99mTc/Re complexes bearing bisnitroimidazole or mononitroimidazole as potential bioreductive markers for tumor: Synthesis, physicochemical characterization and biological evaluation
作者:Lei Mei、Yue Wang、Taiwei Chu
DOI:10.1016/j.ejmech.2012.09.042
日期:2012.12
Four monoamine-monoamide dithiol (MAMA) ligands containing two or one nitroimidazole moieties were synthesized and labeled with Tc-99m (labeling yield > 95%). The proposed structures of Tc-99m-complexes are identified by comparison with analogous Re-MAMA complexes. Tc-99m-MAMA complexes show better physicochemical characters than (TcO)-Tc-99m-(PnAO-1-(2-nitroimidazole)). Reduction potentials of nitro groups of the rhenium complexes are within the range for bioreductive compounds. As expected, biodistribution studies demonstrate that the 2-nitroimidazole complex shows better tumor-to-tissue ratios than 4-nitroimidazole analog for mononitroimidazole complexes, but not for MAMA-bisnitroimidazoles due to higher lipophilicity. Both the bisnitroimidazole compounds show rapider excretion, lower background activity in liver and higher tumor-to-tissue ratios than the mono-nitroimidazoles. Better biodistribution characteristic makes both the MAMA-bisnitroimidazole complexes, especially (TC)-T-99m-15, be potential tumor hypoxia marker. (C) 2012 Elsevier Masson SAS. All rights reserved.