Influence of the oxazole ring connection on the fluorescence of oxazoyl-triphenylamine biphotonic DNA probes

Org Biomol Chem. 2016 Jan 7;14(1):358-70. doi: 10.1039/c5ob02225h. Epub 2015 Nov 24.

Abstract

On the basis of our previous work on DNA fluorophores derived from vinylpyridinium-triphenylamine, we explored the structure space around the electron-rich triphenylamine (TP) core by changing the vinyl bond to an oxazole ring. As 2,5-diaryloxazoles are known to be highly fluorescent and efficient two photon absorbers, we synthesized analogues with two different connections of the oxazole to the triphenylamine core: TP-Ox2Py and TP-Ox5Py sets. Since the benzimidazolium group was proven to be more effective in the TP series than the pyridinium, we also synthesized a TP-Ox5Bzim set. The TP-Ox5Py series retains the TP-Py properties: on/off behavior on DNA, good two-photon cross-section and bright staining of nuclear DNA by microscopy under both one or two-photon excitation. On the other hand, the TP-Ox2Py series does not display fluorescence upon binding to DNA. The TP-Ox5Bzim set is fluorescent even in the absence of DNA and displays lower affinity than the corresponding TP-Ox5Py. CD experiments and docking were performed to understand these different behaviors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aniline Compounds / chemistry*
  • DNA / chemistry*
  • DNA Probes / chemistry*
  • Fluorescence*
  • Fluorescent Dyes / chemistry
  • Molecular Structure
  • Oxazoles / chemistry*
  • Photons*

Substances

  • Aniline Compounds
  • DNA Probes
  • Fluorescent Dyes
  • Oxazoles
  • DNA