Table 1. Compound structures and activity against purified T. cruzi PFT, T. cruzi cells, and murine fibroblast cells.

Compound	R1	R2	% inhibition of T. cruzi PFT at 50 nM of drug	ED50 against T. cruzi,* μM	ED50 against murine 3T3 fibroblasts, μM
1	CO2CH3	Phenyl	0.8	0.0005	>10
2	CO2CH3	H	4	0.08	>10
3	H	Phenyl	10	0.01	10
4		Phenyl	23	0.05	>10
5		Phenyl	16	0.02	>10

R groups in reference to Fig. 1c.

^*Mammalian-stage parasites grown in 3T3 fibroblasts