5,6-Didehydroginsenosides from the roots of Panax notoginseng

Two minor novel dammarane-type saponins - 5,6-didehydroginsenoside Rd (1) and 5,6-didehydroginsenoside Rb1 (2) - were isolated from the dried roots of Panax notoginseng along with sixteen known saponins. The structures of the new compounds were elucidated on the basis of spectroscopic and chemical methods.