Optimization of extraction process of total saponins from Syringa oblate Lindl. leaves by response surface methodology

Total saponins extraction from Syringa oblate Lindl. leaves was performed using the ethanol reflux extraction.Response surface methodology( RSM),based on a three level,four variable Box- Behnken design( BBD),was employed to obtain the best possible combination of ethanol concentration,liqued /material ratio,extraction temperature and extraction time. The optimum extraction conditions were as follows: ethanol concentration of 82%,liqued / material ratio of 25∶ 1 m L / g,extraction temperature of 85 ℃,extraction time of 116 min and extraction times of 2.Under these conditions,the experimental yield was( 69.655 ± 0.0145) mg / g.The difference of extract rate between actual value and theoretical value was 0.461 mg / g,therefore the extraction process obtained by response surface methodology was stable and reasonable,accurate and reliable. It was a feasible method to extract the total saponins from Syringa oblate Lindl.leaves.