Radioiodinated 2-nitrobenzyl carbamates as bioreductive alkylating agents for tissue hypoxia

Three N-methylcarbamates of iodonitrobenzyl alcohols (4-iodo-2-nitrobenzyl alcohol 2, 5-iodo-2-nitrobenzyl alcohol 3 and 4-iodo-2,6-dinitrobenzyl alcohol 4) bearing [125I] have been prepared and characterized for their lipophilicity, their reduction potentials and the in vivo liability of the radioiodine in healthy mice. Based upon these results, 2 and 4 were tested in tumour-bearing mice showing limited uptake of radioactivity in tumours and a tumour-to-blood ratio of less than 1. Consequently these particular carbamates are not satisfactory as hypoxia imaging agents.