Chain conformation and immunomodulatory activity of a hyperbranched polysaccharide from Cordyceps sinensis

Impact of molecular weight and gastrointestinal digestion on the immunomodulatory effects of Lycium barbarum polysaccharides

In traditional Chinese medicine, Lycium barbarum is of rich medicinal value, and its polysaccharides are particularly interesting due to their significant pharmacological effects and potential health benefits. This study investigated the immunomodulatory effects of Lycium barbarum polysaccharides (LBPs) by examining their interaction with the TLR4/MD-2 complex and the impacts of gastrointestinal digestion on these interactions. We discovered that the affinity binding of LBPs for TLR4/MD-2 and their cytokine induction capability are influenced by molecular weight, with medium-sized LBPs (100-300 kDa) exhibiting stronger binding affinity and induction capability. Conversely, LBPs smaller than 10 kDa showed reduced activity. Additionally, the content of arabinose and galactose within the LBPs fractions was found to correlate positively with both receptor affinity and cytokine secretion. Simulated gastrointestinal digestion resulted in the degradation of LBPs into smaller fragments that are rich in glucose. Although these fragments exhibited decreased binding affinity to the TLR4/MD-2 complex, they maintained their activity to promote cytokine production. Our findings highlight the significance of molecular weight and specific monosaccharide composition in the immunomodulatory function of LBPs and emphasize the influence of gastrointestinal digestion on the effects of LBPs. This research contributes to a better understanding of the mechanisms underlying the immunomodulatory effects of traditional Chinese medicine polysaccharides and their practical application.

Natural polysaccharides and their derivatives targeting the tumor microenvironment: A review

Polysaccharides have gained attention as valuable supplements and natural medicinal resources, particularly for their anti-tumor properties. Their low toxicity and potent anti-tumor effects make them promising candidates for cancer prevention and treatment. The tumor microenvironment is crucial in tumor development and offers potential avenues for novel cancer therapies. Research indicates that polysaccharides can positively influence the tumor microenvironment. However, the structural complexity of most anti-tumor polysaccharides, often heteropolysaccharides, poses challenges for structural analysis. To enhance their pharmacological activity, researchers have modified the structure and properties of natural polysaccharides based on structure-activity relationships, and they have discovered that many polysaccharides exhibit significantly enhanced anti-tumor activity after chemical modification. This article reviews recent strategies for targeting the tumor microenvironment with polysaccharides and briefly discusses the structure-activity relationships of anti-tumor polysaccharides. It also summarises the main chemical modification methods of polysaccharides and discusses the impact of chemical modifications on the anti-tumor activity of polysaccharides. The review aims to lay a theoretical foundation for the development of anti-tumor polysaccharides and their derivatives.

Isolation, purification, and structural characterization of polysaccharides from Codonopsis pilosula and its therapeutic effects on non-alcoholic fatty liver disease in vitro and in vivo

Codonopsis pilosula is a famous edible and medicinal plants, in which polysaccharides are recognized as one of the important active ingredients. A neutral polysaccharide (CPP-1) was purified from C. pilosula. The structure was characterized by HPSEC-MALLS-RID, UV, FT-IR, GC-MS, methylation analysis, and NMR. The results showed that CPP-1 was a homogeneous pure polysaccharide, mainly containing fructose and glucose, and a small amount of arabinose. Methylation analysis showed that CPP-1 composed of →1)-Fruf-(2→, Fruf-(1→ and Glcp-(1→ residues. Combined the NMR results the structure of CPP-1 was confirmed as α-D-Glcp-(1 → [2)-β-D-Fruf-(1 → 2)-β-D-Fruf-(1]26 → 2)-β-D-Fruf with the molecular weight of 4.890 × 103 Da. The model of AML12 hepatocyte fat damage was established in vitro. The results showed that CPP-1 could increase the activity of SOD and CAT antioxidant enzymes and reduce the content of MDA, thus protecting cells from oxidative damage. Subsequently, the liver protective effect of CPP-1 was studied in the mouse model of nonalcoholic fatty liver disease (NAFLD) induced by the high-fat diet. The results showed that CPP-1 significantly reduced the body weight, liver index, and body fat index of NAFLD mice, and significantly improved liver function. Therefore, CPP-1 should be a potential candidate for the treatment of NAFLD.

Metabolite profiling and antioxidant capacity of natural Ophiocordyceps gracilis and its cultures using LC-MS/MS-based metabolomics: Comparison with Ophiocordyceps sinensis

INTRODUCTION

Ophiocordyceps gracilis is an entomopathogenic fungus and a precious traditional Chinese medicine with similar medicinal properties to Ophiocordyceps sinensis. However, information on the metabolite profiles of natural O. gracilis and its cultures is lacking, which limits their utilization.

OBJECTIVE

The metabolic variations and antioxidant activities of O. gracilis cultures and natural O. gracilis were analyzed to evaluate the nutritional and medicinal value of O. gracilis and its cultures.

METHOD

The metabolite profiles of O. gracilis cultures (fruiting bodies and aerial mycelia), natural O. gracilis, and natural O. sinensis were compared by LC-MS/MS coupled with multivariate data analysis. Furthermore, their antioxidant activities were evaluated based on their DPPH• , ABTS•+ , and • OH scavenging abilities.

RESULTS

A total of 612 metabolites were identified, and the metabolic compositions of the four Cordyceps samples were similar, with differences observed in the levels of some metabolites. There were 126 differential metabolites between natural O. gracilis and natural O. sinensis, among which fatty acids, carbohydrates, and secondary metabolites are predominant in natural O. gracilis. Furthermore, 116 differential metabolites between O. gracilis cultures and natural Cordyceps were identified, with generally higher levels in O. gracilis cultures than in natural Cordyceps. O. gracilis cultivated fruiting bodies exhibited the strongest antioxidant capacity among Cordyceps samples. Additionally, 46 primary and 24 secondary differential metabolites contribute to antioxidant activities.

CONCLUSION

This study provides a reference for the application of natural O. gracilis and its cultures in functional food and medicine from the perspective of metabolites and antioxidant capacity.

Comparative study on chain conformations, physicochemical and rheological properties of three acidic polysaccharides from Opuntia dillenii Haw. fruits

In this study, three acidic polysaccharides (OFPP-1, OFPP-2 and OFPP-3) were isolated from the pulps of Opuntia dillenii Haw. fruits, and their chain conformations, physicochemical and rheological properties were investigated. The molecular weight and conformational parameters (Mw, Mn, Mz, Rg and Rh) of OFPPs in 0.1 M NaNO3 solution were detected by HPSEC-MALLS-RI. In addition, based on the parameters ρ and v, it was concluded that these three polysaccharide chains exhibited sphere-like conformation in 0.1 M NaNO3 solution, which was consistent with AFM and TEM observations. Furthermore, the Congo Red experiment showed that OFPP-2 had a triple-helix structure, which may be conducive to its biological activity. This study also found that OFPPs were semi-crystalline structures with high thermal and pH stability. The rheological analyses indicated that the apparent viscosity of OFPPs solutions exhibited concentration-, temperature-, and pH-dependence, and the viscoelasticity of them was affected by molecular characteristics and concentration. The results of this study are helpful to elucidate the structure-activity relationship of OFPPs. Moreover, this study can provide theoretical reference for the application of OFPPs as bioactive ingredients or functional materials in the food, pharmaceutical and cosmetic industries and the development and utilization of the O. dillenii Haw. fruits resource.

Effect of free radicals on rheological properties, antioxidant activity, and molecular conformation of chitosan under solution pulsed plasma process based on radical scavengers

Radical scavengers were employed to evaluate the influence of various active species (•OH, •O, and H2O2) on the rheological properties, antioxidant activity, and molecular conformation of chitosan under solution plasma process (SPP) degradation. ESR analysis showed that •OH and •O radicals played important roles in SPP degradation. The results of rheological properties and antioxidant activity indicated that the •OH scavenger (tert-butanol), •O scavenger (1, 4-benzoquinone), and H2O2 scavenger (MnO2) remarkably inhibited the decrease of G' and G" of the degraded chitosan, the formation of gel structure, and the increase of antioxidant activity. The analysis of molecular conformation of the chitosan by particle size analysis, atomic force microscopy (AFM), and high performance size exclusion chromatography coupled with multi-angle laser light scattering (HPSEC-MALLS) revealed that the decrease of particle size, molecular aggregation, and molecular weight of chitosan was inhibited after the addition of radical scavengers. An evident effect of radical scavengers on the hard sphere conformation of chitosan was observed. It was found that the above effects were strongly dependent on the scavenger concentration. These results proved that •OH, •O, and H2O2 played important roles in SPP treatment. For the rheological properties and molecular conformation, H2O2 exhibited the greatest impact. For the antioxidant activity and molecular weight, •OH presented the biggest influence. Besides, •O expressed the weakest effect. This study will be beneficial to reveal the action mechanisms of SPP technology to the degradation of chitosan.

An authentic assessment method for cordyceps sinensis

Cordyceps Sinensis, renowned for its diverse pharmacological properties and the rarity of its natural species, faces significant challenges due to rampant adulteration by counterfeit products. Consequently, there is a crucial need to reliably identify Cordyceps species to ensure their quality and efficacy. While current analytical techniques predominantly rely on LC-MS, there remains a notable deficiency and substantial demand for the development of a unified, reproducible, and fast method suitable for commercial applications. In this study, we employed a cost-effective and straightforward approach utilizing headspace GC-MS to authenticate Cordyceps sinensis. This method enables the comprehensive analysis of the chemical profile, facilitating the identification of quality and authenticity in Cordyceps samples. Through a comparative analysis of the chemical profiles of seven authentic Cordyceps samples with seven other Cordyceps samples, we propose a Quality Assessment System for Authentic Cordyceps, encompassing the following criteria: 1) the presence of 29 compounds commonly found in authentic Cordyceps within the chemical profile, and 2) the area ratio of 3-methylbutanal to 2-methylbutanal falling within the range of 2.09-3.01. This method exhibits considerable promise as a standardized, reproducible, and expeditious technique for the quality assessment and authentication of Cordyceps.

Structural characterization of polysaccharide fractions in areca (Areca catechu L.) inflorescence and study of its immunological enhancement activity in vitro and in vivo

To obtain the structure-function relationship of the polysaccharides derived from areca (Areca catechu L.) inflorescences in the aspect of its immunomodulatory ability, the plant-based polysaccharide was isolated and purified on column chromatography. The purity, primary structure and immune activity of four polysaccharide fractions (AFP, AFP1, AFP2 and AFP2a) were characterized comprehensively. The main chain of AFP2a was confirmed to be composed of → 3,6)-β-D-Galp-(1→, with branch chains linked to the O-3 position on the main chain. The immunomodulatory activity of the polysaccharides was evaluated using the RAW264.7 cells and immunosuppression mice model. It was observed that AFP2a enabled greater NO release (49.72 μmol/L) than other fractions, significantly promoted the phagocytic activity of macrophages, and improved splenocyte proliferation and T lymphocyte phenotype in mice. The present results may shine a light on a new research direction in immunoenhancers and provide a theoretical foundation for the development and application of areca inflorescence.

Cordythiazole A, the first member of thiazole alkaloids from Chinese cordyceps, with α-glucosidase inhibitory activity

Chinese cordyceps, also known as Dong-Chong-Xia-Cao, is widely recognized as a famous precious tonic herb, and used as traditional Chinese medicine for centuries. It is mainly used for regulating the immune system and improving functions of the lung and kidney, with anti-tumor, anti-inflammatory, and anti-diabetic activities. Due to its rarity and preciousness, a few chemical components are isolated and identified. Moreover, most of them are common chemical components and widely distributed in other natural resources, such as nucleosides, sterols, fatty acids, sugar alcohols, and peptides. Therefore, a large number of active substances of Chinese cordyceps is still unclear. During our search for chemical constituents of Chinese cordyceps, a new thiazole alkaloid, cordythiazole A (1), was isolated and identified. Its structure was elucidated by comprehensive spectroscopic analysis and single-crystal X-ray diffraction analysis. This is the first report of the presence of thiazole alkaloid in Chinese cordyceps, which adds a new class of metabolite of Chinese cordyceps. Furthermore, a putative biosynthesis pathway of cordythiazole A was proposed based on possible biogenic precursor, genes, and literatures. In addition, it showed α-glucosidase inhibitory activity with potency close to that of acarbose. The discovery of cordythiazole A with α-glucosidase inhibitory activity adds a new class of potential anti-diabetes ingredient in Chinese cordyceps.

Structure of a highly branched galacturonoglucan from fruits of Schisandra chinensis (Turcz.) Baill

A novel galacturonoglucan, named SCP-1, is isolated and purified from Schisandra chinensis fruits. The structure of SCP-1 is systematically investigated by a combination of monosaccharide compositions, absolute M_w, methylation analysis, partial acid hydrolysis, isoamylase degradations, and nuclear magnetic resonance spectroscopy. The structure of SCP-1 is theoretically described as follows: (i) Glc and GalA in a molar ratio of 17:3; (ii) → 4)-α-Glcp-(1→, →4,6)-α-Glcp-(1→, →3,4,6)-α-Glcp-(1→, α-Glcp-(1→, →4)-α-GalAp-6-OMe-(1→, α-GalAp-6-OMe-(1→, β-Glcp-(1→, →6-)-β-Glcp-(1 → and →3,4)-β-Glcp-(1 → in a molar ratio of 48:5:3:3:10:5:12:5:9; (iii) a repeating unit of →4)-α-Glcp-(1 → as a backbone with branched points at C-3 and C-6, substituted by different types of acidic and neutral side chains to form multiple branches; and (iv) a rigid rod configuration deduced from α value of 1.26 in Mark-Houwink equation ([η] = kM^α). Anti-tumor assay investigated the effects of SCP-1 on human HepG2 cancer cell lines in vitro. This is for the first time to report a galacturonoglucan in S. chinensis fruits.

Integration of Physiological, Transcriptomic and Metabolomic Reveals Molecular Mechanism of Paraisaria dubia Response to Zn2+ Stress

Utilizing mycoremediation is an important direction for managing heavy metal pollution. Zn²⁺ pollution has gradually become apparent, but there are few reports about its pollution remediation. Here, the Zn²⁺ remediation potential of Paraisaria dubia, an anamorph of the entomopathogenic fungus Ophiocordyceps gracilis, was explored. There was 60% Zn²⁺ removed by Paraisaria dubia mycelia from a Zn²⁺-contaminated medium. To reveal the Zn²⁺ tolerance mechanism of Paraisaria dubia, transcriptomic and metabolomic were executed. Results showed that Zn²⁺ caused a series of stress responses, such as energy metabolism inhibition, oxidative stress, antioxidant defense system disruption, autophagy obstruction, and DNA damage. Moreover, metabolomic analyses showed that the biosynthesis of some metabolites was affected against Zn²⁺ stress. In order to improve the tolerance to Zn²⁺ stress, the metabolic mechanism of metal ion transport, extracellular polysaccharides (EPS) synthesis, and microcycle conidiation were activated in P. dubia. Remarkably, the formation of microcycle conidiation may be triggered by reactive oxygen species (ROS) and mitogen-activated protein kinase (MAPK) signaling pathways. This study supplemented the gap of the Zn²⁺ resistance mechanism of Paraisaria dubia and provided a reference for the application of Paraisaria dubia in the bioremediation of heavy metals pollution.

Regulation strategy, bioactivity, and physical property of plant and microbial polysaccharides based on molecular weight

Structural features affect the bioactivity, physical property, and application of plant and microbial polysaccharides. However, an indistinct structure-function relationship limits the production, preparation, and utilization of plant and microbial polysaccharides. Molecular weight is an easily regulated structural feature that affects the bioactivity and physical property of plant and microbial polysaccharides, and plant and microbial polysaccharides with a specific molecular weight are important for exerting their bioactivity and physical property. Therefore, this review summarized the regulation strategies of molecular weight via metabolic regulation; physical, chemical, and enzymic degradations; and the influence of molecular weight on the bioactivity and physical property of plant and microbial polysaccharides. Moreover, further problems and suggestions must be paid attention to during regulation, and the molecular weight of plant and microbial polysaccharides must be analyzed. The present work will promote the production, preparation, utilization, and investigation of the structure-function relationship of plant and microbial polysaccharides based on their molecular weight.

Structural characteristics and gel properties of pectin from citrus physiological premature fruit drop

This study is the first to extract and characterize pectin from citrus physiological premature fruit drop. The extraction yield of pectin reached 4.4 % by acid hydrolysis method. The degree of methoxy-esterification (DM) of citrus physiological premature fruit drop pectin (CPDP) was 15.27 %, indicating it was low-methoxylated pectin (LMP). The monosaccharide composition and molar mass test results showed CPDP was a highly branched macromolecular polysaccharide (β: 0.02, Mw: 2.006 × 10⁵ g/mol) with rich rhamnogalacturonan I domain (50.40 %) and long arabinose and galactose side chain (32.02 %). Based on the fact that CPDP is LMP, Ca²⁺ was used to induce CPDP to form gels. Textural and rheological tests showed that the gel strength and storage modulus of CPDP were higher than commercial citrus pectin (CP) used in this paper due to the lower DM and rich neutral sugar side chains of CPDP. Scanning electron microscope (SEM) results showed CPDP had stable gel network structure.

Structural characterization and immunomodulatory activity of a polysaccharide from finger citron extracted by continuous phase-transition extraction

FCP-2-1, a water-soluble polysaccharide rich in galacturonic acid was isolated by continuous phase-transition extraction and purified with DEAE-52 cellulose and Sephadex G-100 column chromatography from finger citron with essential oil and flavonoids removed. The structural characterization and immunomodulatory activity of FCP-2-1 were further investigated in this work. FCP-2-1 with a M_w and M_n of 1.503 × 10⁴ g/mol and 1.125 × 10⁴ g/mol, respectively, was predominantly composed of galacturonic acid, galactose, and arabinose in a molar ratio of 0.685: 0.032: 0.283. The main linkage types of FCP-2-1 were proved to be →5)-α-L-Araf-(1→ and →4)-α-D-GalpA-(1→ based on methylation and NMR analysis. Moreover, FCP-2-1 was demonstrated to have significant immunomodulatory effects on macrophages in vitro by improving the cell viability, and enhancing phagocytic activity and secretion of NO and cytokines (IL-1β, IL-6, IL-10 and TNF-α), indicating that FCP-2-1 could be used as a natural agent in immunoregulation functional foods.

The invasion process of the entomopathogenic fungus Ophiocordyceps sinensis into the larvae of ghost moths (Thitarodes xiaojinensis) using a GFP-labeled strain

Chinese cordyceps is a well-known and valuable traditional Chinese medicine that forms after Ophiocordyceps sinensis parasitizes ghost moth larvae. The low natural infection rate of O. sinensis limits large-scale artificial cultivation of Chinese cordyceps, and the invasion process is unclear. To investigate the temporal and spatial regulation when O. sinensis enters ghost moths, we constructed an O. sinensis transformant that stably expresses green fluorescent protein (GFP). Inoculating Thitarodes xiaojinensis larvae with a high concentration of GFP-labeled O. sinensis, we observed that O. sinensis conidia could adhere to the host cuticle within 2 days, germinate penetration pegs within 4 days, and produce blastospores in the host hemocoel within 6 days. The reconstructed three-dimensional (3D) structures of the invasion sites showed that penetration pegs germinated directly from O. sinensis conidia at the joining site with the larval cuticle. Differentiated appressoria or hyphae along the host epicuticle are not required for O. sinensis to invade ghost moths. Overall, the specific invasion process of O. sinensis into its host is clarified, and we provided a new perspective on the invasion process of entomopathogenic fungi.

Recent advances in qualitative and quantitative analysis of polysaccharides in natural medicines: A critical review

Polysaccharides from natural medicines, being safe and effective natural mixtures, show great potential to be developed into botanical drugs. However, there is yet one polysaccharide-based case that has fulfilled the Botanical Guidance definition of a botanical drug product. One of the reasons is the analytical methods commonly used for qualitative and quantitative analysis of polysaccharides fall far behind the quality control criteria of botanical drugs. Here we systemically reviewed the recent advances in analytical methods. A critical evaluation of the strength and weaknesses of these methods was provided, together with possible solutions to the difficulties. Mass spectrometry with or without robust chromatographic separation was increasingly employed. And scientists have made significant progress in simplifying polysaccharide quantification by depolymerizing it into oligosaccharides. This oligosaccharides-based strategy is promising for qualitative and quantitative analysis of polysaccharides. And continuous efforts are still needed to develop a standardized quality control method that is specific, accurate, repeatable, and applicable for analyzing individual components in natural medicine formulas.

Effects of steam on polysaccharides from Polygonatum cyrtonema based on saccharide mapping analysis and pharmacological activity assays

Background

Polygonatum cyrtonema, one of origins of Polygonata Rhizoma (HuangJing in Chinese), is traditionally steamed repeatedly before being used as herbal medicine in China. However, there has no standard for steaming of HuangJing. Therefore, a comprehensive study for effects of steam on polysaccharides from Polygonatum cyrtonema based on saccharide mapping, a powerful method developed for polysaccharides analysis, and pharmacological activity are still necessary, which is helpful to explore the effect of steam on the physiochemical and biological activities of its polysaccharides and develop steaming standard of Polygonatum cyrtonema.

Methods

To explore the effect of steam on physiochemical and biological activities of P. cyrtonema polysaccharides (PCP), six polysaccharides named PCP0, PCP1, PCP2, PCP3, PCP4 and PCP5 were extracted from the herb consecutively steamed for 0–5 times, respectively. Their molecular weight distribution, monosaccharide composition and PACE fingerprints were investigated through HPSEC-MALLS-RID, HPAEC-PAD and saccharide mapping based on polysaccharides analysis by using carbohydrate gel electrophoresis (PACE) and HPTLC, respectively. In addition, their antioxidant ability and immunostimulatory activities on RAW 264.7 cells in terms of NO production and phagocytosis were compared.

Results

Results suggested that molecular weights could be changed during steam, which increased by first steaming and then decreased with further steaming though all polysaccharides’ molecular weights were 10⁵-10⁷ Da. They all showed irregularly spherical conformation in aqueous solution based on AFM imaging. Their monosaccharide composition and PACE fingerprints were significantly different after steaming, i.e., galactose increased while glucose and mannose decreased, and β-1,4-Galp appeared while β-1,4-Manp increased, after steaming. Steamed PCP significantly increased scavenging activity against ABTS radicals, while PCP0 had the best immunostimulatory effect on RAW 264.7 in terms of NO production and phagocytosis.

Conclusions

In summary, steam significantly affected the chemical composition and bioactivities of polysaccharides from P. cyrtonema. Considering the balance beneficial effects of steaming on antioxidant and immunopotentiation activities of PCP, 2 times of continuous steam is the optimal choice under the given conditions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00650-3.

Structural Elucidation, Modification, and Structure-Activity Relationship of Polysaccharides in Chinese Herbs: A Review

Chinese herbal polysaccharides (CHPs) are natural polymers composed of monosaccharides, which are widely found in Chinese herbs and work as one of the important active ingredients. Its biological activity is attributed to its complex chemical structure with diverse spatial conformations. However, the structural elucidation is the foundation but a bottleneck problem because the majority of CHPs are heteropolysaccharides with more complex structures. Similarly, the studies on the relationship between structure and function of CHPs are even more scarce. Therefore, this review summarizes the structure-activity relationship of CHPs. Meanwhile, we reviewed the structural elucidation strategies and some new progress especially in the advanced structural analysis methods. The characteristics and applicable scopes of various methods are compared to provide reference for selecting the most efficient method and developing new hyphenated techniques. Additionally, the principle structural modification methods of CHPs and their effects on activity are summarized. The shortcomings, potential breakthroughs, and developing directions of the study of CHPs are discussed. We hope to provide a reference for further research and promote the application of CHPs.

Preparation, characterization, and bioactivity evaluation of oligosaccharides from Atractylodes lancea (Thunb.) DC

Sixteen oligosaccharide monomers with the degree of polymerization 3 to 18 (DP 3 to DP 18) and three active fractions (DP 3-9, DP 8-11, and DP 11-17) were separated from Atractylodes lancea (Thunb.) DC. by optimized fast protein liquid chromatography coupled with refractive index detector (FPLC-RID) and preparation hydrophilic interaction chromatography (Pre-HILIC). Gas chromatography-mass spectrometer (GC-MS), liquid chromatography tandem mass spectrometry (LC-MS/MS), nuclear magnetic resonance (NMR) spectroscopy, and methylation analysis showed that the oligosaccharide in A. lancea was 1-kestose [β-D-fructofuranosyl-(2 → 1)-β-D-fructofuranosyl-(2 → 1)-α-D-glucopyranoside] (inulin-type fructooligosaccharides, FOS). Particularly, DP 3-9 showed the best capacity in stimulating phagocytic, NO, and cytokines production on RAW264.7 cells than any other purified oligosaccharide monomers and active fractions. It could also activate T-cells in Peyer's patch cells and enhance the production of colony stimulation factors. Besides, FPLC-RID showed a good capacity for large-scale preparation of DP 3-9 with the recovery of more than 93%. The bioactivity of sixteen FOS monomers (DP 3 to DP 18) and three FOS fractions (DP 3-9, DP 8-11, and DP 11-17) investigated in this study are beneficial for the utilization of FOS as a functional ingredient in novel product development.

Structure, size and aggregated morphology of a β-D-glucan from Lignosus rhinocerotis as affected by ultrasound

The effect of ultrasonic treatment on the structure, size and aggregated morphology of Lignosus rhinocerotis polysaccharide (LRP) was investigated. Ultrasonic treatment for 10 min has demonstrated to improve the aqueous solubility of LRP, leading to a uniform and narrow LRP particle size distribution. Meanwhile, short-time ultrasound was found to obviously decrease the molecular size parameters (M_w, M_n, <S²>_z^1/2, [η] and R_h) of LRP, and transform the hyperbranched LRP molecules into flexible and extended chains, which would reaggregate to form spherical aggregates under long-time ultrasonication. Additionally, Congo red experiment combined with CD analysis indicated the existence of triple helix structure in LRP, which was still retained after ultrasonic treatment. Furthermore, under short-time ultrasonication, the spherical aggregates with some branched chains in the native LRP solution could disaggregate and form triple helixes that could be further arranged to a dense network structure, but the untangled LRP chains would reaggregate after long-time ultrasonication. CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE: Congo red (PubChem CID: 11313); Sodium hydroxide (PubChem CID: 14798); Potassium bromide (PubChem CID: 253877).

Structural characteristics of tamarind seed polysaccharides treated by high-pressure homogenization and their effects on physicochemical properties of corn starch

In this work, structural characteristics of TSPs treated by high-pressure homogenization (HPH) and their effects on physicochemical properties of corn starch were analyzed. HPH induced monosaccharides change, Gal/Glc ratio decrease from 0.32 to 0.25, and molecular weight (M_w) decrease from 10.55 to 4.47 × 10⁵ Da through damaging glycosidic linkages in the backbone and side-chain of TSPs. Furthermore, 90 MPa homogenized TSP (higher Gal removal) showed inhibitory effects on starch paste retrogradation, and TSPs with a lower M_w (homogenized at 60 and 90 MPa) could limit water precipitation during the long-term storage. Moreover, M_w and Gal/Glc ratio were the major factors for the determined effects of TSPs on physicochemical properties of corn starch. The results could provide new insights into the relationship between TSP structure and their effects on the physicochemical properties of starch.

Classification, structure and mechanism of antiviral polysaccharides derived from edible and medicinal fungus

The deficiency of chemical-synthesized antiviral drugs when applied in clinical therapy, such as drug resistance, and the lack of effective antiviral drugs to treat some newly emerging virus infections, such as COVID-19, promote the demand of novelty and safety anti-virus drug candidate from natural functional ingredient. Numerous studies have shown that some polysaccharides sourcing from edible and medicinal fungus (EMFs) exert direct or indirect anti-viral capacities. However, the internal connection of fungus type, polysaccharides structural characteristics, action mechanism was still unclear. Herein, our review focus on the two aspects, on the one hand, we discussed the type of anti-viral EMFs and the structural characteristics of polysaccharides to clarify the structure-activity relationship, on the other hand, the directly or indirectly antiviral mechanism of EMFs polysaccharides, including virus function suppression, immune-modulatory activity, anti-inflammatory activity, regulation of population balance of gut microbiota have been concluded to provide a comprehensive theory basis for better clinical utilization of EMFs polysaccharides as anti-viral agents.

Structural characteristics and immunopotentiation activity of two polysaccharides from the petal of Crocus sativus

The current experiments were designed to explore the structural features and immunopotentiation activity of two homogeneous polysaccharides PCSPA and PCSPB prepared from Crocus sativus petals using DEAE-Sephadex A-50 and Sephadex G200 column chromatography. The structures of PCSPA and PCSPB were systematically characterized using extensive chemical and spectroscopic methods including colorimetry, HPGPC-RID, GC-MS, Smith degradations, methylation, solvolytic desulfation, UV, FT-IR, NMR, SEM, and AFM. The average molecular weights of PCSPA and PCSPB were 1.98 × 10⁶ and 2.53 × 10⁶ Da, respectively. PCSPA consisted of Gal, Rha, Ara, and Xyl in the molar ratio of 16:5:7:3, while PCSPB were composed of Gal, Glc, Man, Rha, Ara, and Xyl with molar ratio of 16:2:7:19:15:16. Both polysaccharides contained sulfonic and acetyl groups. PCSPA and PCSPB significantly activated RAW264.7 cells by enhancing the phagocytic activity, up-regulating the expression of surface molecules, promoting the production and mRNA expression of cytokines and chemokines via MAPK and NF-κB pathway.

Novel Capsular Polysaccharide from Lobochlamys segnis

In recent years there has been a significant effort from food, nutraceutical, cosmeceutical, pharmaceutical, and biomedical industries to discover and develop new natural ingredients. Microalgae have been recognised as potential sources of high value chemicals, with most attention focused upon antioxidants, pigments, and specialty oils. An under-exploited group of biochemicals produced by microalgae are extracellular polymeric substances (EPS). Lobochlamys segnis (formerly called Chlamydomonas segnis) was previously reported to produce a large amount of capsular polysaccharide (CPS) closely related to hyaluronan (HA) under stress conditions. In this work, the purified CPS was characterised and shown to have an average molecular mass (Mn) of about 3.7 MDa, and displayed a highly branched random coil structure unlike the simple repeating linear HA polysaccharide. Chemical analysis showed the presence of galactose, glucuronic acid, and glucose sugars confirming that the product has a different composition to that of HA. Mixotrophic growth and stress conditions were identified and improved upon with a pH control system using acetic acid solution to induce efficient production of CPS. Extraction and purification conditions were also identified exploiting the high Mn of the product. The CPS showed thickening properties and both significant antioxidant capacity and reducing power, which could have commercial applications. This is the first report on the characterization of this novel polysaccharide with non-Newtonian properties similar to HA.

Fast saccharide mapping method for quality consistency evaluation of commercial xylooligosaccharides collected in China

Due to the extensive use of xylooligosaccharides (XOS) as functional food ingredients, many inferior goods and even adulterants are generally found in the market, which may pose a health hazard to certain populations. Chromatography method such as high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) is traditionally applied for the quality analysis of XOS. However, it is time consuming due to the prolonged separation and pre- or post- derivatization procedure. In this study, a fast saccharide mapping method based on matrix-assisted laser desorption/time-of-flight mass spectrometry (MALDI-TOF-MS) was developed for the quality consistency analysis of 22 batches of XOS collected from different manufacturers in China. The time needed for saccharides analysis using MALDI-MS was less than 30 min for one plate, at least 6 times faster than that by the traditional HPTLC chromatography method. In addition, MALDI-MS possessed higher resolution for XOS with DP4-DP7 based on the difference of m/z, which is hardly separated using HPTLC. The results showed that XOS were present only in samples XY01-XY11, samples XY12-XY14 only consisted of hex oligosaccharides, and samples XY15-XY22 were free of oligosaccharides. These indicate that the quality consistency of XOS products in the China market was poor, which should be carefully investigated.

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Fast saccharide mapping method was developed based on MADLI-TOF-MS.

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Quality consistency of commercial xylooligosaccharides collected in China was evaluated.

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Glycosidic linkage analysis was also used for identification of xylooligosaccharides.

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Fifty percent of commercial xylooligosaccharides are mislabeled.

Structural features of pectic polysaccharides from stems of two species of Radix Codonopsis and their antioxidant activities

In this study, two pectic polysaccharides from stems of Codonopsis pilosula (CPSP-1) and C. tangshen (CTSP-1) were obtained by ion exchange chromatography and gel filtration. The molecular weight of CPSP-1 and CTSP-1 were 13.1 and 23.0 kDa, respectively. The results of structure elucidation indicated that both CPSP-1 and CTSP-1 are pectic polysaccharides with long homogalacturonan regions (HG) (some of galacturonic acid units were methyl esterified) and rhamnogalacturonan I (RG-I) regions. Side chains for CTSP-1 are both arabinogalactan type I (AG-I) and type II (AG-II), while CPSP-1 only has AG-II. The biological test demonstrated that CPSP-1 and CTSP-1 displayed an antioxidant property through mediating the intestinal cellular antioxidant defense system, which could protect cultured intestinal cells from oxidative stress induced oxidative damages and cell viability suppression. CPSP-1 and CTSP-I showed different bioactivities and mechanisms, which may be due to the difference in their structures.

Comparative metabolic profiling of Ophiocordyceps sinensis and its cultured mycelia using GC-MS

Ophiocordyceps sinensis, one of the well-known traditional Chinese medicine, has multiple health-promoting effects. It is used as herbal remedy and health food in Asian countries, together with its cultured mycelia used as a substitute of natural O. sinensis. In the present study, natural O. sinensis collected from three geographical regions and its cultured mycelia derived from three strains were analyzed by gas chromatography-mass spectrometry (GC-MS) combined with chemometrics. A total of 72 metabolites were identified from all samples with different metabolic profiles observed between natural O. sinensis and cultured mycelia. Among them, 50 metabolites showed significant differences between natural O. sinensis and cultured mycelia. Higher levels of trehalose, glycerol and citric acid in natural O. sinensis were found compared to those in cultured mycelia, while myo-inositol and some amino acids were more abundant in cultured mycelia. In addition, chemical compositions of natural O. sinensis varied depending on the geographical regions. Natural O. sinensis from three locations were clearly differentiated by the concentrations of meso-erythritol, D-mannitol, glucose and organic acids. The current study provides a comprehensive metabolic profiles of natural O. sinensis and its cultured mycelia, which is potentially important for understanding the metabolism of O. sinensis and facilitating the application of cultured mycelia as a supplement of natural O. sinensis.

Effects of simulated saliva-gastrointestinal digestion on the physicochemical properties and bioactivities of okra polysaccharides

This study was to investigate the effects of in vitro simulated saliva-gastrointestinal digestion on the physicochemical properties and bioactivities of okra polysaccharides (OPS). Results showed that the digestibilities of OPS were about 5.1%, 37.5%, and 41.3% after saliva digestion (SD), saliva-gastric digestion (SGD), and saliva-gastrointestinal digestion (SGID), respectively. The SGID significantly changed the physicochemical properties of OPS, such as total uronic acids, total flavonoids, monosaccharide composition, rheological properties, and molecular weights (M_w). Especially, M_w changes resulted in the breakdown of glycosidic bonds during SGD, and the degradation of OPS during SGID was mainly caused by disrupting aggregates. Furthermore, the bioactivities of OPS were also affected by SGID. After SGID, OPS still possessed strong antioxidant activities, binding capacities, and prebiotic activities, but the α-glucosidase inhibitory effect was obviously decreased. Overall, results can provide valuable and scientific support on the oral administration of OPS as functional foods and medicines in the future.

Synthesis of hyaluronic acid hydrogels by crosslinking the mixture of high-molecular-weight hyaluronic acid and low-molecular-weight hyaluronic acid with 1,4-butanediol diglycidyl ether

High molecular weight hyaluronic acid (HMW-HA) and low molecular weight hyaluronic acid (LMW-HA) were mixed at different ratios and cross-linked with 1,4-butanediol diglycidyl ether (BDDE) to prepare five hyaluronic acid hydrogels A–E. Enzymolysis stability, swelling rate, crosslinking degree, rheological characteristics, BDDE residual rate, surface microstructure, and cytotoxicity of different hydrogels were investigated. The results showed that hydrogel B obtained by 10% HA (w/v, HMW-HA and LMW-HA having a mass ratio of 4 : 1) crosslinking with 1% BDDE (v/v) had stronger in vitro anti-degradation ability, better mechanical properties and lower cytotoxicity than those prepared by mixing in different proportions. Hydrogel B has potential applications in regenerative medicine and tissue engineering.

High molecular weight hyaluronic acid (HMW-HA) and low molecular weight hyaluronic acid (LMW-HA) were mixed at different ratios and cross-linked with 1,4-butanediol diglycidyl ether (BDDE) to prepare five hyaluronic acid hydrogels A–E.

Structural characterization and immune-enhancing activity of a novel high-molecular-weight polysaccharide from Cordyceps militaris

A novel homogeneous polysaccharide (CMP-III) was extracted and purified from C. militaris. Structural characterization revealed that CMP-III had an average molecular weight of 4.796 × 10⁴ kDa and consisted of glucose, mannose and galactose with the molar ratio of 8.09:1.00:0.25. The main linkage types of CMP-III consisted of 1 → 4)-α-D-Glc (70.08%), 1 → 4,6)-α-D-Man (9.59%), 1→)-α-D-Man (10.79%) and 1 → 2,6)-α-D-Gal (3.93%) based on methylation and NMR analysis. The immunomodulatory assay indicated that CMP-III significantly promoted macrophage phagocytosis and secretion of NO, TNF-α and IL-6. Further study suggested that macrophage activated by CMP-III involved mitogen-activated protein kinases (MAPKs) and nuclear factor kappa-B (NF-κB) signaling pathways. Overall, these results suggested that CMP-III could be developed as a potent immunomodulatory agent for use in functional foods and dietary supplements.

Structural characterization, antioxidant activity, and immunomodulatory activity of non-starch polysaccharides from Chuanminshen violaceum collected from different regions

Chuanminshen violaceum has been used as an important traditional Chinese medicine and a popular tonic food in China. Polysaccharides are considered the major bioactive components in C. violaceum. In this study, in order well understand the chemical structures and bioactivities of non-starch polysaccharides in C. violaceum (CVPs), the physicochemical structures, antioxidant activities, and immunomodulatory activities of CVPs in C. violaceum collected from different regions of China were investigated and compared. Results showed that the constituent monosaccharides and Fourier transform infrared spectra of CVPs in C. violaceum collected from different regions were similar. However, their molar ratios of constituent monosaccharides, molecular weights, and contents of uronic acids were different. Furthermore, CVPs exerted remarkable antioxidant activities (ABTS and nitric oxide radical scavenging capacities) and immunomodulatory activities (promoted production of nitric oxide, IL-6, and TNF-α from RAW 264.7 macrophages in vitro). Meanwhile, the antioxidant and immunomodulatory activities of CVPs extracted from C. violaceum also varied by cultivated regions. Moreover, results indicated that the antioxidant and immunomodulatory activities of CVPs were closely correlated to their α-1,4-d-galactosiduronic linkages. Results are helpful for better understanding of the structure-bioactivity relationships of CVPs, and beneficial for the improvement of their applications in pharmaceutical and functional food industries.

Structural characteristics, rheological properties, and biological activities of polysaccharides from different cultivars of okra (Abelmoschus esculentus) collected in China

In order to well understand the physicochemical characteristics and biological activities of polysaccharides (OPPs) from different cultivars of okra collected in China, the chemical characteristics, rheological properties, antioxidant activities, in vitro binding properties, and in vitro inhibitory effects on α-glucosidase of polysaccharides from five representative okra cultivars, including 'Lvjian', 'Kalong8', 'Shuiguo', 'Taiwanwufu', and 'Kalong3', were investigated and compared. Results showed that the constituent monosaccharides of OPPs were similar, which composed of rhamnose, galacturonic acid, galactose, and arabinose. However, their weight-average molecular weights varied from 2.76 × 10³ to 4.20 × 10³ kDa, and from 0.11 × 10³ to 0.90 × 10³ kDa, respectively. The uronic acids and degrees of esterification of OPPs ranged from 39.32% to 61.68%, and from 21.66% to 30.02%, respectively. OPPs exhibited typical shear-thinning behavior and viscoelastic properties. Furthermore, OPPs exhibited remarkable antioxidant activities, in vitro binding capacities, and inhibitory effects on α-glucosidase, which might be attributed to their relatively high content of uronic acids, high degrees of esterification, and high molecular weights. Results are helpful for better understanding of the physicochemical structures and bioactivities of OPPs, and OPPs had good application prospects as functional food ingredients for industrial applications.

Structure, bioactivity and applications of natural hyperbranched polysaccharides

In recent years, hyperbranched polymers, especially the natural hyperbranched polysaccharides (HBPSs), are receiving much attention due to their diverse biological activities and applications. With high degree of branching (DB), HBPSs mainly exist in the form of either a comb-brush shape, dendrimer-like particulate, or globular particle. HBPSs also possess some unique properties, such as high density, large spatial cavities, and numerous terminal functional groups, which distinguish them from other polymers. As a natural biopolymer, HBPS has excellent bioavailability, biocompatibility, and biodegradability, which have versatile applications in the fields of food, medicine, cosmetic, and nanomaterials. In this review, the source and structure of HBPSs from plant, animal, microbial and fungal origins as well as their biological functions and applications are covered, with the aim of further advancing the research of their structure and bioactivity.

Gastrodia elata Blume Polysaccharides: A Review of Their Acquisition, Analysis, Modification, and Pharmacological Activities

Gastrodia elata Blume (G. elata) is a valuable Traditional Chinese Medicine (TCM) with a wide range of clinical applications. G. elata polysaccharides, as one of the main active ingredients of G. elata, have interesting extraction, purification, qualitative analysis, quantitative analysis, derivatization, and pharmacological activity aspects, yet a review of G. elata polysaccharides has not yet been published. Based on this, this article summarizes the progress of G. elata polysaccharides in terms of the above aspects to provide a basis for their further research and development.

Alkaline Extraction, Structural Characterization, and Bioactivities of (1→6)-β-d-Glucan from Lentinus edodes

The purpose of this study is to develop a robust approach to obtain β glucans from Lentinus edodes and to characterize their structural and biological properties for sustainable utilization. The alkali extraction was optimized with an orthogonal experimental design, and a concise process for obtaining specific targeting polysaccharides from Lentinus edodes was developed in this study. After purification with a Q-Sepharose Fast Flow strong anion-exchange column, the monosaccharide composition, a methylation analysis, and NMR spectroscopy were employed for their structural characterizations. LeP-N2 was found to be composed of (1→6)-β-d-glucans with minor β-(1→3) glucosidic side chains. Atomic force microscopy (AFM) and high-performance gel permeation chromatography–refractive index–multi-angle laser light scattering (HPGPC-RI-MALLS) also revealed LeP-N2 exhibiting a compact unit in aqueous solution. This (1→6)-β-d-glucan was tested for antioxidant activities with IC₅₀ at 157 μg/mL. Moreover, RAW 264.7 macrophage activation indicated that the release of nitric oxide (NO) and reactive oxygen species (ROS) were markedly increased with no cytotoxicity at a dose of 100 μg/mL. These findings suggest that the (1→6)-β-d-glucans obtained from Lentinus edodes could serve as potential agents in the fields of functional foods or medicine.