Water-soluble Neutral Polysaccharide Research Articles

Structure characterisation of polysaccharides purified from Boletus aereus Bull. and its improvement on AD-like behaviours via reliving neuroinflammation in APP/PS1 mice

The water-soluble neutral polysaccharide BEP2, with a molecular weight of 26.65 kDa, was isolated from the aqueous extract obtained from the fruiting bodies of Boletus aereus Bull. BEP2 primarily comprises Gal, with specific site substitutions speculated at partial positions, such as the substitution of -OCH3 at position H-3 or the branch at position C-2 including α-L-Fucp-(1→, α-D-Manp-(1 → and α-D-Manp-(1 → 3)-α-L-Fucp-(1 → 6)-β-D-Glcp-(1→. Treatment with BEP2 significantly enhanced learning, memory, and cognitive function, while concurrently reducing the accumulation of β-amyloid and suppressing neuroinflammation within the brains of APP/PS1 mice. Based on the results of biochemical detection, gut microbiota analysis, and metabolomic profiling, we found that BEP2 significantly upregulated the abundance of two bacterial families while downregulation that of seven bacterial families within the intestinal ecosystem. Notably, the abundance of the S24–7 family was significantly increased. Treatment with BEP2 upregulated five metabolites, while downregulating three metabolites, including norepinephrine. Additionally, BEP2 decreased the levels of interleukin (IL)-1β and IL-6, regulated the activities of microglial cells and astrocytes and increased the levels of the chemokine fractalkine (CX3CL1) and its receptor on microglia (CX3CR1), as well as that of transforming growth factor (TGF)-β1. These findings confirmed the suppressive effects of BEP2 on neuroinflammation.

Structure characterization of an arabinogalactan from Cynanchum atratum and its immune stimulatory activity on RAW264.7 cells

In the present study, a water-soluble neutral polysaccharide (CAPW-1) with an average molecular weight of 64 kDa was purified from the root of Cynanchum atratum Bunge (Apocynaceae). The monosaccharide residue analysis revealed that CAPW-1 was composed of arabinose and galactose with a relative molar ratio of 7: 3. The backbone of CAPW-1 was consisted of 1,3-Galp and 1,3,6-Galp, the branches were attached to the O-6 of 1,3-Galp, and the side chains contained 1,6-Galp, 1,3,6-Galp, 1,5-linked, 1,3-linked, 1,3,5-linked, and terminal-Araf, which was attached to the O-3 of side 1,6-Galp. The bioactivity study indicated CAPW-1 could stimulate the proliferation of RAW264.7 cells and promote the secretion of nitric oxide (NO), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) with no cytotoxicity. The results suggested a potential application of CAPW-1 as an immunostimulant for the treatment of diseases such as infection and tumor.

Structural characterization, antioxidant and immunomodulatory activities of a neutral polysaccharide from Cordyceps militaris cultivated on hull-less barley

A water-soluble neutral polysaccharide (SDQCP-1) was isolated from fruit bodies of Cordyceps militaris cultivated on hull-less barley. SDQCP-1 was composed of mannose, glucose and galactose in the mole ratio of 13.3:1.0:9.7, with an average molecular weight of 19.3 kDa. Based on results from methylation analysis, GC–MS and NMR, SDQCP-1 was elucidated to be a glucogalactomannan with a backbone composed of (1→2)-α-D-Manp (48.4 %) and (1 → 4)-β-D-Glcp (1.2 %) residues. Its side chains were branched at O-6 position of (1→2)-α-D-Manp mainly by (1 → 2)-β-D-Galf or (1 → 6)-α-D-Manp residues which were terminated mainly with α-D-Galf, α-D-Galp residues. Besides exhibiting a good antioxidant capacity with an ORACFL value of 24.7 mmol Trolox/g and a TEAC value of 202.4 μmol Trolox/g, SDQCP-1 also could stimulate macrophages to release NO, TNF-α, IL-6, and IL-10, and mainly induced M1 polarization of macrophages. The findings indicated that SDQCP-1, from C. militaris cultivated on hull-less barley, could be used as potential natural antioxidant and immunomodulator in functional foods or medicine.

Isolation, characterization, and microwave assisted surface modification of Colocasia esculenta (L.) Schott mucilage by grafting polylactide

Mucilage (represented as CEM) is abundantly present in Colocasia esculenta (L.) Schott or taro and is a water-soluble neutral polysaccharide that can act as a binder, thickening agent, and matrix agent in the pharmaceutical fields of research. Presence of hydroxyl groups on its surface structure allows chemical modification. This study describes in details the synthesis and characterization of its graft copolymer with polylactide (CEM-g-PLA). The polymerization has performed using both the microwave irradiation and conventional methods. Ring opening polymerization of lactide onto the mucilage carried out in presence of stannous octoate as catalyst in chloroform medium produced CEM-g-PLA copolymer under optimum condition. The structure of CEM-g-PLA copolymers obtained from both the methods were comprehensively characterized for their physicochemical and thermal properties by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD), differential scanning colorimetric (DSC), thermo-gravimetric analysis (TGA/DTG) and Dynamic light scattering (DLS) measurements. Grafting of lactide onto CEM backbone has changed its water absorption capacity, solubility and swelling power, morphology, crystalline structure, and thermal property of the mucilage. The newly synthesized CEM-g-PLA copolymer may find potential applications in wastewater treatment and for sustained and controlled drug delivery systems.

Cooperative Order–Disorder Transition of Carboxylated Schizophyllan in Water–Dimethylsulfoxide Mixtures

Carboxylated schizophyllan ("sclerox") is a chemically modified polysaccharide obtained by partial periodate oxidation and subsequent chlorite oxidation of schizophyllan, a water-soluble neutral polysaccharide having a β-1,3-linked glucan backbone and a β-1,6-linked d-glucose residue side chain at every third residue of the main chain. The triple helix of schizophyllan in water has a cooperative order-disorder transition associated with the side chains. The transition is strongly affected by the presence (mole fraction) of dimethylsulfoxide (DMSO). In the present study, the solvent effects on the order-disorder transition of sclerox with different degrees of carboxylation (DS) in water-DMSO mixtures were investigated with differential scanning calorimetry and optical rotation. The transition temperature ( Tr) and transition enthalpy (Δ Hr) strongly depended on the mole fraction of DMSO ( xD). Data were further analyzed with the statistical theory for the linear cooperative transition, taking into account the solvent effect, where DMSO molecules are selectively associated with the unmodified side chains. The modified side chain does not contribute to the transition; hence, Δ Hr decreases with increasing DS. The dependence of Tr on the DMSO content becomes weaker than that for unmodified schizophyllan. The theoretical analyses indicated that the number of sites binding with the DMSO molecule and the successive ordered sequence of the ordered unit of the triple helix are changed by carboxylation.

Purification and Structural Characterization of a Novel Water-Soluble Neutral Polysaccharide from Cantharellus cibarius and Its Immunostimulating Activity in RAW264.7 Cells

Polysaccharide is one of the important active ingredients of Cantharellus cibarius. The aims of this work were to analyze preliminary characterization and to investigate immunostimulating activity of a novel water-soluble neutral polysaccharide named JP1, which was purified from the fruiting body of Cantharellus cibarius using DEAE-FF chromatography and Sephadex G-100 chromatography. The characteristics of JP1 were determined by HPGPC, FT-IR spectra, gas chromatography, and Congo Red Method. Immunostimulating activity of JP1 was investigated in RAW264.7 cells. Results indicated that JP1 consisted of L-Arabinose, D-Mannose, D-Glucose, and D-Galactose in a molar ratio of 1 : 1.06 : 1.95 : 1.17 with a molecular weight of 336 kDa. JP1 is nontoxic to RAW264.7 cells at this concentration range (62.5–1000 μg/mL). Furthermore, JP1 can promote mouse peritoneal macrophages to secrete NO and enhance the secretion of macrophages’ cytokines IL-6 in RAW264.7 cells. These results suggested that JP1 could have potential immunostimulating activity applications as medicine or functional food.

Physicochemical properties and structural characterization of a galactomannan from Sophora alopecuroides L. seeds

A water-soluble neutral polysaccharide (F25) was fractionated from crude polysaccharides of Sophora alopecuroides L. seeds. Its physicochemical properties and structural characterization were investigated. The I2-KI and Congo red reactions showed F25 possessed many branches without triple-helical conformation, which coincided with methylation and NMR analyses, i.e., F25 was a galactomannan with 1,4-linked β-d-Manp backbone distributed randomly (M/G 1.48–1.84) by major T-α-d-Galp (86.82%) or minor 1,4-linked α-d-Galp (13.18%) at O-6. Compared with [η] of deionized water (2.98dL/g), it was indicated that NaCl (2.89–2.90dL/g) and NaOH (2.27–2.28dL/g) could affect intrinsic interactions and conformation of F25 in solution, leading to molecular non-entanglements and intramolecular associations. This was demonstrated by 3D molecular modeling. Furthermore, the amorphous nature of F25 was revealed with higher crystallinity (25.7%) and crystallite size (7.6nm) compared to other polysaccharides. In this study, the possible relationships between molecular structure and physicochemical properties were obtained for F25, which could be potentially applied in food and pharmaceutical industries.

Chemical composition and bioactivities of a water-soluble polysaccharide from the endodermis of shaddock

The chemical composition of shaddock (Citrus paradisi) mainly consisted of polyphenols, proteins and polysaccharides. However, polysaccharides from shaddock materials have received much less consideration than polyphenols. Herein, a water-soluble neutral polysaccharide from the endodermis of shaddock was isolated and showed good bioactivities. Crude polysaccharides from the endodermis of shaddock (EPS) was extracted with hot water and separated on a DEAE Sepharose FF gel filtration column to obtain NEPS. The IR and UV spectra of NEPS showed that NEPS was mainly composed of polysaccharide and there are no proteins existing in NEPS. The DPPH radical scavenging and reducing power of NEPS are much lower than those of crude EPS; however, Citrus flavonoids significantly improved the DPPH radical scavenging potential and reducing power of NEPS. The crude EPS (5mg/mL) showed a similar inhibitory effect (77.92±5.03%) with NEPS (5mg/mL) (74.63±4.71%) on α-amylase.

Branching Structure and Chain Conformation of Water-Soluble Glucan Extracted from Auricularia auricula-judae

A water-soluble neutral polysaccharide (AF1) was extracted from Auricularia (A.) auricula-judae with 0.15 M aqueous NaCl at 80-100 °C. Its chemical components and structure were analyzed by GC, GC-MS, and NMR. AF1 was identified as a β-(1→3)-D-glucan with two β-(1→6)-D-glucosyl residues for every three main chain glucose residues, showing a comb-branched structure. The M(w) values of AF1 in both aqueous solution and DMSO determined by LLS and SEC-LLS were in the narrow range of 2.07-2.15 × 10(6), indicating AF1 existed as single chains in the two solvents. The high intrinsic viscosity [η] of 1753 mL/g and the structure-sensitive parameter ρ (≡R(g)/R(h)) value of 2.3 in water revealed that AF1 existed as stiff chain conformation. Moreover, we directly observed the extended stiff chain conformation by AFM. The branching structure led to the water solubility of AF1, and the intramolecular hydrogen bonds sustained the stiff chain conformation. The rheological results showed that this polysaccharide aqueous solution had higher viscosity than even xanthan, a pronounced thickening agent. This work provided important information for developing new thickeners in food fields, and how neutral polysaccharides can be used as good candidates.

Purification and structural characterization of a new water-soluble neutral polysaccharide GLP-F1-1 from Ganoderma lucidum

A water-soluble neutral polysaccharide (GLP-F1-1) was isolated from the fruiting bodies of Ganoderma lucidum by DEAE Sepharose Fast Flow and Sephacryl S-500 High Resolution Chromatography. The neutral polysaccharide had an average molecular weight ( M w) of approximately 2.5 × 10 6 kDa. GC analysis showed that this polysaccharide was mainly composed of glucose and galactose in the molar ratio of 34:1. 1H and 13C NMR spectroscopy in combination with GC–MS technique indicated that the new polysaccharide had a backbone chain of 1,4-disubstituted-β-glucoseopyranose and 1,4,6-trisubstituted-β-glucoseopyranosyl, while the branched chains were mainly composed of 1,6-disubstituted-β-glucopyranosyl and 1,4-disubstituted-β-galactoseopyranosyl residues.

A neutral polysaccharide from the abalone pleopod, Haliotis discus hannai Ino

For the first time, a water-soluble neutral polysaccharide, APP, was obtained from abalone pleopod (Haliotis Discus Hannai Ino) by proteolytic method with papain followed by precipitation with ethanol and purification with gel chromatography. The results of HPLC with TSK-gel column and gel filtration chromatography with Sepharose CL-6B indicated APP was uniform in polarity and its molecular weight (MW) was about 6 kDa. According to chemical methods, IR spectroscopy, and NMR spectroscopy, APP consists of 1-, 1,4-, 1,6-, 1,4,6-linked glucose and 1-, 1,3-, 1,6-, 1,4,6-linked galactose.

Sulphite and oxidative—reductive depolymerization reactions

Addition of sulphite at levels between 0.004 and 1% helps to protect the water soluble neutral polysaccharide guar gum from thermal degradation. The greater the amount of sulphite incorporated the more viscous the guar is post-retorting. Starch granules, from a wide range of sources, swell when heated in excess water. The amount of polysaccharide released from the swollen granule after pasting for 60 min at 95 °C is increased by the inclusion of low levels (~0.01%) of sulphite. For cassava starch, a pronounced minimum in swelling volume is observed at this sulphite level. This minimum has been related to the pro-oxidant activity of the sulphite in contrast to the antioxidant activity shown for the guar. Intrinsic viscosity data indicates that the action of the sulphite is to degrade the polysaccharides within the starch granule and this can be reduced by scavenging oxygen from the system or by the addition of propyl gallate. It therefore appears that low levels of sulphite protect guar gum from degradation but can cause degradation of the starch polysaccharides.

THE COMPOSITION AND PHYLOGENETIC SIGNIFICANCE OF THE MOUGEOTIA (CHAROPHYCEAE) CELL WALL1

ABSTRACTThe two‐layered, fibrillar cell wall of Mougeotia C. Agardh sp. consisted of 63.6% non‐cellulosic carbohydrates and 13.4% cellulose. The orientation of cellulose microfibrils in the native cell wall agrees with the multinet growth hypothesis, which has been employed to explain the shift in microfibril orientation from transverse (inner wall) toward axial (outer wall). Monosaccharide analysis of isolated cell walls revealed the presence of ten sugars with glucose, xylose and galactose most abundant. Methylation analysis of the acid‐modified, 1 N NaOH insoluble residue fraction showed that it was composed almost exclusively of 4‐linked glucose, confirming the presence of cellulose. The major hemicellulosic carbohydrate was semi‐purified by DEAE Sephacel (Cl−) anion‐exchange chromatography of the hot 1 N NaOH soluble fraction. This hemicellulose was a xylan consisting of a 4‐xylosyl backbone and 2,4‐xylosyl branch points. The major hot water soluble neutral polysaccharide was identified as a 3‐linked galactan. Mougeotia cell wall composition is similar to that of (Charophyceae) and has homologies with vascular plant cell walls. Our observations support transtructural evidence which suggests that members of the Charophyceae represent the phylogenetic line that gave rise to vascular plants. Therefore, the primary cell walls of vascular plants many have evolved directly from structures typical of the filamentous green algal cell walls found in the Charophyceae.

ISOLATION, CHARACTERIZATION AND ENZYMIC HYDROLYSIS OF PINEAPPLE GUM

ABSTRACTPineapple gum was isolated and characterized. The gum was a cold. water soluble neutral polysaccharide composed predominantly of galactomannans. Solutions of pineapple gum formed viscous solutions which tended to foam. Studies on the enzymic hydrolysis showed that some commercial enzymes, specifically pectinases, cellulases and hemi‐ cellulases, were effective in degrading pineapple gum.