1,4-Bis-[1-methyl-5-nitroimidazolyl-(2-methyleneimino)]-piperazine, a new drug with marked activity against Entamoeba histolytica. Short communication.

1,4-Bis-[1-methyl-5-nitroimidazolyl-(2-methyleneimino)]-piperazine (HOE 316) administered orally produces an effect which is clearly superior to that of metronidazole against Entamoeba histolytica in the golden hamster and slightly inferior against Trichomonas fetus and T. vaginalis in the mouse. The acute tolerance of the compound is very good (LD 50% greater than 10 g/kg body weight). It is assumed that the possible main metabolite of HOE 316 is a monohydrazone: 1-methyl-2-(4-amino-piperazino-1-imino-methyl)-5-nitroimidazole.