Extraction Method Using Ionic Liquid And Resarch Technology Of Effective Constituent In Glycyrrhiza

Extraction of active ingredients of licorice is an important part of the deep processing of licorice.Taking the ural licorice meal provided by shihezi university from xinjiang as raw material and ionic liquids as extraction agent to extract and purify glycyrrhizic acid, glycyrrhetinic acid and licorice.Based on previous study, this research established a method using HPLC(high performance liquid chromatography) to extract glycyrrhizic acid, glycyrrhetinic acid and licorice simultaneously. The best conditions to extract those three ingredients was to use WondaSil C18 4.6 * 150 mm as chromatographic column. The mobile phase took methanol as A and ice acetic acid solution as B and gradient elution program was as follows: the content of B during0 ~ 10 min was 60 %, 10 ~ 25 min was 60 % ~ 30 %, 25 ~ 40 min was 30 % ~ 20 %, 40 ~ 55 min was 20 %. The detection wavelength of licorice glycosides,glycyrrhizic acid and glycyrrhetinic acid was 274 nm,250 nm and 250 nm respectively. Besides, flow rate of this process was 1 mL/min, column temperature was 25 oC and sample quantity was 20 μL.The optimal extraction process was determined by the single factor experiment and response surface experiment and chose 1- butyl 3- methyl imidazole salt bromine as extraction agent in this study. After series of experiments, the following conditions was determined as the best extraction process parameters: ratio of material to liquor was 1:40, extraction time was 20 min and concentration of ionic liquid was 0.75 mol/L. Under this circumstance, extraction yield of Glycyrrhizic acid,glycyrrhetinic acid and licorice glycosides could reach the highest at the meantime, which was 2.69 %, 0.16 % and 1.33 % respectively.Additionally, preparative chromatography method was studied in this paper. The optimum chromatographic conditions used the combination of methanol and 0.5% acetic acid in the proportion of 65:35 as mobile phase, set flow rate at 10 mL/min, determined sample quantity was 100 mg, selected sample quantity was 25 oC and employed 250 nm was detection wavelength. On above conditions, the purity of glycyrrhizic acid could achieve 98.96 %, Licorice glycosides 97.55 %, which laid a solid research foundation of the eco-friendly production of effective constituent in glycyrrhiza.