Table 4.

Phenotypic activity of analogues with gem‐dimethyl modifications against intracellular amastigotes of T. cruzi (Tulahuen strain) and MRC‐5 cells.

Cmpd	X	Y	Z	R1	pIC50 [a]		SI[b]
					T. cruzi	MRC‐5
120	O	CH	N		5.7	5.2	3
121	O	CH	N		6.0	5.5	3
122	O	CH	N		5.9	6.1	1
123	O	CH	N		6.2	<4.2	>100
124	O	CCH3	N		5.7	5.3	3
132	N	N	O		4.7	<4.2	>3
133	N	N	O		5.0	<4.2	>6
134	N	N	O		4.6	<4.2	>3
135	N	N	O		5.8	<4.2	>40
136	N	N	O		5.7	<4.2	>32
141	S	CH	N		5.6	5.1	3
142	S	CH	N		5.7	5.6	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).