Beyond Retigabine: Design, Synthesis, and Pharmacological Characterization of a Potent and Chemically Stable Neuronal Kv7 Channel Activator with Anticonvulsant Activity

J Med Chem. 2022 Aug 25;65(16):11340-11364. doi: 10.1021/acs.jmedchem.2c00911. Epub 2022 Aug 16.

Abstract

Neuronal Kv7 channels represent important pharmacological targets for hyperexcitability disorders including epilepsy. Retigabine is the prototype Kv7 activator clinically approved for seizure treatment; however, severe side effects associated with long-term use have led to its market discontinuation. Building upon the recently described cryoEM structure of Kv7.2 complexed with retigabine and on previous structure-activity relationship studies, a small library of retigabine analogues has been designed, synthesized, and characterized for their Kv7 opening ability using both fluorescence- and electrophysiology-based assays. Among all tested compounds, 60 emerged as a potent and photochemically stable neuronal Kv7 channel activator. Compared to retigabine, compound 60 displayed a higher brain/plasma distribution ratio, a longer elimination half-life, and more potent and effective anticonvulsant effects in an acute seizure model in mice. Collectively, these data highlight compound 60 as a promising lead compound for the development of novel Kv7 activators for the treatment of hyperexcitability diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anticonvulsants* / chemistry
  • Anticonvulsants* / pharmacology
  • Anticonvulsants* / therapeutic use
  • Carbamates
  • KCNQ2 Potassium Channel
  • KCNQ3 Potassium Channel*
  • Mice
  • Phenylenediamines / chemistry
  • Phenylenediamines / pharmacology
  • Phenylenediamines / therapeutic use
  • Seizures / chemically induced
  • Seizures / drug therapy

Substances

  • Anticonvulsants
  • Carbamates
  • KCNQ2 Potassium Channel
  • KCNQ3 Potassium Channel
  • Phenylenediamines
  • ezogabine