Study On The α-glucosidase Inhibition Activity Of Icarrin And The Degradation Products

The literature suggests that icarrin has many pharmacological activities. Preliminary studies indicate that icarrin has certain α-glucosidase inhibition activity, but it has certain gap compared with the current clinical application of α-glucosidase inhibition inhibitor. To improve the activity of icarrin, the research is to obtain secondary glycoside or aglycone of the icariin by hydrolysis, which have stronger inhibition activity of α-glucosidase. Through the relationship between the structure and activity of each hydrolyzate, this paper determines the active role of the group in the degradation products of icarrin, laying the foundation for the future studies.This research objected Epimedii Folium, and used calcium-ion technology、extractd the flavonoids of Epimedii Folium with water and enriched and purificated by AB-8 macroporous resin, in the end the research got the flavonoids; then this reserch used ODS column to isolate Icariin; and used enzymatic hydrolysis, acid hydrolysis and combination of enzyme and acid hydrolysis to modify the structure of Icariin; furthermore by thin-layer chromatography, physical and chemical methods, nuclear magnetic resonance spectroscopy to identify the structure of the products. The products are Icariside Ⅰ, Icariside Ⅱ, Icaritin, Cycloicaritin, Anhydroicaritin.This reserch established α-glucosidase screening model, and each compound was screened the α-glucosidase inhibition activity by α-glucosidase derived from yeast. The results showed that Icaritin and Cycloicaritin had the worst activity; Icariside Ⅰ, Icariside Ⅱ, Anhydroicaritin had the better activity than Icarrin, and Anhydroicaritin had the best activity(IC50=0.102 mg·m L-1) with low concentration, even better than the Acarbose(IC50=0.850 mg·m L-1). The experiment verified the above-mentioned experimental results by the rat small intestine enzyme, and the results were consistent with the former. and the experiment studied the inhibition types of Anhydroicaritin, and showed that Anhydroicaritin was the competitive inhibitor of α-glucosidase.The research investigated Anhydroicaritin effected the blood sugar by the normal ICR mice and the alloxan-induced diabetic mice with starch loaded, and observed the GSP impact and the INS impact. The results showed that Anhydroicaritin lowered postprandial blood glucose levels of the normal ICR mice and alloxan-induced hyperglycemia mice at each time point, at the same time the alloxan-induced hyperglycemia mice were evident. Anhydroicaritin was slightly better than acarbose at the same dose, and there was a certain dose-effect relationship.In the end, the experiment used Schrodinger software to design the molecular docking, the results of the Docking energy showed that Anhydroicaritin had stronger combining ability, and were consistent with the former. The active detection results and the order of the software analysis results showed that the isoamyl alkenyl and phenolic hydroxyl of molecular may be the α-glucosidase inhibition activity groups in the Icaritin of degradation products.