Chirality of bioactive agents in protein binding storage and transport processes

18F-THK5351: A Novel PET Radiotracer for Imaging Neurofibrillary Pathology in Alzheimer Disease

“…Moreover, 18 F-THK5351 is optically pure, whereas 18 F-THK5105 and 18 F-THK5117 are racemic mixtures. Enantiomers frequently show differences in biologic properties such as metabolism or binding affinity for targets (30). Our preclinical studies demonstrated that the pharmacokinetic profiles of the S-enantiomers of arylquinoline derivatives were more favorable than those of the R-enantiomers (20,24).…”

Preclinical Evaluation of [18F]THK-5105 Enantiomers: Effects of Chirality on Its Effectiveness as a Tau Imaging Radiotracer

“…Following these results, initial human PET studies in AD patients were performed using [ 18 [23,24]. Because enantiomers often differ in their biological activity such as metabolism or binding properties for receptors or plasma proteins [25,26], optically pure radioligands may result in different PET or SPECT images compared with their antipodes. The characterization of each enantiomer is beneficial for the development of imaging agents with optimal binding properties.…”

Structure–Activity Relationship of 2-Arylquinolines as PET Imaging Tracers for Tau Pathology in Alzheimer Disease

“…THK-5151 has a chiral center in its side chain and thus has 2 optical isomers (Fig. 3A), and it was anticipated that the biologic activities would be different between the enantiomers (23). Therefore, we synthesized the THK-5151 enantiomers and evaluated their properties as tau imaging probes (Supplemental Schemes 10 and 11; Supplemental Fig.…”