Table 1.

Structures and Binding Affinity for Scopolamine (1), Compounds 8, and 17–36 at the hM₁ and hM₅ mAcChRs^a

compd	R1	Ki, nM		hM1/hM5
		hM1	hM5
1	-	7.5	17.6	0.4
8		170	420	0.4
17		1,730	1,250	1.4
18		470	150	3.1
19		3,060	3,610	0.8
20		3,290	470	7.0
21		>100,000	>100,000	-
22		200	290	0.7
23		100	190	0.5
24		560	410	1.4
25		240	370	0.6
26		810	440	1.8
27		>100,000	>100,000	-
28		1,390	230	6.0
29		200	280	0.7
30		60	120	0.5
31		11,700	2,460	4.8
32		>100,000	>100,000	-
33		>100,000	>100,000	-
34		410	760	0.5
35		370	140	2.6
36		140	190	0.7

^aAt least three independent experiments with samples evaluated in duplicate were performed to obtain the K_i value.