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

✍ Scribed by Ganghua Tang; Xiaolan Tang; Xinlu Wang

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: French
• Weight: 222 KB
• Volume: 53
• Category: Article
• ISSN: 0022-2135
• DOI: 10.1002/jlcr.1758

✦ Synopsis

Abstract

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