Ultrabright and Serum-Stable Squaraine Dyes

J Med Chem. 2020 Sep 10;63(17):9436-9445. doi: 10.1021/acs.jmedchem.0c00617. Epub 2020 Aug 19.

Abstract

Highly stable symmetric and asymmetric squaraine fluorophores have been synthesized featuring an internal salt bridge between a quaternary ammonium cation and the central oxycyclobutenolate ring of the chromophore. Some of our newly synthesized symmetric and asymmetric compounds display increased molar absorptivity, quantum yield in serum, and thermal/photochemical stability over previously reported squaraine-based dyes. Consequently, both classes show great promise in resurfacing the normal environment-labile squaraine dyes as novel imaging agents and scaffolds for fluorescence sensing. Furthermore, incorporating a covalent attachment point away from the conjugated system allows for biological tagging applications without disturbing the optimum optical characteristics of the newly designed fluorophore.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cyclobutanes / blood
  • Cyclobutanes / chemistry*
  • Cyclobutanes / pharmacokinetics
  • Fluorescent Dyes / chemistry*
  • Fluorescent Dyes / metabolism
  • Fluorescent Dyes / pharmacokinetics
  • Mice
  • Models, Molecular
  • Molecular Conformation
  • Phenols / blood
  • Phenols / chemistry*
  • Phenols / pharmacokinetics
  • Serum / metabolism*
  • Tissue Distribution

Substances

  • Cyclobutanes
  • Fluorescent Dyes
  • Phenols
  • squaraine