Optimization of Extraction Technology for Qixuan Yijianing by Central Composite Design and Response Surface Methodology

Objective: To optimize extraction technology of Qixuan Yijianing.Methods: With soaking time,the amount of water,extraction time and extraction times as independent variables,yields of calycosin-7-O-β-D-glycoside,harpagide and rosmarinic acid as dependent variable,multiple linear regression and binomial of each level of independent variableswere fitted.Optimum technology was selected by central composite design and response surface methodology,and prediction was carried out by comparing the observed and predicted values.Results: Optimum extraction technology parameters were as follows: soaking time 74.4min,the amount of water 13.56-fold,extraction time 1.165h and extraction times twice.Under this condition,maximum estimated value of the sum of calycosin-7-O-β-D-glycoside,harpagide and rosmarinic acid was 0.36,which was agreed with model predicted value.Conclusion: Optimized extraction technology is simple,reliable and highly predictive.