Aβ斑块显像剂:^(11)C-PIB的合成及标记

Synthesis and Carbon Labeling of ^(11)C-PIB for Aβ-Amyloid Imaging

11C标记2-(4′-N-11C-甲胺基苯)-6-羟基苯并噻唑(6-OH-BTA-1)是目前较理想的Aβ斑块显像剂,本研究合成了6-OH-BTA-1的前体:6-羟基-2-(4′-氨基苯基)苯并噻唑,并用11C标记。在常温下,无需保护羟基条件下,标记效率为52.6%(校正,n=35),产品放射化学纯度大于99%,比活度为18.0 TBq/mmol。80℃加热2 min,有副反应发生。采用弱酸性流动相,半制备HPLC分离后产品的放射化学纯度达99%。

Assessing the deposition of Aβ-amyloid in the living brain is important for diagnosis and treatment of Alzheimer＇s disease（AD）.2-（4′-N-11C-methyl-aminophenyl）-6-hydroxybenzothiazole（11C-PIB） was used as a ideal labeled probe imaging Aβ-amyloid for AD.The precursor of 11C-PIB,2-（4′-aminophenyl）-6-hydroxybenzothiazole,was synthesized.11C-PIB was labeled with 11C-CH3-Triflate（Trifluoromethanesulfonate）under unprotect 6-hydroxyl precursor at room temperature.The labeling yield,radiochemistry purity and specific activity are 52.6%（corrected,n=35）,99% and 18.0 TBq/mmoL respectively.The by-reaction occurrs when the reaction is heated 80 ℃ for 2 min.The radiochemistry purity can be improved to 99% by semi-HPLC weak acid mobile phase.