Hydrolysis Of Dioscin To Diosgenin By Enzyme

The paper reports the experiment of diosgenin extraction. The diosgenin was hydrolyzed separately by the enzyme from Dioscorea zingiberensis C.H. wright and the dioscin-glycosidase produced by microorganism Absidia sp.s00. The paper concerns the purification and reaction characters of dioscin-glycosidase produced by Absidia sp.s00.The Dioscorea zingiberensis C.H. Wright was conserved at25℃for30days inoder to hydrolyze dioscin to diosgenin by enzyme of itself. Diosgenin was extracted by the following process:extracting the dioscin by70%ethanol, the extraction rate of dioscin was4.94%. Purified the saponins by AB-8macroporous absorbitive resin, and11.7g diosgenin was obtained by95%ethanol, the extraction rate of diosgenin was2.34%. Purified the diosgenin by D-280macroporous absorbitive resin,10.2g diosgenin was obtained at last. The extraction rate of diosgenin was2.04%. The purity of diosgenin was91%by HPLC.Absidia sp.s00was used to produce dioscin-glycosidase from seven tested species. The result showed the enzyme can hydrolyze the two3-O-a-rhamnosides of the dioscin to produce the diosgenin. The dioscin-glycosidase was purified by DEAE-Cellulose column. The pure enzyme in the SDS-polyacrylamide gel eletrophoresis was one spot, and the molecular weight is56KDa. By studying the response conditions of the reaction, it was found that the optimum substrate concentration is0.2%; The optimal conditions for enzymatic hydrolysis of dioscin was pH5.0at40℃for30h; The dioscin-glycosidase is stable at20℃～40℃and pH2.2-6.0; The enzyme activity was not effected by K+, Na+, but inhibited by Mg2+, Ca2+, Cu2+, Fe3+.According to optimal conditions,1g dioscin hydrolyzed by dioscin-glycosidase obtaining0.1g diosgenin. The purity of diosgenin was over90%by HPLC.