Molecular recognition in naphthoquinone derivatives - G-quadruplex complexes by NMR
Journal article, 2015

Background: G-quadruplexes have become important drug-design targets for the treatment of various human disorders such as cancer, diabetes and cardiovascular diseases. Recently, G-quadruplex structures have been visualized in the DNA of human cells and appeared to be dynamically sensitive to the cell cycle and stabilized by small molecule ligands. A small library of isoxazolo naphthoquinones (1a-h), which exhibited a strong antiproliferafive activity on different cancer cell lines, was studied as potential ligands of G-quadruplex DNA. Methods: The DNA binding properties of a series of the selected compounds have been analyzed by fluorescence assays. NMR/modeling studies were performed to describe the complexes between G-quadruplex DNA sequences and two selected compounds 1a and 1b. Results: 1a and 1b in the presence of G-quadruplexes, d(T(2)AG(3)T)(4), d(TAG(3)T(2)A)(4) and d(T(2)G(3)T(2))(4), showed good ability of intercalation and the formation of complexes with 2:1 stoichiometry. 1a showed an important interaction with the sequence Pu22 belonging to the promoter of oncogenes c-myc. Conclusions: The ligands directly interact with the external G-tetrads of the G-quadruplexes, without alterations in the structure of the G-quadruplex core. The role of the adenine moieties over the G-tetrads in the stabilization of the complexes was discussed. General significance: The results obtained suggested that the strong antiproliferative activity of isoxazolo naphthoquinones is not due to the Hsp90 inhibition, but mainly to the interaction at the level of telomeres and/or at the level of gene promoter. These findings can be used as a basis for the rational drug design of new anticancer agents.

Molecular modeling

DNA-binding drugs

Isoxazolo naphthoquinone

NMR studies



B. Riva

University of Milano-Bicocca

Raphael Ferreira

Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology

L. Musso

University of Milan

R. Artali

L. Scaglioni

University of Milan

S. Mazzini

University of Milan

Biochimica et Biophysica Acta - General Subjects

0304-4165 (ISSN) 18728006 (eISSN)

Vol. 1850 4 673-680

Subject Categories


Bioinformatics and Systems Biology



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