To develop a more green, efficient and low cost process for the extraction of steroidal
saponins from Dioscorea zingiberensis
C. H. Wright.
Six kinds of ionic liquids with different cations and anions were evaluated. In addition, the
extraction parameters of the ionic liquid based ultrasonic/microwave extraction were studied. In order to
quantify the total saponin content accurately, all steroidal saponins were converted into diosgenin and
quantified with an appropriate HPLC procedure. IL-UMAE under optimal conditions was compared with
heat reflux extraction (HRE) and ultrasonic assisted extraction (UAE).
1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIm]BF4) solution at concentration of 0.5 mol
L-1 was selected as extraction solvent. The optimum conditions were as follows: solvent to solid ratio
15:1, microwave power 500 W and extraction time 8 min. Under these optimal conditions, the highest
extraction yield of diosgenin 10.24 ± 0.31 mg g-1 was obtained. It took only 8 min to obtain the 91.67 %
content of diosgenin obtained by traditional HRE. Extracting on time was shortened from 120 min to 8
Compared with traditional methods, IL-UMAE method uses Ionic liquid-solvent which
greatly shortens the extraction time. IL-UMAE as a simple, effective and environmentally friendly
approach shows a broad prospect for active ingredient extraction.