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Updated: Jul 14, 2026

Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
9-Substituted berberine derivatives as G-quadruplex stabilizing ligands in telomeric DNA
Wan-Jin Zhang1, Tian-Miao Ou, Yu-Jing Lu
1School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
Abstract:
The interaction of berberine and its 9-substituted derivatives with human telomeric DNA d[G(3)(T(2)AG(3))(3)](telo21) has been investigated via CD spectroscopy, fluorescence spectroscopy, PCR-stop assay, competitive dialysis, and telomerase repeat amplification protocol (TRAP) assay. The results indicated that these semisynthesized compounds could induce and stabilize the formation of anti-parallel G-quadruplex of telomeric DNA in the presence or absence of metal cations. Compared with berberine, the 9-substituted derivatives exhibit stronger binding affinity with G-quadruplex and higher inhibitory activity for telomerase. Introduction of a side chain with proper length of methylene and terminal amino group to the 9-position of berberine would significantly strengthen the binding affinity with G-quadruplex, resulting in increasing inhibitory effects on the amplification of telo21 DNA and on the telomerase activity.
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