AD显像剂^(11)C-PIB合成效率的影响因素

Optimization of the Radiosynthesis of the 2-(4-N-[^(11)C]methylaminophenyl)-6-hydroxybenzothiazole for AD

11 C-PIB是诊断阿尔茨海默病(AD)的特征靶Aβ斑块的正电子放射性药物,本工作系统研究了以11 CH3-Triflate为甲基化试剂合成11 C-PIB合成的影响因素。在国产碳多功能合成仪上,研究前体量、溶剂、反应温度及体系的pH等对11 C-PIB效率的影响,并对合成条件进行优化。结果显示:前体量、溶剂、反应温度及体系的pH均明显影响合成效率。优化后的合成条件为:丙酮为溶剂,前体浓度为5g/L,反应温度为常温,pH为中性。在此条件下,11 C-PIB的合成效率为65.2%±4.7%(n=8,校正效率),产品的放化纯度大于99%,比活度为70.6GBq/g(18.0TBq/mmoL)。从11 CO2到11 C-PIB的合成时间为30min,单次合成的产量为3.7GBq。以上结果表明,通过优化合成条件,可以稳定、高质量地合成11 C-PIB,以满足临床需要。

11C-PIB was the standard PET radiopharmaceuticals for Alzheimer＇s disease（AD） imaging targeting beta-amyloid plaques.The optimization for high synthesis yield and specific activity was designed with 11CH3-Triflate as methylation agent for 11C-PIB.Synthesis for 11C-PIB were studied with home made carbon-11 synthesis module.The results showed that the amount of precursor,the temperature and pH could effect the labeling yield.The optimum reaction conditions were as fllows： with 5 g/L of precursor,pH=7.0,at room temperature,a yield of 65.2%±4.7%（n=8） and a specific activity of 70.6 GBq/g（18.0 TBq/mmol） were achieved,and radiochemical purity was over 99%.It took 30 min from 11CO2 to 11C-PIB.Single synthesis yielding was 3.7 GBq of 11C-PIB.The quantity and quality of 11C-PIB were suitable for clinical use after optimization.