000825270 001__ 825270
000825270 005__ 20210129225251.0
000825270 037__ $$aFZJ-2016-07741
000825270 041__ $$aEnglish
000825270 1001_ $$0P:(DE-Juel1)157188$$aSchäfer, Dominique$$b0$$eCorresponding author$$ufzj
000825270 1112_ $$a21st International Symposium on Radiopharmaceutical Sciences$$cColumbia$$d2015-05-26 - 2015-05-31$$gISRS 2015$$wUSA
000825270 245__ $$aA new method for the two-step synthesis of n.c.a. 6-[F-18]fluorotryptophan
000825270 260__ $$c2015
000825270 3367_ $$033$$2EndNote$$aConference Paper
000825270 3367_ $$2BibTeX$$aINPROCEEDINGS
000825270 3367_ $$2DRIVER$$aconferenceObject
000825270 3367_ $$2ORCID$$aCONFERENCE_POSTER
000825270 3367_ $$2DataCite$$aOutput Types/Conference Poster
000825270 3367_ $$0PUB:(DE-HGF)24$$2PUB:(DE-HGF)$$aPoster$$bposter$$mposter$$s1482389445_976$$xPlenary/Keynote
000825270 520__ $$aObjectives: 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.
000825270 536__ $$0G:(DE-HGF)POF3-572$$a572 - (Dys-)function and Plasticity (POF3-572)$$cPOF3-572$$fPOF III$$x0
000825270 7001_ $$0P:(DE-Juel1)151340$$aWeiss, Philipp$$b1
000825270 7001_ $$0P:(DE-Juel1)131815$$aCastillo, Johnny$$b2
000825270 7001_ $$0P:(DE-Juel1)131818$$aErmert, Johannes$$b3$$ufzj
000825270 7001_ $$0P:(DE-Juel1)131816$$aCoenen, Heinrich Hubert$$b4$$ufzj
000825270 909CO $$ooai:juser.fz-juelich.de:825270$$pVDB
000825270 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)157188$$aForschungszentrum Jülich$$b0$$kFZJ
000825270 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)131818$$aForschungszentrum Jülich$$b3$$kFZJ
000825270 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)131816$$aForschungszentrum Jülich$$b4$$kFZJ
000825270 9131_ $$0G:(DE-HGF)POF3-572$$1G:(DE-HGF)POF3-570$$2G:(DE-HGF)POF3-500$$3G:(DE-HGF)POF3$$4G:(DE-HGF)POF$$aDE-HGF$$bKey Technologies$$lDecoding the Human Brain$$v(Dys-)function and Plasticity$$x0
000825270 9141_ $$y2016
000825270 915__ $$0StatID:(DE-HGF)0550$$2StatID$$aNo Authors Fulltext
000825270 920__ $$lyes
000825270 9201_ $$0I:(DE-Juel1)INM-5-20090406$$kINM-5$$lNuklearchemie$$x0
000825270 980__ $$aposter
000825270 980__ $$aVDB
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000825270 980__ $$aI:(DE-Juel1)INM-5-20090406