Synthesis and Properties of Novel Hemicyanine Dye-β-Cyclodextrin

A series of novel hemicyanine dye-β-cyclodextrin compounds： mono-6-deoxy-β-cyclodextrin-6-[p-（p-substituted styryl）pyridium] p-totylfulfonates were synthesized by the condensation of mono-6-deoxy-β- cyclodextrin-6-（p-methyl pyridinium） p-toluenesulfonate with （un）substituted benzaldehydes. Their structures were established by 1^H NMR, IR, UV-Vis and elemental analysis. The absorption and fluorescence properties of the novel compounds were measured in solution and the photostability of a selected hemicyanine dye-β-cyclodextrin compound was also investigated.

A sulfur-substituted hemicyanine for cancer photothermal therapy without influence of intracellular viscosity

Although photothermal therapy(PTT) has emerged as an appealing strategy for cancer treatment, the development of photothermal agents capable of precisely controlling temperature remains a challenge. In this paper, we present a novel synthetic photosensitizer based on a sulfur-substituted hemicyanine. It was discovered that replacing an oxygen atom in a hemicyanine derivative with a sulfur atom significantly enhances photothermal efficiency and enables lysosome targeting in cancer cells.More importantly, because of the rigid planer structure of the sulfur-substituted hemicyanine, which differs from traditional photothermal agents(PTAs) based on twisted intramolecular charge transfer(TICT) or group rotation mechanisms, the efficiency of photothermal conversion is not affected by intracellular viscosity, allowing precise temperature control during PTT.Further modifying the agent with a glutathione-responsive moiety allows the PTAs to be activated only in cancer cells. The newly proposed PTA achieves efficient PTT in a tumor-bearing mouse model while having negligible toxic side effects on healthy tissues.

Dual Spectroscopic Responses of Pyridinium Hemicyanine Dyes to Anions

The absorption and fluorescence spectroscopic responses of three pyridinium hemicyanine dyes to anions F , Cl , Br , I-, H2P02, HS04 and OAc- were investigated. At lower concentrations of OAc- （less than 1 equiv.）, both the absorption and the fluorescence intensities of 1--3 were more effectively changed than F at iden- tical concentrations. At higher concentrations of OAc （more than 1 equiv.）, the interaction was opposite for each compound. 1H NMR results indicated the interaction between 1, 2 or 3 and F- proceeded through hydrogen bonding. The results showed that these dyes are promising to develop dual fluorescence and chromogenic chemo- sensors toward F- and OAc- according to the subtle difference in the affinity of F and OAc .

Aggregation Control of Hemicyanine Fluorescent Dye by Using of Cucurbit[7]uril and Pillar[6]arene

The aggregation of cyanine-based fluorescent dyes easily results in the fluorescence quenching,which limits the applications in biological science and materials science.So developing an efficient method to adjust the aggregation of cyanine dyes is very significant.In this work,we employ two different macrocyclic hosts pillar[6]arene(DEP[6])and cucurbit[7]uril(CB[7])to investigate their effects towards fluorescence spectra of dye 1.The result indicates that both of them can disrupt the aggregation of dye 1,resulting in the enhancement of its fluorescence intensity.Interestingly,investigation on the corresponding titration experiments of 1H NMR and density functional theory cal-culations shows that CB[7]and DEP[6]play different roles in the process of disaggregation.