Table 2. Anti-T. cruzi Activity and Mammalian Cytotoxicity of Synthetic Analogues with a Variation of S1 Substitution^a.

			IC50 (μM) ± SDb
entry	compound	S1	trypomastigote	amastigote	CC50 (μM) ± SDc	SId
1	1e	OH	38.6 ± 8.3	86.5 ± 16.2	>200	>2.3
2	2e	OMe	NA	NA	>200	ND
3	5	OMOM	6.5 ± 4.9	24.4 ± 10.3	>200	>8.2
4	6	OPMB	NA	4.0 ± 1.4	>200	>50
5	7f	OAllyl	NA	NA	>200	ND
6	8f	OBn	NA	9.5 ± 1.3	>200	>21.1
7	25	H	NA	10.9 ± 6.5	>200	>18.3
8	benznidazole		17.7 ± 1.9	5.0 ± 1.5	190.6 ± 13.4	38.1

^aSD: standard deviation; ND: not determined; NA: not active.

^bIC₅₀: 50% inhibitory concentration.

^cCC₅₀: 50% cytotoxic concentration.

^dSI: selectivity index, given by the ratio between CC₅₀ in NCTC cells and IC₅₀ in intracellular amastigotes.

^ePublished in ref (18).

^fPublished in ref (20).