Optimization of the preparation of fluorine-18-labeled steroid receptor ligands 16alpha-[<sup>18</sup>
F]fluoroestradiol (FES), [<sup>18</sup>
F]fluoro furanyl norprogesterone (FFNP), and 16beta-[<sup>18</sup>
F]fluoro-5alpha-dihydrotestosterone (FDHT) as radiopharmaceuticals
作者:Dong Zhou、Mai Lin、Norio Yasui、Mohammed H. Al-Qahtani、Carmen S. Dence、Sally Schwarz、John A. Katzenellenbogen
DOI:10.1002/jlcr.3191
日期:2014.5.15
Fluorine-18-labeled steroid receptor tracers, 16α-[18F]fluoroestradiol (FES), [18F]fluoro furanyl norprogesterone (FFNP), and 16β-[18F]fluoro-5α-dihydrotestosterone (FDHT), are important imaging tools for studies of breast and prostate cancers using positron emission tomography (PET). The automated production of these ligands with high specific activity (SA) as radiopharmaceuticals requires modification and optimization of the currently reported methods. [18F]FES with high SA was synthesized in over 60% radiochemical yield (RCY) at the end of synthesis (EOS) using a small amount of precursor (1) (as low as 0.3 mg) and 1 M H2SO4 for deprotection of the intermediate (2). [18F]FFNP was synthesized in up to 77% RCY at EOS using the triflate precursor (4) at room temperature or in 25% RCY using the mesylate precursor (6) at 65°C. Both methods are highly reproducible and afford high SA. [18F]FDHT was synthesized by radiofluoride incorporation at room temperature, reduction with NaBH4, and deprotection with HCl/acetone, giving [18F]FDHT in up to 75% yield (RCY). All of these methods can be easily translated to automated production. The information provided here will aid in the development of automated production of these steroid receptor tracers with high or improved yields, optimal SA, and ease of processing for research and clinical use. Copyright © 2014 John Wiley & Sons, Ltd.
氟-18 标记的类固醇受体示踪剂 16α-[18F]fluoroestradiol (FES)、[18F]fluoro furanyl norprogesterone (FFNP) 和 16β-[18F]fluoro-5α-dihydrotestosterone (FDHT) 是利用正电子发射断层扫描(PET)研究乳腺癌和前列腺癌的重要成像工具。要自动生产这些具有高特异性(SA)的放射性药物配体,需要对目前已报道的方法进行修改和优化。使用少量前体(1)(低至 0.3 毫克)和 1 M H2SO4 对中间体(2)进行脱保护,就能合成具有高 SA 的[18F]FES,合成结束时的放射化学收率(RCY)超过 60%。在室温下使用三late前体(4)在 EOS 下合成 [18F]FFNP 的 RCY 可高达 77%,或在 65°C 下使用甲磺酸盐前体(6)在 EOS 下合成 [18F]FFNP 的 RCY 可高达 25%。这两种方法都具有很高的重现性,并能获得较高的 SA 值。[18F]FDHT 的合成方法是在室温下加入放射性氟化物,用 NaBH4 还原,再用 HCl/ 丙酮脱保护,得到[18F]FDHT,收率高达 75%(RCY)。所有这些方法都可以很容易地转化为自动化生产。本文所提供的信息将有助于开发这些类固醇受体示踪剂的自动化生产,使其具有更高或更高的产率、最佳的 SA 和易于处理的特点,以满足研究和临床使用的需要。Copyright © 2014 John Wiley & Sons, Ltd. All Rights Reserved.