Abstract
A considerable number of saponins and aglycones of the triterpene type has been tested for hemolytic activity. From the results it is deduced, that the optimum hemolytic activity depends on the following structural arrangements. Aglycones require a polar grouping in ring A and a moderate polar grouping in ring D or E. Compounds containing a 16α-OH or 16-keto group together with a 3/β-OH group had the highest hemolytic potential of the substances tested. The distance of 10,5 A between 3/β-OH and 16α·ΟΗ appears to be of special significance. Acylation of either group results in a remarkable loss of activity. With saponins, which bear a sugar chain on 3/β-OH, the distance between the strong and the weak polar grouping is less critical. The composition of the sugar chain has a certain influence on the hemolytic power. A polar grouping in ring D and/or E, such as a sugar chain or a number of OH-groups, results in considerable inactivation of the substance.