Ionic liquid-based ultrasound-assisted extraction of fangchinoline and tetrandrine from Stephaniae tetrandrae

An ionic liquid-based ultrasound-assisted extraction method has been developed for the effective extraction of fangchinoline and tetrandrine from Stephaniae tetrandrae. The effects of some ultrasound-assisted extraction parameters including the concentration of [BMIM][BF4], pH, ultrasonic power and time were investigated to optimize the ultrasound-assisted extraction conditions. Compared to the regular ultrasound-assisted extraction and traditional refluent extraction, the proposed [BMIM][BF4]-based ultrasound-assisted extraction offered shorter extraction times (from 6 h to 40 min) and remarkable higher efficiencies (approximately 30% improved), which supported the suitability of the proposed approach. In addition, the proposed approach was confirmed by the good correlation coefficient (R-2), recovery and reproducibility (RSD, n = 5), which were in the range of 0.9992-0.9995, 85.5-101.1%, and 1.87-4.33%, respectively.