Pronounced enhancement of ·NO-dependent antimicrobial action by an ·NO- oxidizing agent, imidazolineoxyl N-oxide

Abstract

The antimicrobial action of ·NO against Cryptococcus neoformans was investigated by using imidazolineoxyl N-oxide, which we recently reported removes ·NO via oxidation (T. Akaike, M. Yoshida, Y. Miyamoto, K. Sato, M. Kohno, K. Sasamoto, K. Miyazaki, S. Ueda, and H. Maeda, Biochemistry 32:827- 832, 1993). No appreciable fungicidal activity was observed in neutral ·NO solutions. Imidazolineoxyl N-oxide induced or enhanced fungicidal action in neutral or acidic ·NO solutions, respectively. Our results provide convincing evidence that ·NO is not a microbicidal molecular species.