暗褐脉柄牛肝菌发酵液多糖的分离纯化与结构表征OA北大核心CSTPCD

[Objective]This study aimed to efficiently utilize the resources of Phlebopus portentosus and develop its polysaccharide functional food.[Methods]The mycelium of P.portentosus was cultured and fermented,and the combined fermentation broth was concentrated at low a temperature and reduced pressure.Then,precipitated by ethanol,separated,purified by DEAE-52 cellulose column chromatography,and the polysaccharide was finally refined by dialysis to remove the small molecular impurities.The total sugar content was determined by phenol-sulfuric acid colorimetry,the monosaccharide composition was determined by liquid chromatography-mass spectrometry(LC-MS),and the impurities such as nucleic acid and protein were detected by ultraviolet spectrophotometer.The structure of polysaccharides was analyzed preliminarily by infrared spectroscopy(IR)and nuclear magnetic resonance spectroscopy(NMR).[Results]The content of total sugar was 84％.The main monosaccharides of the polysaccharide were glucose,mannose,galactose,and arabinose,the molar ratio of which was 2.07∶1.95∶1.00∶1.58.Obvious polysaccharide absorption peaks were shown in the infrared spectrum and nuclear magnetic resonance spectra,through which an α-type pyranose can be inferred in the polysaccharide.[Conclusion]The polysaccharides prepared from the fermentation broth of P.portentosus were mainly composed of four monosaccharides,the structure of which contained α-pyranose.