不同取代度硫酸酯化裂褶多糖的制备及其降血糖和保湿活性

Preparation of Sulfated Schizophyllan Polysaccharides with Different Degrees of Substitution and Their Hypoglycemic and Moisturizing Activities

摘要:

该研究探讨了以裂褶多糖为原料，采用三氧化硫-吡啶法制备硫酸酯化裂褶多糖以及取代度大小与其体外降血糖、体外保湿之间的关系。实验表明，随着三氧化硫-吡啶质量分数的增加，依次可获得取代度在0.66~1.81的4种硫酸酯化裂褶多糖。硫酸酯化裂褶多糖的重均分子量随着取代度的增加而逐渐降低，从1.67×107 u下降到8.04×105 u。取代度为1.19的硫酸酯化裂褶多糖PDI低至7.84，过度硫酸酯化将导致裂褶多糖内部发生无序降解。刚果红实验结果表明，硫酸酯化裂褶多糖不存在三螺旋结构。取代度为1.81的硫酸酯化裂褶多糖在质量浓度为2 mg/mL时，对α-葡萄糖苷酶抑制率可达73.8%，4种硫酸酯化裂褶多糖均为可逆混合I 型抑制剂。硫酸酯化后裂褶多糖的吸湿与保湿活性均优于改性前，取代度为1.81的硫酸酯化裂褶多糖的吸湿能力可达77.93%（湿度43%）、52.54%（湿度81%），吸湿性仅次于甘油，但优于透明质酸。硫酸酯化裂褶多糖在干燥环境下的保湿性比透明质酸钠稍差。因此，硫酸酯化裂褶多糖具有的较好的α-葡萄糖苷酶抑制活性与吸湿保湿活性，两种活性均随着取代度的升高而增强。

Abstract:

In this study, Schizophyllan Polysaccharides (SPG) was used as the as raw material, sulfated Schizophyllan polysaccharides (S-SPGs) was prepared by the sulfur trioxide-pyridine method , and the relationship between the degree of substitution (DS) of S-SPGs and their in vitro hypoglycemic and moisturizing activitieswas examined. The experimental results showed that four S-SPGs with a DS of 0.66~1.81 could be obtained sequentially with the increase of the mass fraction of sulfur trioxide-pyridine. The weight-average molecular weight Mw of S-SPGs decreased gradually from 1.67×107 u to 8.04×105 u with the increase of DS. The PDI of S-SPG with a DS of 1.19 was as low as 7.84. Excessive sulfation would lead to disordered degradation of S-SPGs. The results of Congo red experiment showed that there was no triple helix structure in S-SPGs. T The inhibitory rate of the S-SPG with a DS of 1.81 and concentration of 2mg/mL against α-glucosidase could reach 73.8%. All the four S-SPGs were reversible mixed type I inhibitors. The moisture-absorbing and moisture-holding capacities of the SPG after sulfation were superior to those before modification, and the moisture-absorbing capacities of the S-SPG with DS1.81 were 77.93% (RH 43%) and 52.54% (RH 81%), respectively, which were second only to glycerol but better than hyaluronic acid. In dry environments, S-SPGs had slightly worse moisture-holding capacities than sodium hyaluronate. Therefore, S-SPGs had better α-glucosidase-inhibitory activity and moisture-absorbing and moisture-holding capacities, and both of the latter capacities increased with the increase of substitution degree.