Extraction,Purification,Structure Characterization And Biological Activity Of Polysaccharide From Black Ginseng

Black ginseng is a new kind of processed product after the ginseng is steamed and exploded for nine times.So far,the research on polysaccharide of black ginseng is not enough,and there are few reports on the biological activity of polysaccharide of black ginseng.Therefore,this paper used black ginseng as raw material to explore the extraction process,separation and purification,content determination and antioxidant and anti-tumor biological activities of polysaccharides from black ginseng.The single factor test was used to explore the liquid-solid ratio,extraction temperature and extraction time.Finally,response surface optimization method was used to obtain the optimal extraction process:liquid-solid ratio of 34.6:1,extraction temperature of 70℃,ultrasonic time of 56min.The process of extracting polysaccharide from black ginseng was repeated,and the optimized process was used to extract polysaccharide from black ginseng again.Finally,the actual extraction rate of polysaccharide from black ginseng was 9.883%.Sevag method was used to remove protein impurities,AB-8 macroporous resin was used for decolorization,distilled water was used to remove small molecular impurities,and a single component OF polysaccharide BGP-1 was separated by Sephadex G-200 glucan gel column.The total sugar content,protein content and uronic acid content of BGP-1 were89.21%,0.34%and 9.32%by phenol sulfuric acid method,Coomassie bright blue method and carbazole method,respectively.The results of HIGH performance liquid chromatography showed that BGP-1 had a single absorption peak at 8.9593 min,and the molecular weight was about 1.8×10~3k Da when substituted into the standard curve.After p MP-precolumn derivatization,it is concluded that BGP-1 is mainly composed of glucose,arabinose and mannose,and its molar ratio is 70.5:17.3:5.6.At the same time,it also contains a small amount of galactose and xylose.Ultraviolet spectrum scanning showed that there was no obvious absorption peak at 260 nm and 280 nm,indicating that the extracted polysaccharides had no obvious impurities such as nucleic acid and protein.Fourier transform infrared spectroscopy(FTIR)and scanning electron microscopy(SEM)analysis showed that BGP-1 had characteristic absorption peak of polysaccharide,and it was a neutral polysaccharide withα-glycoside configuration.The surface of BG-1 has a filamentous structure that is intertwined,indicating its strong rigidity.The scavenging ability and reducing ability of polysaccharides from Black ginseng were tested.The results showed that polysaccharides from black ginseng had certain antioxidant activity in vitro,and the antioxidant ability was concentration-dependent.MTT assay was used to determine the proliferation inhibition rate of polysaccharide from Black ginseng on MGC-803 gastric cancer cells.Under the condition of dosage of 4 mg/m L and action time of 48 h,polysaccharide from black ginseng could inhibit the growth and proliferation of MGC-803 cells.Flow cytometry and Westen Blot were used to further confirm the anti-tumor activity of polysaccharides from Black ginseng,which can promote cell apoptosis through the signal transmission of mitochondrial pathway.