Microwave-assisted Extraction Of The Effective Compounds In Flos Sophorae And Cortex Fraxini

Two microwave-assisted extraction (MAE) methods used for extracting the effective components from Flos Sophorae and Cortex Fraxini were studied. The first method is microwave resonant cavity dynamic extraction. The second method is continuously microwave-assisted reflux extraction. MAE processes of extracting flavonoids in Flos Sophorae and coumarins in Cortex Fraxini were studied, and the contents of total flavonoids and total coumarins were determined by spectrophotometry. The results obtained by MAE were compared with those obtained by Soxhlet extraction. At the same time, the effects of some operation conditions, such as ethanol concentration, solvent volume, microwave irradiation time and microwave power, on the extraction yields of the above mentioned compounds were investigated. The experimental results indicate that, compared with Soxhlet extraction, when MAE was applied, extraction yield can be improved, and the time of extraction and the amount of solvent consumption can be reduced. The results also indicate that the MAE is suitable to extract flavonoids and coumarins from Chinese traditional medicines. Besides, microwave-assisted reflux extraction used for the extraction of aesculin and aesculetin in Cortex Fraxini was studied, and the contents of aesculin and aesculetin were determined by high performance liquid chromatography (HPLC). The results obtained by microwave-assisted reflux extraction were compared with the results obtained by Soxhlet extraction. The experimental results show that microwave-assisted reflux extraction is an efficient method for the extraction of aesculin and aesculetin in Cortex Fraxini. All of the above results show that MAE is a promising technique for extracting the effective components from Chinese herbal medicines.