Spacer-Mediated Control of Coumarin Uncaging for Photocaged Thymidine.
Spacer-Mediated Control of Coumarin Uncaging for Photocaged Thymidine.
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DOI：
10.1021/acs.joc.9b02617
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发表时间：
2020-02
期刊：
影响因子：
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通讯作者：
Shengzhuang Tang;Jayme Cannon;Kelly Yang;M. Krummel;J. R. Baker;S. Choi
中科院分区：
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作者：
Shengzhuang Tang;Jayme Cannon;Kelly Yang;M. Krummel;J. R. Baker;S. Choi
尽管它在光笼化分子的设计中的重要性，但较少注意力集中在连接体化学上，而不是笼本身。在这里，我们描述了两个香豆素笼胸苷化合物，每一个共轭（2）或不（1）扩展，自分解间隔显示独特的uncaging性能。使用长波长UVA（365 nm）或可见光（420，455 nm）的1的光解导致游离胸苷的释放，沿着竞争性产生携带胸苷的重组产物。这种不希望的副反应的发生，这是以前没有报道过的，不存在与2的光解，这释放胸苷专门具有较高的量子效率。我们提出，笼和底物分子之间的空间分离所赋予的扩展连接可以发挥关键作用，在规避这种非生产性的反应。这份报告强调了在设计香豆素笼式双核苷和其他缀合物时接头选择的重要性。
Despite its importance in the design of photocaged molecules, less attention is focused on linker chemistry than the cage itself. Here, we describe unique uncaging properties displayed by two coumarin-caged thymidine compounds, each conjugated with (2) or without (1) an extended, self-immolative spacer. Photolysis of 1 using long-wavelength UVA (365 nm) or visible (420, 455 nm) light led to the release of free thymidine along with the competitive generation of a thymidine-bearing recombination product. The occurrence of this undesired side reaction, which is previously unreported, was not present with the photolysis of 2, which released thymidine exclusively with higher quantum efficiency. We propose that the spatial separation between the cage and the substrate molecule conferred by the extended linker can play a critical role in circumventing this unproductive reaction. This report reinforces the importance of linker selection in the design of coumarin-caged oligonucleosides and other conjugates.