GlycoBODIPYs: Sugars Serving as a Natural Stock for Water-soluble Fluorescent Probes of Complex Chiral Morphology

A range of unprocessed, reducing sugar substrates (mono-, di-, and trisaccharides) is shown to take part in a straightforward four-step synthetic route to water-soluble, uncharged BODIPY derivatives with unimpaired chiral integrity and high fluorescence efficiency. A wide compatibility with several postfunctionalizations is demonstrated, thus suggesting a universal utility of the multifunctional glycoconjugates, which we call GlycoBODIPYs. Knoevenagel condensations are able to promote a red-shift in the spectra, thereby furnishing strongly fluorescent red and far-red glycoconjugates of high hydrophilicity. The synthetic outcome was studied by X-ray crystallography and by comprehensive photophysical investigations in several solvent systems. Furthermore, cell experiments illustrate efficient cell uptake and demonstrate differential cell targeting as a function of the integrated chiral information.

Automated summary

The study demonstrates a straightforward synthetic route to water-soluble, uncharged BODIPY derivatives using unprocessed reducing sugar substrates, showing high fluorescence efficiency and compatibility with various postfunctionalizations. The Knoevenagel condensations result in red and far-red fluorescent glycoconjugates with high hydrophilicity, and the synthetic outcome is confirmed through X-ray crystallography and photophysical investigations. Cell experiments further illustrate efficient cell uptake and differential cell targeting based on chiral information integration.