A number of aryl semicarbazones displayed anticonvulsant activity in t
he maximal electroshock (MES) and subcutaneous pentylenetetrazole (scP
TZ) screens when administered intraperitoneally to mice. When given by
the oral route to rats, protection was afforded in the MES but not sc
PTZ tests. Correlations were noted between the sigma and sigma values
of the aryl substituents, the interplanar angles made by the aryl rin
gs with the adjacent carbimino groups and the shapes of certain semica
rbazones determined by X-ray crystallography, and the activities in th
e rat oral MES screen. Molecular modeling studies revealed a number of
statistically significant descriptors which contributed to anticonvul
sant activity.