Comparison of 4 radiolabeled antagonists for serotonin 5-HT(7) receptor neuroimaging: toward the first PET radiotracer.

Unlabelled: Brain serotonin 7 (5-hydroxytryptamine 7, or 5-HT(7)) is the most recently identified serotonin receptor. It is involved in mood disorders and is studied as a target for antidepressants. Because no radioligand has yet been successfully used to study this receptor by PET neuroimaging, the objective of the present study was to develop a 5-HT(7) (18)F-labeled radiotracer.

Synthesis and biological evaluation of potential 5-HT(7) receptor PET radiotracers.

Brain serotonin 7 receptor (5-HT(7)) is involved in several mood disorders and drug candidates targeting this subtype are currently in development. Positron emission tomography (PET) is a molecular imaging modality offering great promise for accelerating the process from preclinical discovery to clinical phases. As no PET radiopharmaceutical has yet been used successfully to study the 5-HT(7) receptor in vivo, our objective is to develop the first 5-HT(7) fluorine-18 labeled radiotracer.

Looking for a 5-HT7 radiotracer for positron emission tomography.

In search of a serotonin 5-HT(7) radiotracer for positron emission tomography, we developed 1-[2-[(2S)-1-(phenylsulfonyl)pyrrolidin-2-yl]ethyl]piperidin-4-yl 4-fluorobenzoate. After labeling in good yield with fluorine-18 via nitro for fluorine exchange, preliminary biological experiments with autoradiographies failed to evidence any specific 5-HT(7) receptor delineation.

Alkynyl ruthenium colorimetric sensors: optimizing the selectivity toward fluoride anion.

We report on the synthesis of alkynyl ruthenium colorimetric sensors whose receptors are constituted by thiazolidinedione, rhodanine, or barbituric heads as recognition centers for anions. As modifications in the charge density at these recognition centers affect the whole molecule, through the alkynyl ligand acting as a communicating wire, the effects of hydrogen-bonding interactions with the anions were observed with the naked eye and monitored by UV-vis absorption spectrometry. The selectivity of the sensors was improved through electronic modifications of the alkynyl ruthenium subunit: the higher the electron density at the receptor head, the higher the selectivity is.

Naked eye detection of anions by alkynyl-ruthenium exo-receptors: selective recognition of fluoride anion.

Alkynyl-ruthenium complexes bearing terminal hydrogen-bonding receptors act as efficient anion sensors exhibiting large guest-induced colour changes and show unexpectedly high selectivity to fluoride ions.