γ-Aminobutyric acid uptake inhibition and anticonvulsant activity of nipecotic acid esters

Article abstract of DOI:10.1002/jps.2600731132

n-Alkyl esters of nipecotic acid were prepared by Fischer esterification, and the esters were evaluated against bicuculline-induced seizures in mice. Evaluation of the alkyl esters for inhibition of γ-aminobutyric acid uptake into mouse whole brain mini-slices revealed that the order of potency was proportional to chain length. The octyl ester inhibited γ-aminobutyric acid and β-alanine uptakes by apparently nonspecific mechanisms. A variety of phenyl esters of nipecotic acid were also synthesized utilizing either dicyclohexylcarbodiimide or 1,1'-carbonyldiimidazole as the condensing agent. Most of the phenyl esters were potent inhibitors of γ-aminobutyric acid uptake. The uptake inhibition appeared to involve specific and nonspecific (detergent-like) mechanisms. The m-nitrophenyl and p-nitrophenyl esters were particularly potent against bicuculline-induced seizures in mice.