PSB-10 is a drug which acts as a selective
antagonist[1] for the
adenosineA3receptor (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]
^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.
PMID18188542.
S2CID6110998.
^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.
PMID11814828.