Emission tuning of fluorescent kinase inhibitors: conjugation length and substituent effects

J Org Chem. 2014 Jun 6;79(11):4940-7. doi: 10.1021/jo500520x. Epub 2014 May 8.

Abstract

Fluorescent N-phenyl-4-aminoquinazoline probes targeting the ATP-binding pocket of the ERBB family of receptor tyrosine kinases are reported. Extension of the aromatic quinazoline core with fluorophore "arms" through substitution at the 6- position of the quinazoline core with phenyl, styryl, and phenylbutadienyl moieties was predicted by means of TD-DFT calculations to produce probes with tunable photoexcitation energies and excited states possessing charge-transfer character. Optical spectroscopy identified several synthesized probes that are nonemissive in aqueous solutions and exhibit emission enhancements in solvents of low polarity, suggesting good performance as turn-on fluorophores. Ligand-induced ERBB2 phosphorylation assays demonstrate that despite chemical modification to the quinazoline core these probes still function as ERBB2 inhibitors in MCF7 cells. Two probes were found to exhibit ERBB2-induced fluorescence, demonstrating the utility of these probes as turn-on, fluoroescent kinase inhibitors.

Publication types

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

MeSH terms

  • Adenosine Triphosphate / analogs & derivatives*
  • Adenosine Triphosphate / chemistry*
  • Adenosine Triphosphate / metabolism
  • Binding Sites
  • Fluorescent Dyes / chemical synthesis*
  • Fluorescent Dyes / chemistry*
  • Ligands
  • Phosphorylation
  • Protein Kinase Inhibitors / chemical synthesis*
  • Protein Kinase Inhibitors / chemistry*
  • Quantum Theory
  • Quinazolines / chemical synthesis*
  • Quinazolines / chemistry*
  • Receptor, ErbB-2 / antagonists & inhibitors*
  • Receptor, ErbB-2 / metabolism
  • Spectrometry, Fluorescence

Substances

  • Fluorescent Dyes
  • Ligands
  • N-phenyl-4-aminoquinazoline
  • Protein Kinase Inhibitors
  • Quinazolines
  • Adenosine Triphosphate
  • Receptor, ErbB-2