α-(difluoromethyl)-DL-Arginine (RMI 71897) is an enzyma-activated, irreversible inhibitor of arginine decarboxylase for E. coli (Ki = 800 μM), Pseudomonas aeruginosa, and Klebsiella pneumoniae. At 0.01 mM, it has been shown to prevent osmotic stress-induced increases in arginine decarboxylase activity and putrescine synthesis in oat leaf cells. When combined with a variety of polyamine analogues, α-(difluoromethyl)-DL-Arginine inhibited the growth of Trypanosoma Crui in mammalian host cells at a minimum concentration of 10 mM and prevented the growth of Trypanosoma Crui in T-cell receptor alpha-deficient mouse models.