萝藦全草多糖分子质量分布及还原能力的初步研究

Preliminary Study on Molecular Weight Distribution and Reducing Capacity of Metaplexis Japonica Polysaccharide

目的获取不同相对分子质量（Mr）范围的萝藦全草多糖组分并探讨浓度、压力和pH对膜分离的影响,确定最佳分离条件及还原能力。方法将脱蛋白、脱色后的多糖溶液依次过截留分子量300、100、50、10、3 kDa的中空纤维膜,采用单因素实验确定影响萝藦全草多糖膜分离的因素并测定其还原能力。结果 （1）萝藦全草多糖相对分子质量主要集中在50~100 kDa之间;（2）膜分离多糖溶液时,在压力0.2 mPa,浓度30 mg/mL,pH为5时膜通量最大;（3）萝藦全草多糖具有还原能力。结论超滤膜能较好的确定萝藦全草多糖相对分子质量范围;萝藦全草多糖还原能力随着浓度的升高而增强。

Objective To obtain metaplexis japonica polysaccharide components of different ranges of relative molecular weight and to investigate the influence of the concentration,pressure and pH on membrane separation to figure out the best condition for membrane separation and the reducing capacity. Methods The polysaccharide solution that was decoloured and deproteined passed through the hollow fiber membrane with molecular cut off of 300 kDa,100 kDa and 50 kDa,10 kDa and 3 kDa in turn. The single factor experiment was used to explore the influencing factors for the membrane separation of metaplexis japonica and determine the reducing capacity. Results The relative molecular weight of metaplex japonica polysaccharide mostly stayed from 50 kDa to 100 kDa. 2. When the membrane separation was conducted in the polysaccharide solution,the membrane flux reached the highest level with a pressure of 0. 2 m Pa,concentration of 30 mg / m L and pH of 5. 3. Metaplexis japonica owned reducing capacity. Conclusion The range of relative molecular weight of metaplexis japonica polysaccharide can be determined with hyperfiltration membrane. The reducing capacity of the polysaccharide increases with higher concentration.