Five novel benzoxazolium and benzothiazolium derived asymmetric dicationic monomethine cyanine dyes, bearing a thioester group have been synthesised via condensation of quaternary nitrogen containing heterocyclic salts in various anhydrides. Their chemical structures were evaluated by NMR, ESI/MS, IR spectroscopy, and melting point temperatures. Photophysical studies on the title compounds were performed in methanol solutions. The longest wavelength absorption maxima λ_max of the studied dyes are in the region 453–508 nm. The corresponding fluorescence maxima λ_fl were registered within the 489–553 nm. Further spectroscopy and calorimetric techniques including circular dichroism (CD), UV–Vis, fluorescence, thermal denaturation and isothermal titration calorimetry have been applied to the studied dyes in the presence of biopolymers, in order to evaluate their staining ability as fluorescent markers. In aqueous solution the compounds exhibit no intrinsic fluorescence, however upon binding to dsDNA and dsRNA they show considerable enhancement of fluorescence intensity. Binding constants Ks of the complexes [dye–polynucleotide] have been evaluated from fluorescence spectral titrations. Although the intercalation is the predominant binding mode, the compounds show little or no effect on the cell proliferation. Upon fast cell internalization the compounds accumulate in the mitochondrial space.

通过将含季氮原子的杂环盐在各种酸酐中缩合，合成了五种新颖的苯并恶唑鎓和苯并噻唑鎓衍生的带有硫酯基的不对称双单甲亚基花青染料。通过NMR，ESI / MS，IR光谱和熔点温度评估了它们的化学结构。在甲醇溶液中进行了标题化合物的光物理研究。最长波长的吸收最大值λ_最大所研究的染料的是在该区域453-508纳米。对应的荧光最大值_λfl记录在489–553 nm范围内。为了评估它们作为荧光标记物的染色能力，已将进一步的光谱学和量热技术（包括圆二色性（CD），UV-Vis，荧光，热变性和等温滴定量热法）应用于研究的染料。在水溶液中，这些化合物不显示固有的荧光，但是与dsDNA和dsRNA结合后，它们显示出明显的荧光强度增强。结合常数Ks络合物[染料-多核苷酸]的含量已通过荧光光谱滴定法进行了评估。尽管插入是主要的结合方式，但是这些化合物对细胞增殖几乎没有影响。快速细胞内化后，化合物积聚在线粒体空间中。