The effect of the chemical nature of substituents (–H, –CH3–, –OCH3, –F and –Cl) introduced into the tricyclic fragment of hydrogenated pyrido[4,3-b]indoles on the compounds ability to positively modulate the activity of ionotropic glutamate AMPA receptors have been studied. The unsubstituted derivative, compounds with a methyl group and a fluorine atom were found to have the highest bioactivity in this test. The partition coefficients of the synthesized derivatives in the system 1-octanol/buffer pH 7.4 in the temperature range of 293.15–313.15 K have been measured. It has been found that as the lipophilicity of the compounds studied increases, the maximum biological activity is achieved at a higher concentration of the administered substance. The thermodynamic transfer functions of the studied substances from aqueous medium to organic phase have been calculated.
