Relationship between heat treatment on structural properties and antitumor activity of the cold-water soluble polysaccharides from Grifola frondosa

AbstractGrifola frondosa is a basidiomycete fungus with potential biomedical applications owing to the presence of bioactive polysaccharides. The activities of polysaccharides are influenced by many factors, particularly temperature; however, the optimal temperature and conditions for preparation of polysaccharides from this organism have not yet been determined. Therefore, in this study, cold-water soluble polysaccharides fromGrifola frondosa were extracted at 4 °C (GFP-4) and purified. GFP-4-30, GFP-4-60 and GFP-4-90 were obtained from GFP-4 after treatment at 30 °C, 60 °C, or 90 °C, respectively, for 6 h. MTT results showed that GFP-4 had the highest inhibitory effects on the proliferation of SPC-A-1 cellsin vitro. High-performance gel permeation chromatography results demonstrated that the molecular weight of GFP-4 was 1.05 × 106 Da and that GFP-4-30, GFP-4-60, and GFP-4-90 showed different levels of degradation and generated small molecule sugars. Fourier transform infrared spectroscopy, gas chromatography, and nuclear magnetic resonance results indicated that GFPs mainly consisted of α-d-Galp, α-d-Manp and α-d-Glcp. Periodate oxidation, Smith degradation, and methylation results showed that the backbones of the molecules consisted of 1,3-linked-Galp. After heat treatment, percentages of (1 → 3,4) α-d-Galp in heat-treated polysaccharides were obviously decreased, indicating their lower branching degree, and resulting in weaker antitumor effects. Overall, our f...

Source: Glycoconjugate Journal - December 9, 2019 Category: Biochemistry Source Type: research