Extraction, separation and kinetics of phenylethanosides from L. by an innovative extraction technology-deep eutectic solvent-based ultrasound-assisted extraction.

In this paper, the total phenylethanosides (TPS) were extracted efficiently by an innovative extraction technology--deep eutectic solvent-based ultrasound-assisted extraction (DES-UAE) from L. Ten diverse types of DESs were synthesized as alternative extraction solutions. The extraction efficiency of DES-3 (constituted by choline chloride and lactic acid) was much higher than those of other DESs. On the basis of single factor tests and Box-Behnken design (BBD), the optimum processing parameters of DES-UAE as follow: DES-3 with molar ratio of 1:3, extraction temperature 51 °C, solid/liquid 22.5 mg/ml, water content 30%, ultrasonic power 65 W, extraction time 23 min. The extraction efficiency of TPS from L. was 8.395 mg/ml, which was more superior than those of organic solvents (water, methanol, 50% methanol, ethanol, 50% ethanol). The extraction kinetics experiment results showed that water content had a significant influence upon the extraction efficiency of TPS. At the same time, AB-8 macroporous resin column was used to efficiently isolate TPS from DES extraction with a recovery rate of 88.5%.