title: Hydroxylated Fluorescent Dyes for Live-Cell Labeling: Synthesis, Spectra and Super-Resolution STED.
abstract: Hydroxylated rhodamines, carbopyronines, silico- and germanorhodamines with absorption maxima in the range of 530-640 nm were prepared and applied in specific labeling of living cells. The direct and high-yielding entry to germa- and silaxanthones tolerates the presence of protected heteroatoms and may be considered for the syntheses of various sila- and germafluoresceins, as well as -rhodols. Application in stimulated emission depletion (STED) fluorescence microscopy revealed a resolution of 50-75 nm in one- and two-color imaging of vimentin-HaloTag fused protein and native tubulin. The established structure-property relationships allow for prediction of the spectral properties and the positions of spirolactone/zwitterion equilibria for the new analogues of rhodamines, carbo-, silico-, and germanorhodamines using simple additive schemes.
authors.affiliation: Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry (MPIBPC), Am Fassberg 11, 37077, Göttingen, Germany.
authors.forename: Alexey N
authors.initials: AN
authors.lastname: Butkevich
authors.affiliation: Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry (MPIBPC), Am Fassberg 11, 37077, Göttingen, Germany.
authors.forename: Vladimir N
authors.identifier: http://orcid.org/0000-0002-7741-4653
authors.initials: VN
authors.lastname: Belov
authors.affiliation: Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry (MPIBPC), Am Fassberg 11, 37077, Göttingen, Germany.
authors.forename: Kirill
authors.initials: K
authors.lastname: Kolmakov
authors.affiliation: Department of Chemistry, St. Petersburg State University, Universitetskiy Pr. 26, 198504, St. Petersburg, Russia.
authors.forename: Viktor V
authors.initials: VV
authors.lastname: Sokolov
authors.affiliation: Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry (MPIBPC), Am Fassberg 11, 37077, Göttingen, Germany.
authors.forename: Heydar
authors.initials: H
authors.lastname: Shojaei
authors.affiliation: Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry (MPIBPC), Am Fassberg 11, 37077, Göttingen, Germany.
authors.forename: Sven C
authors.initials: SC
authors.lastname: Sidenstein
authors.affiliation: Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry (MPIBPC), Am Fassberg 11, 37077, Göttingen, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Kamin
authors.affiliation: German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.
authors.forename: Jessica
authors.initials: J
authors.lastname: Matthias
authors.affiliation: German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.
authors.forename: Rifka
authors.initials: R
authors.lastname: Vlijm
authors.affiliation: German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.
authors.forename: Johann
authors.initials: J
authors.lastname: Engelhardt
authors.affiliation: Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry (MPIBPC), Am Fassberg 11, 37077, Göttingen, Germany.
authors.forename: Stefan W
authors.identifier: http://orcid.org/0000-0002-9638-5077
authors.initials: SW
authors.lastname: Hell
keywords: dyes/pigments; fluorescence; living cells; optical microscopy; rhodamines