洋葱多肽的凝胶色谱分离及体外降糖活性研究

Analysis on in vitro hypoglycemic activity of onion polypeptide separated by gel filtration chromatography

目的：建立洋葱多肽凝胶过滤色谱分离条件,构建体外降糖评价体系,评价洋葱多肽体外降糖活性。方法：通过正交实验确定洋葱多肽粗提物的凝胶色谱分离方法;以α-葡萄糖苷酶抑制率和α-淀粉酶抑制率为指标,比较洋葱多肽各组分的体外降糖活性。结果：洋葱多肽凝胶色谱最佳分离条件为0.01 mol/L磷酸盐缓冲溶液（pH6.0,含0.05 mol/L NaCl）为洗脱液,进样浓度为8.0 mg/m L,收集P1~P4 4个组分。相同浓度下P1组分的α-葡萄糖苷酶抑制率和α-淀粉酶抑制率均明显高于其他组分,分别达到53.8%和92.6%。结论：利用凝胶过滤色谱可将洋葱多肽粗提物分离为4个组分,其中分子量较大的P1组分显示了较高的体外降糖活性。

Objective： To establish conditions to separate onion crude polypeptide by gel filtration chromatography, and create an in vitro system to evaluate their hypoglycemic activity. Method： The or thogonal tests were used to determine the gel filtration chromatographic conditions, and then α-glucosidase inhibitory rate and α-amylase inhibitory rate were utilized as indexes to compare the in vitro hypoglycemic activity of onion polypeptide components. Results： The optimum gel separation conditions were as followed： phosphate buffer（0.01 mol/L, p H6.0, containing 0.05 mol/L Na Cl） was as eluent, and the loading concentration was 8.0 mg/m L, then four components of onion polypeptide were collected and defined as P1~P4. Moreover, α-glucosidase and α-amylase inhibitory rate of P1 were significant higher than that of other three components under the same conditions, which reached 53.8% and 92.6%, respectively. Conclusion： Four components of onion polypeptide were obtained by gel filtration chromatography, and P1, with the larger molecular weight, exhibited the more obvious in vitro hypoglycemic activity.