Medical Isotope and Cyclotron Facility, Cross Cancer Institute, University of Alberta, Alberta, Canada.
Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Germany.
Semin Nucl Med. 2017 Sep;47(5):474-492. doi: 10.1053/j.semnuclmed.2017.07.001. Epub 2017 Jul 17.
Prosthetic group (PG) applications in F-radiochemistry play a pivotal role among current Flabeling techniques for the development and availability of F-labeled imaging probes for PET (Wahl, 2002) (). The introduction and popularization of PGs in the mid-80s by pioneers in F-radiochemistry has profoundly changed the landscape of available tracers for PET and has led to a multitude of new imaging agents based on simple and efficiently synthesized PGs. Because of the chemical nature of anionic F (apart from electrophilic low specific activity F-fluorine), radiochemistry before the introduction of PGs was limited to simple nucleophilic substitutions of leaving group containing precursor molecules. These precursors were not always available, and some target compounds were either hard to synthesize or not obtainable at all. Even with the advent of recently introduced "late-stage fluorination" techniques for the F-fluorination of deactivated aromatic systems, PGs will continue to play a central role in F-radiochemistry because of their robust and almost universal usability. The importance of PGs in radiochemistry is shown by its current significance in tracer development and exemplified by an overview of selected methodologies for PG attachment to PET tracer molecules. Especially, click-chemistry approaches to PG conjugation, while furthering the historical evolution of PGs in PET tracer design, play a most influential role in modern PG utilization. All earlier and recent multifaceted approaches in PG development have significantly enriched the contingent of modern F-radiochemistry procedures and will continue to do so.
在 F 放射性化学中，拟肽基团 (PG) 的应用在当前的 Flabeling 技术中起着关键作用，为 PET 成像探针的 F 标记的发展和可用性提供了支持 (Wahl, 2002) ()。80 年代中期，F 放射性化学的先驱们引入并推广了 PGs，这深刻地改变了 PET 可用示踪剂的格局，并基于简单且高效合成的 PGs 产生了许多新的成像剂。由于阴离子 F 的化学性质（除了亲电的低特异性活性 F-氟），在引入 PGs 之前的放射性化学仅限于含离去基团的前体分子的简单亲核取代。这些前体分子并不总是可用的，并且一些靶化合物要么难以合成，要么根本无法获得。即使最近引入了用于去活化芳环系统的 F-氟化的“晚期氟化”技术，PGs 由于其强大且几乎普遍可用的特性，仍将在 F 放射性化学中发挥核心作用。PGs 在放射性化学中的重要性体现在其在示踪剂开发中的当前意义上，并通过概述将 PG 连接到 PET 示踪分子的选定方法来举例说明。特别是，PG 偶联的点击化学方法，在推进 PG 在 PET 示踪剂设计中的历史发展的同时，在现代 PG 利用中发挥着最具影响力的作用。PG 开发的所有早期和最近的多方面方法都极大地丰富了现代 F 放射性化学程序的内容，并将继续如此。
