The nonpolar fractions of the tertiary alkaloid extracts of Strychnos dale DE WILD. and Strychnos elaeocarpa GILG ex LEEUWENBERG show strong convulsant activity, of both clonic and tonic type. The polar fractions of the extracts have a muscle-relaxant effect. The same five alkaloids have been isolated from each of the nonpolar fractions of the two Strychnos species: Akagerine and four new indole alkaloids, 17-O-methyl-akagerine, kribine, 21-O-methyl-kribine and epi-21-O-methyl-kribine.