Issue 39, 2022

Self-reporting styrylthiazolium photopharmaceuticals: mitochondrial localisation as well as SAR drive biological activity

Abstract

Novel photoswitches offering features complementary to the well-established azobenzenes are increasingly driving high-precision research in cellular photopharmacology. Styrylthiazolium (StyTz) and styrylbenzothiazolium (StyBtz) are cellularly untested E/Z-isomerisation photoswitches which are nearly isosteric to azobenzenes, but have distinct properties: including ca. 60 nm red-shifted π → π* absorption, self-reporting fluorescence, ZE relaxation on typical biological timescales, and decent solubility (positive charge). We tested StyTz and StyBtz for their potential as photopharmaceutical scaffolds, by applying them to photocontrol microtubule dynamics. They light-specifically disrupt microtubule network architecture and block cell proliferation: yet, testing lead compound StyBtz2 for its molecular mechanism of action showed that it did not inhibit microtubule dynamics. Using its self-reporting fluorescence, we tracked its localisation in live cells and observed accumulation of E-StyBtz2 into mitochondria; during prolonged illumination, it was released into the cytosol, and blebbing and cell death were observed. We interpret this as light-dependent rupturing of mitochondria on acute timescales. We conclude that StyTz/StyBtz can be interesting photopharmaceutical scaffolds for addressing mitochondrial, rather than cytosolic, targets.

Graphical abstract: Self-reporting styrylthiazolium photopharmaceuticals: mitochondrial localisation as well as SAR drive biological activity

  • This article is part of the themed collection: New Talent

Supplementary files

Article information

Article type
Paper
Submitted
18 Feb 2022
Accepted
25 Sep 2022
First published
26 Sep 2022

Org. Biomol. Chem., 2022,20, 7787-7794

Self-reporting styrylthiazolium photopharmaceuticals: mitochondrial localisation as well as SAR drive biological activity

L. Gao, Y. Kraus, A. Stegner, T. Wein, C. Heise, L. von Brunn, E. Fajardo-Ruiz, J. Thorn-Seshold and O. Thorn-Seshold, Org. Biomol. Chem., 2022, 20, 7787 DOI: 10.1039/D2OB00347C

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