FIG 4.

Compound 9 inhibits T. gondii tachyzoite proliferation only when it is applied early during infection. HFF monolayers grown in 96-well plates were treated with complex 9 (100 nM) either 10 min prior to infection or 1 h, 5 h, or 24 h after infection with T. gondii tachyzoites. The proliferation of tachyzoites was measured after 2 days of culture by beta-galactosidase assay, as described in Materials and Methods. OD570, optical density at 570 nm.