New 23, 27-dihydroxy-oleanane-type triterpenoid saponins from Anemone Raddeana Regel.

Two new 23, 27-dihydroxy-oleanane-type triterpenoid saponins named Raddeanoside Rf and Raddeanoside Rg (1 and 2), along with thirteen known triterpenoid saponins (3-15) were isolated from the rhizome of Anemone raddeana Regel. Their structures were determined by chemical and spectral analysis, including 1 D, 2 D NMR data and HRESIMS. The type of aglycone 23, 27-dihydroxy oleanolic acid is extremely rare in natural products. In addition, the anti-cancer activity for all the compounds were evaluated. Compounds 9 and 10 exhibited significant cytotoxicity with IC₅₀ values of 4.47 and 8.97 μM against human pancreatic cancer lines (PANC-1), while compound 6 with IC₅₀ value of 8.19 μM against human lung lines (A549). The possible structure-activity relationships of these triterpenoid saponins were also tentatively discussed.