Solid-phase fluorescent BODIPY-peptide synthesis via in situ dipyrrin construction.

Area of Science:

• Chemical Synthesis
• Bioconjugation
• Medicinal Chemistry

Background:

• Traditional fluorescent peptide synthesis is limited by specific amino acids and multiple purification steps.
• Developing efficient methods for creating fluorescent peptide conjugates is crucial for biomedical applications.

Purpose of the Study:

• To develop a facile and efficient protocol for in situ construction of dipyrrins on peptides.
• To enable direct formation of boron-dipyrromethene (BODIPY)-peptide conjugates without pre-functionalization.

Main Methods:

• Utilized Fmoc-based solid-phase peptide synthesis for in situ dipyrrin construction.
• Employed simple aldehyde and pyrrole derivatives for BODIPY conjugation.
• Performed a single-time chromatographic purification for the final product.

Main Results:

• Successfully synthesized BODIPY-peptide conjugates using 20 natural and five unnatural amino acids.
• Demonstrated intact in vitro selectivity and responsive fluorescence enhancement in a model peptide (BODIPY1-Pep4).
• Achieved higher phototoxicity due to photo-generated singlet oxygen.

Conclusions:

• The novel strategy provides a practical synthetic platform for fluorescent peptides.
• This method simplifies the synthesis of BODIPY-peptide conjugates, reducing costs and complexity.
• The developed fluorescent peptides show potential for multifaceted biomedical applications, including targeted cancer therapy.