Table 2. Binding affinities (K_i) of indole and benzimidazole carboxamides to wild type and A147T TSPO-expressing HEK-293 membranes. The affinity of all compounds was indexed by the displacement of [³H]PK-11195 (10 nM) in radioligand binding assays. Values represent the mean ± SD from at least three independent experiments performed in duplicate.

Compound	K i (nM)		A147T : wild type
	A147T	Wild type
4	>10 000	>10 000	N/A
5	>10 000	3061.3 ± 1380.2	>3.3
6	2570.0 ± 731.3	>10 000	<0.3
7	>10 000	>10 000	N/A
8	>10 000	∼10 000 a	N/A
9	>10 000	3282.4 ± 1842.0	>3.0
10	>10 000	>10 000	N/A
11	>10 000	>10 000	N/A
12	>10 000	>10 000	N/A
13	>10 000	>10 000	N/A
14	2861.4 ± 892.3	2073.3 ± 683.8	1.4
15	760.9 ± 149.4	1496.3 ± 176.9	0.5
16	982.7 ± 233.9	>10 000	0.1

^aAffinity not high enough to give accurate fit (mean 47% inhibition of [³H]PK-11195 binding at 10 μM).