Chain conformation and anti-tumor activity of derivatives of polysaccharide from Rhizoma Panacis Japonici

A comprehensive review of sulfated fucan from sea cucumber: Antecedent and prospect

Sulfated fucan from sea cucumber is mainly consists of L-fucose and sulfate groups. Recent studies have confirmed that the structure of sulfated fucan mainly consists of repeating units, typically tetrasaccharides. However, there is growing evidence indicating the presence of irregular domains with heterogeneous units that have not been extensively explored. Moreover, as a key contributor to the nutritional benefits of sea cucumbers, sulfated fucan demonstrates a range of biological activities, such as anti-inflammatory, anticancer, hypolipidemic, anti-hyperglycemic, antioxidant, and anticoagulant properties. These biological activities are profoundly influenced by the structural features of sulfated fucan including molecular weight and distribution patterns of sulfate groups. The latest research indicates that sulfated fucan is dispersed in the extracellular matrix of the body wall of sea cucumbers. This article aimed to review the research progress on the in-situ distribution, structures, structural elucidation strategies, functions, and structure-activity relationships of sulfated fucan, especially in the last decade. It also provided insights into the major challenges and potential solutions in the research and development of sulfated fucan. Moreover, the fucanase and carbohydrate binding modules are anticipated to play pivotal roles in advancing this field.

Polysaccharides in fruits: Biological activities, structures, and structure-activity relationships and influencing factors-A review

Fruits are a rich source of polysaccharides, and an increasing number of studies have shown that polysaccharides from fruits have a wide range of biological functions. Here, we thoroughly review recent advances in the study of the bioactivities, structures, and structure-activity relationships of fruit polysaccharides, especially highlighting the structure-activity influencing factors such as extraction methods and chemical modifications. Different extraction methods cause differences in the primary structures of polysaccharides, which in turn lead to different polysaccharide biological activities. Differences in the degree of modification, molecular weight, substitution position, and chain conformation caused by chemical modification can all affect the biological activities of fruit polysaccharides. Furthermore, we summarize the applications of fruit polysaccharides in the fields of pharmacy and medicine, foods, cosmetics, and materials. The challenges and perspectives for fruit polysaccharide research are also discussed.

Effect of ultrasound assisted H2O2/Vc treatment on the hyperbranched Lignosus rhinocerotis polysaccharide: Structures, hydrophobic microdomains, and antitumor activity

The effect of ultrasonic intensity (28.14, 70.35, and 112.56 W/cm2) on Lignosus rhinocerotis polysaccharide (LRP) degraded by ultrasound assisted H2O2/Vc system (U-H/V) was investigated. U-H/V broke the molecular chain of LRP and improved the conformational flexibility, decreasing the molecular weight, intrinsic viscosity ([η]) and particle size. The functional groups and hyperbranched structure of LRP were almost stable after U-H/V treatment, however, the triple helix structure of LRP was partially disrupted. With increasing ultrasonic intensity, the critical aggregation concentration increased from 0.59 mg/mL to 1.57 mg/mL, and the hydrophobic microdomains reduced. Furthermore, the LRP treated with U-H/V significantly inhibited HepG2 cell proliferation by inducing apoptosis. The increase in antitumor activity of LRP was closely associated with the reduction of molecular weight, [η], particle size and hydrophobic microdomains. These results revealed that U-H/V treatment facilitates the degradation of LRP and provides a better insight into the structure-antitumor activity relationship of LRP.

A glucuronogalactomannan isolated from Tetrastigma hemsleyanum Diels et Gilg: Structure and immunomodulatory activity

A novel acidic glucuronogalactomannan (STHP-5) was isolated from the aboveground part of Tetrastigma hemsleyanum Diels et Gilg with a molecular weight of 3.225 × 105 kDa. Analysis of chain conformation showed STHP-5 was approximately a random coil chain. STHP-5 was composed mainly of galactose, mannose, and glucuronic acid. Linkages of glycosides were measured via methylation analysis and verified by NMR. In vitro, STHP-5 induced the production of nitric oxide (NO) and secretion of IL-6, MCP-1, and TNF-α in RAW264.7 cells, indicating STHP-5 had stimulatory activity on macrophages. STHP-5 was proven to function as a TLR4 agonist by inducing the secretion of secreted embryonic alkaline phosphatase (SEAP) in HEK-Blue™-hTLR4 cells. The TLR4 activation capacity was quantitatively measured via EC50, and it showed purified polysaccharides had stronger effects (lower EC50) on activating TLR4 compared with crude polysaccharides. In conclusion, our findings suggest STHP-5 may be a novel immunomodulator.

Recent advances in natural polysaccharides against hepatocellular carcinoma: A review

Hepatocellular carcinoma (HCC) is a malignant tumor of the digestive system that poses a serious threat to human life and health. Chemotherapeutic drugs commonly used in the clinic have limited efficacy and heavy adverse effects. Therefore, it is imperative to find effective and safe alternatives, and natural polysaccharides (NPs) fit the bill. This paper summarizes in detail the anti-HCC activity of NPs in vitro, animal and clinical trials. Furthermore, the addition of NPs can reduce the deleterious effects of chemotherapeutic drugs such as immunotoxicity, bone marrow suppression, oxidative stress, etc. The potential mechanisms are related to induction of apoptosis and cell cycle arrest, block of angiogenesis, invasion and metastasis, stimulation of immune activity and targeting of MircoRNA. And on this basis, we further elucidate that the anti-HCC activity may be related to the monosaccharide composition, molecular weight (Mw), conformational features and structural modifications of NPs. In addition, due to its good physicochemical properties, it is widely used as a drug carrier in the delivery of chemotherapeutic drugs and small molecule components. This review provides a favorable theoretical basis for the application of the anti-HCC activity of NPs.

Panax japonicus C.A. Meyer: a comprehensive review on botany, phytochemistry, pharmacology, pharmacokinetics and authentication

BACKGROUND

Panax japonicus C.A. Meyer (Zhujieshen) is widely used in traditional medicine as a tonic hemostatic and anti-inflammatory agent in China, Japan, and Korea. Furthermore, it is used as an important substitute for ginseng roots by minority ethnic groups in China. The purpose of this review is to summarize the latest research on Zhujieshen in recent years, aiming at providing a systematic overview of the current knowledge, and perspectives for future research and exploitation.

MAIN BODY

This review examines the research advances in botanical profile, phytochemicals, pharmacology, pharmacokinetics, and authentication of Zhujieshen. Various compounds have been reported as active components, mainly including saponins, volatile oils, and polysaccharides. Pharmacological investigations have demonstrated that Zhujieshen is an important herb with significant bioactivities, such as anti-inflammatory, hepato-protective, cardio-protective, neuro-protective, anti-tumor, anti-oxidant, anti-thrombotic and immunomodulatory activities.

CONCLUSION

Currently, research on Zhujieshen is in the preliminary stages, and further research is required to understand the active compounds present and mechanisms of action. We hope that this comprehensive review of Zhujieshen will serve as a background for future research and exploitation.

A polysaccharide from Inula japonica showing in vivo antitumor activity by interacting with TLR-4, PD-1, and VEGF

Polysaccharides, an important class of carbohydrate polymers, are considered as one of the sources of drug molecules. To discover bioactive polysaccharides as potential agents against cancer, a homogeneous polysaccharide (IJP70-1) has been purified from the flowers of Inula japonica, which is a traditional medicinal plant used for various medical indications. IJP70-1 with a molecular weight of 1.019 × 105 Da was mainly composed of →5)-α-l-Araf-(1→, →2,5)-α-l-Araf-(1→, →3,5)-α-l-Araf-(1→, →2,3,5)-α-l-Araf-(1→, →6)-α-d-Glcp-(1→, →3,6)-α-d-Galp-(1→, and t-α-l-Araf. Apart from the characteristics and structure elucidated by various techniques, the in vivo antitumor activity of IJP70-1 was assayed using zebrafish models. In the subsequent mechanism investigation, it was found that the in vivo antitumor activity of IJP70-1 was not cytotoxic mechanism caused, but related to the activation of the immune system and inhibition of angiogenesis by interacting with the proteins toll-like receptor-4 (TLR-4), programmed death receptor-1 (PD-1), and vascular endothelial growth factor (VEGF). The chemical and biological studies have shown that the homogeneous polysaccharide IJP70-1 has the potential to be developed into an anticancer agent.

Application of natural polysaccharides and their novel dosage forms in gynecological cancers: therapeutic implications from the diversity potential of natural compounds

Cancer is one of the most lethal diseases. Globally, the number of cancers is nearly 10 million per year. Gynecological cancers (for instance, ovarian, cervical, and endometrial), relying on hidden diseases, misdiagnoses, and high recurrence rates, have seriously affected women's health. Traditional chemotherapy, hormone therapy, targeted therapy, and immunotherapy effectively improve the prognosis of gynecological cancer patients. However, with the emergence of adverse reactions and drug resistance, leading to the occurrence of complications and poor compliance of patients, we have to focus on the new treatment direction of gynecological cancers. Because of the potential effects of natural drugs in regulating immune function, protecting against oxidative damage, and improving the energy metabolism of the body, natural compounds represented by polysaccharides have also attracted extensive attention in recent years. More and more studies have shown that polysaccharides are effective in the treatment of various tumors and in reducing the burden of metastasis. In this review, we focus on the positive role of natural polysaccharides in the treatment of gynecologic cancer, the molecular mechanisms, and the available evidence, and discuss the potential use of new dosage forms derived from polysaccharides in gynecologic cancer. This study covers the most comprehensive discussion on applying natural polysaccharides and their novel preparations in gynecological cancers. By providing complete and valuable sources of information, we hope to promote more effective treatment solutions for clinical diagnosis and treatment of gynecological cancers.

The in-situ dextran produced in rice protein yogurt: Effect on viscosity and structural characteristics

Phase separation is one of the primary quality control issues for plant-based beverages during storage. This study applied the in-situ-produced dextran (DX) from Leuconostoc citreum DSM 5577 to solve this problem. Rice flour milled from broken rice was used as the raw material and Ln. citreum DSM 5577 as the starter to prepare rice-protein yogurt (RPY) under different processing conditions. The microbial growth, acidification, viscosity change, and DX content were first analyzed. Then, the proteolysis of rice protein was evaluated, and the role of the in-situ-synthesized DX in viscosity improvement was explored. Finally, the in-situ-synthesized DXs in RPYs under different processing conditions were purified and characterized. The in-situ-produced DX caused a viscosity increase up to 1.84 Pa s in RPY and played a major role in this improvement by forming a new network with high water-binding capacity. The processing conditions affected the content and the molecular features of DXs, with a DX content up to 9.45 mg/100 mg. A low-branched DX (5.79 %) with a high aggregating ability possessed a stronger thickening ability in RPY. This study may guide the application of the in-situ-synthesized DX in plant protein foods and may promote the utilization of broken rice in the food industry.

Structural Characterization and Anti-Nonalcoholic Fatty Liver Effect of High-Sulfated Ulva pertusa Polysaccharide

The high-sulfated derivative of Ulva pertusa polysaccharide (HU), with unclear structure, has better anti-hyperlipidmia activity than U pertusa polysaccharide ulvan (U). In this study, we explore the main structure of HU and its therapeutic effect against nonalcoholic fatty liver disease (NAFLD). The main structure of HU was elucidated using FT-IR and NMR (13C, 1H, COSY, HSQC, HMBC). The anti-NAFLD activity of HU was explored using the high-fat diet mouse model to detect indicators of blood lipid and liver function and observe the pathologic changes in epididymal fat and the liver. Results showed that HU had these main structural fragments: →4)-β-D-Glcp(1→4)-α-L-Rhap2,3S(1→; →4)-α-L-Rhap3S(1→4)-β-D-Xylp2,3S(1→; →4)-α-L-Rhap3S(1→4)-β-D-Xylp(1→; →4)-α-L-IdopA3S(1→4)-α-L-Rhap3S(1→; →4)-β-D-GlcpA(1→3)-α-L-Rhap(1→; →4)-α-L-IdopA3S(1→4)-β-D-Glcp3Me(1→; →4)-β-D-Xylp2,3S(1→4)-α-L-IdopA3S(1→; and →4)-β-D-Xylp(1→4)-α-L-IdopA3S(1→. Treatment results indicated that HU markedly decreased levels of TC, LDL-C, TG, and AST. Furthermore, lipid droplets in the liver were reduced, and the abnormal enlargement of epididymal fat cells was suppressed. Thus, HU appears to have a protective effect on the development of NAFLD.

Synthesis and application of phosphorylated saccharides in researching carbohydrate-based drugs

Phosphorylated saccharides are valuable targets in glycochemistry and glycobiology, which play an important role in various physiological and pathological processes. The current research on phosphorylated saccharides primarily focuses on small molecule inhibitors, glycoconjugate vaccines and novel anti-tumour targeted drug carrier materials. It can maximise the pharmacological effects and reduce the toxicity risk caused by nonspecific off-target reactions of drug molecules. However, the number and types of natural phosphorylated saccharides are limited, and the complexity and heterogeneity of their structures after extraction and separation seriously restrict their applications in pharmaceutical development. The increasing demands for the research on these molecules have extensively promoted the development of carbohydrate synthesis. Numerous innovative synthetic methodologies have been reported regarding the continuous expansion of the potential building blocks, catalysts, and phosphorylation reagents. This review summarizes the latest methods for enzymatic and chemical synthesis of phosphorylated saccharides, emphasizing their breakthroughs in yield, reactivity, regioselectivity, and application scope. Additionally, the anti-bacterial, anti-tumour, immunoregulatory and other biological activities of some phosphorylated saccharides and their applications were also reviewed. Their structure-activity relationship and mechanism of action were discussed and the key phosphorylation characteristics, sites and extents responsible for observed biological activities were emphasised. This paper will provide a reference for the application of phosphorylated saccharide in the research of carbohydrate-based drugs in the future.

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

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

Different molecular sizes and chain conformations of water-soluble yeast β-glucan fractions and their interactions with receptor Dectin-1

Although β-glucan could bind to Dectin-1 to exert bioactivity, the influence of molecular size and chain conformation of β-glucan on its interaction with Dectin-1 is still unclear. This work investigated the molecular sizes and chain conformations of five water-soluble yeast β-glucan (WYG1-5) fractions as well as their interactions with Dectin-1 by fluorescence spectroscopy and microscale thermophoresis. Results revealed a spherical conformation for higher molecular weight WYG and a stiff chain conformation for smaller molecular weight WYG. The WYG and Dectin-1 interactions were in the order of WYG-2 > WYG-1 > WYG-3 > WYG-4 > WYG-5. The spherical WYG-2 exhibited the largest binding constant of 7.91 × 10⁵ M¹ and the lowest dissociation constant of 22.1 nM to Dectin-1. Additionally, the underlying interaction mechanism showed that it may be easier for spherical WYG with longer side chains to interact with receptor Dectin-1.

Sulphation and Hydrolysis Improvements of Bioactivities, and Immuno-Modulatory Properties of Edible Amanita hemibapha Subspecies javanica (Corner and Bas) Mucilage Polysaccharide as a Potential in Personalized Functional Foods

In this study, the mucilage polysaccharide (MP) from Amanita hemibapha subspecies javanica was prepared by hot water extraction and ethanol precipitation and then fractionated using anion-exchange chromatography equipped with a DEAE Sepharose fast flow column. The most immune-enhancing polysaccharide fraction 2 (MPF2) was subjected to a structural modification such as hydrolysis or over-sulphation. The sulphate and molecular weight (Mw) of over-sulphated (OS1-3) and hydrolysed (HS1-3) derivatives of MPF2 differed between 9.85% and 14.2% and 32.8 and 88.1 × 103 g/mol, respectively. Further, the immune-enhancing properties of MPF2 and its derivatives were tested on RAW264.7 and NK cells through various in vitro assays. Interestingly, a low molecular weight of HS1-3 significantly increased the nitric oxide (NO) production (p < 0.05) more than MPF2, indicating that Mw is a major factor in RAW264.7 cell stimulation. In addition, RAW264.7 cells produced various cytokines by up-regulating mRNA expression levels and the activation of nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. On the other hand, OS1-3-treated natural killer (NK) cells induced cytotoxicity in HepG2 cells through the expression of IFN-γ, Grandzyme-B, perforin, NKp30, and FasL. These results demonstrated that sulphate derivatives play an important role in NK cell activation. Further, this study also explores how polysaccharide binds to RAW264.7 and NK cells. MPF2 and HS3 may activate RAW264.7 cells via binding to TLR4 receptors, and OS2 could be activated through the CR3 signalling pathways.

New insights into the anti- hepatoma mechanism of triple-helix β- glucan by metabolomics profiling

Natural polysaccharide as the third abundant biomacromolecule has attracted considerable attentions due to their superior anti-tumor activities. However, the anti-tumor mechanism of polysaccharides has not been completely understood. Herein, the anti-tumor effects of black fungus polysaccharide (BFP), a typical β-glucan was comprehensively investigated, and the anti-tumor mechanism was obtained from metabolomics profiling. The in vitro results demonstrate that BFP inhibited the proliferation, migration and invasion of hepatoma carcinoma cells (HCC) through inducing the cell apoptosis and arresting the cell cycle at S phase without direct cytotoxicity. The hepatoma-bearing nude mice experiments further demonstrate that BFP could significantly inhibit the growth without system toxicity in vivo. Mass spectrometry-based metabolomics unveils that BFP significantly disturbed the multiple metabolic pathways, leading to the inhibition of tumor cells proliferation by promoting DNA damage, attenuating DNA damage repair, and inhibiting DNA synthesis. This study provides new insights for pharmacological research and clinical practice of polysaccharides.

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).

Effect of steaming process on the structural characteristics and antioxidant activities of polysaccharides from Polygonatum sibiricum rhizomes

Polygonatum sibiricum (P. sibiricum) rhizomes are widely used as a tonic and functional food, and are often processed to enhance their tonic function by repeated steaming and drying. As the most important constituent, the polysaccharide from P. sibiricum rhizomes (PSP) has demonstrated various activities, but the alteration of structural characteristics and activities of the purified PSPs during steaming process was rarely investigated. To well understand the effect of steaming process on the polysaccharides of P. sibiricum, neutral polysaccharides from P. sibiricum rhizomes (PSP0 ~ PSP9) after steaming were first isolated and purified, and then the chemical properties and antioxidant activities were determined. The results showed that the molar ratios of monosaccharides in PSPs were different. The molecular weights of PSPs were increased significantly after the fourth steaming. Morphological studies showed that the surface of PSPs became much tighter during the steaming process. Fourier transform infrared spectroscopy spectra displayed the polysaccharides had similar backbones and chemical groups. Furthermore, the antioxidant activity of PSPs was measured through radical scavenging tests. It was found that the radical scavenging activity of PSPs was elevated strikingly after steaming, and increased gradually with numbers of steaming process. The biological and chemical variance of PSPs revealed considerable segregation of PSP0, PSP1 ~ PSP4 and PSP5 ~ PSP9. In conclusion, our results proposed the fourth time as the optimal number of steaming to extract functional polysaccharide from P. sibiricum rhizomes.

Phosphorylation of polysaccharides: A review on the synthesis and bioactivities

Polysaccharides are macromolecules obtained from a wide range of sources and are known to have diverse biological activities. The biological activities of polysaccharides depend on their structure and physicochemical properties, including water solubility, monosaccharide composition, degree of branching, molecular structure, and molecular weight. Phosphorylation is a commonly used chemical modification method that improves the physicochemical properties of native polysaccharides, thus enhancing their biological activity, or even imparting novel biological activity. Therefore, phosphorylated polysaccharides have attracted increasing attention owing to their antioxidant, antitumor, antiviral, immunomodulatory, and hepatoprotective effects. In this review, we have discussed recent advances in the phosphorylation of polysaccharides, and the methods used for phosphorylation, structural characterization, and determination of biological activities, to provide a theoretical basis for the use of polysaccharides. The structure-activity relationship of phosphorylated polysaccharides and their use in the food and pharmaceutical industries needs to be further studied.

Effects of different chemical modifications on the structure and biological activities of polysaccharides from Orchis chusua D. Don

In this study, an enzyme-assisted extraction method was used to extract Orchis chusua D. Don (Salep) polysaccharide (SP), which was then modified by sulfation, acetylation, phosphorylation, and carboxymethylation to obtain modified polysaccharides. Furthermore, their degree of substitution, chemical composition, and molecular weight were evaluated. The primary structural features were characterized by UV spectra, FT-IR spectra, Congo-red test, and scanning electron microscope. The phosphorylated polysaccharide (SP-P) was demonstrated the highest scavenging ability on hydroxyl radical and growth-promoting activity on Lactobacillus Bulgaricus. The carboxymethylated polysaccharide (SP-C) was exhibited the strongest DPPH and ABTS radical scavenging effects. The acetylated polysaccharide (SP-A) displayed the best proliferation effects on Bifidobacterium adolescentis, whereas the sulfated polysaccharide (SP-S) maintained moderately stable antioxidant and probiotic ability. These findings indicate that the modified polysaccharides had their potential significance as new antioxidants and probiotics for the food industry. PRACTICAL APPLICATION: This article provides a new source for the development of polysaccharide derivatives as new antioxidants and probiotics for the food industry.

Hydrogen Peroxide Effects on Natural-Sourced Polysacchrides: Free Radical Formation/Production, Degradation Process, and Reaction Mechanism-A Critical Synopsis

Numerous reactive oxygen species (ROS) entities exist, and hydrogen peroxide (H2O2) is very key among them as it is well known to possess a stable but poor reactivity capable of generating free radicals. Considered among reactive atoms, molecules, and compounds with electron-rich sites, free radicals emerging from metabolic reactions during cellular respirations can induce oxidative stress and cause cellular structure damage, resulting in diverse life-threatening diseases when produced in excess. Therefore, an antioxidant is needed to curb the overproduction of free radicals especially in biological systems (in vivo and in vitro). Despite the inherent properties limiting its bioactivities, polysaccharides from natural sources increasingly gain research attention given their position as a functional ingredient. Improving the functionality and bioactivity of polysaccharides have been established through degradation of their molecular integrity. In this critical synopsis; we articulate the effects of H2O2 on the degradation of polysaccharides from natural sources. Specifically, the synopsis focused on free radical formation/production, polysaccharide degradation processes with H2O2, the effects of polysaccharide degradation on the structural characteristics; physicochemical properties; and bioactivities; in addition to the antioxidant capability. The degradation mechanisms involving polysaccharide's antioxidative property; with some examples and their respective sources are briefly summarised.

Carboxymethylation of polysaccharides: Synthesis and bioactivities

Polysaccharides are a structurally diverse class of biomolecules with a wide variety of bioactivities. Natural polysaccharides isolated from plants and fungi are used as raw materials in food and pharmaceutical industries due to their therapeutic properties, non-toxicity, and negligible side effects, but many natural polysaccharides possess low bioactivities when compared to synthetic medicines due to their structure and physicochemical properties. Literature studies revealed that carboxymethylation of polysaccharides enhances the bioactivities and water solubility of native polysaccharides significantly, and provide structural diversity and even the addition of new bioactivities. This review article mainly focuses on the recent research on carboxymethylation of polysaccharides including preparation, characterization, and bioactivities. This article also throws light on future directions and scope to develop new carboxymethylated polysaccharide derivatives for many industries such as food processing, cosmetics, nutraceuticals, and pharmaceutical industry.

The role of Rho GTPases' substrates Rac and Cdc42 in osteoclastogenesis and relevant natural medicinal products study

Recently, Rho GTPases substrates include Rac (Rac1 and Rac2) and Cdc42 that have been reported to exert multiple cellular functions in osteoclasts, the most prominent of which includes regulating the dynamic actin cytoskeleton rearrangements. In addition, natural products and their molecular frameworks have a long tradition as valuable starting points for medicinal chemistry and drug discovery. Although currently, there are reports about the natural product, which could play a therapeutic role in bone loss diseases (osteoporosis and osteolysis) through the regulation of Rac1/2 and Cdc42 during osteoclasts cytoskeletal structuring. There have been several excellent studies for exploring the therapeutic potentials of various natural products for their role in inhibiting cancer cells migration and function via regulating the Rac1/2 and Cdc42. Herein in this review, we try to focus on recent advancement studies for extensively understanding the role of Rho GTPases substrates Rac1, Rac2 and Cdc42 in osteoclastogenesis, as well as therapeutic potentials of natural medicinal products for their properties on the regulation of Rac1, and/or Rac2 and Cdc42, which is in order to inspire drug discovery in regulating osteoclastogenesis.

Structural Features, Modification, and Functionalities of Beta-Glucan

Β-glucan is a strongly hydrophilic non-starchy polysaccharide, which, when incorporated in food, is renowned for its ability to alter functional characteristics such as viscosity, rheology, texture, and sensory properties of the food product. The functional properties of β-glucans are directly linked to their origin/source, molecular weight, and structural features. The molecular weight and structural/conformational features are in turn influenced by method of extraction and modification of the β-glucan. For example, whereas physical modification techniques influence only the spatial structures, modification by chemical agents, enzyme hydrolysis, mechanical treatment, and irradiation affect both spatial conformation and primary structures of β-glucan. Consequently, β-glucan can be modified (via one or more of the aforementioned techniques) into forms that have desired morphological, rheological, and (bio)functional properties. This review describes how various modification techniques affect the structure, properties, and applications of β-glucans in the food industry.

Chemical modifications of polysaccharides and their anti-tumor activities

With the rising trend of incidence of cancers, effective therapies are urgently needed to control human malignancies. However, the chemotherapy drugs currently on the market cause serious side effects. Polysaccharides belong to a class of biomacromolecules, which have drawn considerable research interest over the years as it possess anti-cancer activities or can increase the efficacy of conventional chemotherapy drugs with fewer side effects. The antitumor activity of many polysaccharides was significantly increased after modification. Based on these encouraging observations, a great deal of effort has been focused on discovering anti-cancer polysaccharides and modified derivatives for the development of effective therapeutics for various human cancers. This review highlights recent advances on the major chemical modification methods of polysaccharides, and discusses the effect of molecular modification on the physicochemical properties and anti-tumor activities of polysaccharides. Meanwhile, the underlying anti-tumor mechanisms of polysaccharide and its modified derivatives were also discussed.

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.

Production, structural characterization, and antiproliferative activity of exopolysaccharide produced by Scleroderma areolatum Ehrenb with different carbon source

The effects of different three carbon sources, that is, glucose, fructose, and sucrose, on production, molecular properties and antiproliferative activity of exopolysaccharide (EPS), were evaluated in the submerged culture of Scleroderma areolatum Ehrenb. Among carbon sources examined, the addition of sucrose maximizes the mycelia production, while fructose could maximize the EPS yield. Although the predominant carbohydrate compositions identified were gluconic acid and mannose, the monosaccharide composition of EPSs was also different significantly. FT-IR spectral analysis revealed there was no significant difference among the prominent characteristic groups in three EPSs. The molecular weight of EPSs was also affected by carbon source, being generally lower compared with that with glucose. However, all EPSs molecule existed as nearly globular shape form in aqueous solution. The variation of carbon sources also affected antiproliferative activity examined in vitro using cell proliferation assay. Fructose was optimal carbon source giving higher antiproliferative activity probably due to the relatively high contents of xylose in the EPS with low molecular weight.

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.

A novel polysaccharide from Rhizoma panacis japonica exerts anti-inflammatory effects via STAT3 signal pathway

PJ-1 modulates the function of macrophages via the STAT3 signal pathway.

The preparation of three selenium-containing Cordyceps militaris polysaccharides: Characterization and anti-tumor activities

In the present work, three fractions of selenized Cordyceps militaris polysaccharides (SeCPS) named SeCPS- I, SeCPS- II and SeCPS- III were isolated and purified by ultra-filtration. Their selenium content were measured as 541.3, 863.7 and 623.3μg/g respectively by a graphite furnace atomic absorption spectroscopy. The monosaccharide comformation analysis showed that they were mainly consisted of D-Mannose, D-Glucose, and D-Galactose in mole ratios of 1:7.63:0.83, 1:1.34:0.31 and 1:3.77:0.41 respectively. Their structure characteristics were compared by IFR and NMR spectroscopy. Scanning electron microscopy (SEM) and Congo red (CR) spectrophotometric method were used to investigate their morphological characteristics and conformational transition. SeCPS-II showed the strongest anti-tumor effects judging from the result of in vitro anti-tumor assays against two tumor cell lines (hepatocellular carcinoma HepG-2 cells and lung adenocarcinom A549 cells).

β-Glucans: Relationships between Modification, Conformation and Functional Activities

β-glucan is a type of polysaccharide which widely exists in bacteria, fungi, algae, and plants, and has been well known for its biological activities such as enhancing immunity, antitumor, antibacterial, antiviral, and wound healing activities. The conformation of β-glucan plays a crucial role on its biological activities. Therefore, β-glucans obtained from different sources, while sharing the same basic structures, often show different bioactivities. The basic structure and inter-molecular forces of polysaccharides can be changed by modification, which leads to the conformational transformation in solution that can directly affect bioactivity. In this review, we will first determine different ways to modify β-glucan molecules including physical methods, chemical methods, and biological methods, and then reveal the relationship of the flexible helix form of the molecule chain and the helix conformation to their bioactivities. Last, we summarize the scientific challenges to modifying β-glucan's conformation and functional activity, and discuss its potential future development.