Research On Extraction And Purification Of Total Flavonoids From Glycyrrhiza Residues

Glycyrrhiza residue was the waste of the Glycyrrhiza after the glycyrrhizic acid extraction.Therefore,the total flavonoids extracted from Glycyrrhiza residue which was used as the raw material,was not only the waste utilization and protection in the environment,but also expand the scope of total flavonoids extraction.This paper mainly focus on the extraction and purification process by determining the determination method that the total flavonoids from Glycyrrhiza residue.We optimized the conditions for Glycyrrhiza residue ultrasonic parameters-microwave synergistic extraction to improve the flavonoid yield.Through the macroporous resin absorption and desorption characteristics of separating and purifying the total flavones to predicting its adsorption balance.To the prediction in resin adsorption equilibrium,two representative resins(AB-8 and SP825)were chosen for adsorption thermodynamics and kinetics model studies.We also optimized the total flavonoids parameters of separation and purification.The test results are as follows:(1)Screening of standard and chromogenic agent,the determination method of total flavonoids from Glycyrrhiza residues was chosen.Eventually the rutin and KOH were chosen as the standard and chromogenic agent.Maximum absorption wavelengt h,chromogenic time and chromogenic agent were studied.The optimum process conditions for determining the total flavonoids is maximum absorption wavelength of 409 nm,chromogenic time of 5 min,chromogenic agent 0.5 mL.This method is suitable for determine total content of flavonoids from Glycyrrhiza residues rapidly and clearly.(2)Comparing different extraction methods,the ultrasound-microwave-synergized extraction method was the optimal one.Single factor experiment were used in predicting the influence of output rate on the analysis extraction time,the ratio of liquid to material,the concentration of ethanol and microwave power.Box-Behnken central-composite design theory was used to provide experimental data for analyzing the interactive effect.The optimum process conditions for extracting the total flavonoids was extraction time of 32 min,the ratio of liquid to material of 28.4 mL/g,the concentration of ethanol of 79% and microwave power of 125 W,extraction rate of total flavonoids on value was 2.59%.It turned out that this method we used can well optimize the extraction technology of total flavonoids from Glycyrrhiza residues.(3)To get the optimum macroporous resin,two macroporous resins(AB-8 and SP825)were used in the static adsorption method.The adsorption process is simulated by different dynamic and thermodynamic model.Single factor analysis of the purification parameters of AB-8 showed that the AB-8 and SP825 resin are suitable for flavonoids.And the kinetics results showed that the whole adsorption process can be described better by the pseudo-second order kinetics model,regression coefficients were 0.99993 and 0.99999.Along with the temperature change,the rule of the adsorption rate was analyzed.The thermodynamics results showed that the adsorption process fits the Freundlich isothermal model,regression coeffic ients were 0.99565 and 0.99592.(4)The optimized conditions result showed the optimum process conditions for purifying using AB-8 resin were determined as follows: flow velocity of 3 mL/min,sample concentration of 1.089 mg/mL,amount of 80% ethanol as desorption solvent 3 BV,flow velocity of 1.5 mL/min and with a high desorption rate 91.67%.It provides a theoretical basis for market evaluation.In conclusion,we aim to make the most use of Glycyrrhiza residue to recycle and reduce the pollution of the environment.The extraction rate of total flavonoids in Glycyrrhiza residue was improved,and the purification process was controlled.It provides theoretical support fo r the protection of Glycyrrhiza resources and the deep processing of flavonoids.