Chapter 15. Antiparasitic Agents

Abstract

The synthesis of new quinoline methanols, phenanthrene methanols, and naphthalene methanols aims at finding compounds of high activity and low phototoxicity. The transfer of drug resistance do not take place between different species but occurs between different variants of the same species 96 hours after inoculation or later. Treatment with acriflavin has no effect on the transfer suggesting genetic recombination. The polyether ionophores lasalocid and monensin are highly active, whereas ormetoprim and sulfadimethoxime or a combination is inactive or weakly active. The diastereomers of phenanthrene methanols and quinoline methanols shows striking differences in antimalarial activity postulate to relate to the distance between oxygen and the nonaromatic nitrogen atoms. Clindamycin, doxymycin, tetracycline, and spiramycin show causal prophylactic activity at the tissue stage of P. berghei development. The bloodstream forms of African trypanosomes depend on glycolysis for energy supply because a mitochondrial respiratory chain is lacking. Nicotinamide adenine dinucleotide (NADH) generated by glyceraldehyde phosphate dehydrogenase is reoxidized by a α-glycerol phosphate oxidase system unique to trypanosomes. Although the correct pathway of anaerobic glucose metabolism in African trypanosomes still remains unknown, the production of equimolar amounts of pyruvate and glycerol under anaerobic conditions are also discussed in the chapter. Nitrofurans, such as nitrofurazone, nitrofurantoin, have long been used as urinary tract antiseptics.