Table 1. In VitroP. falciparum Growth Inhibition of 1a, 13e Stereoisomers, and 7e·HCl.

Compound	EC50 (nM)a	IPP rescueb
1a	250 ± 70c	100% @ 2.5 μM
(1R,3S)-(−)-13e	1,950 ± 240	50% @ 5 μM
(1S,3S)-(−)-13e	1,300 ± 100	nd
(1S,3R)-(+)-13e	3,690 ± 310	nd
(1R,3R)-(+)-13e	1,430 ± 70	nd
7e·HCl	108 ± 7	0% @ 2.5 μM

^aGrowth inhibition (72 h) of asexual blood stages determined using SYBR Green I assay. Values represent average ± SEM from at least three independent biological replicates. The Dd2 strain is resistant to chloroquine, pyrimethamine, and mefloquine.

^bRecovery of parasite growth in the presence of 200 μM IPP, at the indicated concentration of the test compound (Supporting Information); nd designates “not determined”.

^cReported previously.⁸