One-step iodination of the diazocyclopentadien-2-ylcarbonyl group—a new and convenient preparation of effective radiolabelled photoaffinity probes
作者:Elena L. Vodovozova、Ekaterina V. Tsibizova、Julian G. Molotkovsky
DOI:10.1039/b104945n
日期:——
A detailed study devoted to direct iodination of the photoactivatable diazocyclopentadien-2-ylcarbonyl (Dcp) group is presented. The iodination does not influence the high carbene reactivity of the Dcp-generated carbene. It was shown that the Dcp substituent forms 4-mono-, 5-mono- and 4,5-diiododerivatives upon iodination under oxidative conditions (76, 20 and 4%, respectively, when DcpOMe 2 is iodinated). Photolysis of the individual products of iodination in cyclohexane resulted in rather high insertion into non-activated CH bonds, without noticeable loss of iodine. Syntheses of new phospholipid and ganglioside membrane probes are also described which incorporate the Dcp function via a labile ester bond. A [125I]-Dcp-phosphatidylcholine probe exhibiting high specific radioactivity (â¼500 Ci mmolâ1) was easily
prepared at yields of 90% (on the starting Na125I), by using peracetic acid as an oxidant. Furthermore, it was successfully used for photolabelling of the integral protein hemagglutinin in a well-characterised influenza virus model. In summary, the Dcp group is efficient for labelling a wide variety of molecules, and as such, it provides a new tool for exploring a diverse range of biological systems.
本文详细研究了光活化重氮环戊二烯-2-基羰基(Dcp)基团的直接碘化。碘化不影响Dcp生成碳烯的高反应性。研究表明,在氧化条件下碘化时,Dcp取代基形成4-单碘、5-单碘和4,5-双碘衍生物(当DcpOMe 2碘化时,分别为76%、20%和4%)。在环己烷中对碘化产物的单个产物进行光解时,结果显示在非活化CH键上插入了相当高的插入量,且没有明显的碘损失。还描述了通过不稳定酯键引入Dcp功能的新磷脂和神经节苷脂膜探针的合成。通过使用过乙酸作为氧化剂,在高比活度(约500 Ci mmol-1)的[125I]-Dcp-磷脂酰胆碱探针的制备中,产率达到了90%(相对于起始的Na125I)。此外,它成功用于在经过良好表征的流感病毒模型中光标记整合蛋白凝集素。总之,Dcp基团对于标记各种分子是高效的,因此,它为探索多种生物系统提供了一种新工具。