Optimization of Microwave-assisted Extraction Technology of Catalpol from Rehmannia Glutinosa Libosch by Orthogonal Method

Objective: To optimize the microwave assisted extraction technology of catalpol from Rehmannia glutinosa Libosch.Methods: The content of catalpol in the extract was determined by high performance liquid chromatography(HPLC).The orthogonal test table L9(34) was used with the factors of concentration of ethanol(A),ratio of solvent to material(B),extracting time(C) and extracting times(D).Results: According to the results of the test,the optimum extraction conditions for catalpol were 60 % ethanol,material to liquid phase 4 w/v,3 minutes and 3 times extraction.Conclusions: The extraction rate of catalpol is high and steady by this technology,which provides new evidence for further utilization.