Structure Characterization, Phosphorylation And Activities Of Polysaccharides Produced By Lachnum YM120

In this paper, the fermentation and extraetion,fractionation and purification, structure characterization, phosphorylation, antioxidant activity, preventive effect of ethanol induced gastric ulcer and anti-tumor activity of polysaccharides prouduced by Lachnum YM120were studied.The main results were as follow:The results of in vitro antioxidant activity experiments showed that both exopolysaccharide and proteoglycan both had significant reducing capacity and scavenging abilities to·OH、nitrite、O2-·and DPPH, which displayed dose-effect relationship between polysaccharide level and activity. The scavenging abilities to O2-·and DPPH of exopolysaccharide were better than that of proteoglycan, however, the reducing capacity and the scavenging abilities to·OH and nitrite were less than that of proteoglycan.The polysaccharides prouduced by Lachnum YM120(LEP) was purified by Cellulose DEAE-52column chromatography and Sepharose CL-6B column chromatography. The purified polysaccharide (LEP-la) was identified to be a homogeneous component with the molecular weight of32,237Da. After hydrolysis, periodate oxidation, Smith degradation, GC-MS, IR,1H NMR and13C NMR analysis, it was found that LEP-1a was a (1�'3)-,(1�'6)-β-D-pyran glucan, with the backbone chain and the branch chain were linked by1,3-glycosidic linkage while the branch chain was linked at C6of the backbone chain by1,6-glycosidic linkage.LEP-1a was given to mice by gavage for2weeks. Results showed that LEP-1a significantly decreased the ulcer bleeding areas, pepsin activity, gastric juice volume and total acidity and the malondialdehyde (MDA) content in serum. Meanwhile, the superoxide dismutase (SOD) increased significantly. These results indicated that LEP-1a had significant preventive effect against the ethanol induced gastric ulcer.Phosphorylated polysaccharide of PLEP-1a, with the PO43-content of6.39%, was prepared from LEP-1a by phosphorylation. The results of IR,13C NMR and31P NMR showed that the original basic structure of LEP-1a was not changed, and the-H2PO3group was linked at C6of LEP-la. Anti-tumor experiments results showed that100mg/kg and400mg/kg of LEP-la could significantly improve the food consumption, body weight, the tumor inhibition rate and thymus index of S180sarcoma mice, increase SOD, IL-2and TNF-a levels in mice, indicating that LEP-1a had significant anti-tumor activity. Furthermore, PLEP-1a performed better inhibitory effect on S180Sarcoma mice than that of LEP-1a.