Table 2.

Radioligand competitive binding assays for 9H-carbazole analogues: focusing on the role of the carbonyl group with concomitant variation in basicity.

Compound	R	TPSAa	rCB1 Kib (nM)	hCB2 Kib (nM)	CB1/CB2 Ratioc
24		28.72	n.b.	n.b.
25		8.17	40.6 ± 4.2	49.6 ± 4.4	0.82
26		9.37	122.0 ± 28.1	370 ± 85.2	0.33
28		12.61	244.0 ± 56.2	740.0 ± 119.3	0.33
30		24.78	n.b.	n.b.	–

^aTopological polar surface area[25].

^bValues are means of three experiments run in triplicates with standard deviation.

^cK_i of CB1/K_i of CB2;

n.b. no binding.