Aminotriazines with indole motif as novel, 5-HT₇ receptor ligands with atypical binding mode

Developing new and selective 5-HT₇R ligands may have a key impact on the treatment of central nervous system diseases including depression. We have found that indoleaminotriazine core fused with alkyl aryl moiety exhibits high affinity and selectivity to 5-HT₇R. SAR analysis demonstrated that the ethyl or ethoxy group (5c 5-HT₇R K_i = 8 nM; 5d 5-HT₇R K_i = 55 nM) is the optimal carbon linker between triazine and aryl moiety. The results of the molecular dynamics simulations show stable interaction with E7.34 upon binding to a 5-HT₇R. Compounds 5c and 5d were tested for early ADMET parameters. Compounds are not hepatotoxic and exhibit moderate potential interaction with other drugs metabolized by CYP3A4 or CYP2D6.