Optimization of Saikosaponin Extraction from Bupleuri Radix Based on Response Surface Methodology

In order to get an optimal technology for saikosaponin extraction from Bupleuri Radix, the factors affecting the saikosaponin extraction rate were screened primitively by single factor experiment. The important parameters in the extraction process of saikosaponin, such as extraction time, microwave extraction temperature, solid-liquid ratio and methanol concentration, were optimized based on response surface design. The results show that the interactions of extraction temperature with time, with methanol concentration, and with solid-liquid ratio have evidently influence on the saikosaponin extraction rate. The optimum technological parameters verified by experiments present, when extraction time is 30 min, microwave extraction temperature is 68 °C, solid-liquid ratio is 1∶59 g/mL and methanol concentration is 60%, the extraction rate of saponins is the most, can reach 5.14 mg/g with better repeatability. The achievement has laid a foundation for the industrialized extraction of saikosaponin.