Search

Polysaccharides are a major class of biomacromolecules. Their bioactivities depend on chemical structure, which includes monosaccharide composition, linkages below sugar residues, and solution conformation. Many researchers report that chemical modifications of polysaccharides lead to a significantly increase in the structural diversity, promoting bioactivity and even add new bioactivities, including antioxidant and anti-tumor properties as well as anticoagulant and immunoregulatory activities. This paper reviews the recent progress of chemical modification of polysaccharides, including i) the common synthetic methods of chemical modification; ii) their structural characterization; iii) their bioactivities; and iv) the structure activity relationships of these modified polysaccharides. This review also suggests future directions for researchers and new applications for chemically modified polysaccharide derivatives in the pharmaceutical and food industries. • Chemically modified polysaccharides of the past two decades of online review research. • These generalizations are better for people to understand the research status of chemical modified polysaccharides. • This review suggests future directions and new applications for researchers and in the pharmaceutical and food industries. [ABSTRACT FROM AUTHOR]

Coix seed polysaccharides had received increasing attention due to their diverse biological activities. In this study, a homogeneous polysaccharide (CSPW) was extracted and purified from coix seed. Furthermore, the saliva-gastrointestinal digestion and fecal fermentation behavior of CSPW were simulated in vitro. The results showed that CSPW was mainly composed of glucose. It cannot be degraded by the simulated salivary and intestinal digestive system, but can be degraded by the simulated gastric digestive system. After fermentation for 24 h, CSPW promoted the production of short-chain fatty acids (SCFAs), with acetic acid, propionic acid and n-butyric acid being the main metabolites. In addition, CSPW could significantly regulate the composition and microbial diversity of gut microbiota by increasing the relative abundance of beneficial bacteria, such as Limosilicactobacillus, Bifidobacterium and Collinsella. Finally, further analysis of functional prediction revealed that amino acid metabolism, nucleotide metabolism and carbohydrate metabolism were the most important pathways for CSPW to promote health. In summary, our findings suggested that CSPW could potentially be used as a good source of prebiotics because it can be used by gut microbiota to produce SCFAs and regulate the gut microbiota. • CSPW was a homogeneous polysaccharide from coix seed and can be consumed by gut microbiota. • CSPW was beneficial for the growth of beneficial bacteria and inhibited harmful microbiota. • The gut microbiota produced more beneficial metabolites by CSPW modulated. • CSPW showed the potential of prebiotics and had beneficial effects on the host. [ABSTRACT FROM AUTHOR]

Abstract: A novel water-soluble heteropolysaccharide termed PBF2 was isolated from the fruiting bodies of Phellinus baumii Pilát using hot water extraction and purified on Sephacryl S-1000. PBF2 was shown to be composed of l-fucose, d-mannose and d-glucose. Its structural characteristics were further investigated by FT-IR spectroscopy, sugar analysis, methylation analysis and NMR spectroscopy. Based on the data obtained, PBF2 was found to be a heteropolysaccharide containing a β-(1→6)-d-glucopyranose backbone with a fucosyl unit on O-3 of the 3,6-di-O-substituted-d-glucosyl units and it also contained a minor (1→3, 6)-β-d-mannose residue and terminal glucose residues. [Copyright &y& Elsevier]

Abstract Tremella fuciformis is an important edible mushroom that has been widely cultivated and used as food and medicinal ingredient in traditional Chinese medicine. In the past decades, many researchers have reported that T. fuciformis polysaccharides (TPS) possess various bioactivities, including anti-tumor, immunomodulatory, anti-oxidation, anti-aging, repairing brain memory impairment, anti-inflammatory, hypoglycemic and hypocholesterolemic. The structural characteristic of TPS has also been extensively investigated using advanced modern analytical technologies such as NMR, GC–MS, LC-MS and FT-IR to dissect the structure-activity relationship (SAR) of the TPS biomacromolecule. This article reviews the recent progress in the extraction, purification, structural characterization and applications of TPS. [ABSTRACT FROM AUTHOR]

A water-soluble heteropolysaccharide (PUP60W-1) was purified from the hot water extract of sclerotia of P. umbellatus by chromatography with DEAE Sepharose Fast Flow and Sephacryl S200 High-Resolution. The primary structure of PUP60W-1 was elucidated by GC, GC–MS and NMR. PUP60W-1 was identified as a highly branched polysaccharide composed of fucose, glucose and galactose in a ratio of 1.0:0.9:13.3. The main repeating unit was identified as α-(1 → 6)- d -galactopyranan backbone with substitution of terminal α-galactopyranosyl residues at O -2 for two out of every three main chain galactose residues. Its chain conformation was studied by atom force microscopy and size exclusion chromatography coupled with multiple detectors. The results revealed that PUP60W-1 had a molecular weight of 2.47 × 10 4 Da with a polydispersity index of 1.04, and existed in water as compact sphere structures which could be disrupted into smaller spherical chain blocks after dispersion with sodium dodecyl sulfate. [ABSTRACT FROM AUTHOR]

A novel water-soluble polysaccharide PUP60S2, with a molecular weight of 1.44 × 10 4 Da, was obtained from the sclerotia of Polyporus umbellatus by hot water extraction, ethanol precipitation, anion-exchange and size-exclusion chromatography. PUP60S2 was a polysaccharide comprised of about 22.3% glucuronic acid. Monosaccharide composition analysis showed that PUP60S2 was only comprised of glucose and glucuronic acid. Reduction of carboxyl groups, sugar analysis, methylation analysis, together with one and two dimension NMR spectra disclosed that the backbone of PUP60S2 consisted of (1 → 6)-β- d -glucopyranosyl, every second of which was substituted at O -3 by side chains consisting of terminal β- d -Glc p , (1 → 3)-β- d -Glc p , (1 → 3)-β- d -Glc p A, (1 → 4)-β- d -Glc p and (1 → 4)-β- d -Glc p A units. The antioxidant activity assay in vitro showed that PUP60S2 exerted a significant scavenging effect on DPPH, hydroxyl radical and superoxide radical in a dose-dependent manner. [ABSTRACT FROM AUTHOR]

Highlights: [•] It was isolated and purified by columns of DEAE-Sepharose F. F. and Sephacryl S H.R. [•] It was a homogeneous polysaccharide and the molecular weight was estimated to be 1.08×104 Da by HPLC. [•] The composition of it was determined as l-fucose, d-mannose, d-glucose and d-galactose by GC analysis. [•] Its structure was determined by MS, along with 1H, 13C and 2D NMR spectroscopy. [ABSTRACT FROM AUTHOR]

Highlights: [•] We purified a novel water-soluble polysaccharide from Wedelia prostrata called WPP60A. [•] Homogeneity and molecular weight (2.40×103 Da) of WPP60A were determined by HPLC. [•] Its structure was established by GC–MS, 1H, 13C, and 2D NMR analysis. [•] The repeating unit consists of [β-d-Fruf-(6→2)-β-d-Fruf-]. [ABSTRACT FROM AUTHOR]

Abstract: A novel water-soluble heteropolysaccharide (PEPS1), with a molecular weight of 1.88×104 Da as determined by high performance liquid chromatography (HPLC), specifically size exclusion chromatography, was isolated from the fruiting bodies of Pleurotus eryngii by hot water extraction and further purification by DEAE Sepharose Fast Flow and Sephacryl S-300 and S-100 High-Resolution chromatography. By use of compositional analysis, methylation analysis, together with 1H, 13C NMR and 2D NMR spectroscopy including COSY, TOCSY, HMQC, HMBC and NOESY experiments, the PEPS1 was identified as a heteropolysaccharide that consists of a α-d-(1→6)-Galactopyranan backbone with a β-d-Mannosyl unit on O-2 of the 2,6-di-O-substituted-d-Galactosyl units, α-(1→6)-3-O-Me-d-Galactopyranan backbone with a terminal α-3-O-Me-d-Galactosyl unit and it also contained a minor 2,3,6-α-d-Galatopyranan units and 4-β-d-Mannopyranan residues. [Copyright &y& Elsevier]

Abstract: A novel water-soluble polysaccharide named PGPB-1, with a molecular weight of 1.3×104 Da as determined by high-performance liquid chromatography (HPLC), was isolated from the fruiting bodies of Pleurotus geesteranus by boiling water as well as DEAE-Sepharose Fast Flow and High-Resolution Sephacryl S-300. On the bases of compositional analysis, methylation analysis and NMR spectroscopy (1H NMR, 13C NMR, 2D-COSY, TOCSY, HMQC, HMBC and NOESY spectra) analysis, the structural elucidation of PGPB-1 consisted of a α-d-(1→6)-galactopyranan and a α-d-3-O-Me-d-galactosyl unit backbone with a α-d-Mannosyl unit on O-2 of the 2,6-di-O-substituted-d-galactosyl units. The repeating unit of the polysaccharide was established as: Display Omitted PGPB-1 also contains a minor proportion of 6-linked-d-Glcp. [Copyright &y& Elsevier]

Abstract: A new heteropolysaccharide (HEPF4), with a molecular weight of 2.03×104 Da as determined by high-performance liquid chromatography (HPLC), was obtained from the fruiting bodies of Hericium erinaceus. It is composed of 3-O-methylrhamnose, l-fucose, d-galactose and d-glucose in the ratio of 0.12:1.00:3.27:0.28. Its chemical structure was characterized by sugar and methylation analysis, along with 1H and 13C NMR spectroscopy, including NOESY and HMBC experiments for linkage and sequence analysis. The polysaccharide is composed of a tetrasaccharide repeating unit (described in the results section). HEPF4 also contains a minor proportion of glucose and 3-O-methylrhamnose which is believed to terminate the polymer main chain. [Copyright &y& Elsevier]

Abstract: A novel water-soluble heteropolysaccharide FVP60-B was extracted from the fruiting bodies of Flammulina velutipes with boiling water and purified by Sephacryl S-300 and S-400, which molecular weight was estimated to be 1.3×104 Da by HPLC. It is composed of l-fucose, d-mannose, d-glucose and d-galactose in a ratio of 1.16:0.82:1.00:3.08. Sugar analysis, methylation analysis together with 1H, 13C and 2D NMR spectroscopy disclosed that FVP60-B is consisted of a α-(1→6)-d-galactopyranan backbone with a terminal fucosyl, terminal glucosyl and α-(1→6)-d-mannopyranan units on O-2 of 2,6-O-substituted-d-galactosyl units. [Copyright &y& Elsevier]