Table 1. Affinities of 8 and Derivatives (1–6) in Radioligand Binding Assays on the Human Adenosine Receptors.

	pKi or % displacementa
compound	A1ARb	A2AARc	A2BARd	A3ARe
8	8.52 ± 0.04	8.13 ± 0.05	7.40 ± 0.05	7.38 ± 0.01
1	7.07 ± 0.01	7.17 ± 0.08	51%f	6.46 ± 0.06
2	6.54 ± 0.05	6.25 ± 0.08	2%f	5.42 ± 0.06
3	7.16 ± 0.02	8.00 ± 0.05	50%f	5.94 ± 0.05
4	6.38 ± 0.06	6.42 ± 0.01	6.43 ± 0.03	5.57 ± 0.05
5	12%g	–17%g	–12%f	46%g
6	6.95 ± 0.08	5.99 ± 0.12	37%f	5.87 ± 0.10

^aData are expressed as mean ± SEM of three separate experiments each performed in duplicate, unless indicated otherwise.

^bDisplacement of [³H]DPCPX binding in CHO cells expressing hA₁AR.

^cDisplacement of [³H]ZM241385 binding in HEK293 cells expressing hA_2AAR.

^dDisplacement of [³H]PSB-603 binding in CHO cells expressing hA_2BAR.

^eDisplacement of [³H]PSB-11 binding in CHO cells expressing hA₃AR.

^fPercent displacement (n = 2) of specific [³H]PSB-603 binding in CHO cells expressing hA_2BAR at 1 μM ligand concentrations.

^gPercent displacement (n = 2) of specific radioligand binding at 10 μM ligand concentrations.