Majjigapu Janaki R R, Kurchan Alexei N, Kottani Rudresha, Gustafson Tiffany P, Kutateladze Andrei G
Department of Chemistry and Biochemistry, University of Denver, 2190 East Iliff Avenue, Denver, Colorado 80208-2436, USA.
J Am Chem Soc. 2005 Sep 14;127(36):12458-9. doi: 10.1021/ja053654m.
A new efficient photocaging system with a fluorescence reporting function has been developed. The photolabile latch is based on adducts of C-nucleophiles with aromatic ketones, such as thioxanthones and xanthones. The system is designed to quantify the release of biological effectors and to monitor their spatial distribution and localization by single- and two-photon fluorescence microscopy. In the armed state the ketone's conjugation is disrupted by nucleophilic addition, resulting in a blue shift of the absorption maxima and a dramatic decrease in fluorescence intensity. The mechanism of the photoinduced uncaging involves homolytic C-C bond fragmentation followed by radical disproportionation, regenerating the carbonyl moiety and restoring fluorescence. The uncaging can be initiated via either a one- or two-photon process, offering a new powerful tool for molecular life sciences. The synthesis and uncaging of dendrimer- and polymeric bead-based model systems are described.
一种具有荧光报告功能的新型高效光笼系统已被开发出来。光不稳定锁扣基于C-亲核试剂与芳香酮（如噻吨酮和呫吨酮）的加合物。该系统旨在定量生物效应物的释放，并通过单光子和双光子荧光显微镜监测其空间分布和定位。在武装状态下，酮的共轭通过亲核加成被破坏，导致吸收最大值发生蓝移，荧光强度急剧下降。光诱导解笼的机制涉及均裂C-C键断裂，随后是自由基歧化，再生羰基部分并恢复荧光。解笼可以通过单光子或双光子过程启动，为分子生命科学提供了一种新的强大工具。描述了基于树枝状聚合物和聚合物珠的模型系统的合成和解笼。
