NO, NITROSONIUM IONS, NITROXIDE IONS, NITROSOTHIOLS AND IRON-NITROSYLS IN BIOLOGY - A CHEMISTS PERSPECTIVE

The multiplicity of biological functions thus far attributed to NO has led to suggestions that some effects might be mediated by other, rela ted species instead. The radical nature of NO cannot account for its c ytotoxicity, but its reaction with superoxide to form peroxynitite and highly reactive hydroxyl radicals may be important in this context. T he ease with which NO can react with and destroy Fe-S clusters is also an important factor. Nitrosonium and nitroxide ions can be produced i n vivo and will react under conditions that are physiologically releva nt. Both could, in theory, serve in cell signalling or as cytotoxic ag ents. More direct experimental evidence for their involvement is neede d before we can confidently assign them specific biological roles. In this article, Anthony Butler, Frederick Flitney and Lyn Williams discu ss the chemistry of NO and related species.