PSB-KD107 is an agonist of the orphan G protein-coupled receptor GPR18 (EC50 = 0.56 µM in a β-arrestin recruitment assay using CHO cells expressing the human receptor).1,2 It is selective for GPR18 over GPR55, as well as cannabinoid (CB) receptor 1 (CB1) and CB2, at 10 µM but also binds to the adenosine A2A receptor (Ki = 0.33 µM for the rat receptor).1,3
1.Schoeder, C.T., Kaleta, M., Mahardhika, A.B., et al.Structure-activity relationships of imidazothiazinones and analogs as antagonists of the cannabinoid-activated orphan G protein-coupled receptor GPR18Eur. J. Med. Chem.155381-397(2018) 2.Schoeder, C.T., Mahardhika, A.B., Drabczyńska, A., et al.Discovery of tricyclic xanthines as agonists of the cannabinoid-activated orphan G?protein-coupled receptor GPR18ACS Med. Chem. Lett.(2020) 3.Drabczyńska, A., MÜller, C.E., Schiedel, A., et al.Phenylethyl-substituted pyrimido[2,1-f]purinediones and related compounds: Structure-activity relationships as adenosine A1 and A2A receptor ligandsBioorg. Med. Chem.15(22)6956-6974(2007)