Synthesis of hybrid distamycin-cysteine labeled with Tc-99m: a model for anovel 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 tu mor imaging agent in diagnostic nuclear medicine. The preparation of the hy brid distamycin A-cysteine 4 has been achieved by coupling deformyldistamyc in A and Boc-Dmt-OH. Compound 4 was then successfully labeled with Tc-99m b y reaction with the novel, high-electrophilic, metal-containing fragment [T c-99m(N)(PP)](2+) (PP = diphosphine ligand) yielding the 1:1 complex 5. (C) 2000 Elsevier Science Ltd. All rights reserved.