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El-Feky Hesham H. Behiry Mohamed S. Amin Alaa S. Nassar Mostafa Y. 《Journal of Inorganic and Organometallic Polymers and Materials》2022,32(3):1129-1141
Journal of Inorganic and Organometallic Polymers and Materials - We herein report a direct and facil sol–gel method for the preparation of porous silicon dioxide nanoparticles using dissolved... 相似文献
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Luxi Qiao Dr. Emily Fisher Dr. Lindsay McMurray Dr. Selena Milicevic Sephton Dr. Matthew Hird Dr. Nisha Kuzhuppilly-Ramakrishnan Dr. David J. Williamson Dr. Xiouyun Zhou Dr. Eryn Werry Prof. Michael Kassiou Dr. Saijinder Luthra Dr. William Trigg Prof. Franklin I. Aigbirhio 《ChemMedChem》2019,14(9):982-993
Translocator protein (TSPO) is a biomarker of neuroinflammation, which is a hallmark of many neurodegenerative diseases and has been exploited as a positron emission tomography (PET) target. Carbon-11-labelled PK11195 remains the most applied agent for imaging TSPO, despite its short-lived isotope and low brain permeability. Second-generation radiotracers show variance in affinity amongst subjects (low-, mixed-, and high-affinity binders) caused by the genetic polymorphism (rs6971) of the TSPO gene. To overcome these limitations, a new structural scaffold was explored based on the TSPO pharmacophore, and the analogue with a low-affinity binder/high-affinity binder (LAB/HAB) ratio similar (1.2 vs. 1.3) to that of (R)-[11C]PK11195 was investigated. The synthesis of the reference compound was accomplished in six steps and 9 % overall yield, and the precursor was prepared in eight steps and 8 % overall yield. The chiral separation of the reference and precursor compounds was performed using supercritical fluid chromatography with >95 % ee. The absolute configuration was determined by circular dichroism. Optimisation of reaction conditions for manual radiolabelling revealed acetonitrile as a preferred solvent at 100 °C. Automation of this radiolabelling method provided R and S enantiomers in respective 21.3±16.7 and 25.6±7.1 % decay-corrected yields and molar activities of 55.8±35.6 and 63.5±39.5 GBq μmol−1 (n=3). Injection of the racemic analogue into a healthy rat confirmed passage through the blood–brain barrier. 相似文献