In the last few decades, the novel functions of polysaccharides have provided a major impetus for increasing scientific attention. Among the most promising aspects are their immunomodulatory and antitumor effects, thickening agents and stabilizer effects.
In the last few decades, the novel functions of polysaccharides have provided a major impetus for increasing scientific attention. Among the most promising aspects are their immunomodulatory and antitumor effects, thickening agents and stabilizer effects.
It is well known that the molecular weight, conformation, chemical modification, and solubility of the polysaccharides significantly affect their antitumor and immunomodulatory activities. However, the studies on molecular weight, solution property, and chain conformation of these polymer solutions have seldom been published. The scant evidence available inspired us to embark on the present study: the isolation and purifi cation of polysaccharide fractions from an edible fungus, Lentinus edodes, the determination of its chemical structure and molecular weight; the assay of antitumor activity of polysaccharides and their sulfated derivatives in vivo and in vitro.
Figure 1
The light-scattering intensities were measured with a DAWN® multi-angle light scattering instrument (MALS) equipped with a He–Ne laser at 25°C. The refractive index of 0.25 M LiCl–Me2SO, measured by an Abbe refractometer, was 1.4795. The refractive index increments (dn/dc) were measured with a double-beam differential refractometer at 633 nm and 25°C. The polysaccharide solutions were dialyzed against solvent for 72 h. The values of specific refractive index increment dn/dc in 0.25 M LiCl– Me2SO and in aq 0.5 M NaCl were determined to be 0.058 and 0.133 cm3 /g, respectively. ASTRA software was utilized for data acquisition and analysis.
Figure 2
Two kind of α- and β- glucans co-exist in the extract from fruiting bodies of Lentinus edodes. The water-insoluble fraction was identified to be α-(1, 3)-D-glucan with a few (1, 6) branch linkages, and the most abundant polysaccharide component. The water-soluble fraction was β-(1, 3)-D-glucan with (1, 6) branches. Strong intermolecular hydrogen bonds exist in the α-glucan, resulting in its water-insolubility, but there are not any aggregates or multiple-helix structures for the α-glucan in aqueous 0.5 M urea/0.5 M NaOH or DMSO/0.25 M LiCl. The Mw values for α-glucan in the above solvents were 24.1 × 104 and 10.9 × 104 , respectively. [η]- Mw relationship of the β-glucan in 0.5 M NaCl solution at 25°C was [η]=7.69 × 10-6 Mw 1.32 at Mw from 1.87 × 105 to 1.2 × 106 . Predominant species of the β-glucan exist as triple-stranded helical chains in 0.5 M NaCl solution, and as single-flexible chains in DMSO.
Wyatt Technology Corporation
6300 Hollister Avenue
Santa Barbara, CA 93117
Tel. (805) 681-9009; Fax (805) 681-0123
Email: info@wyatt.com
Analysis of Greenhouse Gases by Gas Chromatography
May 15th 2024This application note demonstrates the use of SCION's 8500GC system for the analysis of key greenhouse gases—carbon dioxide, methane, and nitrous oxide—in a single atmospheric air matrix. Highlighting the system's excellent sensitivity and repeatability, this method is crucial for understanding emission sources and combating climate change.
Analysis of DEHP in Drinking Water by HPLC-DAD
May 15th 2024This application note outlines a method for detecting low levels of 1,4-Dioxane, a likely carcinogenic compound, in drinking water using SCION GC-MS technology. It details the procedure for analyzing water samples spiked with 1,4-Dioxane, achieving excellent sensitivity and low detection limits, demonstrating the method's effectiveness for environmental monitoring.
Plant Protection Product Impurity Screening by GC-FID with GC-MS Confirmation
May 15th 2024This application note from SCION Instruments delves into the meticulous screening of impurities in plant protection products using GC-FID, with GC-MS for confirmation. It emphasizes the necessity of identifying and quantifying impurities to comply with regulatory standards in industries such as pharmaceuticals, food, and agriculture. The study specifically examines eugenol, showcasing how to determine significant impurities for regulatory submission. The approach integrates GC-MS and analytical standards, ensuring precise impurity identification and quantification critical for product approval.