Herzig L-M, Elamri I, Schwalbe H, Wachtveitl J
Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue Str. 7, 60438 Frankfurt/Main, Germany.
Phys Chem Chem Phys. 2017 Jun 7;19(22):14835-14844. doi: 10.1039/c7cp02030a.
A synthesis route for puromycin caged with the photo-responsive 7-diethylaminocoumarinyl protecting group carbamate was developed. The inactivation and recovery of the cytotoxic effect of puromycin was tested with a XTT cell viability assay. The uncaging mechanism was studied by ultrafast transient absorption spectroscopy and by time-correlated single photon counting. The combination of these results with quantum-chemical calculations provided detailed insights in dynamics upon excitation. Interestingly, a change of the dipole moment due to structural rearrangements of the amino moiety led to an intermolecular charge transfer on the picosecond time-scale. IR measurements marked the successful uncaging via the release of CO, resulting from the carbamate linker. This decarboxylation constituted the rate-limiting step of the uncaging reaction and occurred on the subsecond timescale. DEACM-puromycin, thus, represents an efficient photo-activatable antibiotic for in-cell applications.
开发了一种用具有光响应性的7-二乙氨基香豆素基保护基团氨基甲酸酯笼蔽嘌呤霉素的合成路线。用XTT细胞活力测定法测试了嘌呤霉素细胞毒性作用的失活和恢复情况。通过超快瞬态吸收光谱和时间相关单光子计数研究了解笼机制。这些结果与量子化学计算相结合，提供了激发态动力学的详细见解。有趣的是，由于氨基部分的结构重排导致偶极矩的变化，从而在皮秒时间尺度上发生了分子间电荷转移。红外测量表明，通过氨基甲酸酯连接基释放CO成功实现了解笼。这种脱羧反应构成了解笼反应的限速步骤，且发生在亚秒时间尺度上。因此，DEACM-嘌呤霉素是一种用于细胞内应用的高效光激活抗生素。
