Neutral Polysaccharide (neutral + polysaccharide)

Distribution by Scientific Domains

Selected Abstracts

Antiviral activity and constituent of Ardisia chinensis benth against coxsackie B3 virus

Miaoxian Su
Abstract Ardisia chinensis Benth is a medicinal plant traditionally used in the area of Yao minority in Southern China. The in vitro antiviral activities of extracts and fractions from Ardisia chinensis were tested by the cytopathic effect (CPE) reduction assay in the present study. As a result, both the aqueous extract and the 95% ethanol extract of Ardisia chinensis showed in vitro antiviral activity against Coxsackie B3 (Cox B3) virus to different extents, and the aqueous extract possessed more potent activity than the ethanol extract. Bioassay-guided fractionation revealed that the antiviral activity of Ardisia chinensis was attributed mainly to its high polar fractions, and finally identified to be a polysaccharide. The Ardisia chinensis polysaccharide (ACP) fractionated from the aqueous extract exhibited a significant antiviral effect against Cox B3 with a 50% inhibitory concentration (IC50) of 3.9 g/mL and a selective index (SI) over 256. Preliminary characterization indicated that ACP is a neutral polysaccharide in which d -glucose is the major component. The average molecular weights of ACP were determined to be 40037 Da (Mw), 28297 Da (Mn) and 33758 Da (Mp) by gel permeation chromatography. Copyright 2006 John Wiley & Sons, Ltd. [source]

Heating-induced conformational change of a novel ,-(1,3)- D -glucan from Pleurotus geestanus

BIOPOLYMERS, Issue 2 2010
Mei Zhang
Abstract Recently, we isolated and purified a neutral polysaccharide (PGN) from edible fungus Pleurotus geestanus. Its structure was characterized by a range of physical,chemical methods, including high performance anion exchange chromatography, uronic acid, and protein analyses, size exclusion chromatography with ultraviolet, refractive index and light scattering detectors, and nuclear magnetic resonance. Our results revealed that PGN is a novel ,-(1,3)- D -glucan with glucose attached to every other sugar residues at Position 6 in the backbone. It has a degree of branching of 1/2. Such structure is different from typical ,-(1,3)- D -glucans schizophyllan and lentinan in which DB is 1/3 and 2/5, respectively. Rheological study showed a very interesting melting behavior of PGN in water solution: heating PGN in water leads to two transitions, in the range of 8,12.5C and 25,60C, respectively. The melting behavior and conformational changes were characterized by rheometry, micro-differential scan calorimetry, atomic force microscopy, static and dynamic light scattering at different temperatures. The first heating-induced transition corresponds to the disintegration of polymer bundles into small helical clusters, resembling the heating-induced dissociation of SPG in water at 7C; the second one might correspond to the dissociation of helical strands to individual chains. The ability of PGN to undergo a conformation/viscosity transition in water upon heating is very valuable to immobilize cells or enzymes or therapeutic DNA/RNA, which makes PGN a potentially useful biomaterial. 2009 Wiley Periodicals, Inc. Biopolymers 93: 121,131, 2010. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at [source]

Similarity of permeabilities for Ficoll, pullulan, charge-modified albumin and native albumin across the rat peritoneal membrane

D. Asgeirsson
Abstract Aim:, Compared to neutral globular proteins, neutral polysaccharides, such as dextran, pullulan and Ficoll, appear hyperpermeable across the glomerular filtration barrier. This has been attributed to an increased flexibility and/or asymmetry of polysaccharides. The present study investigates whether polysaccharides are hyperpermeable also across the continuous capillaries in the rat peritoneum. Methods:, In anaesthetized Wistar rats, FITC,Ficoll or FITC,pullulan together with 125I-human serum albumin (RISA) or neutralized 125I-bovine serum albumin (nBSA) were given intravenously, after which peritoneal dialysis (PD) using conventional PD fluid (Gambrosol 1.5%) was performed for 120 min. Concentrations of FITC-polysaccharides and radioactive albumin species in plasma and dialysis fluid were analysed with high-performance size exclusion chromatography and a gamma counter respectively. Transperitoneal clearance values were calculated for polysaccharides in the molecular radius range 36,150 , and for RISA and nBSA. Results:, Ficoll and pullulan showed more or less identical permeabilities, compared to RISA and nBSA, across the peritoneal membrane. Although RISA-clearance, 5.50 0.28 (,L min,1; SEM), tended to be lower than the clearances of Ficoll36 (6.55 0.25), pullulan36 (6.08 0.22) and nBSA (6.56 0.23), the difference was not statistically significant. This is in contrast to the hyperpermeability exhibited by polysaccharides across the glomerular filtration barrier and also contrasts with the charge selectivity of the latter. Conclusion:, The phenomenon of molecular flexibility is more important for a macromolecule's permeability through the glomerular filter than across the continuous peritoneal capillary endothelium. Furthermore, it seems that charge plays a subordinate role in the steady-state transport across the combined peritoneal capillary,interstitial barrier. [source]

Ultrastructural and histochemical study of the salivary glands of Aplysia depilans (Mollusca, Opisthobranchia)

ACTA ZOOLOGICA, Issue 3 2001
Alexandre Lobo-da-Cunha
Abstract The digestive system of the sea hare, Aplysia depilans, includes a pair of ribbon-shaped salivary glands. A central duct and a large blood vessel run close to each other along the length of these glands and both are surrounded by a layer of muscle cells. Three cell types form the glandular epithelium: granular cells, vacuolated cells and mucocytes. The granular cells possess cilia and spherical secretion granules, located primarily in the apical region. The granules of immature cells have a low electron density and are mainly formed by neutral polysaccharides with small amounts of proteins. The granules of mature cells are larger, have a high electron density and are mainly formed by proteins with lower amounts of neutral polysaccharides. Transition stages between immature and mature granular cells are observed. The vacuolated cells are large and frequently pyramidal in shape, but after the application of histochemical techniques almost all vacuoles remain uncoloured. The numerous vacuoles contain flocculent material in a clear background and the mitochondria possess large crystalline structures in the matrix. A pyramidal shape is also typical of the mucocytes, which are filled with vesicles containing granular masses surrounded by a network of secretion material. These large cells are strongly stained by Alcian blue, revealing the presence of acidic mucopolysaccharides. This is the first ultrastructural study of the salivary glands in opisthobranch gastropods. [source]