Study On Water - Soluble Polysaccharide From

Ferula sinkiangensis K. M. Shen is a perennial herb belonging to Umbelliferae, Ferula. Commonly known as the resin ferulic (glue) is important in our country traditional Chinese medicinal materials, has a very high medicinal value, fetida is the medicine of the treatment of rheumatoid arthritis, stomach trouble, the applied in Xinjiang ethnic medicine. Because Ferula sinkiangensis K. M. Shen was an endangered species, in the study of it mainly focused on seed germination, tissue culture, breeding characteristics, etc. In recent years, along with the successful implementation artificial cultivation of Ferula sinkiangensis K. M. Shen, the study on the chemical composition of Ferula sinkiangensis K. M. Shen will become a new focus. Few reports on the study of Ferula sinkiangensis K. M. Shen polysaccharide, currently limited to determine the polysaccharide content of crude polysaccharide, therefore, the further research on the polysaccharide of Ferula sinkiangensis K. M, Shen has been carried on in this paper.the response surface methodology was used to optimize microwave-assisted extraction process of water-soluble polysaccharides from Ferula sinkiangensis K. M. Shen(AWc). Result showed the optimum conditions as follows:1) liquid/ solid ratio is 120ml/g; 2) extraction temperature is 80℃; 3) extraction time is 13min; 4) microwave power is 600W. Under these conditions, the experimental value is 6.93%, which is quite close with the predicted value in the model.AWc was destarched by amylase and deproteinated according to the method of enzymatic and Sevage, AWp was producted. The fraction AW4,which get by acidic ethanol from AWp, was dissolved in distilled water and loaded onto DEAE-A25 column and Sephadex CL-4B, and eluted with a gradient of 0→0.5mol/L NaCl and ultrapure water, respectively. The collected fractions were dialyzed and dried which named as AW4b. SepharoseCL-4B column chromatography and HPLC indicating AW4b is a homogeneity polysaccharide, and the average molecular weight of AW4b was approximately 10826.46.GC analysis demonstrated that AW4b is mainly composed of glucose (Glc).According to IR, partial acid hydrolysis,NMR spectra, Methylation, periodate oxidation and Smith degradation, the structure of AW4b was identified. The results revealed that AW4b was inclues branched structure. The chain was composed of 1→4 by Glc, Glc are substituted at 6-O,the side chain was composed of 1→4 by Glc, too.AW4b has positive scavenging effects on DPPH·radical. When the polysaccharide concentration is 1000 μ g/mL, the scavenging effect of AWc on DPPH·radical is 76.46%.