1192559-65-1Relevant articles and documents
Conformational Restriction and Enantioseparation Increase Potency and Selectivity of Cyanoguanidine-Type Histamine H4 Receptor Agonists
Geyer, Roland,Nordemann, Uwe,Strasser, Andrea,Wittmann, Hans-Joachim,Buschauer, Armin
, p. 3452 - 3470 (2016)
2-Cyano-1-[4-(1H-imidazol-4-yl)butyl]-3-[2-(phenylsulfanyl)ethyl]guanidine (UR-PI376, 1) is a potent and selective agonist of the human histamine H4 receptor (hH4R). To gain information on the active conformation, we synthesized analogues of 1 with a cyclopentane-1,3-diyl linker. Affinities and functional activities were determined at recombinant hHxR (x: 1-4) subtypes on Sf9 cell membranes (radioligand binding, [35S]GTPγS, or GTPase assays) and in part in luciferase assays on human or mouse H4R (HEK-293 cells). The most potent H4R agonists among 14 racemates were separated by chiral HPLC, yielding eight enantiomerically pure compounds. Configurations were assigned based on X-ray structures of intermediates and a stereocontrolled synthetic pathway. (+)-2-Cyano-1-{[trans-(1S,3S)-3-(1H-imidazol-4-yl)cyclopentyl]methyl}-3-[2-(phenylsulfanyl)ethyl]guanidine ((1S,3S)-UR-RG98, 39a) was the most potent H4R agonist in this series (EC50 11 nM; H4R vs H3R, >100-fold selectivity; H1R, H2R, negligible activities), whereas the optical antipode proved to be an H4R antagonist ([35S]GTPγS assay). MD simulations confirmed differential stabilization of the active and inactive H4R state by the enantiomers.
Synthesis and histamine H3 and H4 receptor activity of conformationally restricted cyanoguanidines related to UR-PI376
Geyer, Roland,Buschauer, Armin
scheme or table, p. 775 - 785 (2012/03/12)
Recently, we identified highly potent agonists of the human histamine H4 receptor (hH4R) among a series of imidazolylbutylcyanoguanidines. Aiming at improved selectivity for the hH 4R relative to the H3 receptor
