| Pholiota nameko which is also called Pearl mushroom and Light cap phosphorus umbrella, doesn't only contain lots of nutrients, but also has the higy medicinal value. Pholiota nameko mucilage can promote immunity and combat signs of ageing. The polysaccharides of Pholiota nameko are able to resist oxidation, stand up to tumor, keep the bad effects of aging away and improve immunity. The polysaccharides of Pholiota nameko are one of the main active ingredients of Pholiota nameko, and very important to the biological function of it. Therefore,it is necessary to conduct the comprehensive thorough research to the structure and activity of the polysaccharides of Pholiota nameko. The study uses Pholiota nameko as the raw materials, researches the extracting, isolation and purification, bioactivity and structure of the polysaccharides. The creative results obtained are as follows:1. Pholiota nameko polysaccharides are abstracted by the hot water extraction and ultrasonic method. The yield of wPNP is2.463%, and4.376%of uPNP. The content of polysaccharide in wPNP is65.17%, and60.59%in uPNP. This suggests that the extraction rate can be increased by the ultrasonic, but it is not useful for the content of polysaccharide.2. The wPNP and uPNP are isolated by CTAB, and obtained three kinds of polysaccharides, the acidic polysaccharide (wPNP-a&uPNP-a), the neutral polysaccharide (wPNP-b&uPNP-b), the basic polysaccharide (wPNP-c&uPNP-c). And what the yield is most are wPNP-a and uPNP-b, wPNP-b and uPNP-a take second place, wPNP-c and uPNP-c are least. This suggests that the most content of wPNP is wPNP-a, but uPNP-b to uPNP. The wPNP-a, uPNP-a, wPNP-b and uPNP-b are purified by SephadexG-150gel filtration chromatography, and the purity of these polysaccharides are identified by HPLC. The results show that the four components, wPNP-a1, wPNP-b1, uPNP-a1, uPNP-b1, are all homogeneous. 3. The structure characterizations of wPNP-a1, uPNP-a1, wPNP-b1and uPNP-b1are analyzed by HPLC, FTIR and NMR. These researches have got the following results.(1) The molecular weight of them are419310Da,312760Da,27991Da and21455Da respectively. The components which are extracted by ultrasonic have low molecular weight.(2) Both wPNP-al and uPNP-al are all have stretching vibration and variable angle vibration of O-H in hydroxyl, variable angle vibration of N-H in amino or stretching vibration of C=O in carbonyl, stretching vibration of C-O in carboxyl. The only difference is that maybe there is asymmetric telescopic vibration of C=O of carboxyl in wPNP-a1, but variable angle vibration of N-H of acylamino in uPNP-a1. The wPNP-b1and uPNP-bl are maybe equipped with variable angle vibration and stretching vibration of O-H in hydroxyl, stretching vibration of C-O in carboxyl, stretching vibration of C=O of carboxyl or carbonyl, variable angle vibration of N-H of amidogen or acylamion. The difference is wPNP-bl also has stretching vibration of C-O-S in the axial coordination of sulfonyl, or variable angle vibration of C-H of equatorial bond excepting the anomer of pyranoid ring.(3) wPNP-a1, uPNP-a1, wPNP-b1and uPNP-b1are all β-configuration, and do not contain acetyl.4. The antioxidant activity of wPNP and uPNP are researched in vitro. The experimental results demonstrate that Pholiota nameko polysaccharides what are extracted by hot water and ultrasonic possess excellent oxidation resistance. In addition, the antioxidant activity of Pholiota nameko polysaccharides could be promoted by ultrasonic.5.The structure is studiede by GC, AFM and ESEM. The wPNP-al is composed of xylose, mannose, galactose and glucose. The molar tatio of them is3.91:2.77:1.91:1. wPNP-al formed as linear chain on the surface of mica, the width was23nm,and the height was0.7-0.8nm... |
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