Table 1.

Beta-arrestin and cAMP profiling of selected lead compounds

	EC50, μM	Efficacy, %
C1A [NCGC00120943]
β-arrestin	0.93	47.0
cAMP	0.38	−46.2
C1B [NCGC00120919]
β-arrestin	3.79	43.0
cAMP	0.32	−30.7
C2A [NCGC00135472]
β-arrestin	0.37	60.8
cAMP	0.05	−29
C2B [NCGC00134314]
β-arrestin	1.17	46.6
cAMP	0.19	−32.6
pMPPF
β-arrestin	1.16	20.5
cAMP	n/a	n/a
pMPPI
β-arrestin	n/a	n/a
cAMP	2.5	24.4

Both β-arrestin and cAMP assays were performed in CHO-GPR32 cell line. In β-arrestin assay, cellular basal activity (0%) is vehicle stimulation (DMSO, 0.57%; 100% activity is a 2-fold signal increase above the basal activity. cAMP assay was performed in the presence of forskolin stimulation (8 μM). Forskolin alone was taken as 0%, while vehicle alone (DMSO, 0.57%) was taken as −100%. EC₅₀: half maximal effective concentration. Efficacy: the highest activity of each compound expressed as % increase or decrease of forskolin stimulation. The numbers are mean values from two separate experiments in triplicates (average of 6 determinations) for both β-arrestin and cAMP assays.

Full chemical names: C1A: chemotype-1A; NCGC00120943 [3-methoxy-N-(5-morpholin-4-ylsulfonyl-1,3,4-thiadiazol-2-yl)benzamide]

C1B: chemotype-1B; NCGC00120919 [3-bromo-N-(5-morpholin-4-ylsulfonyl-1,3,4-thiadiazol-2-yl)benzamide]

C2A: chemotype-2A; NCGC00135472 [3,4-difluoro-N-[3-(3-methylimidazo[1,2-a]pyrimidin-2-yl)phenyl]benzamide]

C2B: chemotype-2B; NCGC00134314 [3-methoxy-N-[3-(3-methylimidazo[1,2-a]pyrimidin-2-yl)phenyl]benzamide]

p-MPPF: 4-Fluoro-N-{2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl}-N-(2-pyridinyl)benzamide

p-MPPI: 4-iodo-N-{2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl}-N-(2-pyridinyl)benzamide