A first screening (Table and Figure ) of all compounds against T. gondii β-gal tachyzoites and HFF was carried out at concentrations of 0.1 and 1 µM. In a second screening, the selected compounds (which at 1 µM inhibited T. gondii-β-gal proliferation by at least 90% and impaired the HFF viability not more than 50%) were submitted to dose response studies to determine the IC50 values, while cytotoxicity in HFF was assessed at 2.5 µM (the results are summarized in Table ). The same screening strategy has been applied in previous studies 114 .