Structure-Dependent Cytotoxic Effects of Eremophilanolide Sesquiterpenes.

The aim of this research was to determine the cytotoxic action of sixteen structurally-related eremophilane-type sesquiterpenes, isolated from several species of Senecio, against a panel of cancer cell lines. The cytotoxic activities were evaluated by WST-I test and the ICso values calculated. The investigated compounds exerted dose-dependent cytotoxic actions against selected cancer cell lines and no-tumoral HS5 cell line. The comparative structure-activity relationships demonstrated the importance of C-1, C-6, and C-8 substituents in the molecule. Our results show that eremophilane-type sesquiterpenes may represent an important source of novel potential antitumor agents due to their pronounced cytotoxic actions towards malignant cells.