QF2004B, a potential antipsychotic butyrophenone derivative with similar pharmacological properties to clozapine.

The aim of the present work was to characterize a lead compound displaying relevant multi-target interactions, and with an in vivo behavioral profile predictive of atypical antipsychotic activity. Synthesis, molecular modeling and in vitro and in vivo pharmacological studies were carried out for 2-[4-(6-fluorobenzisoxazol-3-yl)piperidinyl]methyl-1,2,3,4-tetrahydro-carbazol-4-one (QF2004B), a conformationally constrained butyrophenone analogue. This compound showed a multi-receptor profile with affinities similar to those of clozapine for serotonin (5-HT2A, 5-HT1A, and 5-HT2C), dopamine (D1, D2, D3 and D4), alpha-adrenergic (alpha1, alpha2), muscarinic (M1, M2) and histamine H1 receptors. In addition, QF2004B mirrored the antipsychotic activity and atypical profile of clozapine in a broad battery of in vivo tests including locomotor activity (ED50 = 1.19 mg/kg), apomorphine-induced stereotypies (ED50 = 0.75 mg/kg), catalepsy (ED50 = 2.13 mg/kg), apomorphine- and DOI (2,5-dimethoxy-4-iodoamphetamine)-induced prepulse inhibition (PPI) tests. These results point to QF2004B as a new lead compound with a relevant multi-receptor interaction profile for the discovery and development of new antipsychotics.