%0 Journal Article %A Murineddu, Gabriele %A Deligia, Francesco %A Ragusa, Giulio %A García Toscano, Laura %A Gómez Cañas, María %A Asproni, Battistina %A Satta, Valentina %A Cichero, Elena %A Pazos, Ruth %A Fossa, Paola %A Loriga, Giovanni %A Fernández Ruiz, José Javier %A Pinna, Gerard A. %T Novel sulfenamides and sulfonamides based on pyridazinone and pyridazine scaffolds as CB1 receptor ligand antagonists %D 2018 %@ 0968-0896 %U https://hdl.handle.net/20.500.14352/131205 %X A series of sulfenamide and sulfonamide derivatives was synthesized and evaluated for the affinity at CB1 and CB2 receptors. The N-bornyl-S-(5,6-di-p-tolylpyridazin-3-yl)-sulfenamide, compound 11, displayed good affinity and high selectivity for CB1 receptors (Ki values of 44.6 nM for CB1 receptors and >40 μM for CB2 receptors, respectively). The N-isopinocampheyl-sulfenamide 12 and its sulfonamide analogue 22 showed similar selectivity for CB1 receptors with Ki values of 75.5 and 73.2 nM, respectively. These novel compounds behave as antagonists/inverse agonists at CB1 receptor in the [35S]-GTPγS binding assays, and none showed adequate predictive blood–brain barrier permeation, exhibiting low estimated LD50. However, testing compound 12 in a supraspinal analgesic test (hot-plate) revealed that it was as effective as the classic CB1 receptor antagonist rimonabant, in reversing the analgesic effect of a cannabinoid agonist. %~