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.