Glycyrrhetinic amides and their cytotoxicity

3-O-Acetyl-glycyrrhetinic amides were prepared, and sulforhodamine B assays investigated their cytotoxicity. Their cytotoxicity strongly depended on the substitution pattern of the respective compounds. Thereby, an ethylenediamine-derived compound 2 performed the best, acting mainly by apoptosis. As far as heterocyclic amides are concerned, ring enlargement and the replacement of the distal nitrogen invariably led to a more or less complete loss of cytotoxic activity. Thus, the presence of a carbonyl function (C-30) seems necessary for providing significant cytotoxicity.