Synthesis, in vitro binding and biodistribution in B16 melanoma-bearing mice of new iodine-125 spermidine benzamide derivatives

In the course of our investigations aimed at improving the biological characteristics of iodobenzamides for melanoma therapeutic applications, four new derivatives containing a spermidine chain have been prepared and radiolabeled with 125I. In vitro studies showed that all compounds displayed high affinity for melanin superior to the reference compound BZA, thus validating our experimental approach. In vivo biodistribution was investigated in B16 melanoma-bearing mice. All four compounds, particularly benzamide 3, showed accumulation in the tumor, but lower, however, than that of BZA. Moreover, high concentrations of radioactivity in other organs, namely, the liver and lung, demonstrated nonspecific tumoral uptake. In view of these results, compounds 1 2 3 4 do not appear to be suitable radiopharmaceuticals for melanoma radionuclide therapy.