Table 1.

Structures and Activities of Cyclic Pyrrolidinone M₁ PAMs^a

Compound	Structure	hM1 EC50 (nM)	hM1 ACh Max
8a		>10,000	-
8b		2000b	60
8c		8000	30
8d		1920b	75
8e		1020	59
8f		2870	60
8g		3970	67
8h		2780	51
8i		2164b	66
8j		246	40
8k		4900	67
12a		>10,000	-
12b		>10,000	-
12c		992	45
16a		6450	58
16b		5580	67
16c		2920	56
20a		1120c	85
20b		3540b	61
20c		3930	84
20d		739b	87
20e		5180	57
20f		1510c	84
20g		1660b	79
20h		3220	77
20i		6890	66
20j		3580	65
25a		>10,000	-

^aCalcium mobilization assays with hM₁-CHO cells performed in the presence of an EC₂₀ fixed concentration of acetylcholine for PAM, no exogenous acetylcholine (ACh) for the agonist EC₅₀; values represent means from one (n = 1)

^btwo (n = 2)

^cthree (n = 3) independent experiments performed in triplicate.