Extraction, Isolation And Biological Activity Of Polysaccharides From American Ginseng

American ginseng (Panax quinquefolium L.) belongs to the genus Panax of thefamily araliaceae, has a variety of physiological activities and pharmacologicalfunctions, such as Yin-enriching and Qi-reinforcing effect in Chinese traditionalmedicine. It is widely accepted in the world. Polysaccharide is one of the functionalcomponents. At present, the industry of American ginseng is main processing theginsenosides and water-soluble polysaccharides. After extraction, the residues areabandoned, which has caused heavy resource waste. In fact, there are still somepolysaccharides in the residues. In the paper, the American ginseng was removedginsenosides and some water-soluble polysaccharides. The residues were treated withalkali solution, then separated, purified and characterized by using a variety of moderntechniques. The bioactivities of them were evaluated by in vitro antioxidant and cellexperiments. Hope for the work paly a role in the resource use and development ofAmerican ginseng. The main contents and results are as follows:1. American ginseng was treated by70%ethanol and hot water. Then the residueswere dealed with alkali solution. After centrifugalization, the supernatant was collected,neutralized, dialyzed and then removed protein. The yield of crude polysaccharide AEPwas2.85%.2. The crude polysaccharide AEP was loaded on DEAE-Sepharose Fast Flow anionexchange column chromatography, which eluted by ultrapure water and2mol/L NaCl.Two fractions were collected. The fractions were loaded on Sephacryl S-300HR gelcolumn chromatography. Both of the two fractions were acquired single peak, namedAEP-1and AEP-2, respectively.3. Both AEP-1and AEP-2had no absorptions at260nm and280nm in Ultravioletspectrum figures. This indicated both of them didn’t contain protein or nucleic acid. Thefigures of gel permeation chromatography suggested AEP-1and AEP-2were singlecomponents. The molecular weight of AEP-1was7.71×105, and the monosaccharidecomposition was glucose, galactose, and glucuronic acid (4.67:0.97:3.92). Themolecular weight of AEP-2was1.12×105, and the monosaccharide composition wasarabinose, mannose, galactose, glucose, galacturonic acid, and glucuronic acid(1.03:0.76:1.68:3.02:3.65). Infrared spectroscopy showed that both AEP-1and AEP-2had typical absorptions of polysaccharides and β-pyranoses. 4. Antioxidant and immunomodulatory effects of polysaccharides wereinvestigated by in vitro assays. AEP and AEP-2had good ability of scavenging freeradical. However, AEP-1had no significant difference. The result ofimmunomodulatory effects was similar to the antioxidan experiment. AEP-2couldsignificantly increase the production of NO, TNF-α, IL-6of macrophage.