Development of a method for preparing octreotide derivative for diagnosis of neuroendocrine tumors

Currently the development of technologies for labeling somatostatin with technetium-99m for diagnosing radionuclide neuroendocrine tumors is under way. Somatostatin analogues are binded with technetium- 99m only by the preliminary addition of a chelating agent. Therefore, it is important to develop a method for preparation of an octreotide derivative by modifying octreotide with precursors: ligands with high chelating ability for its tight binding with technetium-99m. ω-Bis(pyridin-2-ylmethyl)amino)aliphatic acids can be used successfully as such precursors. The purpose of the study was to develop a method for obtaining a new octreotide derivative for diagnosing neuroendocrine tumors. Materials and methods. The somatostatin octreotide analogue was used as the object of the study; succinimid-1-yl 6-(bis(pyridin-2-ylmethyl)amino)hexanoate was used as a chelating agent. Methods of high performance liquid chromatography and mass spectrometry were used to separate and analyze the synthesized compounds. Results. A method to produce an original octreotide derivative using a succinimid-1-yl 6-(bis(pyridin- 2-ylmethyl)amino)hexanoate as a chelating agent was proposed. The conditions of analytical and semipreparative HPLC for the analysis and purification of the active octreotide derivative (a monosubstituted derivative of the amino acid residue of D-phenylalanine) were suggested. Conclusion. The synthesized derivative of octreotide has a chelating center for strong binding to technetium-99m in its structure, which can be useful for diagnosing neuroendocrine tumors.