Table 3.

Phenotypic activity of dihydropyrazolone bio‐isosteres against intracellular amastigotes of T. cruzi (Tulahuen strain) and MRC‐5 cells.

Cmpd	Headgroup	pIC50 [a]		SI[b]
		T. cruzi	MRC‐5
95		4.5	4.3	2
98		<4.2	<4.2	‐
99		6.3	4.8	32
104		5.0	4.6	3
109		4.8	<4.2	>4

[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).