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.


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.


RESULTS
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.


CONCLUSIONS
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.
Department of Pharmacy, Hebei North University, Zhangjiakou, PR China.
Jin
J
Wang
Yong-Ming
YM
Zhao
Chun-Yan
CY
Guo
Shao-Meng
SM
Zhang
Chun-Lei
CL
Liu
Dan-Shen
DS
Zhang
Xue-Mei
XM
Bai