Synthesis, structure, DNA binding and anticancer activity of a new tetranuclear Pb(II) complex constructed by 8-hydroxyquinolinate and 4-nitrobenzoate ligands

• Main Authors: Lv Lu-Lu, Xia Wei-Min, Cheng Yuan-Zheng, Zhang Li-Ping, Wang Xue-Dong
• Format: Article
• Language: English
• Published: De Gruyter 2019-06-01
• Series: Main Group Metal Chemistry
• Subjects: pb(ii); 8-hydroxyquinolinate; 4-nitrobenzoate; crystal structure; dna-binding; anticancer activity
• Online Access: https://doi.org/10.1515/mgmc-2019-0006

A new Pb(II) complex, [Pb(8-OQ)(4-NB)], where 8-OQ = 8-hydroxyquinolinate, 4-NB = 4-nitrobenzoate, has been synthesized and characterized by elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction. The single crystal X-ray analysis reveals that the complex possesses a tetranuclear Pb4O4 cubane structure. The Pb(II) atom is coordinated by three triply bridging phenolic hydroxyl O atoms of 8-OQ ligands, then the tetranuclear Pb system is formed resulting in a tetrahedral cage. The interaction of complex with HS-DNA in Tris buffer was studied by UV−vis absorption spectrum and fluorescence ethidium bromide displacement experiment with an intrinsic binding constant of 1.52×104 M-1 and a linear Stern–Volmer quenching constant of 6.77×103 M-1. Anticancer activity against MCF-7, HepG-2 and A549 cell lines of complex was also determined by the MTT-based assay. The results showed the complex can inhibit proliferation of these three kinds of tumor cells and is less cytotoxic than cisplatin.