title: The mode of action of nanaomycins D and A on a gram-negative marine bacterium Vibrio alginolyticus.
abstract: Nanaomycin (NNM) D had a higher growth inhibitory activity than NNM-A against a Gram-negative marine bacterium, Vibrio alginolyticus. These quinone antibiotics were reduced by the respiratory chain-linked flavin dehydrogenase of the organism and the reduced forms of NNMs were quickly autoxidized by molecular oxygen to produce superoxide radicals (O2-). NNM-D was more effective than NNM-A both in the induction of KCN-insensitive oxygen consumption with the intact cells and in the production of O2- by the redox cycling. The growth inhibitory activities of NNM-D and A were partly reduced by raising the superoxide dismutase level of the cells. Thus, the ability to produce O2- at the cell membrane was correlated to the antibacterial activities of NNM-D and A.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004579:Electron Transport; D009245:NADH Dehydrogenase / Q000378:metabolism; D009285:Naphthoquinones / Q000378:metabolism / Q000494:pharmacology; D010101:Oxygen Consumption / Q000187:drug effects; D013482:Superoxide Dismutase / Q000032:analysis; D013481:Superoxides / Q000378:metabolism; D014733:Vibrio / Q000187:drug effects* / Q000378:metabolism; D014871:Water Microbiology; D000095622:Benzoisochromanequinones
chemical_list: D000900:Anti-Bacterial Agents; D009245:NADH Dehydrogenase; D009285:Naphthoquinones; D013482:Superoxide Dismutase; D013481:Superoxides; C008638:nanaomycin A; D000095622:Benzoisochromanequinones; C013079:kalafungin