Comparison of extraction methods for the hypotensive drugs from Eucommia ulmoides

Extraction methods using Soxhlet extraction (SE), enzyme-assisted aqueous extraction (EE), semi-bionic extraction (SBE) and supercritical fluid extraction (SFE) were evaluated for the yields of geniposidic acid (GPA) and geniposide (GPS) from the bark of Eucommia ulmoides. The results showed that the yields of GPA and GPS attained by EE and SBE were highest, respectively. Compared with various extraction methods for the extraction of GPA and GPS, the SBE was more efficient than other methods. There was no organic solvent used in SBE. The pH values of semi-bionic extraction were the same as in the human body. The results indicate that SBE can be used for large-scale and efficient extraction of GPA and GPS from plant materials. The time taken by SFE was longer than other methods, but the yields of GPA and GPS were the lowest.