Table 2.

Binding Affinity and Selectivity over α4β2 and α3β4 nAChR of a Series of Compounds Having Three Small R1 Functionalities with an Adjusted R2 Group^a

compd	R1	R2	α3β4	α4β2	selectivity
1	hydrogen	2-(3,4-dichlorophenyl)ethyl	711 ± 18	1296 ± 44	0.5
2	hydrogen	pyridine-4-ylmethyl	50107 ± 1806	652 ± 166	77
3	hydrogen	phenylethyl	325 ± 40	361 ± 1	0.9
5	S-methyl	2-(pyridine-3-yl)ethyl	1026 ± 254	18 ± 3	57
8	hydrogen	2-(pyridine-3-yl)ethyl	644 ± 17	58 ± 3	11
13	R-hydroxymethyl	2-(pyridine-3-yl)ethyl	964 ± 193	13 ± 1	74
14	S-methyl	pyridine-3-ylmethyl	36547 ± 729	1358 ± 9	27
15	hydrogen	pyridine-3-ylmethyl	98927 ± 1106	3750 ± 81	26
16	S-methyl	phenylethyl	N/A	2250 ± 20	N/A
17	R-hydroxymethyl	2-(3,4-dichlorophenyl)ethyl	321 ± 33	1045 ± 91	0.3
18	hydrogen	3-fluorophenylethyl	633 ± 6	221 ± 17	3
19	S-methyl	3-fluorophenylethyl	N/A	474 ± 12	N/A
20	R-hydroxymethyl	3-fluorophenylethyl	N/A	704 ± 36	N/A
21	hydrogen	3-bromophenylethyl	314 ± 26	601 ± 42	0.5
22	S-methyl	3-bromophenylethyl	628 ± 61	361 ± 30	1.7
23	R-hydroxymethyl	3-bromophenylethyl	1090 ± 123	640 ± 72	1.7
24	S-methyl	2-(6-chloropyridin-3-yl)ethyl	125 ± 6	11 ± 1	11
25	hydrogen	2-(6-chloropyridin-3-yl)ethyl	471 ± 16	80 ± 5	6
26	R-hydroxymethyl	2-(6-chloropyridin-3-yl)ethyl	281 ± 19	20 ± 2	14

^aAll experiments are performed in duplicate or triplicate and repeated 2–3 times. Data are presented as the mean ± SEM.