Jackson P. English

Chapter 13(b). Animal Antiparasitic Agents

Publisher Summary This chapter elaborates the development of animal antiparasitic agents. A wide spectrum of activity against round worms in many host species is reported. 1,4-Bis(2-diethylaminoethoxy)anthraquinone dihydrochloride, RO2-9009, was reported active in mice versus Hymenolepis nana , Syphacia oblevata , and migrating ascarid larvae, but inactive versus N. dubius. Compound uptake by the parasites was observed fluorimetrically but was not related to the removal of worms in vivo or to their death in vitro . Preparation and testing of analogs of dithiazinine with substituents in the 6-position of the benzothiazole ring, varying R to methyl, and with n = 0, 1, 2, and 3 did not produce more active and/or less toxic compounds when tested against migrating A. suum larvae in mice. In the case of tetramisole, VI, it was reported that anthelmintic activity is almost exclusively a property of the S{−} isomer and that the toxicity of the two optical isomers is equal. An extensive study on methyl benzoquate VIII, buquinolate X, and metichlorpindol, XI, showed that all were active in suppressing sporozoite development at an early stage.