Abstract
A genuine sapogenin, saikogenin E, was isolated by applying the Smith-type controled degradation procedure for saikoside II fraction, one of the main saponins of Bupleurum falcatum L. It was also obtained by alkaline degradation of the periodate oxidized saponin. The structure of saikogenin E (Ia) was elucidated and saikogenins B and C were proved to be the artifacts derived from it. Saikogenin G, the genuine sapogenin corresponding to saikogenin D, was also obtained by modified de Mayo-type degradation method and its structure was established as (Va).
