A SIMULTANEOUS COLORIMETRIC ESTIMATION OF BIOLOGICALLY ACTIVE AND INACTIVE SAIKOSAPONINS IN BUPLEURUM FALCATUM EXTRACTS

Abstract

A color reaction of saponin and sapogenin with vanillin and sulfuric acid was applied to a colorimetry of purified saikosaponin and saikogenin from Bupleurum falcatum L. Saikosaponins a and d gave a greenish blue color, but saikosaponin c gave a red-purple color after the color reaction. The relationship between the maximum absorbance value and quantity of each saponin or sapogenin followed Beer's law for 40–200 fig of saikosaponin, or 20–120 fig of saikogenin, per 6 ml of reaction mixture. The colorimetric reaction was applied to estimate the contents of the biologically active saikosaponins a and d, and of the inactive saikosaponin c, in mixtures of purified saikosaponins a–c and d–c, and in several crude saponin preparations from B. falcatum plants grown under various conditions.