Design, Synthesis, and Preliminary Evaluation of SPECT Probes for Imaging β-Amyloid in Alzheimer’s Disease Affected Brain
作者:Yuki Okumura、Yoshifumi Maya、Takako Onishi、Yoshinari Shoyama、Akihiro Izawa、Daisaku Nakamura、Shigeyuki Tanifuji、Akihiro Tanaka、Yasushi Arano、Hiroki Matsumoto
DOI:10.1021/acschemneuro.8b00064
日期:2018.6.20
In this study, we synthesized of a series of 2phenyl- and 2-pyridyl-imidazo[1,2-a]pyridine derivatives and examine their suitability as novel probes for single-photon emission computed tomography (SPECT)-based imaging of beta-amyloid (A beta). Among the 11 evaluated compounds, 10 showed moderate affinity to A beta(1-42) aggregates, exhibiting half-maximal inhibitory concentrations (IC50) of 14.7 +/- 6.07-87.6 +/- 39.8 nM. In vitro autoradiography indicated that 1231 labeled triazole-substituted derivatives displayed highly selective binding to A beta plaques in the hippocampal region of Alzheimer's disease (AD)-affected brain. Moreover, biodistribution studies performed on normal rats demonstrated that all I-123-labeled probes featured high initial uptake into the brain followed by a rapid washout and were thus well suited for imaging A beta plaques, with the highest selectivity observed for a 1H-1,2,3-triazole-substituted 2-pyridyl-imidazopyridine derivative, [I-123]ABC577. This compound showed good kinetics in rat brain as well as moderate in vivo stability in rats and is thus a promising SPECT imaging probe for AD in clinical settings.