Solid-phase synthesis of 2-[18F]fluoropropionyl peptides

Area of Science:

• Radiochemistry
• Bioconjugation Chemistry
• Medical Imaging

Background:

• 2-[(18)F]fluoropropionic acid (2-[(18)F]FPA) is a prosthetic group for radiolabeling proteins and peptides.
• Positron emission tomography (PET) requires efficient and specific radiolabeling methods for targeted imaging.
• Labeling peptides with multiple functional groups can result in complex product mixtures.

Purpose of the Study:

• To investigate a solid-phase approach for regioselective preparation of 2-[(18)F]fluoropropionyl peptides.
• To optimize conditions for radiolabeling peptides using [(18)F]FPA on a solid support.
• To assess the yield, purity, and applicability of this method for various peptides.

Main Methods:

• Preparation of [(18)F]FPA.
• Conjugation of [(18)F]FPA to peptides immobilized on a solid-phase support.
• Evaluation of different coupling reagents and solid supports.
• Analysis of radiolabeled peptides using HPLC.

Main Results:

• The solid-phase method successfully prepared (18)F-labeled peptides.
• Radiolabeling was achieved in 175 minutes with decay-corrected yields of 10% (relative to [(18)F]fluoride).
• Purity of the (18)F-labeled peptides ranged from 76-99% before HPLC purification.

Conclusions:

• Solid-phase synthesis offers a regioselective route for preparing 2-[(18)F]fluoropropionyl peptides.
• This method is suitable for radiolabeling various peptides for PET imaging applications.
• Further optimization of coupling reagents and solid supports can enhance the efficiency and applicability of this technique.