2-Styrylindolium based fluorescent probes visualize neurofibrillary tangles in Alzheimer’s disease

Conjugated, trans‐Spanning Ligands as Models for Multivalent p‐Phenyleneethynylenes

“…We recently reported that 2,3,3‐trimethyl indolinium derivatives can visualize NFTs in AD brain sections,21 and to continue with this, here we report trimethine cyanines of 2,3,3‐trimethyl indolinium as more sensitive and benign probes to stain NFTs in human tissues. One of the major tasks was to improve solubility and decrease toxicity; these probes might be employed to visualize tau deposits in the olfactory epithelium of AD patients for the noninvasive diagnosis of the disease in the early stages.…”

“…In previous work, IC 50 values were determined from the results of a competition assay rather than K i values 19. 21 The in vitro aggregates of Aβ 40 and Aβ 42 display differences in the binding sites for amyloid ligands, which depend on the aggregation conditions and differ from the binding situation observed in human tissue. Thus we selected Aβ 40 for the aggregation assay as it is the predominant component in amyloid plaques and thus likely to be engaged in binding of the probes.…”

Design, Synthesis and Biological Evaluation of Trimethine Cyanine Dyes as Fluorescent Probes for the Detection of Tau Fibrils in Alzheimer’s Disease Brain and Olfactory Epithelium

“…However, replacement of the alkyl chain substituents on the nitrogen atom by PEG chains ( 5 d and 5 e ) gave rise to a decrease in cLog P value and an increase in aqueous solubility (>0.5 g L −1 in distilled water at 25 °C). The solubility of established imaging agents, such as [ 18 F]FDDNP, methoxy‐X04 and 2‐[(4‐methylamino)phenyl]quinoline (BF‐158), is in the same range or inferior to the solubility of these trimethine cyanine derivatives 21. Moreover, PEGylated probes 5 d and 5 e displayed decreased cytotoxicity in comparison with alkyl derivatives 5 b and 5 c .…”

Surfactant-modulated discriminative sensing of HNO and H2S with a Cu2+-complex-based fluorescent probe

“…18 Finally, hemicyanine was incorporated into the fluorophore via Knoevenagel condensation to provide the desired probe HCD. 19 The structure of HCD and intermediates were determined by 1 H, 13 C NMR and high resolution mass spectroscopies (see supporting information). In addition, the chelated complex CuHCD was facilely prepared by addition of aqueous CuCl 2 to HCD solution, 6b and the 1:1 stoichiometry was confirmed by mass spectrometry and fluorescence titration, indicating that there was only one copper ion binding site in the sensor molecule.…”