It was confirmed by infrared spectral analysis that rhodea-sapogenin and rhodea-isosapogenin are steroidal sapogenins respectively possessing normal and isospiroketal side chain. At the same time, rhodea-sapogenin diacetate was decomposed to pregnenolone (or allopregnenolone) derivative through pseudo compound. The pregnenolone or al-lopregnenolone thereby obtained also failed to precipitate with digitonin.
