Table 1.

Phenotypic activity of core‐phenyl modifications against intracellular amastigotes of T. cruzi (Tulahuen strain) and MRC‐5 cells.

Cmpd	R1	R2	R3	R4	pIC50 [a]		SI[b]
					T. cruzi	MRC‐5
3	H	H	MeO	H	6.4	4.4	100
57	H	MeO	H	H	5.1	4.5	4
58	H	MeO	MeO	H	4.3	<4.2	>1
59	H	−CH2CH2O−		H	5.8	4.6	16
60	H	Br	MeO	H	5.1	4.6	3
61	H	H	H	H	5.5	4.2	20
62	H	H	F	H	5.2	<4.2	>10
63	H	H	Cl	H	5.5	4.8	5
64	H	H	Me	H	5.6	<4.2	>25
65	H	H	MeO	F	5.6	<4.2	>25
66	F	H	MeO	H	5.3	<4.2	>13
67	H	Me	MeO	H	4.9	<4.2	>5
68	Me	H	MeO	H	4.5	<4.2	>2
74	H	H	CN	H	4.3	<4.2	>1

[a] All reported values are within a standard deviation of ±0.2 and the result of at least n=2. [b] The selectivity index is calculated by dividing the cytotoxicity (IC₅₀) by the T. cruzi activity (IC₅₀).