13399-022-03386-0.