AUTHOR=Stark Holger 

TITLE=Novel Chalcone-Based Fluorescent Human Histamine H3 Receptor Ligands as Pharmacological Tools

JOURNAL=Frontiers in Systems Neuroscience

VOLUME=6

YEAR=2012

URL=https://www.frontiersin.org/journals/systems-neuroscience/articles/10.3389/fnsys.2012.00014

DOI=10.3389/fnsys.2012.00014

ISSN=1662-5137

ABSTRACT=<p>Novel fluorescent chalcone-based ligands at human histamine H<sub>3</sub> receptors (hH<sub>3</sub>R) have been designed, synthesized, and characterized. Compounds described are non-imidazole analogs of ciproxifan with a tetralone motif. Tetralones as chemical precursors and related fluorescent chalcones exhibit affinities at hH<sub>3</sub>R in the same concentration range like the reference antagonist ciproxifan (hH<sub>3</sub>R p<italic>K</italic><sub>i</sub> value of 7.2). Fluorescence characterization of our novel ligands shows emission maxima about 570 nm for yellow fluorescent chalcones and ≥600 nm for the red fluorescent derivatives. Interferences to cellular autofluorescence could be excluded. All synthesized chalcone compounds could be used to visualize hH<sub>3</sub>R proteins in stably transfected HEK-293 cells using confocal laser scanning fluorescence microscopy. These novel fluorescent ligands possess high potential to be used as pharmacological tools for hH<sub>3</sub>R visualization in different tissues.</p>