Design, synthesis, and development of novel caprolactam anticonvulsants

Bioorg Med Chem. 2003 Sep 1;11(18):4133-41. doi: 10.1016/s0968-0896(03)00400-0.

Abstract

Epilepsy afflicts 1-2% of the world's population and often goes untreated; nearly 70% of those with a form of epilepsy fail to receive proper treatment. Therefore, there is great demand for the design of novel, effective anticonvulsants to combat epilepsy in its numerous forms. Previously, alpha-hydroxy-alpha-phenylcaprolactam was found to have rather potent antiepileptic activity [anti-maximal electroshock (MES) ED(50)=63 mg/kg and anti-subcutaneous Metrazol (scMet) ED(50)=74 mg/kg] when administered intraperitoneally in mice. We focused our attention on the development of this compound through traditional medicinal chemistry techniques-including the Topliss approach, isosteric replacement, methylene insertion, and rigid analogue approach-in the hopes of determining the effect of caprolactam alpha-substitution and other structural modifications on anticonvulsant activity. A number of the desired targets were successfully synthesized and submitted to the Anticonvulsant Screening Program of the National Institute of Neurological Disorders and Stroke (NINDS). Phase I results were quite promising for at least three of the compounds: alpha-ethynyl-alpha-hydroxycaprolactam (10), alpha-benzyl-alpha-hydroxycaprolactam (11), and alpha-hydroxy-alpha-(phenylethynyl)caprolactam (13). Phase II results for 11 strongly suggested it as a new structural class for further development, as it exhibited an anti-MES T.I. in excess of 4.0. Further, the potent activity of 13 in all models also pointed to the substituted alkynylcaprolactams as a new anticonvulsant structural class.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Anticonvulsants / chemical synthesis*
  • Anticonvulsants / pharmacology
  • Brain / drug effects
  • Brain / metabolism
  • Caprolactam / analogs & derivatives*
  • Caprolactam / chemical synthesis
  • Caprolactam / pharmacology
  • Drug Design
  • Epilepsy / drug therapy
  • Injections, Intraperitoneal
  • Mice
  • Rats
  • Structure-Activity Relationship

Substances

  • Anticonvulsants
  • Caprolactam