Pyrene-nucleobase conjugates: synthesis, oligonucleotide binding and confocal bioimaging studies

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Biophysical Chemistry

Background:

• Development of fluorescent probes for biological applications.
• Understanding the self-assembly of nucleobase conjugates.
• Investigating structure-property relationships in fluorescent molecules.

Purpose of the Study:

• Synthesize and characterize fluorescent pyrene-linker-nucleobase conjugates.
• Evaluate their photochemical and self-assembly properties.
• Assess their potential for biological imaging.

Main Methods:

• Organic synthesis of pyrene-nucleobase conjugates.
• X-ray single-crystal structure analysis.
• Photochemical characterization (fluorescence spectroscopy).
• Oligonucleotide binding studies (UV-Vis spectroscopy).
• Confocal microscopy in living HeLa cells.

Main Results:

• Synthesis and characterization of thymine and adenine conjugates.
• Structure-dependent fluorescence: hydroxy linkers are stronger emitters than carbonyl linkers.
• Adenine derivative 5 shows significant self-assembly with single- and double-stranded DNA templates.
• Compound 5 exhibits dual-staining in HeLa cells, localizing in mitochondria and nucleoli.

Conclusions:

• Fluorescent pyrene-nucleobase conjugates possess tunable fluorescence properties.
• Derivative 5 demonstrates effective DNA binding and potential as a dual-targeting bioimaging agent.
• The study highlights the interplay between molecular structure, self-assembly, and cellular localization.