Research On Ultrasonic-assisted Multi-stage Dynamic Countercurrent Extraction Of Imperatorin And Isoimperatorin From Angelica Dahurica

Ultrasonic assisted multistage continuous countercurrent extraction technology (UMCE) is a novel extraction method for Chinese traditional medicine, which integrates characteristics of ultrasonic assisted extraction and multistage continuous countercurrent extraction. Ultrasonic assisted extraction and ultrasonic assisted multistage countercurrent extraction of imperatorin and isoimperatorin from Angelica dahurica were developed in this paper. The effects of ultrasonic power, ethanol concentration, ratio of liquid to solid, extraction temperature, extraction time, and medicinal material granularity on the extraction yields of imperatorin and isoimperatorin from Angelica dahurica were investigated. The optimal extraction conditions were achieved using orthogonal array experimental design technique. The optimal conditions of ultrasonic assisted extraction are as follows:ethanol concentration is 60%, ratio of liquid to solid is 14 ml-g-1, and extraction time is 20min. The optimal conditions of three-stage UMCE are as follows:ethanol concentration is 60%, extraction time is 15min, and ratio of liquid to solid is 6 ml/g.According to the Fick's first law;. a kinetic model of ultrasonic extracting effective components from Chinese herb is presented. The experiments of extracting imperatorin and iscinperatorin from Angelica dahurica under different extraction methods are performed. The modified model fits the experiment data well and can provide a theoretical reference for the extraction of Chinese traditional medicine. Based on the dynamic model, different thermodynamic parametersΔH°,ΔS°andΔG°in different extraction methods were also investigated.The various extraction methods produced distinguishable physical changes in Angelica dahurica. Compared to solvent extraction, ultrasonic assisted extraction reduces extraction time and obtains higher product recovery. The effect of ultrasonic on cell destruction of plant material was observed by scanning electron microscopy (SEM). The SEM indicated that ultrasonic wave treatment affects the structure of Angelica dahurica cell due to the sudden temperature rising and the internal pressure increasing. During the rupture process, the major chemical substances within the cell could diffuse into the surrounding solvents rapidly.Compared to the previous extraction methods, the UMCE has several advantages, such as shortening extraction time, low energy consumption, and so on. The UMCE extraction process is easily industrialized and has a wide application prospect.