The design, synthesis, spectroscopic and photochemical properties, and biological evaluation of a novel molecular hybrid that is able to deliver nitric oxide (NO) into mitochondria are reported. This molecular conjugate unites a tailored o‐CF₃‐p‐nitroaniline chromophore, for photo‐regulated NO release, and a rhodamine moiety, for mitochondria targeting, in the same molecular skeleton via an alkyl spacer. A combination of steady‐state and time‐resolved spectroscopic and photochemical experiments demonstrate that the two chromogenic units preserve their individual photophysical and photochemical properties in the conjugate quite well. Irradiation with violet light triggers NO release from the nitroaniline moiety and photoionization in the rhodamine center, which also retains considerable fluorescence efficiency. The molecular hybrid preferentially accumulates in the mitochondria of A549 lung adenocarcinoma cells where it induces toxicity at a concentration of 1 μm, exclusively upon irradiation. Comparative experiments, carried out with ad‐hoc‐synthesized model compounds, suggest that the phototoxicity observed at such a low concentration is probably not due to NO itself, but rather to the formation of the highly reactive peroxynitrite that is generated from the reaction of NO with the superoxide anion.

中文翻译：

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用于线粒体靶向NO光传递的分子杂交体

报道了能够将一氧化氮（NO）传递到线粒体中的新型分子杂种的设计，合成，光谱和光化学性质以及生物学评估。该分子共轭物将定制的o‐ CF ₃ ‐ p结合在一起硝基苯胺生色团用于光调节NO的释放，罗丹明部分用于线粒体靶向，通过烷基间隔子在同一分子骨架中。稳态和时间分辨光谱与光化学实验的结合表明，这两个生色单元在共轭物中能很好地保留其各自的光物理和光化学性质。紫光照射触发NO从硝基苯胺部分释放并在若丹明中心发生光电离，这也保留了相当大的荧光效率。分子杂交体优先聚集在A549肺腺癌细胞的线粒体中，并在1μm的浓度下诱导毒性，仅在辐射下。使用临时合成的模型化合物进行的比较实验表明，在如此低的浓度下观察到的光毒性可能不是由于NO本身，而是由于NO反应生成的高反应性过氧亚硝酸盐的形成。与超氧阴离子。