Study on the structural characterization and biological activities of polysaccharides from Dictyophora rubrovolvata...

Dictyophora rubrovolvata was a valuable medicinal and edible fungus with a wealth of nutrients. In this study, a polysaccharide (DXBP-0) was isolated and purified from D. rubrovalvata and silver nanoparticles (DXBP₀-AgNPs) were synthesized for the first time using DXBP-0 as a stabilising agent. The structural analyses showed that DXBP-0 was composed of glucose with a molecular weight of 2711 kDa. The main chain of DXBP-0 was composed of →3)-β-D-Glcp-(1→. The branched structure of β-D-Glcp-(1 → was attached to the main chain via the O-6 position of →3,6)-β-D-Glcp-(1→. The optimum synthesis conditions of DXBP₀-AgNPs were identified to be the polysaccharide concentration of 2 mg/mL, silver nitrate concentration of 15 mmol/L, reaction temperature of 120 °C, reaction time of 240 min and reaction ratio of 1: 2.5. The DXBP₀-AgNPs are spherical and have good dispersion in solution. Antibacterial experiments showed that DXBP₀-AgNPs inhibited the growth of E. coli and S. aureus by disrupting cell membranes, promoting leakage of contents and disrupting the redox state. These results suggest that DXBP₀-AgNPs may be a potential antimicrobial wound dressing.