Unsymmetric indolylmaleimides: Synthesis, photophysical properties and amyloid detection

•Synthesis of various unsymmetric indolylmaleimides.•Unsymmetric indolylmaleimides having large Stokes shifts and different fluorescence emissions.•Unsymmetric indolylmaleimide detecting amyloid fibrils in senile systemic amyloidosis.

Various unsymmetric indolylmaleimides were synthesized. Their photophysical properties and affinities for amyloid fibrils were evaluated. Some unsymmetric indolylmaleimides have large Stokes shifts of more than 120 nm, fluorescence emission maxima wavelengths of more than 550 nm and different emissions under UV irradiation at 365 nm. From the results of histopathologic methods using stains, 3-(1H-indol-3-yl)-1-methyl-4-phenyl-1H-pyrrole-2,5-dione has high selectivity for amyloid fibrils in senile systemic amyloidosis.

Graphical abstractSome unsymmetric indolylmaleimides have large Stokes shifts of more than 120 nm, fluorescence emission maxima wavelengths of more than 550 nm and different emissions under UV irradiation at 365 nm. 3-(1H-indol-3-yl)-1-methyl-4-phenyl-1H-pyrrole-2,5-dione detects amyloid fibrils in senile systemic amyloidosis.Figure optionsDownload full-size imageDownload as PowerPoint slide