F16 is a mitochondria-targeted, broad-spectrum anticancer agent in the pre-clinic cancer therapy. Here we developed two fluorescent isomers of F16 (o-F16 and m-F16) with entirely different photophysical properties, uncoupling activity, and cytotoxicity by merely modifying the linking orientation of pyridinium and indole units. Individually, o-F16 acted as a strong uncoupler to reduce the mitochondrial respiration efficiency, while m-F16 could hardly uncouple the mitochondrial respiration due to its poor proton dissociation capability. Owing to their intrinsic fluorescence, o-F16 and m-F16 could specifically image mitochondria in the green and red channel, respectively. This work could provide useful information for the development of uncouplers and design of mitochondrial-targeted drugs.

F16是在临床前癌症治疗中针对线粒体的广谱抗癌药。在这里，我们通过仅修饰吡啶鎓和吲哚单元的连接方向，开发了两种具有完全不同的光物理性质，解偶联活性和细胞毒性的F16荧光异构体（o-F16和m-F16）。单独地，o-F16充当降低线粒体呼吸效率的强解偶联剂，而m-F16由于质子解离能力差而几乎无法解耦线粒体呼吸。由于其固有的荧光，o-F16和m-F16可以分别在绿色和红色通道中分别对线粒体成像。这项工作可以为开发解偶联剂和设计针对线粒体的药物提供有用的信息。