Biological Studies on Nicarbazin, a New Anticoccidial Agent

NICARBAZIN, an equimolecular complex of 4,4′-dinitrocarbanilide and 2-hydroxy-4,6-dimethylpyrimidine, has been studied extensively and found to be an effective anticoccidial agent for chickens. This paper summarizes the presently available information on this anticoccidial agent. CHEMICAL NATURE OF NICARBAZIN During the investigation of the therapeutic potentialities of arylureas, Cuckler, Malanga, Basso and O’Neill (1955) observed that molecular complexes of certain substituted carbanilides possessed antiparasitic activity. The complex formed with 4,4′-dinitrocarbanilide (DNC) and 2-hydroxy-4,6-dimethylpyrimidine (HDP) was the most effective anticoccidial compound (Figure 1). In addition to HDP, several other compounds form equimolecular complexes with DNC. These include 2-hydroxy pyrimidine, 3-amino-as-triazine, 2-hydroxypyridine, 2-mercapto-4,6-dimethyl pyrimidine, formamide, dimethylacetamide, dimethylformamide, tetramethylurea, acetylpiperidine, and the hydrochlorides of pyridine and trimethylamine. Although the complexes formed with DNC and these various compounds had demonstrable anticoccidial activity, none was more potent than nicarbazin. Furthermore, several structural analogues of DNC were either ineffective as anticoccidial agents, or failed to form a complex …