A water-soluble polysaccharide from the roots of Eremurus spectabilis M. B. subsp. spectabilis: Extraction, purification and structural features

Lipid-Lowering Effects of a Novel Polysaccharide Obtained from Fuzhuan Brick Tea In Vitro

Lipid accumulation causes diseases such as obesity and abnormal lipid metabolism, thus impairing human health. Tea polysaccharide is one of the natural, active substances that can lower lipid levels. In this paper, an oleic-acid-induced HepG2 cell model was established. The lipid-lowering effects of a novel group of Fuzhuan brick tea polysaccharides (FTPs)-obtained from Fuzhuan brick tea-were examined in vitro. The monosaccharide composition of FTP3 was Glc, Gal, Ara, Man, Rha, GalAc, GlcAc, and Xyl with a molar ratio of 23.5:13.2:9.0:5.5:5.4:2.7:1.3:1.0, respectively. A molecular weight of 335.68 kDa was identified for FTP3. HepG2 cells treated with FTP3 achieved a prominent lipid-lowering effect compared with cells treated with oleic acid. Images of the Oil Red O staining treatment showed that FTP3-treated groups had significantly fewer red fat droplets. TC and TG levels were lower in FTP3-treated groups. FTP3 alleviated lipid accumulation in HepG2 cells, activated AMPK, and decreased the SREBP-1C and FAS protein expressions associated with fatty acid synthesis. FTP3 holds promising potential for its lipid-lowering effects.

Preparation and characterization of active Cirish fructans-fish gelatin film: Physicochemical, antioxidant, and antimicrobial properties

This study was aimed to evaluate the film-forming ability and characterization of ultrasonically extracted Cirish fructans (CF) and CF-cold-water fish gelatin (G) composite films. The film-forming solutions were prepared at different levels (CF100-0G, CF75-G25, CF50-G50, CF25-G75, and CF0-G100) and the corresponding data were analyzed based on one-way analysis of variance. The results indicated that CF addition led to an impressive increase in composite films thickness (69.38-86.45 μm), moisture content (16.05%-27.8%), surface hydrophobicity, tensile strength (5.73-17.89 MPa), elongation at break (0.83%-1.66%), Young's modulus (77.12-88.15 MPa), and Tg (38.83-47.4°C) which CF75-G25 had the highest values. Meanwhile, the solubility (77.12%-88.15%), WVP (1.89-2.86 × 10^-10gm^-1 s^-1 Pa^-1), and oxygen permeability (1.53-3.26 × 10¹⁴ cm³ m^-1 s^-1 Pa^-1) of the composite films decreased. The FTIR spectra indicated the protein-polysaccharide interactions and revealed that the secondary structure of gelatin was shifted from triple-helix structure (1661 cm^-1) toward α-helix structure (1650-1657 cm^-1) when CF was incorporated. The microstructure observations indicated that unlike gelatin film, CF film exhibited the smooth and uniform surface without cracks and phase separation. It was found that CF films had high total phenolic content (6.73 mg GEA g^-1) and showed DPPH radical scavenging activity (67.86%). On the other hand, it showed inherent antimicrobial activity against both gram-positive and gram-negative bacteria. The results indicated that CF and CF-cold fish gelatin have great potential as active films with improved physical, mechanical, and barrier properties.

Structural Features and Immunomodulatory Effects of Water-Extractable Polysaccharides from Macrolepiota procera (Scop.) Singer

Macrolepiota procera (MP) is an edible mushroom used in the treatment of diabetes, hypertension and inflammation. However, the structure and biological effects of its polysaccharides (PSs) are unclear. This study investigates the structural features of a PS complex from MP (MP-PSC), its immunomodulatory activities and effects on probiotic and pathogenic bacteria. MP-PSC was obtained by boiling water, and PSs were characterized by 2D NMR spectroscopy. The immunomodulatory effects on blood and derived neutrophils, other leukocytes, and murine macrophages were studied by flow cytometry, chemiluminescence, spectrophotometry, and ELISA. The total carbohydrate content of MP-PSC was 74.2%, with glycogen occupying 36.7%, followed by β-D-glucan, α-L-fuco-2-(1,6)-D-galactan, and β-D-glucomannan. MP-PSC (200 μg/mL) increased the number of CD14+ monocyte cells in the blood, after ex vivo incubation for 24 h. It dose-dependently (50–200 μg/mL) activated the spontaneous oxidative burst of whole blood phagocytes, NO, and interleukin 6 productions in RAW264.7 cells. MP-PSC exhibited a low antioxidant activity and failed to suppress the oxidative burst and NO generation, induced by inflammatory agents. It (2.0%, w/v) stimulated probiotic co-cultures and hindered the growth and biofilm development of Escherichia coli, Streptococcus mutans and Salmonella enterica. MP PSs can be included in synbiotics to test their immunostimulating effects on compromised immune systems and gut health.

Structure characterization, antioxidant and emulsifying capacities of exopolysaccharide derived from Pantoea alhagi NX-11

Pantoea alhagi exopolysaccharides (PAPS) have been shown to enhance crop resistance to abiotic stress. However, physicochemical properties and structure of PAPS have not yet been analyzed. In this study, two PAPSs, named PAPS1 and PAPS2, were isolated and purified from the P. alhagi NX-11. The results showed PAPS1 and PAPS2 were composed of glucose, galactose, glucuronic acid, glucosamine and mannose with average molecular weight of 1.326 × 10⁶ Da and 1.959 × 10⁶ Da, respectively. Moreover, the structure of PAPS1 and PAPS2 was investigated by FT-IR and NMR analysis. PAPS1 was identified to have the backbone structure of →4)-β-D-GlcpA-(1→2)-α-D-Galp-(1→3)-β-D-Galp-(1→3)-β-D-GlcpN- (1→3)-α-D-Galp-(1→3)-β-D-Galp-(1→. PAPS2 had the backbone structure of →4)-β-D-GlcpA-(1→2)-α-D-Galp-(1→3)-β-D-Glcp-(1→3)-β-D-GlcpN-(1→3)-α-D-Galp-(1→3)-α-D-GlcpN-(1→. In addition, PAPS1 and PAPS2 had moderate antioxidant and emulsifying capacities. Overall, the structure analysis of PAPS may point out the direction for the subsequent study of PAPS-mediated microbial and plant interactions, and further exploration of the application of PAPS.

Characterization of selenized polysaccharides from Ribes nigrum L. and its inhibitory effects on α-amylase and α-glucosidase

The polysaccharide from Ribes nigrum L. (RCP) was modified by nitric acid-sodium selenite method. After purification by Sepharose-6B, high purity native (PRCP) and three selenized polysaccharides (PRSPs) with different selenium contents were obtained. Compared with PRCP, PRSPs possessed the lower molecular weight, better water-solubility, physical stability and rheological properties. FT-IR and NMR spectra confirmed PRSPs had the characteristic absorption peaks of polysaccharides and the glycosidic bond types were not changed after selenylation modification, whereas the selenyl groups existing in PRSPs were mainly introduced at the C-6 position of sugar residue →4)-β-d-Manp-(1→. Moreover, PRSPs displayed obviously smoother and smaller flaky structure than PRCP, and their inhibitory effects on α-amylase and α-glucosidase also were greater than PRCP. PRSPs exhibited a reversible inhibition on two enzymes in competitive manner and quenched their fluorescence through the static quenching mechanism. The polysaccharide-enzyme complex was spontaneously formed mainly driven by the hydrophobic interaction and hydrogen bonding.

Structure, preparation, modification, and bioactivities of β-glucan and mannan from yeast cell wall: A review

In order to solve the antibiotic resistance, the research on antibiotic substitutes has received an extensive attention. Many studies have shown that β-glucan and mannan from yeast cell wall have the potential to replace antibiotics for the prevention and treatment of animal diseases, thereby reducing the development and spread of antibiotic-resistant bacterial pathogens. β-Glucan and mannan had a variety of biological functions, including improving the intestinal environment, stimulating innate and acquired immunity, adsorbing mycotoxins, enhancing antioxidant capacity, and so on. The biological activities of β-glucan and mannan can be improved by chemically modifying its primary structure or reducing molecular weight. In this paper, the structure, preparation, modification, and biological activities of β-glucan and mannan were reviewed, which provided future perspectives of β-glucan and mannan.

Degradation models, structure, rheological properties and protective effects on erythrocyte hemolysis of the polysaccharides from Ribes nigrum L

The polysaccharides from blackcurrant (Ribes nigrum L.) fruits were degraded by ultrasonic irradiation. Results showed that viscosity-average molecular weight decreased with increasing ultrasonic time or power. The degradation was fitted to the second-order kinetics model and midpoint chain scission model. Gas chromatographic analysis demonstrated that the native polysaccharide and three degraded polysaccharides were composed of the same monosaccharides but in different ratios. Fourier transform infrared and nuclear magnetic resonance spectroscopic analyses revealed the presence of α-, β-pyranose rings and the same six sugar residues in the four blackcurrant polysaccharides. Compared to the native polysaccharide, three degraded polysaccharides displayed better rheological properties and stronger protective effects against erythrocyte hemolysis. Collectively, the results support the potential utility of blackcurrant polysaccharides as natural antioxidants.

Production, medium optimization, and structural characterization of an extracellular polysaccharide produced by Rhodotorula minuta ATCC 10658

Several strains of microorganism are capable of converting carbohydrates into extracellular polysaccharide. The preset research is a first effort made to optimize extracellular polysaccharide (CRMEP) by Rhodotorula minuta ATCC 10658 using one factor at time and response surface methods. One factor at time was applied in the initial screening of substrates prior to optimization study. Of all the substrates examined, starch as carbon source and defatted soy bean powder as protein source were discovered to be best for CRMEP production. Response surface analysis revealed that 15 g/L starch and 30g/L defatted soy bean powder were the optimal chemical conditions. The model predicted 13.22 g/L for CRMEP, which went along with the experimentally observed result. Purification of CRMEP by anion-exchange column of DEAE-cellulose yielded RMEP. Structural investigation indicated that the main chain of RMEP was composed of (1 → 3) and (1 → 4)-linked mannopyranosyl residues, with branches attached to O-6 of some (1 → 3)-linked mannopyranosyl residues. The branches were composed of Glcp-(1 → residues.