Table 1.

K_i Values for the inhibition of μ, δ and κ opioid binding to CHO membranes by uni- and bivalent ligands

Compound/Structure		Ki (nM) ± SE			Selectivity
		μ	δ	κ	μ/δ/κ
Butorphana		0.23 ± 0.01	5.9 ± 0.55	0.079 ± 0.003	3/75/1
9b		0.71 ± 0.02	18 ± 0.6	0.29 ± 0.02	2.4/62/1
7a		0.46 ± 0.024	20 ± 0.074	0.42 ± 0.0081	1/48/1
6a		1.7 ± 0.11	42 ± 2.8	0.94 ± 0.02	1.8/45/1
7b		47 ± 3.1	390 ±11	18 ± 0.48	3/22/1
6c		8.6 ± 0.63	210 ±30	4.7 ± 0.68	1.8/45/1
10c		0.090 ± 0.004	4.2 ± 0.4	0.049 ± 0.0001	2/90/1
4a		0.95 ± 0.057	37 ± 1.8	0.62 ± 0.071	1.5/60/1
4b		0.47 ± 0.027	15 ± 0.86	0.47 ± 0.046	1/32/1
4c		2.9 ± 0.091	50 ± 2.6	2.2 ± 0.096	1.3/23/1
11a		0.43 ± 0.001	39 ±2	0.13 ± 0.03	3.3/300/1
8		3.7 ± 0.36	130 ± 5.4	3.4 ± 0.22	1/38/1

^aReference ⁹.

^bReference ¹.

^cReference ².