Synthesis of hybrid distamycin-cysteine labeled with 99mTc:: a model for a novel class of cancer imaging agents

The synthesis of a hybrid constituted by distamycin A and cysteine labeled with the gamma-emitting radionuclide Tc-99m to afford the conjugate complex 5 is reported, This new radiopharmaceutical is of potential interest as tumor imaging agent in diagnostic nuclear medicine. The preparation of the hybrid distamycin A-cysteine 4 has been achieved by coupling deformyldistamycin A and Boc-Dmt-OH. Compound 4 was then successfully labeled with Tc-99m by reaction with the novel, high-electrophilic, metal-containing fragment [Tc-99m(N)(PP)](2+) (PP = diphosphine ligand) yielding the 1:1 complex 5. (C) 2000 Elsevier Science Ltd. All rights reserved.