茯苓多糖的提取及生物活性研究.pdf

华中科技大学 硕士学位论文 茯苓多糖的提取及生物活性研究 姓名：刘迎鸣 申请学位级别：硕士 专业：生物化学与分子生物学 指导教师：何光源;陈明洁 20080527 I 1 PC1 PC2 PC3-I PC3-II sevage sevage 7 15 TCA PC2 sevage 7 PC3-I TCA PC3-I 2 3 MTT PC3-I HepG2 MDA-MB-231 IC 50 74.1 ug/ml 152.4 ug/ml PC2 IC 50 897.4 ug/ml PC3-I HepG2 6 PC3-I 1 10 4 PC3-I HepG2 II Abstract Fungal polysaccharides have been found to exhibit many bioactivities, such as antiviral, anti-flammation, hypoglycemic, hypocholesterolemic, and hypotensive .they are good immunomodulators to inhibit cancer cells growth without any damage to normal cells. Poria cocos is a traditional Chinese medicine, and play an important role in improving immunity, anti-tumor, sedation, diuresis, and detumescence, which obtained more and more attention by researchers. Poria cocose contains a variety of ingredients, mainly are poria polysaccharides, xylan, acid polysaccharide, mannan, and poria acid, which the highest constituent is poria polysaccharides. We did research work from extraction, purification, biological activity, and to other aspects of Poria cocos. The results obtained from these experiments are as follows. (1) Ultrasound in extracting poria polysaccharide is effective. We have set up a multi-level system to isolate poria polysaccharides from Poria cocos. Form this system we obtained PC1, PC2, PC3-I, PC3-II four different poria polysaccharides. Through spectral scanning of those polysaccharides, their protein content was relatively low, and polysaccharides were gained with a high purity. Trypsin combined with sevage is a perfect method to remove protein impurities in poria polysaccharides. “Sevage” and 15% TCA is effective in removing protein impurities in polysaccharide PC2, but the efficiency is low. The TCA method does not effective in PC3-I protein impurities removal. 2 Preliminary results showed that poria polysaccharide did not have clear antibacterial activity. 3 From MTT assay, PC3-I can restrain HepG2 and breast carcinoma MDA-MB-231 , with IC 5074.1 ug/ml and 152.4 ug/ml, respectively. PC2 can inhibit breast carcinoma also, IC50 is 897.4 ug/ml. PC3-I has high inhibiting intensity in the first six hours, after adding PC3-I to the cells in vitro. The estimated average molecular weight of PC3-I is 1 10 4 by viscosity measuring method. Through dialysis we found that different components of PC3-I in inhibiting breast carcinoma and HepG2, are differently. The result speculates that poria polysaccharides for different cancer their bioactivities may differ, and their specific mechanism may also be different. In all, this paper explored the polysaccharides purification, antibacterial and anti-tumor effect of poria cocose, strengthened the people’s awareness and understanding of it. We need do more research in poria polysaccharides’ anti-tumor activity and their mechanisms. Key words: Poria cocos polysaccharide extraction purification bioactivity 。