Virtual screening-driven discovery of dual 5-HT6/5-HT2A receptor ligands with pro-cognitive properties.

ABSTRACT

A virtual screening campaign aimed at finding structurally new compounds active at 5-HT6R provided a set of candidates. Among those, one structure, 4-(5-{[(2-{5-fluoro-1H-pyrrolo[2,3-b]pyridin-3-yl}ethyl)amino]methyl}furan-2-yl)phenol (1, 5-HT6R Ki = 91 nM), was selected as a hit for further optimization. As expected, the chemical scaffold of selected compound was significantly different from all the serotonin receptor ligands published to date. Synthetic efforts, supported by molecular modelling, provided 43 compounds representing different substitution patterns. The derivative 42, 4-(5-{[(2-{5-fluoro-1H-pyrrolo[2,3-b]pyridin-3-yl}ethyl)amino]methyl}furan-2-yl)phenol (5-HT6R Ki = 25, 5-HT2AR Ki = 32 nM), was selected as a lead and showed a good brain/plasma concentration profile, and it reversed phencyclidine-induced memory impairment. Considering the unique activity profile, the obtained series might be a good starting point for the development of a novel antipsychotic or antidepressant with pro-cognitive properties.