hCB₂R potency and predicted log D_7.4 of fluorescent probes 12–18.

Cmpd	EC50 or IC50a (nM)	E max b (%)	Function	Parent cmpds	Dye	c log D7.4c
12	82	80	Partial agonist	1/10b	TAMRA	3.7
13	528	127	Full agonist	1/10b	SiR	3.9
14	77	79	Partial agonist	1/10b	Alexa488	−0.5
15	523	129	Full agonist	1/10b	Alexa467	−0.9
16	114	−29	Inverse agonist	2/11b	TAMRA	3.6
17	129	−29	Inverse agonist	2/11b	SiR	2.2
18	262	−26	Inverse agonist	2/11b	Alexa488	−0.9

^aThe potency (EC₅₀ or IC₅₀) of fluorescent probes 12–18 was measured using cells stably expressing hCB₂R in homogeneous time-resolved fluorescence (HTRF) cAMP assay. The data are the means of four or seven independent experiments performed in technical replicates.

^bMaximum effect (E_max in %) was normalized to reference full agonist APD371.

^cFor computational calculation of c log D_7.4 see ref. 36.