Table 3. Structure–Functional Selectivity Relationship Study of Phenoxy Derivatives.

				hEP2
				G protein (cAMP)		β arrestin
cmpd	R1	R2	R3	EC50 (nM)a	Emax (%)b	EC50 (nM)a	Emax (%)
prostaglandin E2				1.9	105	346	107
18a	H	H	H	13	118	>10,000	28
18b	Cl	H	H	3.3	95	203	78
18c	CF3	H	H	0.5	119	11	121
18d	F	H	H	23	59	>10,000	38
18e	H	Me	H	3.6	100	>10,000	38
18f	H	Cl	H	6.5	65	>10,000	27
18g	H	OCF3	H	0.9	119	69	79
18h	H	CF3	H	0.9	112	9	62
18i	H	F	H	5.4	94	>10,000	35
18j	H	H	Me	27	85	>10,000	20
18kc	H	H	Cl	3.9	96	>10,000	12
18l	H	H	OCF3	14	110	4500	57
18m	H	H	CF3	13	103	>10,000	23
18n	H	H	F	7	99	>10,000	22

^aAssay protocols are provided in the Supporting Information. EC₅₀ values represent the mean of two experiments.

^bAll E_max were normalized to PGE₂ results.

^cConcentration–response data is shown in Figure S2 (Supporting Information).