5-HT2 receptor affinity, docking studies and pharmacological evaluation of a series of 1,3-disubstituted thiourea derivatives

Abstract

A series of 10 thiourea derivatives have been synthesized by the reaction of aromatic amine with a substituted aryl (compounds 1–3, 6–8) and alkylphenyl (4, 5, 9, 10) isothiocyanates. Their in vitro and in vivo pharmacological properties were studied. Among the evaluated compounds, two displayed very high affinity for the 5-HT2A receptor (1–0.043 nM and 5–0.6 nM), being selective over the 5-HT2C receptor. Derivatives 3, 5, 9, 10 by 70–89% diminished L-5-HTP-induced head twitch episodes. Compounds 1 and 5 as the 5-HT2A receptor antagonists produced a dose-dependent decrease in the number of DOI-elicited HTR. Compounds 1–5 strongly reduced amphetamine-evoked hyperactivity in rodents. In another test, 1 and 2 caused hyperthermia in mice, whereas 9 and 10 led to hypothermia. Antinociceptive and anticonvulsant properties of selected derivatives were demonstrated. Molecular docking studies using a homology model of 5-HT2A revealed a significant role of hydrogen bonds between both thiourea NH groups and Asp155/Tyr370 residues, as well as π–π interaction with Phe339.