Radiosynthesis of ¹⁸F-labeled d-allose

Area of Science:

• Radiochemistry
• Organic Synthesis
• Biomedical Imaging

Background:

• Rare sugars, like d-allose, possess unique physiological effects.
• Investigating the in vivo behavior of rare sugar analogs is crucial for understanding their physiological roles.
• Positron Emission Tomography (PET) offers a noninvasive method for such investigations.

Purpose of the Study:

• To develop synthetic procedures for novel 18F-labeled rare sugars of d-allose.
• To prepare labeling precursors for 3-deoxy-3-[18F]fluoro-d-allose ([18F]3FDA) and 6-deoxy-6-[18F]fluoro-d-allose ([18F]6FDA).
• To facilitate in vivo PET studies of d-allose analogs.

Main Methods:

• Identification and synthesis of five practical precursors for radiolabeling.
• Optimization of manual synthesis for [18F]3FDA and [18F]6FDA, achieving high radiochemical conversion rates.
• Evaluation of automated synthesis yields for both radiolabeled compounds.

Main Results:

• Successful synthesis of [18F]3FDA and [18F]6FDA using optimized precursors.
• Manual synthesis yielded up to 75% radiochemical conversion for [18F]3FDA and 69% for [18F]6FDA.
• Automated synthesis achieved 67% yield for [18F]3FDA and 49% for [18F]6FDA.
• Both radiolabeled compounds demonstrated stability in rabbit blood plasma for up to 6 hours.

Conclusions:

• Established practical synthetic routes for [18F]3FDA and [18F]6FDA.
• Demonstrated the feasibility of both manual and automated synthesis for these novel radiotracers.
• The stability and successful synthesis pave the way for in vivo PET imaging applications.