Structure and physicochemical properties of arabinan-rich acidic polysaccharide from the by-product of peanut oil processing

Structural characterisation and anti-colon cancer activity of an arabinogalactan RSA-1 from Raphani semen

RSA-1 is a polysaccharide obtained from Raphani semen with a relatively clear structure and anti-colon cancer activity. In this study, high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) spectroscopy were applied to characterise the complex chain structure of RSA-1. Subsequently, the inhibitory effect on colon cancer growth through apoptosis induction in colon cancer cells was explored. The findings indicate that the main chain of RSA-1 consists of →3)-β-D-Galp-(1 → and 3,6)-β-D-Galp-(1 → substituted at C-6 with branched α-L-Araf side chains. RSA-1 disrupts the Bax/Bcl-2 ratio and thus inhibits the viability of colon cancer cells in vitro. Furthermore, it inhibits colon cancer migration by attenuating epithelial-mesenchymal transition. Notably, RSA-1 exhibited negligible impact on the growth of human intestinal epithelial cells within a relevant concentration range. This study establishes a theoretical foundation and provides technical support for the prospective development and application of RSA-1 as a dual-purpose anti-colon cancer drug and functional food.

Structural characteristics of a purified Evodiae fructus polysaccharide and its gastroprotection and relevant mechanism against alcohol-induced gastric lesions in rats

Evodiae fructus polysaccharide (EFP) has been previously shown to protect against alcohol-induced gastric lesions. However, which and how active fractions in EFP exert gastroprotection remains unclear. This study aimed to characterize the structure of the purified fraction (EFP-2-1) of EFP, and investigate its gastroprotection and underlying mechanisms. EFP-2-1 was obtained through column chromatography, and was characterized using instrumental analytical techniques. Gastroprotective effect of EFP-2-1 was evaluated using alcohol-induced gastric lesions in rats, and its mechanism was explored through proteomics, metabolomics and diversity sequencing. Results showed that EFP-2-1 had a molecular weight of 7.3 kDa, and consisted mainly of rhamnose, galacturonic acid, galactose and arabinose. Its backbone contained HG and RG-I domains, and branched with →5)-α-l-Araf-(1→, α-l-Araf-(1→ and →4)-β-d-Galp-(1→ residues. EFP-2-1 reduced gastric lesions and the levels of MDA, TNF-α and IL-6, activated PPARγ, primarily altered protein digestion and absorption and bile secretion metabolic pathways, regulated gut microbiota like Faecalibaculum and Lachnoclostridium, and increased short-chain fatty acids production. Correlations were observed among the gut microbiota, metabolites and biochemical indexes influenced by EFP-2-1. These findings suggest that EFP-2-1 is an active fraction of EFP for protecting against alcohol-induced gastric lesions, which may be linked to PPARγ activation, gut microbiota and serum metabolism.

In vitro digestion and fermentation of polysaccharides from nine common Polygonatum spp. and their impact on human gut microbiota

This study aimed to investigate the dynamic changes in the physicochemical properties of polysaccharides from nine common Polygonatum spp. during in vitro simulated saliva-gastrointestinal digestion, in vitro fermentation, and their subsequent effects on human gut microbiota. Results revealed that the total sugar contents of Polygonatum spp. polysaccharides almost had little changes during the vitro digestion, and the molecular weight presented a downward trend. The in vitro digestion process produced almost no free monosaccharide, with small variations on FT-IR spectroscopy analysis. However, during the in vitro fermentation process, the polysaccharides generated remarkable changes, the total sugar showed a downward trend, and the molecular weight was degraded. There were significant changes in the monosaccharide composition, and possibly the sugar occurred isomerism. Regarding the concentrations of short-chain fatty acids, both acetic acid and propionic acid were found to be significantly elevated in the treatment group compared to the control group, and the pH value dramatically decreased. Simultaneously, Polygonatum spp. polysaccharides could remarkably modulate the richness of microbial communities and improved their diversity, especially Narrowly Defined Clostridium, and Bacteroidetes. In general, this study can be helpful to better understand the potential digestion and fermentation mechanism of the genus Polygonatum polysaccharides.

Structural analysis, anti-inflammatory activity of the main water-soluble acidic polysaccharides (AGBP-A3) from Panax quinquefolius L berry

Background

Panax quinquefolius L, widely recognized for its valuable contributions to medicine, has aroused considerable attention globally. Different from the extensive research has been dedicated to the root of P. quinquefolius, its berry has received relatively scant focus. Given its promising medicinal properties, this study was focused on the structural characterizations and anti-inflammatory potential of acidic polysaccharides from the P. quinquefolius berry.

Materials and methods

P. quinquefolius berry was extracted with hot water, precipitated by alcohol, separated by DEAE-52-cellulose column to give a series of fractions. One of these fractions was further purified via Sephadex G-200 column to give three fractions. Then, the main fraction named as AGBP-A3 was characterized by methylation analysis, NMR spectroscopy, etc. Its anti-inflammatory activity was assessed by RAW 264.7 cell model, zebrafish model and molecular docking.

Results

The main chain comprised of α-L-Rhap, α-D-GalAp and β-D-Galp, while the branch consisted mainly of α-L-Araf, β-D-Glcp, α-D-GalAp, β-D-Galp. The RAW264.7 cell assay results showed that the inhibition rates against IL-6 and IL-1β secretion at the concentration of 625 ng/mL were 24.83 %, 11.84 %, while the inhibition rate against IL-10 secretion was 70.17 % at the concentration of 312 ng/mL. In the zebrafish assay, the migrating neutrophils were significantly reduced in number, and their migration to inflammatory tissues was inhibited. Molecular docking predictions correlated well with the results of the anti-inflammatory assay.

Conclusion

The present study demonstrated the structure of acidic polysaccharides of P. quinquefolius berry and their effect on inflammation, providing a reference for screening anti-inflammatory drugs.

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.

Characterization of the structure, anti-inflammatory activity and molecular docking of a neutral polysaccharide separated from American ginseng berries

AIM

American ginseng berries, grown in the aerial parts and harvested in August, are a potentially valuable material. The aim of the study was to analyze the specific polysaccharides in American ginseng berries, and to demonstrate the anti-inflammation effect through in vitro and in vivo experiments and molecular docking.

METHODS

After deproteinization and dialysis, the extracted crude polysaccharide was separated and purified. The structure of the specific isolated polysaccharide was investigated by Fourier Transform infrared spectroscopy (FT-IR), GC-MS and nuclear magnetic resonance (NMR), and anti-inflammatory activity was evaluated using in vitro and in vivo models (Raw 264.7 cells and zebrafish). Molecular docking was used to analyze the binding capacity and interaction with cyclooxygenase-2 (COX-2).

RESULTS

A novel neutral polysaccharide fraction (AGBP-A) was isolated from American ginseng berries. The structural analysis demonstrated that AGBP-A had a weight-average molecular weight (Mw) of 122,988 Da with a dispersity index (Mw/Mn) value of 1.59 and was composed of arabinose and galactose with a core structure containing →6)-Gal-(1→ residues as the backbone and a branching substitution at the C3 position. The side-chains comprised of α-L-Ara-(1→, α-L-Ara-(1→, →5)-α-L-Ara-(1→, β-D-Gal-(1→. The results showed that it significantly decreased pro-inflammatory cytokines in the cell model. In a zebrafish model, AGBP-A reduced the massive recruitment of neutrophils to the caudal lateral line neuromast, suggesting the relief of inflammation. Molecular docking was used to analyze the combined capacity and interaction with COX-2.

CONCLUSION

Our study indicated the potential efficacy of AGBP-A as a safe and valid natural anti-inflammatory component.

Acid-induced conformation regulation of peanut polysaccharide and its effect on stability and digestibility of oil-in-water emulsion

BACKGROUND

Developing the stable and healthy emulsion-based food is in accord with the needs of people for health. In the present study, acidification at pH 3.0 of peanut polysaccharide (APPSI) was employed to regulate its conformation and further improve its advantages in preparing oil-in-water emulsion.

RESULTS

The results indicated that acidification induced conversion of PPSI aggregates into linear chains. Increasing concentration promoted formation of cross-linked network structure shown in transmission electron microscopy images. Consequently, the viscosity, yield stress, storage modulus and flow activation energy significantly increased, further fabricating gel structure. Moreover, aggregation behavior suggested that more exposed proteins were involved in gel structure, thereby forming many hydrophobic cores as verified by fluorescence spectroscopy of pyrene. Afterwards, emulsion characteristics indicated that APPSI produced strong and thick steric hindrance around oil droplets and the coil-like interweaved chains locked the continuous phase, bringing strong elasticity and resistance to stress and creaming. Meanwhile, the lower fatty acid in APPSI-emulsion was released after simulated gastrointestinal digestion, mainly as a result of the high retention ratio of emulsion droplets. Furthermore, the elastic and viscous Lissajous curves suggested that the structure strength of APPSI-emulsion was similar to that of the salad dressing within the strain 53.22%.

CONCLUSION

The conformation of PPSI after acidification at pH 3.0 was suitable for preparing the stable emulsion. The obtained emulsion could resist digestion and maintain a strong structure, comprising a cholesterol-free and low-fat salad dressing substitute. © 2023 Society of Chemical Industry.

Influence of physicochemical changes and aggregation behavior induced by ultrasound irradiation on the antioxidant effect of highland barley β-glucan

The effect of ultrasonic treatment on the structure, morphology and antioxidant activity of highland barley β-glucan (HBG) was investigated. Ultrasonic treatment for 30 min was demonstrated to improve the aqueous solubility of HBG, leading to a decrease in turbidity. Meanwhile, moderate ultrasound was found to obviously reduce the particle size distribution of HBG, and transform the entangled HBG molecules into flexible and extended chains, which reaggregated to form larger aggregates under long-time ultrasonication. The in vitro antioxidant capacity of HBG treated by ultrasonic first increased and then decreased compared to native HBG. Congo red complexation analysis indicated the existence of helix structure in HBG, which was untwisted after ultrasonic treatment. Furthermore, ultrasound treatment influenced the glucopyranose on HBG, which weakened the intramolecular hydrogen bond of HBG. The microscopic morphology showed that the spherical aggregates in native HBG solution were disaggregated and the untangled HBG chains reaggregated with excessive ultrasonication.

Research Advances in the High-Value Utilization of Peanut Meal Resources and Its Hydrolysates: A Review

Peanut meal (PM) is a by-product of extracting oil from peanut kernels. Although peanut meal contains protein, carbohydrates, minerals, vitamins, and small amounts of polyphenols and fiber, it has long been used as a feed in the poultry and livestock industries due to its coarse texture and unpleasant taste. It is less commonly utilized in the food processing industry. In recent years, there has been an increasing amount of research conducted on the deep processing of by-products from oil crops, resulting in the high-value processing and utilization of by-products from various oil crops. These include peanut meal, which undergoes treatments such as enzymatic hydrolysis in industries like food, chemical, and aquaculture. The proteins, lipids, polyphenols, fibers, and other components present in these by-products and hydrolysates can be incorporated into products for further utilization. This review focuses on the research progress in various fields, such as the food processing, breeding, and industrial fields, regarding the high-value utilization of peanut meal and its hydrolysates. The aim is to provide valuable insights and strategies for maximizing the utilization of peanut meal resources.

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.

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

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

Emulsifying capacity of peanut polysaccharide: Improving interfacial property through the co-dissolution of protein during extraction

The co-dissolution of residual protein from byproduct (PPSI) was employed to improve the interfacial property of peanut polysaccharide (PPS). Protein content in the PPSI and PPS were 16.89% and 2.58%, respectively. The convent bonding and intermolecular interaction maintained the complex structure in PPSI. More protein promoted the shift from linear chain conformation to spherical particle, weakened surface charge, induced stronger intermolecular attraction and wettability, which facilitated interfacial adsorption of PPSI. Concomitantly, the linear chain after adsorbing the O/W interface was observed in PPSI-polystyrene, promoting the cross-linking between adsorption layers and thereby forming the elastic interfacial film. Consequently, the emulsion borne smaller size. Subsequently, the particles in continuous phase moved to the adsorption layer via intermolecular interaction and then formed a gel, enhancing stability against oil coalescence, the thermal and refrigerated treatments. Additionally, the acidified (pH 3.0) PPSI further strengthened the emulsion structure and improved its creaming and freeze-thaw stability.

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).

Structure, Antioxidant Activity and In Vitro Hypoglycemic Activity of a Polysaccharide Purified from Tricholoma matsutake

The structure, antioxidant activity and hypoglycemic activity in vitro of a novel homogeneous polysaccharide from Tricholoma matsutake (Tmp) were investigated. Structural features suggested that Tmp was consisted of arabinose (Ara), mannose (Man), glucose (Glc) and galactose (Gal) with a molar ratio of 1.9:13.6:42.7:28.3, respectively, with a molecular weight of 72.14 kDa. The structural chain of Tmp was confirmed to contain →2,5)-α-l-Arabinofuranose (Araf)-(1→, →3,5)-α-l-Araf-(1→, β-d-Glucopyranose (Glcp)-(1→, α-d-Mannopyranose (Manp)-(1→, α-d-Galacopyranose (Galp)-(1→, →4)-β-d-Galp-(1→, →3)-β-d-Glcp-(1→, →3)-α-d-Manp-(1→, →6)-3-O-Methyl (Me)-α-d-Manp-(1→, →6)-α-d-Galp-(1→, →3,6)-β-d-Glcp-(1→, →6)-α-d-Manp-(1→ residues. Furthermore, Tmp possessed strong antioxidant activity and showed the strong inhibitory effect on α-glucosidase and α-amylase activities. Then, a further evaluation found that there was a dramatic improvement in the glucose consumption, glycogen synthesis and the activities of pyruvate kinase and hexokinase when the insulin-resistant-human hepatoma cell line (IR-HepG2) was treated with Tmp. The above results indicated that Tmp had good hypoglycemic activity and also exhibited great potentials in in terms of dealing with type 2 diabetes mellitus.