Sultone opening with [18F]fluoride: an efficient 18F-labelling strategy for PET imaging

Area of Science:

• Radiochemistry
• Organic Synthesis
• Bioconjugation

Background:

• Sultones are cyclic esters of sulfonic acids.
• Radiolabeling with fluorine-18 is crucial for Positron Emission Tomography (PET) imaging.
• Efficient methods for incorporating fluorine-18 into biomolecules are highly sought after.

Purpose of the Study:

• To develop a novel method for radiolabeling using sultones and fluoride-18.
• To synthesize easily purified, hydrophilic sulfonated products.
• To establish a model approach for labeling biopolymers.

Main Methods:

• Nucleophilic ring opening of sultones with fluoride-18.
• Purification of the resulting sulfonated products.
• Development of a two-step sequence involving radiofluorination and lysine coupling using a bis-sultone precursor.

Main Results:

• Sultones underwent ring opening with fluoride-18 to yield hydrophilic sulfonated products.
• The radiolabeled products were easily purified.
• High yields of the desired products were achieved.
• A two-step labeling sequence was successfully demonstrated on a bis-sultone precursor.

Conclusions:

• Nucleophilic attack on sultones with fluoride-18 is an effective strategy for synthesizing radiolabeled compounds.
• This method provides easily purified, hydrophilic sulfonated products in high yields.
• The developed two-step sequence serves as a viable model for future biopolymer labeling applications.