Separation,purification And Functional Verification Of Hypoglycemic Components From Cordyceps Cicadae

Cordyceps cicadae is similar to Cordyceps sinensis,and it belongs to the entomogenous fungi.Paecilomyces cicadae is a Cordyceps fungus of the Clavicepitaceae family,which transforms to Cordyceps cicada.There are many pharmacological effects of Cordyceps cicadae,such as immune regulation,anti-oxidation,anti-tumor,anti-inflammatory and analgesic,kidney function improvement,and hypoglycemic.In order to further develop Cordyceps cicadae,the hypoglycemic effects of 10 Paecilomyces cicadae strains isolated from different Cordyceps cicadae were investigated in this study.The strains with the highest hypoglycemic activity were screened out,and the active ingredients of it were also separated.In addition,the liquid culture conditions of this strains were optimized.The main results obtained are as follows.The hypoglycemic effects of Cordyceps cicadae were studied by diabetic mice model.The results showed that all strains had hypoglycemic effects,and the optimal effect obtained at medium dose（5.00 g/kg）.Among them,the 5704s strains showed the highest hypoglycemic activity,and the hypoglycemic rate was 36.85%.The polysaccharides and protein were separated from Paecilomyces cicadae（5704s）.The peak 1 and peak 2 were isolated from the mycelium extract of Paecilomyces cicadae（5704s）by molecular sieve chromatography.The results showed that peak 1 had the highest hypoglycemic activity both in vitro test and mice model test.And the molecular weight（57781 Da）of the active ingredient from Paecilomyces cicadae was determined by SDS PAGE electrophoresis.The optimal culture conditions of strains 5740s were investigated by response surface methodology.The medium with 20 g/L of glucose,3 g/L of peptone,2 g/L of yeast extract,1 g/L of KH₂PO₄,0.5 g/L of MgSO₄ was the most suitable.The optimal pH of media used in this study was 7.11,and optimal room temperature conditions（25±1℃）were required.The optimal inoculation volume was 8.04%.Under the optimized conditions,the protein content of peak 1 reached 43.528 mg/L,which was 7.612 times higher than that of 5.718 mg/L before optimization.