Extraction, Structure And Bioactivity Of Polysaccharides From Stropharia Rugoso-annulata

Stropharia rugoso-annulata （ King Stropharia or Winecap ） is easy to cultivated ,delicious and high price. It is one of the most famous edible fungi in international exchange markets. Polysaccharides are linked by more than ten monosaccharides through glucosidic bonds. They widely take part in life activity such as cell recognition, cell differentiation, immune response etc. They are the focus of modern medicine and food chemistry research. The study aims to explore the optimum extract conditions, structure, physicochemical property and bioactivity of polysaccharides from Stropharia rugoso-annulata.The polysaccharides are extracted from Stropharia rugoso-annulata cultivated by 100% cavings. The study selects extract temperature,extract time and solid-liquid ratio as the influencing factors, builds the corresponding two-order polynomial equation by Box-Behnken experiment design method. The equation is Y=7.37+0.61A+0.53B+0.52C-0.03AB-0.12AC-0.10BC-0.62A²-0.60B²-0.65C². And by the equation, the optimum extract conditions are obtained. The highest yield rate of polysaccharides is 7.637% in the condition of extract temperature 73.8℃,extract time 22.7min and solid-liquid ratio 1:26.2. Study has shown that the optimum condition of Sevag method is Sevag reagent 7.5mL, shaking time 15min, centrifugal speed 4000rpm, centrifugal time 3min. By this treatment condition, protein concentration is 24μg/mL and polysaccharides concentration is 544μg/mL in 1mg/mL pre-configured rude polysaccharides solution.The results indicates that the sulfate group and uronic acid content is 12.45% and 10.01% in polysaccharides from Stropharia rugoso-annulata. The molecular weight distribution of water soluble polysaccharides is near 22kDa. According to the results of IR , monosaccharides analysis and NMR,αandβglucosidic bonds are co-exist in polysaccharides molecule which might content 5 kinds of monosaccharides. The monosaccharides are present as pyran. D-fructose, D-glucose and D-xylose might exist in polysaccharides chains. The intrinsic viscosity of polysaccharides from Stropharia rugoso-annulata is 68mL/g in 0.1MNaCl solution at 30℃. The apparent viscosity is of 10%polysaccharides is ascend by the the shear time more longer at 25℃.The effect on scavenging·OH and·O₂^- of polysaccharides from Stropharia rugoso-annulata were studied by Fenton system and Pyorgallol Autoxidation Method respectively, which was compared with the effect of Vc and polyphenols. The results show that the IC50 of polysaccharides on scavenging·OH and·O₂^- is 0.6mg/mL and 0.4mg/mL. Polysaccharides of Stropharia rugoso-annulata have certain of effect on in vitro antibacterial properties, but not obviously.