A facile automated synthesis of N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB) for 18F-labeled cell-penetrating peptide as PET tracer

Authors

  • Ganghua Tang,

    Corresponding author
    1. PET-CT Center, Department of Nuclear Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, People's Republic of China
    2. Nan Fang PET Centre, Nan Fang Hospital, Southern Medical University, Guangzhou 510515, People's Republic of China
    • PET-CT Center, Department of Nuclear Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, People's Republic of China
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  • Xiaolan Tang,

    1. Science College, South China Agricultural University, Guangzhou 510642, People's Republic of China
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  • Xinlu Wang

    1. Nan Fang PET Centre, Nan Fang Hospital, Southern Medical University, Guangzhou 510515, People's Republic of China
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Abstract

A fully automated synthesis of N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB) was carried out by a convenient three-step, one-pot procedure on the modified TRACERlab FXFN synthesizer, including [18F]fluorination of ethyl 4-(trimethylammonium triflate)benzoate as the precursor, saponification of the ethyl 4-[18F]fluorobenzoate with aqueous tetrapropylammonium hydroxide instead of sodium hydroxide, and conversion of 4-[18F]fluorobenzoate salt ([18F]FBA) to [18F]SFB treated with N,N,N′,N′-tetramethyl-O-(N-succinimidyl)uranium tetrafluoroborate (TSTU). The purified [18F]SFB was used for the labeling of Tat membrane-penetrating peptide (containing the Arg-Lys-Lys-Arg-Arg-Arg-Arg-Arg-Arg-Arg-Arg-Pro-Leu-Gly-Leu-Ala-Gly-Glu-Glu-Glu-Glu-Glu-Glu-Glu sequence, [18F]CPP) through radiofluorination of lysine amino groups. The uncorrected radiochemical yields of [18F]SFB were as high as 25–35% (based on [18F]fluoride) (n=10) with a synthesis time of∼40 min. [18F]CPP was produced in an uncorrected radiochemical yields of 10–20% (n=5) within 30 min (based on [18F]SFB). The radiochemical purities of [18F]SFB and [18F]CPP were greater than 95%. Copyright © 2010 John Wiley & Sons, Ltd.

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