Curcumin Knoevenagel's Schiff Base as a Promising Stabilizer of G-Quadruplex Structure

Area of Science:

• Medicinal Chemistry
• Molecular Biology
• Biophysics

Background:

• G-quadruplex DNA in promoter and telomere regions are cancer therapeutic targets.
• Curcumin derivatives are explored for G-quadruplex binding and cancer apoptosis induction.

Purpose of the Study:

• Synthesize and evaluate a novel curcumin Schiff base ligand (Sb-NBC) as a G-quadruplex binder.
• Compare the binding affinity and G-quadruplex stabilizing properties of Sb-NBC with its parent compound (NBC).
• Assess the selective cytotoxicity of Sb-NBC against cancer cells.

Main Methods:

• Synthesis of the Schiff base ligand Sb-NBC from L-tryptophan and 4-nitrobenzylidene curcumin (NBC).
• Spectroscopic and biophysical techniques to study G-quadruplex binding.
• Thermal denaturation assays to determine G-quadruplex stabilization.
• Cytotoxicity assays on cancer and normal cell lines.

Main Results:

• The Sb-NBC ligand demonstrated higher binding affinity to promoter and telomere G-quadruplex sequences than NBC.
• Sb-NBC significantly stabilized parallel and hybrid G-quadruplex topologies (10.5°C-6.4°C).
• Sb-NBC exhibited selective cytotoxicity, targeting cancer cells more effectively than normal cells.

Conclusions:

• Curcumin Schiff base ligands, like Sb-NBC, are potent G-quadruplex binders.
• Sb-NBC shows promise as a therapeutic agent for cancer by targeting G-quadruplex DNA.
• This study supports the application of curcumin Schiff bases in cancer therapy for oncogene regulation.