Hemolytic and cytotoxic activity of dammarane-type triterpenoids

The relationship between chemical structure and hemolytic and cytotoxic activity was studied for dammarane-type triterpenoids isolated from leaves of various Betula species. It was shown that an acyclic sidechain (betulafolienetriol and betulafolienetetraol) imparted significantly higher hemolytic and cytotoxic activity than a cyclic sidechain. The activity of epoxydammaranetriol with an 11 alpha-OH group was slightly higher than that of epoxydammaranetriol with a 12 beta-OH group. The activity of C-3 epimeric epoxydammaranetriols and-tetraols with a 12 beta-OH group was independent of the configuration of the C-3 hydroxyl. Epoxydammaranetriols with an 11 alpha-OH group and epoxydammaranediols with a 3 alpha-OH group were more active than those with a 3 beta-OH group. The effect of the most active compounds on the microviscosity of tumor-cell membranes was determined.