Ultrasound-assisted extraction of total flavonoids from Inula helenium

BACKGROUND: Inula helenium was a perennial herb belonging to composite family and the roots of I. helenium have been widely used in traditional Chinese medicine. In this study, I. helenium was used as an experimental matrix. MATERIALS AND METHODS: Ultrasound-assisted extraction (UAE) of total flavonoids from I. helenium was studied with dual wavelength UV-VIS spectrophotometer. Effects of various factors including ratio of material to liquid, ultrasonic time, ethanol concentration and extraction times on extraction yield of total flavonoids were evaluated. Then, orthogonal design of four factors at three levels was applied for optimization the extraction yields of flavonoids from the root of I. helenium. RESULT: The optimal extracting process of the total flavonoids from the root of the I. helenium was 1 g plant sample with 20 ml of 60% ethanol, extracting twice and each time for 20 min. CONCLUSION: Under these optimal conditions, the yield of total flavonoids was (17.36±0.94) mg/g. UAE was more efficient and time saving for the extraction of flavonoids from plant materials.