“…Of the seven denitrosated nitrosamidines and nitrosamides tested (Table 2), N-methyl-N-nitroguanidine, 2-nitramino-2-imidazoline, N-methylurea, N-ethylurea, 2-imidazolidone, N-methylurethane, and N-ethylurethane were incapable of prophage induction, although all of their parent N-nitroso derivatives were effective inducers, demonstrating the necessity of the nitroso group for the biological response. Denitrosated derivatives, generally, appear to be biologically inert (11,27,40).…”