Clinical data
Other namesPSB-10
CAS Number
PubChem CID
Chemical and physical data
Molar mass400.690 g/mol g·mol−1
3D model (JSmol)
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PSB-10 is a drug which acts as a selective antagonist[1] for the adenosine A3 receptor (ki value at human A3 receptor is 0.44 nM), with high selectivity over the other three adenosine receptor subtypes (ki values at human A1, A2A and A2B receptors are 4.1, 3.3 and 30 μM). Further pharmacological experiments in a [35S]GTPγS binding assay using hA3-CHO-cells indicated that PSB-10 acts as an inverse agonist (IC50 = 4 nM). It has been shown to produce antiinflammatory effects in animal studies.[2] Simple xanthine derivatives such as caffeine and DPCPX have generally low affinity for the A3 subtype and must be extended by expanding the ring system and adding an aromatic group to give high A3 affinity and selectivity.[3] The affinity towards adenosine A3 subtype was measured against the radioligand PSB-11.[4]


  1. ^ Ozola V, Thorand M, Diekmann M, Qurishi R, Schumacher B, Jacobson KA, Müller CE (2003). "2-Phenylimidazo[2,1-i]purin-5-ones: structure-activity relationships and characterization of potent and selective inverse agonists at Human A3 adenosine receptors". Bioorg Med Chem. 11 (3): 347–56. doi:10.1016/S0968-0896(02)00456-X. PMID 12517430.
  2. ^ Bilkei-Gorzo A, Abo-Salem OM, Hayallah AM, Michel K, Müller CE, Zimmer A (March 2008). "Adenosine receptor subtype-selective antagonists in inflammation and hyperalgesia". Naunyn-Schmiedeberg's Archives of Pharmacology. 377 (1): 65–76. doi:10.1007/s00210-007-0252-9. PMID 18188542.
  3. ^ Müller CE (2003). "Medicinal chemistry of adenosine A3 receptor ligands". Current Topics in Medicinal Chemistry. 3 (4): 445–62. doi:10.2174/1568026033392174. PMID 12570761.
  4. ^ Müller CE, Diekmann M, Thorand M, Ozola V (2002). "[(3)H]8-Ethyl-4-methyl-2-phenyl-(8R)-4,5,7,8-tetrahydro-1H-imidazo[2,1-i]-purin-5-one ([(3)H]PSB-11), a novel high-affinity antagonist radioligand for human A(3) adenosine receptors". Bioorg Med Chem Lett. 12 (3): 501–3. doi:10.1016/S0960-894X(01)00785-5. PMID 11814828.