180302-35-6Relevant articles and documents
Synthesis and Biological Evaluation of Quinoxaline Derivatives for PET Imaging of the NMDA Receptor
Milicevic Sephton, Selena,Vetterli, Peter T.,Pedani, Valentina,Cermak, Stjepko,Chiotellis, Aristeidis,Roscales, Sylvia,Müller Herde, Adrienne,Schibli, Roger,Auberson, Yves P.,Ametamey, Simon M.
, (2017)
Due to the biological complexity of the N-methyl-d-aspartate receptor (NMDAR), the development of a positron emission tomography radiotracer for the imaging of NMDAR has met with limited success. Recent studies have established the presence of GluN2A subunit of the NMDAR in the heart and its role in the regulation of intracellular calcium levels. In our efforts to develop an imaging agent for the GluN2A subunit, we designed three new compounds based on a quinoxaline scaffold. The synthesis of the analogues was based on a two-step Kabachnik–Fields reaction in sequence with Suzuki cross-coupling and acid hydrolysis. They exhibited comparable high binding affinity values below 5 nm. A two-step radiolabeling procedure was successfully developed for the synthesis of [18F]1. [18F]1 was obtained in a modest overall radiochemical yield of 5.5 ± 4.2%, a good specific radioactivity of 254 ± 158 GBq/μmol, and a radiochemical purity > 99%. While compounds 2 and 3 showed comparable binding affinity towards NMDAR, sluggish radiolabeling, prevented their further evaluation. For [18F]1, in vitro autoradiography on rat heart slices demonstrated heterogeneous but unspecific accumulation, whereas for the brain a high in vitro specificity towards NMDAR, could be demonstrated.
Synthesis, in Vitro Evaluation, and Radiolabeling of Fluorinated Puromycin Analogues: Potential Candidates for PET Imaging of Protein Synthesis
Betts, Helen M.,Milicevic Sephton, Selena,Tong, Carmen,Awais, Ramla O.,Hill, Philip J.,Perkins, Alan C.,Aigbirhio, Franklin I.
supporting information, p. 9422 - 9430 (2016/11/11)
There is currently no ideal radiotracer for imaging of protein synthesis rate (PSR) by positron emission tomography (PET). Existing fluorine-18-labeled amino acid-based radiotracers predominantly visualize amino acid transporter processes, and in many cases they are not incorporated into nascent proteins at all. Others are radiolabeled with the short-half-life positron emitter carbon-11, which is rather impractical for many PET centers. Based on the puromycin (6) structural manifold, a series of 10 novel derivatives of 6 was prepared via Williamson ether synthesis from a common intermediate. A bioluminescence assay was employed to study their inhibitory action on protein synthesis, which identified the fluoroethyl analogue 7b as a lead compound. The fluorine-18 analogue was prepared via nucleophilic substitution of the corresponding tosylate precursor in a modest radiochemical yield of 2 ± 0.6% with excellent radiochemical purity (>99%) and showed complete stability over 3 h at ambient temperature.
TRIAZOLE AND IMIDAZOLE DERIVATIVES FOR USE AS TGR5 AGONISTS IN THE TREATMENT OF DIABETES AND OBESITY
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Page/Page column 86, (2012/01/30)
The present invention comprises TGR5 agonists of structural formula I, wherein X, R1, R2, and R5 are defined herein, as well as N-oxides of them and pharmaceutically acceptable salts thereof. The invention further comprise
