Related Experiment Video
Updated: Jan 29, 2026
09:45
Modification and Functionalization of the Guanidine Group by Tailor-made Precursors
Published on: April 27, 2017
11.1K
Streamlined Radiosynthesis of [18F]Fluproxadine (AF78): An Unprotected Guanidine Precursor Enables Efficient
Xinyu Chen1, Kaito Ohta2,3, Hiroyuki Kimura4
1Nuclear Medicine, Faculty of Medicine, University of Augsburg, 86159 Augsburg, Germany.
Pharmaceutics
|January 28, 2026
Summary
A new one-step radiosynthesis simplifies [18F]fluproxadine production for PET imaging. This method avoids harsh deprotection, making the norepinephrine transporter (NET) tracer more accessible for clinical use.
Area of Science:
- Radiochemistry
- Nuclear Medicine
- Organic Synthesis
Background:
- [18F]Fluproxadine is a PET tracer for norepinephrine transporter (NET) imaging.
- Its guanidine structure complicates radiosynthesis, requiring harsh conditions and multistep procedures.
- Previous methods hindered clinical translation due to complexity and low yield.
Purpose of the Study:
- Develop a simplified, one-step radiosynthesis for [18F]fluproxadine.
- Optimize the process for routine and automated production.
- Enhance clinical feasibility of NET-targeted PET imaging.
Main Methods:
- Direct SN2 nucleophilic [18F]fluorination using an unprotected guanidine precursor.
- Optimization of reaction parameters (base, solvent, temperature) under conventional and microwave heating.
- Evaluation of radiochemical conversion (RCC), robustness, and purification for automation.
Main Results:
- Reduced synthesis time to 60-70 minutes.
- Achieved up to 33% RCC with conventional heating and 64% RCC within 1.5 min using microwave irradiation.
- Demonstrated robustness and compatibility with isocratic HPLC purification.
Conclusions:
- A practical one-step radiosynthesis for [18F]fluproxadine has been established.
- This method eliminates harsh deprotection steps, improving yield and efficiency.
- The simplified, automation-ready process enhances the clinical applicability of [18F]fluproxadine for NET imaging.
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