The 1,3,5-Triazine Derivatives as Innovative Chemical Family of 5-HT 6 Serotonin Receptor Agents with Therapeutic Perspectives for Cognitive Impairment.

Among serotonin receptors, the 5-HT ₆ subtype is the most controversial and the least known in the field of molecular mechanisms. The 5-HT ₆ R ligands can be pivotal for innovative treatment of cognitive impairment, but none has reached pharmacological market, predominantly, due to insufficient "druglikeness" properties. Recently, 1,3,5-triazine-piperazine derivatives were identified as a new chemical family of potent 5-HT ₆ R ligands. For the most active triazine 5-HT ₆ R agents found ( 1 - 4 ), a wider binding profile and comprehensive in vitro evaluation of their drug-like parameters as well as behavioral studies and an influence on body mass in vivo were investigated within this work. Results indicated the most promising pharmacological/druglikeness profiles for 4-((1H-indol-3-yl)methyl)-6-(4-methylpiperazin-1-yl)-1,3,5-triazin-2-amine ( 3 ) and 4-((2-isopropyl-5-methylphenoxy)methyl)-6-(4-methylpiperazin-1-yl)-1,3,5-triazin-2-amine ( 4 ), which displayed a significant procognitive action and specific anxiolytic-like effects in the behavioral tests in vivo together with satisfied pharmaceutical and safety profiles in vitro. The thymol derivative ( 4 ) seems to be of higher importance as a new lead candidate, due to the innovative, non-indole and non-sulfone structure with the best 5-HT ₆ R binding properties.