Synthesis of Fluorine-Containing Phosphodiesterase 10A (PDE10A) Inhibitors and the In Vivo Evaluation of F-18 Labeled PDE10A PET Tracers in Rodent and Nonhuman Primate
作者:Junfeng Li、Xiang Zhang、Hongjun Jin、Jinda Fan、Hubert Flores、Joel S. Perlmutter、Zhude Tu
DOI:10.1021/acs.jmedchem.5b01205
日期:2015.11.12
A series of fluorine-containing PDE10A inhibitors were designed and synthesized to improve the metabolic stability of [C-11]MP-10. Twenty of the 22 new analogues had high potency and selectivity for PDE10A: 18a-j, 19d-j, 20a-b, and 21b had IC50 values <5 nM for PDE10A. Seven F-18 labeled compounds [F-18](18)a-e, [F-18]18g, and [F-18]20a were radiosynthesized by F-18-introduction onto the quinoline rather than the pyrazole moiety of the MP-10 pharmacophore and performed in vivo evaluation. Biodistribution studies in rats showed similar to 2-fold higher activity in the PDE10A-enriched striatum than nontarget brain regions; this ratio increased from 5 to 30 min postinjection, particularly for [F-18]18a-d and [F-18]20a. Micro-PET studies of [F-18]18d and [F-18]20a in nonhuman primates provided clear visualization of striatum with suitable equilibrium kinetics and favorable metabolic stability. These results suggest this strategy may identify a F-18-labeled PET tracer for quantifying the levels of PDE10A in patients with CNS disorders including Huntington's disease and schizophrenia.