Jalilian Amir R, Akhlaghi Mehdi, Mirzaii Mohammad, Karimian Alireza R
Cyclotron and Nuclear Medicine Department, Nuclear Research Centerfor Agriculture and Medicine (NRCAM), Karaj, Iran.
Nucl Med Rev Cent East Eur. 2006;9(2):108-13.
[(18)F]-6-thia-14-fluoro-heptadecanoic acid 3b, a free fatty acid, has been used in myocardial PET imaging. In order to establish an automated synthesis module for routine production in the country, a study was performed for optimization of the production conditions as well as making modifications.
[(18)F]Benzyl-14-Fluoro-6-thia-heptadecanoate 2b was prepared in no-carrier-added (n.c.a) form from Benzyl-14-tosyloxy-6-thia-heptadecanoate 1 in one step at 90 degrees C in Kryptofix2.2.2/[(18)F] with acetonitrile as the solvent followed by Silica column chromatography. The radiolabelled ester 2 was then hydrolysed to yield [(18)F]-6-thia-14-fluoro-heptadecanoic 3b. The final solution was concentrated using the C(18) SPE system and administered to normal rats for biodistribution and co-incidence imaging studies.
The synthesis took 15 min with overall radiochemical yield of 15-25% (EOS) and chemical-radiochemical purity of more than 90%. Automation was performed using a two-pot synthesis. The best imaging time was shown to be 140-180 minutes post injection.
Using this procedure a fast, reliable, automated synthesis for the cardial PET tracer, i.e. [(18)F]FTHA, can be obtained without an HPLC purification step.
游离脂肪酸[(18)F]-6-硫杂-14-氟-十七烷酸3b已用于心肌PET成像。为在国内建立用于常规生产的自动化合成模块，开展了一项优化生产条件及进行改进的研究。
以苄基-14-对甲苯磺酰氧基-6-硫杂-十七烷酸酯1为原料，在90℃下，以乙腈为溶剂，在Kryptofix2.2.2/[(18)F]体系中一步法制备无载体添加(n.c.a)形式的苄基-14-氟-6-硫杂-十七烷酸酯2b，随后进行硅胶柱色谱分离。然后将放射性标记的酯2水解，得到[(18)F]-6-硫杂-14-氟-十七烷酸3b。最终溶液使用C(18)固相萃取系统浓缩，并给予正常大鼠进行生物分布和符合成像研究。
合成耗时15分钟，总放射化学产率为15 - 25%（放化纯），化学-放射化学纯度大于90%。采用两罐合成法实现了自动化。最佳成像时间显示为注射后140 - 180分钟。
使用该方法，无需HPLC纯化步骤即可快速、可靠地自动化合成心脏PET示踪剂[(18)F]FTHA。
