[Potential filaricides. Suramin analogs].

A series of suramin analogues has been synthesized in which the methyl groups of suramin have been replaced by hydrogen, alkyl, phenyl, and fluoro substituents, or which contain more than two methyl groups. The substances have been screened against Dipetalonema viteae in Meriones unguiculatus, Litomosoides carinii in Sigmodon hispidus and L. carinii in Mastomys natalensis, respectively. Small structural modifications have a marked influence on the antifilarial activity. There are marked differences between antifilarial and trypanocidal activities. A symmetrical molecule structure seems not to be essential for the antifilarial activity.