肿瘤分子显像剂^(18)F-氟乙基胆碱的自动化合成

Automatic synthesis of ^(18)F-FeCH as molecular imaging agent for tumor diagnosis

18F-氟标记的胆碱衍生物18F-氟乙基胆碱(18F-FeCH)对前列腺癌等多种肿瘤的显像诊断均比较敏感,具有良好的临床应用前景。本文基于"两步-一锅法",经过对商品化Explora FDG4合成模块进行合理的改装发展了18F-FeCH的自动化合成方法。第一步是18F离子与1,2-二对甲苯磺酰基乙烷的亲核取代反应,90℃反应5min,生成标记中间体18F-氟乙基对甲苯磺酰酯。第二步是18F-氟乙基对甲苯磺酰酯与N,N-二甲基-2-羟乙基铵之间的烷基化反应,100℃反应8min,经过Sep-pak硅胶柱分离,获得目标产物18F-FeCH。总合成时间约65min,放射化学产率为30%(未衰变校正),放射化学纯度大于99%。

18F-Fluoroethylcholine （18F-FeCH）, a 18F-labeled choline derivatives, is a very sensitive molecular imaging agent for diagnosis of prostate cancer and other types of cancers, indicating a promising future for clinic applications. In this study, automatic synthesis of 18F-FeCH was developed using a ＂two-step one-pot＂ method modified from Explora FDG4 synthesis module that are commercially available. The fh-st step is the nuclophilic displacement reaction of 18F-fluoride and 1,2-bis（tosyloxy）ethane at 90℃ for 5 rain to form labeled intermediate 18F-fluoroethyltosylate. The second step is to form alkylation between 18F-fluoroethyltosylate and N,N-dimethyl- 2-hydroxyethylammonium at 100℃ for 8 rain. The target product of 18F-FeCH was obtained via Sep-pak cartridge separation with about 30% of radiochemical yields （no decay corrected） and more than 99% of radiochemical purity within 65 min of total synthesis time.