001     825270
005     20210129225251.0
037 _ _ |a FZJ-2016-07741
041 _ _ |a English
100 1 _ |a Schäfer, Dominique
|0 P:(DE-Juel1)157188
|b 0
|e Corresponding author
|u fzj
111 2 _ |a 21st International Symposium on Radiopharmaceutical Sciences
|g ISRS 2015
|c Columbia
|d 2015-05-26 - 2015-05-31
|w USA
245 _ _ |a A new method for the two-step synthesis of n.c.a. 6-[F-18]fluorotryptophan
260 _ _ |c 2015
336 7 _ |a Conference Paper
|0 33
|2 EndNote
336 7 _ |a INPROCEEDINGS
|2 BibTeX
336 7 _ |a conferenceObject
|2 DRIVER
336 7 _ |a CONFERENCE_POSTER
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336 7 _ |a Output Types/Conference Poster
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336 7 _ |a Poster
|b poster
|m poster
|0 PUB:(DE-HGF)24
|s 1482389445_976
|2 PUB:(DE-HGF)
|x Plenary/Keynote
520 _ _ |a Objectives: Tryptophan was recently described as a possible radiotracer for tumors diagnostics1,2. Furthermore the amino acid is the precursor of serotonin biosynthesis and acts as a part in neuronal functions which seems to be inhibited by fluorinated tryptophan3. Earlier approaches using the Balz-Schiemann reaction yielded [18F]fluorotryptophan in low radiochemical yields (RCY). Newer approaches as the isotopic exchange in the carbonyl activated aromatic system with subsequent Baeyer-Villiger oxidation required three radiosynthetic steps and [18F]fluorotryptophan in carrier-added form. The aim of this work was to develop a two-step synthesis of n.c.a. 6-[18F]fluorotryptophan with high RCY.Methods: The concept of radiosynthesis is illustrated in figure 1. The precursor 2 for 6-[18F]fluorotryptophan was prepared from 6-bromo-indole. The precursor includes the Schöllkopf’s amino acid auxiliary and a boronic ester group at the desired position in the aromatic ring. The radiosynthesis was performed by a novel copper(II) mediated 18F-fluorination4 and a subsequent hydrolysis as a two-step reaction. Figure 1: Pathway to 6-[18F]fluorotryptophan 3 starting from 6-bromo indole 1 (PG = protecting group).Results: Preparation of the precursor was accomplished in a linear six-step synthesis with an overall yield of 23 %. The following n.c.a. 18F-fluorination, performed under modified conditions of the [Cu(OTf)2(py)4] mediated n.c.a. 18F-fluorination4 gave radiochemical yields of 60-65 %. After separating the product, an acidic hydrolysis was performed with about 20 % RCY. Finally L-6-[18F]fluorotryptophan was purified by HPLC with an overall RCY of about 8 % and a molar activity of XX MBq/mmol within 95 min total reaction time.Conclusions: The radiosynthesis of n.c.a. L-6-[18F]fluorotryptophan was performed in a short two-step synthesis. The radiotracer is selectively labeled in 6-position and has a high molar activity. Therefore it can be used for neuronal studies without inhibitional effects. References: [1] J. Lin et al., J. Membrain Biol. 1988, 104, 1, [2] G.C. Prendergast, Nature 2011, 478, 192, [3] C. Jacquot et al., Biochem. Pharm., 1992, 45, 1049, [4] V. Gouverneur et al., Angew. Chem. 2014, 53, 7751.
536 _ _ |a 572 - (Dys-)function and Plasticity (POF3-572)
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|f POF III
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700 1 _ |a Weiss, Philipp
|0 P:(DE-Juel1)151340
|b 1
700 1 _ |a Castillo, Johnny
|0 P:(DE-Juel1)131815
|b 2
700 1 _ |a Ermert, Johannes
|0 P:(DE-Juel1)131818
|b 3
|u fzj
700 1 _ |a Coenen, Heinrich Hubert
|0 P:(DE-Juel1)131816
|b 4
|u fzj
909 C O |o oai:juser.fz-juelich.de:825270
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910 1 _ |a Forschungszentrum Jülich
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910 1 _ |a Forschungszentrum Jülich
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913 1 _ |a DE-HGF
|b Key Technologies
|l Decoding the Human Brain
|1 G:(DE-HGF)POF3-570
|0 G:(DE-HGF)POF3-572
|2 G:(DE-HGF)POF3-500
|v (Dys-)function and Plasticity
|x 0
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914 1 _ |y 2016
915 _ _ |a No Authors Fulltext
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920 _ _ |l yes
920 1 _ |0 I:(DE-Juel1)INM-5-20090406
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980 _ _ |a poster
980 _ _ |a VDB
980 _ _ |a UNRESTRICTED
980 _ _ |a I:(DE-Juel1)INM-5-20090406


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