. Author manuscript; available in PMC: 2019 Mar 28.

Published in final edited form as: J Med Chem. 2019 Feb 13;62(4):1761–1780. doi: 10.1021/acs.jmedchem.8b01679

Table 5.

KOR, MOR, DOR Antagonist Activity of Compounds 29, 46–50, 58–62

Compound	R	R¹	IC₅₀(nM)^a			Selectivity	Calculated Physicochemical Properties^{50, 51}
Compound	R	R¹	KOR^b	MOR	DOR	MOR/KOR	cLogP	tPSA	cpK_a
29			3.0	79	4410	26	1.6	71	10.5
46	H		3.6	1200	>10000	333	2.2	71	10.5
47	H		1.1	1400	>10000	1273	3.1	71	9.9
48	H		2.1	6200	>10000	2952	3.1	71	9.9
49	H		2.3	6400	>10000	2783	2.7	71	9.8
50	H		2.4	6500	>10000	2708	2.7	71	9.8
58	Me		0.8	110	6500	138	2.4	71	10.5
59	Me		0.26	100	4500	384	3.3	71	9.9
60	Me		0.53	400	>10000	754	3.3	71	9.9
61	Me		0.78	1100	>10000	1410	2.9	71	9.8
62	Me		0.88	1400	>10000	1591	2.9	71	9.8

Values are reported as mean of n = 3 determinations.

This assay uses Tango OPRK1-bla U2OS cells which express KOR linked to a GAL4-VP16 transcription factor via a TEV protease site. Stimulation of the KOR by U-50488 causes migration of the β-arrestin fusion protein to the GPCR, and through proteolysis liberates GAL4-VP16 from the receptor. Assay protocols are described in ref 37.