Table 3.

Opioid Receptor Binding^a and Efficacy^b of Compounds 4A-F and 5A-F

^aBinding affinities (K_i) were obtained by competitive displacement of [³H]-diprenorphine in membrane preparations.

^bEfficacy and potency data were obtained measuring agonist-induced stimulation of [³⁵S]-GTPγS binding. Efficacy is represented as percent maximal stimulation relative to a standard agonist at 10 μM: DAMGO (MOR), DPDPE (DOR), or U69,593 (KOR). Values are expressed as the mean of three separate assays performed in duplicate with standard error of the mean (SEM) in parentheses. dns = does not stimulate.

^cFirst reported in reference 38.