Orthogonal Design for Optimization of Ultrasonic Extracting Procedure for Total Saponins from Dioscoreae Nipponicae Rhizoma

OBJECTIVE To determine the best ultrasonic extracting procedure for total saponins from Dioscoreae Nipponicae Rhizoma. METHODS Orthogonal experiment was used to optimize the condition. The content of total saponins was determined by spectrophotometric method. RESULTS The wavelength of the maximum absorption was 410 nm. Diosgenin showed a good linear relationship at the range of 0.004-0.020 mg·mL^-1(r=0.999 8). The optimum ultrasonic extraction conditions were water-saturated n-butanol as extraction agent, solid-liquid ratio 1∶30, temperature 70 ℃ and ultrasonic power 180 W. CONCLUSION The ultrasonic extracting procedure is reasonable, economical and feasible.