Novel anilide and benzylamide derivatives of arylpiperazinylalkanoic acids as 5-HT1A/5-HT7 receptor antagonists and phosphodiesterase 4/7 inhibitors with procognitive and antidepressant activity

A library of novel anilide and benzylamide derivatives of ω-(4-(2-methoxyphenyl)piperazin-1-yl)alkanoic acids as combined 5-HT_1A/5-HT₇ receptor ligands and phosphodiesterase PDE4B/PDE7A inhibitors was designed using a structure-based drug design approach. The in vitro studies of 33 newly synthesized compounds (7-39) allowed us to identify 22 as the most promising multifunctional 5-HT_1A/5-HT₇ receptor antagonist (5-HT_1AK_i = 8 nM, K_b = 0.04 nM; 5-HT₇K_i = 451 nM, K_b = 460 nM) with PDE4B/PDE7A inhibitory activity (PDE4B IC₅₀ = 80.4 μM; PDE7A IC₅₀ = 151.3 μM). Compound 22 exerted a very good ability to passively penetrate through biological membranes and a high metabolic stability in vitro. Moreover, the pharmacological evaluation of 22 showed its procognitive and antidepressant properties in rat behavioral tests. Compound 22 at a dose of 3 mg/kg (i.p.) significantly reversed MK-801-induced episodic memory deficits in the novel object recognition test, while at a dose of 10 mg/kg (i.p.) reduced the immobility time of Animals (by about 34%) in the forced swimming test. The antidepressant-like effect produced by compound 22 was stronger than that of escitalopram used as a reference drug. This study opens a new perspective in the search for efficacious drugs for the treatment of cognitive and depressive disorders.