Marked stereospecificity in a new class of anticonvulsants.

N-Acetyl-D,L-alanine-N-benzylamide and N-acetyl-D,L-phenylglycine-N-benzylamide are two novel anticonvulsants that selectively blocked maximal electric shock-induced tonic extensor seizures in mice. For both compounds, the anticonvulsant activity is due to the D-stereoisomer, and the L-stereoisomer is virtually inactive as an anticonvulsant. The marked stereoselectivity of these anticonvulsants may make them very useful pharmacological tools for the study of the mechanism(s) of anticonvulsants that selectively inhibit maximal electric shock-induced seizures.