New Phenylglycinamide Derivatives with Hybrid Structure as Candidates for New Broad-Spectrum Anticonvulsants.

In the present study, a focused combinatorial chemistry approach was applied to merge structural fragments of well-known TRPV1 antagonists with a potent anticonvulsant lead compound, , that was previously discovered by our group. Consequently, a series of 22 original compounds has been designed, synthesized, and characterized in the in vivo and in vitro assays. The obtained compounds showed robust in vivo antiseizure activity in the maximal electroshock (MES) test and in the 6 Hz seizure model (using both 32 and 44 mA current intensities). The most potent compounds and displayed the following pharmacological profile: ED = 89.7 mg/kg (MES), ED = 29.9 mg/kg (6 Hz, 32 mA), ED = 68.0 mg/kg (6 Hz, 44 mA), and ED = 73.6 mg/kg (MES), ED = 24.6 mg/kg (6 Hz, 32 mA), and ED = 56.3 mg/kg (6 Hz, 44 mA), respectively. Additionally, and were effective in the PTZ seizure threshold and had no influence on the grip strength and body temperature in mice. The in vitro binding and functional assays indicated a multimodal mechanism of action for and . These molecules, beyond TRPV1 antagonism, inhibited calcium currents and fast sodium currents in patch-clamp assays. Further studies proved beneficial in vitro ADME-Tox properties for and (i.e., high metabolic stability, weak influence on CYPs, no neurotoxicity, etc.). Overall, and seem to be interesting candidates for future preclinical development in epilepsy and pain indications due to their interaction with the TRPV1 channel.