Table 3. Exploration of SARs on the Para-position of the Phenyl Ring.

code	R3	MWa	cLogPa	PSAa	T. b. brucei pIC50b	MRC-5 pIC50b
34 (NPD-3377)	-OiPr	312.4	3.2	79.4	<4.2	<4.2
35 (NPD-3201)	-CF3	322.3	3.4	70.1	5.9 ± 0.1	<4.2
36 (NPD-3597)	-OCF3	338.3	3.8	79.4	5.9 ± 0.2	<4.2
37 (NPD-3203)	-CN	279.3	2.1	93.9	6.6 ± 0.3	<4.2
38 (NPD-3305)	-COOMe	312.3	2.4	96.4	<4.2	<4.2
39 (NPD-3489)	-COOH	298.3	2.1	107.4	<4.2	<4.2
40 (NPD-3371)	-CONH2	297.3	1.3	113.2	<4.2	<4.2
41 (NPD-3376)	-SO2CH3	332.4	1.2	104.3	4.3 ± 0.1	<4.2
42 (NPD-3372)	-SO2NH2	297.3	1.0	113.2	4.4 ± 0.1	<4.2
43 (NPD-3280)	-NHCOCH3	311.3	1.7	99.2	<4.2	<4.2
44 (NPD-3283)	-piperidine	337.4	3.6	73.4	<4.2	<4.2
45 (NPD-3282)	-methylpiperazine	352.4	2.1	76.6	4.7 ± 0.4	4.4 ± 0.1
46 (NPD-3490)	-tetrazole	322.3	2.0	124.6	<4.2	<4.2

^acLogP and PSA (polar surface area) are calculated using CDD.

^bMean values of at least 2 independent experiments.