Synthesis and pharmacological evaluation of new 5-(cyclo)alkyl-5-phenyl- and 5-spiroimidazolidine-2,4-dione derivatives. Novel 5-HT1A receptor agonist with potential antidepressant and anxiolytic activity

The synthesis of 5-(cyclo)alkyl-5-phenyl- and 5-spiroimidazolidine-2,4-dione derivatives with an arylpiperazinylpropyl moiety (12–23) and their in vitro and in vivo pharmacological properties and molecular characteristics were described. The investigated compounds exhibited high affinity for 5-HT1A (13–22) and 5-HT2A (18, 20, 21, 23) receptors and diversified pharmacological profile. Compounds 17, 20 and 22 showed antagonistic, partial agonistic and agonistic activity, respectively, toward 5-HT1A receptor and they were investigated as potential antidepressants and/or anxiolytics. The most interesting compound 22 (1-[3-(4-(2-methoxyphenyl)piperazin-1-yl)propyl]-3′,4′-dihydro-2′H-spiro[imidazolidine-4,1′-naphthalene]-2,5-dione), a pre- and postsynaptic 5-HT1A receptor agonist produced an antidepressant-like effect, which was more pronounced than that of imipramine in the forced swim test in mice, without affecting locomotor activity. Moreover, compound 22 produced a weak anxiolytic-like effect in the four-plate test in mice. Molecular docking studies of compound 22 to the homology model of the 5-HT1A receptor showed that a 3′,4′-dihydro-2′H-spiro[imidazolidine-4,1′-naphthalene]-2,5-dione moiety played an important role in stabilizing the ligand–receptor complex.

Several investigated compounds exhibited high affinity for 5-HT1A/5-HT2A receptors and diversified pharmacological profile. The presence of spiroarylcycloalkyl system in amide fragment may contribute to anxiolytic/antidepressant activity.Figure optionsDownload as PowerPoint slide