The capability of three quaternized styryl-azinium iodides to bind cellular RNA has been tested by means of Fluorescence Confocal Microscopy imaging of stained MCF-7 cells treated with RNase. Their association constants have been estimated through spectrophotometric and fluorimetric titrations with tRNA and compared to their affinity toward DNA. Transient absorption spectroscopy with femtosecond resolution confirmed the binding of the investigated compounds with tRNA and shed new light on the excited state dynamics of their complexes, by revealing a significant lengthening of the lifetime of S₁ upon complexation, which parallels the fluorescence quantum yield enhancement.

中文翻译：

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季铵化苯乙烯基叠氮基荧光团作为细胞RNA结合剂

三种季铵化的苯乙烯基叠氮化碘化物结合细胞RNA的能力已通过荧光共聚焦显微镜成像法对经RNase处理的染色MCF-7细胞进行了测试。它们的缔合常数已经通过tRNA的分光光度法和荧光滴定法进行了估算，并与它们对DNA的亲和力进行了比较。飞秒分辨率的瞬态吸收光谱法证实了所研究化合物与tRNA的结合，并通过揭示络合后S ₁的寿命显着延长而与复合物的激发态动力学相吻合，这与荧光量子产率的提高相平行。