Arginine–glycine–aspartic acid (RGD)-containing peptides have been traditionally used as PET probes to noninvasively image angiogenesis, but recently, small selective molecules for α5β1 integrin receptor have been developed with promising results. Sixty-one antagonists were screened, and tert-butyl (S)-3-(2-((3R,5S)-1-(3-(1-(2-fluoroethyl)-1H-1,2,3-triazol-4-yl)propanoyl)-5-((pyridin-2-ylamino)methyl)pyrrolidin-3-yloxy)acetamido)-2-(2,4,6-trimethylbenzamido)propanoate (FPMt) was selected for the development of a PET tracer to image the expression of α5β1 integrin receptors. An alkynyl precursor (PMt) was initially synthesized in six steps, and its radiolabeling was performed according to the azide–alkyne copper(II)-catalyzed Huisgen's cycloaddition by using 1-azido-2-[18F]fluoroethane ([18F]12). Different reaction conditions between PMt and [18F]12 were investigated, but all of them afforded [18F]FPMt in 15 min with similar radiochemical yields (80–83%, decay corrected). Overall, the final radiopharmaceutical ([18F]FPMt) was obtained after a synthesis time of 60–70 min in 42–44% decay-corrected radiochemical yield. Copyright © 2014 John Wiley & Sons, Ltd.
含精
氨酸-甘
氨酸-
天冬氨酸(RGD)的
多肽传统上一直被用作 PET 探针,用于对血管生成进行无创成像,但最近开发的针对 α5β1 整合素受体的小分子选择性药物也取得了可喜的成果。筛选出了 61 种拮抗剂,其中(S)-3-(2-((3R,5S)-1-(3-(1-(2-
氟乙基)-
1H-1,2,3-三唑-4-基)丙酰基)-5-((
吡啶-2-基
氨基)甲基)
吡咯烷-3-基氧基)乙酰胺基)-2-(2、4,6-三甲基苯甲酰胺基
丙酸酯 (FPMt) 被选中用于开发 PET 示踪剂,对 α5β1 整合素受体的表达进行成像。一种炔基前体(PMt)最初是通过六个步骤合成的,其放射性标记是根据
叠氮-炔
铜(II)催化的惠斯根环化反应,使用 1-
叠氮-2-[18F]
氟乙烷([18F]12)进行的。研究人员研究了 PMt 和 [18F]12 之间的不同反应条件,但所有这些条件都能在 15 分钟内生成 [18F]FPMt,且放射
化学收率相似(80-83%,衰变校正)。总体而言,在合成时间为 60-70 分钟后,可获得最终的放射性药物([18F]FPMt),衰变校正后的放射
化学收率为 42-44%。Copyright © 2014 John Wiley & Sons, Ltd. All Rights Reserved.