FIG. 1.
Inhibitory activity of selected tryptanthrin and indirubin compounds. The values on the y axis represent the amount of β-Gal activity measured following 5 days of cultivation of 50 tachyzoites of a β-Gal-producing strain of T. gondii in human foreskin fibroblast cells inoculated along with the indicated concentration of the compound. The full chemical structures are shown in Tables 1 and 2. The values in panel A indicate the activity of the tryptanthrin derivatives, and the values depicted in panel B indicate the activity of the indirubin derivatives. The effect of trimethoprim (Tm) is shown for comparison. None of the indicated compounds demonstrated cytotoxicity at the concentrations tested. Compounds with ID50 values of more than 100 μg/ml are not depicted.