Comparison of Silica-, C₁₈−, and NH₂−HPLC Columns for the Separation of Neutral Steroid Saponins from Dioscorea Plants

Abstract

Six neutral steroid saponins including dioscin and gracillin from the tubers of Dioscorea plants and their peracetates were chromatographed by silica-, C₁₈−, and NH₂−column high-performance liquid chromatography (HPLC). The eluent containing water was used in the silica-column HPLC for the separation of these saponins. These HPLC systems complement each other and allow separation of the saponins. The number of carbohydrate units in the saponin molecule plays the most important role for the separations. The more carbohydrate units in the molecule, the more polar is the saponin or its peracetate. Separation of saponins containing the same number of carbohydrate units can be improved by using their peracetates.