Compound induced activation of caspases 3 and 7 was analyzed using the CellEvent Caspase-3/7 green detection reagent (Thermo Scientific, Waltham, Massachusetts) according to the manufacturers' instructions. Cal27 cells were seeded in 96-well-plates (Corning, Incorporated, New York City, New York) at a density of 2500 c/w. After 24 h, cells were exposed to the described compounds for 48 h.