Eboracin: a substituted indenopyrrole active against metrazol-induced, audiogenic and electroshock seizures in mice.

1. Pretreatment with eboracin, a methyl ester of a trioxyindenopyrrole, inhibited the tonic phase of pentylenetetrazol (Metrazol)-induced, audiogenic and electroshock seizures in mice. 2. In animals challenged with Metrazol a dose of 28 mg/kg eboracin prevented 50% of tonic-clonic responses. 3. In animals exposed to electroshock or auditory stimulation the dose required to produce a 50% reduction in tonic-clonic seizures was 30 mg/kg and 35 mg/kg, respectively. 4. The 50% lethal dose was 832 mg/kg, indicative of eboracin's relatively low toxicity and high therapeutic index. 5. Pretreatment with eboracin led to a prolongation of the myoclonic phase of Metrazol seizures, similar to that observed after phenytoin.