Bioreductive mechanisms.

The design, development, and application of bioreductive antitumor agents in a rational way requires a detailed understanding of the mechanisms involved in their action. In addition to measuring and manipulating tumor hypoxia, we need to elucidate the particulars of the activation versus bioprotection pathways and the nature and properties of the participating enzymes. These areas are reviewed with particular reference to the development of novel quinone, nitro and N-oxide bioreductives.