The objectives of this contract are to design, synthesize and characterize new and/or novel non-nitro radiosensitizers. The contractor is expected to develop the leads which result from the screening effort (NCI contract N01-CM-67868), which evaluates compounds for their radiosensitivity activity. The contractor is expected to synthesize analogs of the lead compounds and develop in vitro and in vivo data on the efficacy of these compounds as radiosensitizers. New radiosensitizers for clinical use are expected from this contract.