Two New Triterpenoid Saponins from the Structural Modification of Pseudoginsenoside-F11 and their Cytotoxic Activities.

Two ginsenoside derivatives (1, 2) along with 2 known ginsenosides (3, 4) were isolated from the acid hydrolysis products of pseudoginsenoside-F-11. Their structures were elucidated on the basis of spectroscopic analyses, including ID, 2D NMR and HR-BSI-MS. Among them, (12R, 20S, 24S)-20, 24; 12, 24-diepoxy-dammarane-3 beta, 6 alpha-diol (1) and (20R, 24R)-dammar-20, 24-epoxy-3 beta, 6 alpha, 12,3, 25-tetraol (2) were identified as new triterpenoid saponins. They were subjected to assay for cytotoxic activities against six human tumor cells lines.