[Saponins of polygalacic acid type from Platycodon grandiflorum].

Aim: To isolate triterpene saponins of polygalacic acid type from the roots of Platycodon grandiflorum (Jacq.) A. DC and to identify their structures.
Methods: The compounds were separated by means of extraction, chromatography on silica gel, MPLC and HPLC, and their structures were elucidated on the basis of spectral analyses (FAB-MS, IR, 1H NMR, 13C NMR etc.).
Results: Three triterpene saponins were isolated from the roots of Platycodon grandiflorum. They were identified as 3-O-beta-D-laminaribiosyl polygalacic acid (I), 3-O-beta-D-glucopyranosyl polygalacic acid (II), polygalacin D (III), separately.
Conclusion: Compound I is a new compound, compounds II, III are known triterpene saponins. The compound I and II were isolated from the plant for the first time, which is also the monodesmoside from the plant for the first time.