title: Novel cyclopentadienyl tricarbonyl complexes of (99m)Tc mimicking chalcone as potential single-photon emission computed tomography imaging probes for β-amyloid plaques in brain.
abstract: Rhenium and technetium-99m cyclopentadienyl tricarbonyl complexes mimicking the chalcone structure were prepared. These complexes were proved to have affinity to β-amyloid (Aβ) in fluorescent staining on brain sections of Alzheimer's Disease (AD) patient and binding assay using Aβ(1-42) aggregates, with K(i) values ranging from 899 to 108 nM as the extension of conjugated π system. In vitro autoradiograpy on sections of transgenic mouse brain confirmed the affinity of [(99m)Tc]5 (K(i) = 108 nM). In biodistribution, all compounds showed good initial uptakes into the brain and fast blood clearance, while the decreasing of initial brain uptakes correspond to increasing of conjugation length, from 4.10 ± 0.38% ID/g ([(99m)Tc]3) to 1.11 ± 0.34% ID/g ([(99m)Tc]5). These small technetium-99m complexes (<500 Da) designed by an integrated approach provide encouraging evidence that development of a promising (99m)Tc-labeled agent for imaging Aβ plaques in the brain may be feasible.
authors.affiliation: Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China.
authors.forename: Zijing
authors.initials: Z
authors.lastname: Li
authors.forename: Mengchao
authors.initials: M
authors.lastname: Cui
authors.forename: Jiapei
authors.initials: J
authors.lastname: Dai
authors.forename: Xuedan
authors.initials: X
authors.lastname: Wang
authors.forename: Pingrong
authors.initials: P
authors.lastname: Yu
authors.forename: Yanping
authors.initials: Y
authors.lastname: Yang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Jia
authors.forename: Hualong
authors.initials: H
authors.lastname: Fu
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ono
authors.forename: Hongmei
authors.initials: H
authors.lastname: Jia
authors.forename: Hideo
authors.initials: H
authors.lastname: Saji
authors.forename: Boli
authors.initials: B
authors.lastname: Liu
mesh_terms: D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D002599:Chalcone / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D051379:Mice; D008822:Mice, Transgenic; D008958:Models, Molecular; D015609:Organotechnetium Compounds; D049268:Positron-Emission Tomography / Q000379:methods*
chemical_list: D016229:Amyloid beta-Peptides; D015609:Organotechnetium Compounds; C116453:cyclopentadienyl tricarbonyl technetium; D002599:Chalcone