Nematocide activity of 6,7-diarylpteridines in three experimental models

The in vitro nematocide activity of seventeen 6,7-diarylpteridines has been tested using three different experimental models, Caenorhabditis elegans, Nippostrongylus brasiliensis and Heligmosomoides polygyrus. The method of e valuation of inhibition in the secretion of acetylcholinesterase by H. poly gyrus seems to be the most indicated to avoid false positives. The in vivo activities, against Trichinella spiralis, of the most in vitro active pteri dines have been assayed. All pteridine derivatives bearing 6,7-di-p-bromoph enyl substituents have shown in vitro nematocide activites in the three exp erimental models used. Amongst all the pteridines tested in vivo, only 2,4- pteridinedithione derivatives exhibited moderate activity.