[<sup>76</sup>Br]BMK-I-152, a non-peptide analogue for PET imaging of corticotropin-releasing hormone type 1 receptor (CRHR1)
作者:L. Lang、Y. Ma、B. M. Kim、E. M. Jagoda、K. C. Rice、L. P. Szajek、C. Contoreggi、P. W. Gold、G. P. Chrousos、W. C. Eckelman、D. O. Kiesewetter
DOI:10.1002/jlcr.1616
日期:2009.7
The study of corticotropin-releasing hormone is of significant interest in mental health. We have developed a radiobromination procedure for the preparation of [76Br]BMK-I-152, a high-affinity corticotropin-releasing hormone type 1 receptor antagonist. The radiobromination procedure resulted in the formation of two radiobrominated products from the same trialkyltin precursor. Utilizing the results of several reaction conditions and the chromatographic and mass spectral data obtained from Waters Acquity and Q-TOF, we determined that both 3-bromo and 4-bromo isomers could be obtained. The authentic sample of the 3-bromo isomer was prepared to confirm the identity of a previously unknown radioactive side product; affinity assays revealed that the 4-bromo isomer had ∼70 times higher affinity than that of the 3-bromo compound. By manipulation of reaction conditions, the individual products could be selected. Under no-carrier-added conditions at room temperature in aqueous acetonitrile, the major radioactive product (>80%) was identified as the 3-[76Br]bromo-4-tributylstannyl analogue of BMK-I-152. The 4-[76Br]bromo isomer accounted for less than 1% of the total activity. The 3-[76Br]bromo BMK-I-152 could be obtained by treating this intermediate with trifluoroacetic acid to effect removal of the trialkyltin. If the radiobromination was conducted after first evaporating the water from the aqueous ammonium hydroxide solution of [76Br]bromide, the desired 4-[76Br]bromo isomer was obtained with a 58% radiochemical yield. Copyright © 2009 John Wiley & Sons, Ltd.
促肾上腺皮质激素释放激素的研究对心理健康具有重要意义。我们开发了一种放射性溴化方法来制备 [76Br]BMK-I-152,一种高亲和力促肾上腺皮质激素释放激素 1 型受体拮抗剂。放射性溴化过程导致由相同的三烷基锡前体形成两种放射性溴化产物。利用几种反应条件的结果以及从Waters Acquity和Q-TOF获得的色谱和质谱数据,我们确定可以获得3-溴和4-溴异构体。制备 3-溴异构体的真实样品是为了确认以前未知的放射性副产物的身份;亲和力测定表明,4-溴异构体的亲和力比 3-溴化合物高约 70 倍。通过控制反应条件,可以选择单独的产物。在室温下无载体添加的条件下,在乙腈水溶液中,主要放射性产物 (>80%) 被鉴定为 BMK-I-152 的 3-[76Br]溴-4-三丁基甲锡烷基类似物。 4-[76Br]溴异构体占总活性不到1%。可以通过用三氟乙酸处理该中间体以除去三烷基锡来获得3-[76Br]溴BMK-I-152。如果在首先从[76Br]溴化物的氢氧化铵水溶液中蒸发水之后进行放射性溴化,则以58%的放射化学收率获得所需的4-[76Br]溴异构体。版权所有 © 2009 约翰·威利父子有限公司