Figure 3.

Morphological changes and apoptosis induction by compounds 3g, 3h, 3j, and 4a on human leukemia cells. A) Upper row: photomicrographs of representative fields of U937 cells stained with Hoechst 33258 to evaluate nuclear chromatin condensation (apoptosis) after treatment with the indicated concentrations of compound 3h for 6 h. Lower row: U937 cells were incubated with medium alone (control) or the indicated compounds; images of cells in culture were obtained with an inverted phase-contrast microscope. B) HL-60 cells were incubated with the indicated compounds at the indicated concentrations for 6 h, and genomic DNA was extracted, separated on an agarose gel, and visualized under UV light by ethidium bromide staining.