Reactivity of nitro-thiophene derivatives with electron and oxygen radicals studied by pulse radiolysis and polarographic techniques.

A new series of nitrothiophene derivatives have been synthetized and some of the physico-chemical parameters which can influence both their radiosensitizing efficiency and toxicity have been investigated. These include octanol/water partition coefficient (P), one-electron reduction potential (E7(1] and reactivity of the drugs towards primary radical species. For these studies, pulse radiolysis techniques and conventional polarography have been extensively used. Biological responses (both sensitization and toxicity) have been tested towards Chinese Hamster cells in vitro. The results are valuable in selecting, among the tested compounds, 5-NTMA, 5-NTM, 4- and 5-NTCA as the nitrohiophenes promising for in vivo applications.