178433-03-9Relevant articles and documents
Fast and reliable generation of [18F]triflyl fluoride, a gaseous [18F]fluoride source
Pees,Sewing,Vosjan,Tadino,Herscheid,Windhorst,Vugts
, p. 10179 - 10182 (2018)
A novel strategy for the production of reactive [18F]fluoride has been developed, omitting time consuming azeotropic drying procedures. Gaseous [18F]triflyl fluoride is formed instantaneously at room temperature from hydrated [18F]fluoride, followed by distillation in less than 5 minutes into a dry aprotic solvent, in which dry [18F]fluoride is released in presence of base with >90% radiochemical yield. The reactivity of the [18F]fluoride has been confirmed by reaction with several model compounds and by the synthesis of the PET tracers [18F]fluoroestradiol ([18F]FES) and O-2-[18F]fluoroethyl-l-tyrosine ([18F]FET), providing good isolated radiochemical yields and molar activities of up to 123 GBq μmol?1.
Effect of α-Methyl versus α-Hydrogen Substitution on Brain Availability and Tumor Imaging Properties of Heptanoic [F-18]Fluoroalkyl Amino Acids for Positron Emission Tomography (PET)
Bouhlel, Ahlem,Alyami, Wadha,Li, Aixiao,Yuan, Liya,Rich, Keith,McConathy, Jonathan
, p. 3515 - 3531 (2016)
Two [18F]fluoroalkyl substituted amino acids differing only by the presence or absence of a methyl group on the α-carbon, (S)-2-amino-7-[18F]fluoro-2-methylheptanoic acid ((S)-[18F]FAMHep, (S)-[18F]14) and (S)-2-amino-7-[18F]fluoroheptanoic acid ((S)-[18F]FAHep, (S)-[18F]15), were developed for brain tumor imaging and compared to the well-established system L amino acid tracer, O-(2-[18F]fluoroethyl)-l-tyrosine ([18F]FET), in the delayed brain tumor (DBT) mouse model of high-grade glioma. Cell uptake, biodistribution, and PET/CT imaging studies showed differences in amino acid transport of these tracer by DBT cells. Recognition of (S)-[18F]15 but not (S)-[18F]14 by system L amino acid transporters led to approximately 8-10-fold higher uptake of the α-hydrogen substituted analogue (S)-[18F]15 in normal brain. (S)-[18F]15 had imaging properties similar to those of (S)-[18F]FET in the DBT tumor model while (S)-[18F]14 afforded higher tumor to brain ratios due to much lower uptake by normal brain. These results have important implications for the future development of α-alkyl and α,α-dialkyl substituted amino acids for brain tumor imaging.
A resin-linker-vector approach to radiopharmaceuticals containing 18F: Application in the synthesis of O-(2-[18F]- Fluoroethyl)-L-tyrosine
Topley, Amy C.,Isoni, Valerio,Logothetis, Thomas A.,Wynn, Duncan,Wadsworth, Harry,Gibson, Alex M. R.,Khan, Imtiaz,Wells, Neil J.,Perrio, Cécile,Brown, Richard C.D.
supporting information, p. 1720 - 1725 (2013/02/25)
A Resin-linker-vector (RLV) strategy is described for the radiosynthesis of tracer molecules containing the radionuclide 18F, which releases the labelled vector into solution upon nucleophilic substitution of a polystyrene-bound arylsulfonate linker with [18F]-fluoride ion. Three model linker-vector molecules 7 a-c containing different alkyl spacer groups were assembled in solution from (4-chlorosulfonylphenyl)alkanoate esters, exploiting a lipase-catalysed chemoselective carboxylic ester hydrolysis in the presence of the sulfonate ester as a key step. The linker-vector systems were attached to aminomethyl polystyrene resin through amide bond formation to give RLVs 8 a-c with acetate, butyrate and hexanoate spacers, which were characterised by using magic-angle spinning (MAS) NMR spectroscopy. On fluoridolysis, the RLVs 8 a, b containing the longer spacers were shown to be more effective in the release of the fluorinated model vector (4-fluorobutyl)phenylcarbamic acid tert-butyl ester (9) in NMR kinetic studies and gave superior radiochemical yields (RCY≈60 %) of the 18F- labelled vector. The approach was applied to the synthesis of the radiopharmaceutical O-(2-[18F]-fluoroethyl)-L-tyrosine ([ 18F]-FET), delivering protected [18F]-FET in >90 % RCY. Acid deprotection gave [18F]-FET in an overall RCY of 41 % from the RLV. Copyright
