Activity of compounds 1, 5, and 6 against ex vivo parasites. Compounds were added to cultures of A. adult worms and B. schistosomula, and worm survival was followed by monitoring worm movement. Compounds 1 (♦), 5 (■), and 6 (•) were tested at 50 μM against adult worms and 10 μM against schistosomula; control, untreated worms (▲). C. TGR activity in treated worms. Worms were cultured in the presence of 50 μM of 5 (■) or 6 (•). At the indicated times worms were collected and tested for residual TrxR activity (closed symbols) or GR activity (open symbols). All worms were alive when collected. Activity is expressed as compared to carrier (DMSO) alone treated worms cultured ex vivo for the same length of time.