Table 3.
Affinities of orthosteric adenosine receptor ligands that are commonly used as pharmacological probes. Affinity is shown at the human adenosine receptors, unless noted. Structures are shown in Figures 1A and 2A.
| No. | Compound | Affinity, pKia | |||
|---|---|---|---|---|---|
| A1 | A2A | A2Bb | A3 | ||
| Adenosine receptor agonists | |||||
| 1 | adenosineb | ~7 7.14 (r) |
6.49 6.82 (r) |
4.82 5.29 (r) |
6.54 5.19 (r) |
| A1-selective | |||||
| 2 | R-PIA | 8.69 8.92 (r) |
6.66 (r) | 3.82 | 7.48 6.80 (r) |
| 3 | CPA | 8.64 | 6.10 | 4.73 | 7.14 |
| 4 | CCPA | 9.08 8.89 (r) |
5.64 6.02 (r) |
4.73 | 7.42 6.63 (r) |
| 5 | 5′-Cl-5′-deoxy-ENBA | 9.29 | 5.89 | 5.87 | 5,56 |
| A2A-selective | |||||
| 6 | CGS21680 | 6.54 5.74 (r) |
7.57 7.72 (r) |
<5 <5 (r) |
7.17 6.23 (r) |
| 7 | UK432,097 | ND | 8.4 | ND | ND |
| A2B-selective | |||||
| 8 | BAY 60-6583 | <5b | <5b | 8–8.5 | <5b |
| A3-selective | |||||
| 9 | IB-MECA (CF101) | 7.29 | 5.54 | 4.96 | 8.74 |
| 10 | Cl-IB-MECA (CF102) | 6.66 6.55 (r) |
5.27 6.33 (r) |
<5 | 8.85 9.48 (r) |
| 11 | thio-Cl-IB-MECA | 6.71 | 6.63 | ND | 9.42 |
| 12 | MRS5698 | <5 | <5 | <5 | 8.5 |
| Adenosine receptor antagonists | |||||
| Non-selective | |||||
| 13 | Caffeine | 4.97 4.39 (r) |
5.02 4.32 (r) |
4.98 4.52 (r) |
4.88 <4 (r) |
| 14 | Theophylline | 5.17 5.06 (r) |
5.17 25,300 (r) |
5.04 4.82 (r) |
4.65 4.07 (r) |
| 15 | CGS15943 | 8.46 8.19 (r) |
8.92 | 7.49 | 7.46 |
| 16 | XAC | 7.54 8.92 (r) |
9.0 7.20 (r) |
7.91 | 7.04 |
| A1-selective | |||||
| 17 | DPCPX (CPX) | 8.52 9.0 (r) |
7.22 6.30 (r) |
7.29 6.73 (r) |
6.61 4.37 (r) |
| 18 | PSB-36 | 9.2 9.91 (r) |
6.01 6.26 (r) |
6.73 | 5.64 5.19 (r) |
| A2A-selective | |||||
| 19 | KW6002 | 6.08b 6.64(r)b |
7.92 8.66 (r) |
<5b | 5.35b |
| 20 | CSCd | 4.55 (r) | 7.27 (r) | 5.09 | <5 (r) |
| 21 | ZM241,385 | 6.11 | 8.80 | 7.12 | 6.13 |
| 22 | SCH442,416 | 5.95 | 8.39 | <5 | <5 |
| A2B-selective | |||||
| 23 | MRS1754 | 6.39 7.77 (r) |
6.30 6.21 (r) |
8.70 7.89 (r) |
6.24 |
| 24 | MRS1706 | 6.80 | 6.91 | 8.86 | 6.64 |
| 25 | MRE2029-F20 | 6.70 | <6 | 8.26 | <6 |
| 26 | PSB-603 | <5 <5 (r) |
<5 <5 (r) |
9.26 | <5 |
| 27 | PSB-1115 | <5 5.66 (r) |
4.62 (r) | 7.27 | <5 |
| A3-selective | |||||
| 28 | MRS1523 | <5 4.81 (r) |
5.44 5.69 (r) |
<5 | 7.72 6.95 (r) |
| 29 | PSB-10 | 5.77 6.09 (r) |
5.57 5.22 (r) |
ND | 9.36 |
| 30 | VUF5574 | ≤5 (r) | ≤5 (r) | ND | 8.39 |
| 31 | MRS1191 | <5 4.40 (r) |
<5 <5 (r) |
<5 | 7.50 5.73 (r) |
| 32 | MRS1334 | <5 (r) | <5 (r) | ND | 8.57 |