Syntheses, characterization, DNA/HSA binding ability and antitumor activities of a family of isostructural binuclear lanthanide complexes containing hydrazine Schiff base

Abstract

Three dinuclear lanthanide complexes, [Ln₂(L)₂(μ₃-OAc)₄(H₂O)₂]⋅2H₂O (Ln = La (1), Eu (2) and Dy (3), HL = N’-(2-hydroxybenzylidene) nicotinohydrazide), have been synthesized and characterized by IR, elemental analysis and X-ray single-crystal diffraction. Crystallographic study revealed that the representative complex 1 displays a discrete dinuclear structure with a distorted tricapped trigonal prismatic geometry around La(III) ion. The interaction of complexes 1–3 with CT-DNA was investigated by absorption spectra, fluorescence quenching and viscosity, which reveals that the complexes bind to CT-DNA with a moderate intercalative mode. The complexes exhibited obvious DNA cleavage activities in the presence of H₂O₂. All complexes could bind to human serum albumin (HSA) with medium affinity through static mode; thus, HSA could effectively transport complexes. Furthermore, three complexes exhibited specific cytotoxicity to A549 cancer cells in micromole magnitude than other cancer cells tested and less toxicity than cisplatin for normal human cells HUVEC, in which massive cell apoptosis was induced by complexes through producing DNA damage and suppressing DNA synthesis.

Communicated by Ramaswamy H. Sarma

Keywords:

• Lanthanide-based anticancer agent
• hydrazine
• DNA interaction
• HSA binding
• A549 cell

Disclosure statement

There are no conflicts of interest to declare.

Data availability statement

The data that support the findings of this study are available on request from the corresponding authors [C.Z. X and J.Y. X] upon reasonable request.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [No. 21371135, 21401141] and Tianjin Municipal Natural Science Foundation [No. 17JCZDJC33100, 18JCYBJC91300].