Harold King

Experimental Chemotherapy of Typhus Anti-Rickettsial Action of p-sulphonamidobenzamidine and Related Compounds

The discovery of the pronounced anti-rickettsial activity of p-sulphonamidobenzamidine on experimental typhus infections in mice has led to a search for compounds of enhanced therapeutic action. A large number of compounds have been prepared in development of the sulphonamido-amidine structure, but anti-rickettsial activity has been found to be confined to about a dozen substances intimately related to p-sulphonamidobenzamidine, only one, namely, p-sulphonamidobenzamidoxime, having a very slightly superior therapeutic action. The significance of the discovery of yet another sulphonamide type with pronounced biological activity is discussed.

Amoebicidal Action and Chemical Constitution

This communication describes some of the results which have been obtained in the search for an amoebicidal agent which might replace emetine. Eighty-seven compounds have been synthesized starting from two 4-chloroquinolines with a methyl or anilino group in the 2-position. A number of compounds have been found with an in vitro activity on Entamoeba histolytica slightly inferior to that of emetine.

Antiplasmodial Action and Chemical Constitution. IX. Carbinolamines Derived from 6:7-Dimethylquinoline

This communication completes this series of investigations. Ten carbinolamines derived from 6:7-dimethylquinoline and based on the quinine model are described. Three of the substances containing the 2-phenyl-6:7-dimethylquinoline nucleus show antiplasmodial activity on malaria in canaries much superior to the activity of quinine. The 6:7-dimethyi groups present in these compounds show a structural affinity with riboflavin but the antiplasmodial results are not favourable to the view that riboflavin-antagonism plays any significant part in the mechanism of action of these active bases.