ABSTRACT
Objective To establish a complexation extraction and back extraction technology for the separation and purification of liquiritin from Glycyrrhiza uralensis ultrafiltrate. Methods Taking the extraction rate of liquiritin as an index, the optimum composition of complexing extractant was first determined by uniform design, and then orthogonal experiments were used to optimize the conditions of complexing extraction. Taking the back extraction rate of liquiritin as an index, the process conditions for the back extraction of liquiritin were determined by investigating the type and concentration of back extractant. Results The complexation extraction research found that the complexing extractant should be a binary complexing extractant composed of trialkyl phosphine oxide (TRPO) and sulfonated kerosene. The optimum extraction conditions for liquiritin were as follows: TRPO-sulfonated kerosene (9∶91), pH value of G. uralensis ultrafiltrate was adjusted to 4, volume ratio of organic phase to aqueous phase was 1∶1, and average extraction rate of liquiritin reached 99.6%. The study of back extraction process showed that under the condition that the volume ratio of organic phase to back extractant was 1∶1, 17.5 mmol/L NaOH aqueous solution was the best back extractant, and the back extraction rate of liquiritin was 99.3%. Conclusion Under the optimized conditions, the liquiritin in G. uralensis ultrafiltrate can smoothly transfer from the ultrafiltrate to the complexing extractant and then to the alkaline back extractant. The total transfer rate of liquiritin is as high as 98.9%. This paper can provide a new preparation technology for the separation and purification of liquiritin.
ABSTRACT
Objective: To establish a technique for preparing glycyrrhizin acid (GA) by ultrafiltration-complexation extraction. Methods The effect of pH on the extraction rate of GA from ultrafiltrate was investigated in the range of 4-8; The orthogonal test was used to optimize the technological conditions for complexation extraction of GA; The extraction conditions of GA were determined by investigating the type and concentration of the extractant. Results The optimum extraction conditions for GA were as follows: pH value of Glycyrrhiza uralensis ultrafiltrate was adjusted to 2, TRPO-sulfonated kerosene (5:95, volume percent), volume ratio of organic phase to aqueous phase was 1:1, and average extraction rate of GA reached 99.2%. The best back extraction conditions for GA were as follows: 22.5 mmol/L NaOH aqueous solution was used as the stripping agent, the volume ratio of organic phase to stripping agent was 1:1, the single back extraction rate of GA reached 98.8%, and the total transfer rate of GA was 98.1%. Conclusion Ultrafiltration-complexation extraction technology can be used as a new process for the preparation of GA.
ABSTRACT
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.