Abstract: Ultrasound-assisted extraction of diosgenin from rhizome of Dioscorea zingiberensis C.H.Wright was optimized. Compared with the traditional spontaneous fermentation, the effects of operating conditions were studied according to single factor and orthogonal design. The optimal condition was achieved as follows:crude powder of D.zingiberensis 10g materials to solvent ratio 1:10 (g:mL), 70% alcohol, extracted twice under ultrasonic power of 100W, each time for 30min. Under the above conditions, diosgenin can be obtained at the yield of 2.57%. By contrast, the maximum yield of diogenin is only 2.13% by traditional method after spontaneous fermentation for 24 h. Therefore, ultrasonic-assisted technology was more effective with the advantages of much shorter extracting time and higher yield of diosgenin.

Key words: Dioscorea zingiberensis C.H.Wright, diosgenin, ultrasound-assisted extraction