Xanthene dyes: Old scaffold offering new possibilities

                                            Peter Šebej

            RECETOX and Department of Chemistry, Faculty of Science, Masaryk university

                                        sebej@mail.muni.cz

Since the von Bayer synthesis of fluorescein in 1871 the synthetic dyes emerged as one of the most
successful fields of chemistry. Small molecule organic fluorophores are now essential tools in
molecular biology, medicine and material science. But the xanthene scaffold could also be turned
into a photoactivatable system allowing release of caged substrates as diverse as carboxylates,
phosphates and CO – all biologically relevant molecules.

In addition the xanthene moiety could be modified on four principal positions – two of them are
very well mapped, while the influence of the various functionalities positioned in the other two
are not so well explored. Our journey on mapping these unexplored areas of chemistry will be
discussed with the following examples: 9-Imido-pyronin analogues - small-molecule fluorophores with
large Stokes shifts and 9-Phenylethylene-pyronin analogues – dually addressable fluorophores.

The build chemical library of xanthene dyes also allows us to understand the structure-properties
relationship within the old xanthene scaffold and rationally design new xanthene analogues and
fine-tuning their photophysical properties.

References

Šebej P., Wintner J., Müller P., Slanina T., Al Anshori J., Antony L.A.P., Klán P., Wirz J.: J.
Org. Chem., 2013, 78(5), 1833–1843.

Antony L.A.P., Slanina T., Šebej P., Šolomek T., Klán P.: Org. Lett., 2013, 15(17), 4552–4555.

Pastierik T., Šebej P., Medalová J., Štacko P., Klán P: J. Org. Chem., 2014, 79 (8), 3374–3382.

Horváth P., Šebej P., Šolomek T., Klán P.: J. Org. Chem., 2015, 80 (3), 1299-1311.