RESUMEN
Objective: A technological route was established for preparing liquiritigenin from the licorice ultrafiltrate. Methods: U5(53) uniform design was used to optimize the ultrafiltration process with the retention rate of liquiritigenin as the index; Box-Behnken response surface method was used to optimize the complexation extraction process with the extraction rate of liquiritigenin as the index; The technological condition of back extraction of liquiritigenin was determined by the liquiritigenin stripping rate. Results: The optimal ultrafiltration conditions for liquiritigenin were inorganic ceramic membranes with a pore size of 10 nm, a pressure of 0.12 MPa, and solution temperature of 25 ℃, retention rate of liquiritigenin was 98.74%. Optimum complexation extraction conditions were as following: 1% TRPO complexing agent, extraction for 10 min in 5 mL organic phase solution, the extraction rate of liquiritigenin was 99.44%; The 12.5 mmol/L NaOH aqueous solution was the best back-extractant, and the back extraction rate was 98.88%. Conclusion: As a new Chinese medicine extraction technology, ultrafiltration-complexation extraction and back extraction technology have the advantages of high selectivity, high efficiency, and recycling of extractant, which can provide a new preparation technology for the research of liquiritigenin.