0000000000053788
AUTHOR
S. Comagic
Synthesis and evaluation of (S)-2-(2-[18F]fluoroethoxy)-4-([3-methyl-1-(2-piperidin-1-yl-phenyl)-butyl-carbamoyl]-methyl)-benzoic acid ([18F]repaglinide): a promising radioligand for quantification of pancreatic β-cell mass with positron emission tomography (PET)
18F-labeled non-sulfonylurea hypoglycemic agent (S)-2-(2-[(18)F]fluoroethoxy)-4-((3-methyl-1-(2-piperidin-1-yl-phenyl)-butylcarbamoyl)-methyl)-benzoic acid ([(18)F]repaglinide), a derivative of the sulfonylurea-receptor (SUR) ligand repaglinide, was synthesized as a potential tracer for the non-invasive investigation of the sulfonylurea 1 receptor status of pancreatic beta-cells by positron emission tomography (PET) in the context of type 1 and type 2 diabetes. [(18)F]Repaglinide could be obtained in an overall radiochemical yield (RCY) of 20% after 135 min with a radiochemical purity higher than 98% applying the secondary labeling precursor 2-[(18)F]fluoroethyltosylate. Specific activity w…
Efficient synthesis of 2-bromo-1-[18F]fluoroethane and its application in the automated preparation of 18F-fluoroethylated compounds
An efficient synthesis of 2-bromo-1-[18F]fluoroethane from commercially available 1,2-dibromoethane and its integration into an automated preparation device was developed for the routine synthesis of 18F-fluoroethylated compounds. The 1,2-dibromoethane was reacted with the [18F]fluoride/Kryptofix 2.2.2./carbonate complex in acetonitrile at 70 degrees C for 3 min resulting in 60-70% radiochemical yields. The crude reaction mixture was diluted with water, loaded on a LiChrolute EN-cartridge, eluted with acetonitrile and passed through an AluminaB-cartridge. This method provides 2-bromo-1-[18F]fluoroethane with 98% radiochemical purity and <0.1 micromol of 1,2-dibromoethane within 10 min, thus…
Establishment and functional validation of a structural homology model for human DNA methyltransferase 1
Changes in DNA methylation patterns play an important role in tumorigenesis. The DNA methyltransferase 1 (DNMT1) protein represents a major DNA methyltransferase activity in human cells and is therefore a prominent target for experimental cancer therapies. However, there are only few available inhibitors and their high toxicity and low specificity have so far precluded their broad use in chemotherapy. Based on the strong conservation of catalytic DNA methyltransferase domains we have used a homology modeling approach to determine the three-dimensional structure of the DNMT1 catalytic domain. Our results suggest an overall structural conservation with other DNA methyltransferases but also in…
Efficient and Mild Ytterbium(III)-Catalyzed Tosylation of Alcohols.
Ytterbium(III) trifluoromethanesulfonate efficiently catalyzes the reaction of primary and secondary alcohols with toluenesulfonic acid anhydride to yield the alkyl tosylates in high yields. The reactions were carried outunder neutral and mild conditions and product purification was easily achieved by means of short column chromatography.
Synthesis of a technetium-99m labelledL-tyrosine derivative with thefac-99mTc(I)(CO)3-core using a simple kit-procedure
Summary The synthesis of a novel technetium-99m labelled derivative of l-tyrosine as a potential tumour imaging agent for nuclear medicine diagnosis is reported. The synthesis involved the labelling precursor fac-[ 99m Tc(OH2)(CO)3] + which was synthesized using the commercially available Isolink 1 -labelling kit and the tyrosine derivative O-(N,Nbis(carboxymethyl)aminoethyl)-l-tyrosine trifluoroacetate. The labelled compound O( 99m Tc(I)-tricarbonyl-N,N-bis(carboxymethyl)aminoethyl)-l-tyrosine was obtained in a radiochemical yield of 70–80% within 60 min with a radiochemical purity greater than 98% without any HPLC purification step. Purification was achieved merely by solid phase extracti…
Efficient synthesis of 2-bromo-1-[18F]fluoroethane and its application in the automated preparation of 18F-fluoroethylated radiopharmaceuticals
An efficient synthesis of 2-bromo-1-[18F]fluoroethane from commercially available 1,2-dibromoethane and its integration into an automated preparation device was developed for the routine synthesis of 18F-fluoroethylated radiopharmaceuticals. The precursor 1,2-dibromoethane was reacted with the [18F]fluoride/Kryptofix®2.2.2./carbonate-complex in acetonitrile at 70°C for 3 minutes. The crude reaction mixture was diluted with water, loaded on a LiChrolute ®EN-cartridge, eluated with acetonitrile and passed through an Alumina ®B-cartridge. The method can provide 2-bromo-1-[18F]fluoroethane with 98% radiochemical purity completely free of 1, 2-dibromoethan within 10 min, thus avoiding a purifyin…