Table 2. Binding Affinities of a Series of 1,2,4-Triazole Derivatives at the Human A₁, A_2A, and A₃ARs Measured in Radioligand Binding Assays and Percent Inhibition of cAMP Accumulation in the Presence of 300 nM NECA in a Functional Assay for the A_2BAR.

		Ki (μM) or % inhibition at 10 μMa
compd	R	A1	A2A	A3	A2B
25	CH3	18%	43%	0.3 ± 0.01	10%
26	CH2CH3	39%	2.5 ± 0.6	0.3 ± 0.2	8%
27	(CH2)2CH3	0.8 ± 0.2	1.1 ± 0.2	0.2 ± 0.04	5%
28		3.2 ± 0.7	5.9 ± 0.5	3.1 ± 0.7	–7%
	X
29	H	1.9 ± 0.3	0.4 ± 0.02	0.3 ± 0.2	72%
30	4-CH3	1.3 ± 0.4	0.3 ± 0.1	0.1 ± 0.04	29%
31	4-Cl	31%	2.8 ± 0.8	0.2 ± 0.1	–2%
32	2-OCH3	0.5 ± 0.1	0.2 ± 0.06	0.6 ± 0.2	16%
33		22%	0.2 ± 0.04	0.3 ± 0.2	10%
34		29%	1.0 ± 0.2	1.0 ± 0.3	–6%

^aMeasured in three independent experiments.