Isolation and purification of soyasapogenol A and B starting from soy hypocotyls: High-speed counter-current chromatography versus preparative high-performance liquid chromatography

Soyasapogenols derived from soyasaponins, which abundantly occur in soy hypocotyls, are of great importance as bioactive compounds due to their physiological activities. However, there is a lack of a high-efficiency and scalable preparation and isolation procedure. This work extends research on applying and comparing high-speed countercurrent chromatography (HSCCC) and preparative high-performance liquid chromatography (prep-HPLC) either singly and/or combinedly in preparative isolation of soyasapogenol A and B. The comparison reveals that the yield of 0.24 and 0.21% of soyasapogenol A and B with the purity of 98.09 and 98.90%, respectively, were obtained from the starting material of soy hypocotyls in two-steps HSCCC separation procedure. In contrast, prep-HPLC allowed isolation and purification of these two target compounds with significantly lower productivity and higher solvent consumption. An optimal two-phase solvent system of n-hexane-ethyl acetate-methanol-water (3:6:4:2, v/v/v/v) was selected to separate soyasapogenols in HSCCC procedure. The present investigation indicates that two-steps HSCCC can potentially provide a fast, high yielding, and more environmentally friendly tool for the preparative separation and purification of soyasapogenol A and B starting from the materials of soy hypocotyls.