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Synthesis and Autoradiography of Novel F-18 Labeled Reversible Radioligands for Detection of Monoamine Oxidase B
[Image: see text] Monoamine oxidase B (MAO-B) is an important enzyme regulating the levels of monoaminergic neurotransmitters. Selective MAO-B inhibitors have been labeled with carbon-11 or fluorine-18 to visualize the localization of MAO-B in vivo by positron emission tomography (PET) and thereby h...
Autores principales: | , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical
Society
2020
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7747220/ https://www.ncbi.nlm.nih.gov/pubmed/33284012 http://dx.doi.org/10.1021/acschemneuro.0c00631 |
Sumario: | [Image: see text] Monoamine oxidase B (MAO-B) is an important enzyme regulating the levels of monoaminergic neurotransmitters. Selective MAO-B inhibitors have been labeled with carbon-11 or fluorine-18 to visualize the localization of MAO-B in vivo by positron emission tomography (PET) and thereby have been useful for studying neurodegenerative diseases. The aim of this study was to develop promising fluorine-18 labeled reversible MAO-B PET radioligands and their biological evaluation in vitro by autoradiography. Radiolabeling was achieved by classical one-step fluorine-18 nucleophilic substitution reaction. The stability and radiochemical yield was analyzed with HPLC. All five fluorine-18 labeled compounds were tested in human whole hemisphere autoradiography experiments. Five compounds (GEH200439, GEH200448, GEH200449, GEH200431A, and GEH200431B) were successfully radiolabeled with fluorine-18, and the incorporation yield of the fluorination reactions varied from 10 to 45% depending on the compound. The radiochemical purity was higher than 99% for all at the end of synthesis. Radioligands were found to be stable, with a radiochemical purity of >99% in a sterile phosphate buffered saline (pH = 7.4) over the duration of the study. The ARG binding density of only (18)F-GEH200449 was consistent with known MAO-B expression in the human brain. Radiolabeling of five new fluorine-18 MAO-B reversible inhibitors was successfully accomplished. Compound (18)F-GEH200449 binds specifically to MAO-B in vitro postmortem brain and could be a potential candidate for in vivo PET investigation. |
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