Design and synthesis of new photocaging chromophores and phototchemical carbanion progenitors

新型光笼发色团和光化学碳负离子祖细胞的设计与合成

• 批准号: 326969-2006
• 负责人: Lukeman, Matthew
• 金额: $ 2.7万
• 依托单位: Acadia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=363994
• 关键词: Design; synthesis; new; photocaging; chromophores

Protecting groups are molecular entities that can be attached to a variety of molecules of interest in order to deactivate a certain feature of that molecule, such as its chemical reactivity or its biological function.  'Photocages' are protecting groups that detach from the molecule of interest when they absorb light (usually in the UVA wavelength range), thereby reactivating the molecule.  Exposure of a 'caged' molecule to brief pulses of light can  cause a sudden increase in the concentration of the molecule of interest in its active form. Photocages are used extensively in this way to suddenly introduce a variety of molecules into biological systems.  Biochemists are then able to study very fast biological events that are triggered by this sudden concentration increase, such as the movements of muscle tissues and communication between nerve cells.  Unfortunately, all currently available photocages suffer from one or more serious drawbacks which limits their utility.  For example, the most popular photocage exhibits poor solubility in water, slow release rate, and leads to formation of interfering by-products.   This research plan is devoted to developing new photocages primarily for use in biological studies and in synthetic applications, that remedy the drawbacks associated with those currently available.  The proposed photocages are of two main types: 1) 'carbocation-mediated' photocages that release the protected molecule by formation of a carbocation reactive intermediate, and 2) 'carbanion-mediated' photocages that release the protected molecules from a first formed carbanion reactive intermediate.  All proposed photocages are expected to show excellent release rates, high efficiency, good aqueous solubility, good absorption in the UVA wavelength range, and formation of benign photoproducts. This research also seeks to broaden the range of light absorbing molecules that can be used to generate carbanion reactive intermediates.  This will enable the creation of new photocages with tunable properties such as reactivity and water solubility.

保护基团是可以连接到各种感兴趣的分子上以使该分子的某些特征（例如其化学反应性或其生物学功能）失活的分子实体。“光笼”是当它们吸收光时从感兴趣的分子上脱离的保护基团（通常在UVA波长范围内），将“笼状”分子暴露于短暂的光脉冲可以导致其内部感兴趣的分子浓度突然增加，活动形式。光笼以这种方式被广泛使用，以突然将各种分子引入生物系统。生物化学家然后能够研究由这种突然浓度增加触发的非常快速的生物事件，例如肌肉组织的运动和神经细胞之间的通信。不幸的是，所有目前可用的光笼都存在一个或多个严重的缺点，这限制了它们的实用性。例如，最流行的光笼在水中的溶解性差、释放速率慢，并导致干扰副产物的形成。 该研究计划致力于开发新的光笼，主要用于生物学研究和合成应用，以弥补现有光笼的缺点。拟议的光笼主要有两种类型：1）“碳阳离子介导的”光笼，其通过形成碳阳离子反应性中间体来释放受保护的分子，和2）“碳负离子介导的”光笼，其从最初形成的碳负离子反应性中间体释放被保护的分子。预期所有提出的光笼显示优异的释放速率、高效率、良好的水溶性、在UVA波长范围内的良好吸收，和良性光产物的形成。这项研究还旨在拓宽可用于产生碳负离子活性中间体的光吸收分子的范围。这将使创造新的光笼具有可调特性，如反应性和水溶性。