The ultimate goal of our project was to investigate candiate small molecules with a potential anticancer activity and characterize their mode of action. Cardiac glycosides are important group of molecules for both their treating properties in heart failure and their potential effects in cancer therapy. We investigated the cardiac glycosides that are extracted from Digitalis Ferruginea which can be frequently found in Turkey. These glycosides are Lanatoside A, Lanatoside C and Glucogitorosid. Our results showed that they constitute high cytotoxicity effect against liver cancer cell lines. In addition they cause G2/M cell cycle arrest and thereby induce apoptosis. For the synthetic molecules, we first tested a set of molecules that are synthesized as derivatives of kinase inhibitors. There are some commercial drugs such as imatinib or erlotinib that are used frequently for cancer treatment. Thus we wanted to investigate if these molecules comprise cytotoxic activities. Our data revealed that especially one of the molecules out of 16 display high cytotoxicity and high kinase inhibitory effect in liver cancer cell lines. The final group of molecules we tested was compoused of thiazolidine ring. In this group of molecules, only one molecule, the one with alkyne terminal precursor, caused cytotoxicity against cancer cell lines. Besides, we have shown that it induces SubG1/G1 cell cycle arrest in cancer cell lines.