Imidazodiazepinediones: A New Class of Adenosine Receptor Antagonists

Article abstract of DOI:10.1021/jm00172a022

A series of imidazo<4,5-e><1-4>diazepine-5,8-diones were synthesized from hypoxanthines.Certain of these cyclic homologues of caffeine, theophylline theobromine, 3-isobutyl-1-methylxanthine, and enprophylline were inhibitors of binding of adenosine analogues to rat brain A₁ and A₂ adenosine receptors and were antagonists of A₂ adenosine receptors stimulatory to adenylate cyclase in rat PC12 cell membranes.Activity at adenosine receptors was lower than the corresponding xanthines, perhaps because imidazodiazepinediones contain a boat-shaped seven-membered ring rather than the planar ring system of the xanthines.The imidazodiazepinediones had low affinity for brain benzodiazepine sites.