Study On Preparation And Activity Of Low Molecule Weight And Water-soluble β-1,3-glucan

In recent years, extensive researches were implemented on water-soluble β-1,3-glucan because of the unique biological and pharmacological activities. Reseachesfrom this paper are listed as following:1.The crude of curdlan was deproteinized with the method of Sevage. The proteincontent of the samples was reduced from the initial state of5.88g/100g to the finalstate of1.53g/100g. The rate of deproteinization reached up to74.01%. Then,additional methods were used to degrade curdlan like ultraviolet degradation,sonication, alkaline degradation, microwave degradation, enzymatic degradation,oxidative degradation and so on. Finally, low molecule weight and soluble β-1,3-oligosaccharide was prepared from curdlan by oxide degradation of hydrogen peroxidein alkaline homogeneous phase.2.On the basis of results from single factor experiment, we used four factors andthree levels of orthogonal experiment to optimize the degradation of curdlan conditions.The optimal hydrolysis condition was confirmed as follows: sodium hydroxideconcentration2.5mol/L, H2O2dosage1.5%(v/v), temperature40℃and reactiontime as long as60h. Confirmatory experiments showed that the yield of β-1,3-oligosaccharide was increased from25.61%to63.24%, which increased by59.50%.3.The structure of low molecular weight and water-soluble β-1,3-oligosaccharidewhich was prepared by oxide degradation of hydrogen peroxide was represented indetail with paper chromatography and infrared spectrum analysis. The result of paperchromatography clearly showed that the structural units of β-1,3-oligosaccharide wasglucose, which demonstrated that β-1,3-oligosaccharide was component of singleglucose polymer. In addition, infrared spectra showed that the structure of the β-1,3-oligosaccharide was basically consistent with standard curdlan. The result indicatedthat the chemical structure of the hydrolysates was not damaged after oxidedegradation. The result of vivo antitumor test showed that soluble β-1,3-oligosaccharide could inhibited the growth of tumor and the effect was associated withdosage. At low doses, the inhibitory effect is relatively weak. When compared with thecontrol group, the50mg/kg group showed significant inhibition of tumor effect andinhibition rate was48.73%. The antimicrobial tests indicated that the water-solubleβ-1,3-oligosaccharide had certain antibacterial effect on staphylococcus aureus and had weak antimicrobial effect on E. coli, but had no inhibition on angel yeast. Theminimum inhibitory concentration (MIC) for different bacteria were E. coli40mg/mL,and staphylococcus aureus20mg/mL, and with the concentration of β-1,3-oligosaccharide increased, the inhibitory effect also gradually enhanced.