3beta,12beta,25-Trihydroxydammar-(E/Z)-20(22)-ene-6-O-alpha-L-rhamnopyranosyl-(1right arrow2)-beta-D-glucopyranoside, 3beta,2beta,25-trihydroxydammar-(E/Z)-20(22)-ene-6-O-beta-D-glucopyranoside, and dammar-20(22)-ene-3,6,12,25-tetrol(3beta,6beta,12beta,20E/Z) were synthesized from the ginsenosides Re, Rh1, and PPT, respectively, via a simple three-step process involving acetylation, elimination-addition, and saponification. We obtained the detailed structures of these compounds by 1D and 2D NMR, and by HR-ESI-MS. Among them, dammar-20(22)-ene-3,6,12,25-tetrol(3beta,6beta,12beta,20Z) was identified as a new triterpenoid ginsenoside. The cytotoxic and hemolytic effects of these compounds towards cancer cells and erythrocytes were also evaluated.