Synthesis and characterization of heterobimetallic Sn^IV–Cu^II/Zn^II complexes: DFT studies, cleavage potential and cytotoxic activity

Abstract

Heterobimetallic complexes [Cu(L)Sn(CH₃)₂(H₂O)(Cl)] (3) and [Zn(L)Sn(CH₃)₂(H₂O)(Cl)] (4) have been synthesized from their monometallic analogs [Cu(L)(H₂O)(Cl)] (1) and [Zn(L)(H₂O)(Cl)] (2) of Schiff base ligand (L) which were characterized by various spectroscopic and analytical methods. DFT calculations were carried out to simulate the vibrational spectra to support the anticipated structures. The interaction studies of ligand (L) and complexes (1–4) with CT–DNA were performed by employing UV–vis, and fluorescence spectroscopic techniques which revealed that heterobimetallic complexes 3 and 4 showed higher affinity with DNA due to dual mode of action as compared to monometallic complexes 1 and 2. Further, validation of the interaction studies was accomplished by carrying out molecular docking studies with DNA. Gel assay displayed that both the complexes have ability to cleave DNA efficiently and are specific minor groove binders. Cu^II–Sn^IV complex 3 cleaved pBR322 DNA via oxidative mechanism, while Zn^II–Sn^IV complex 4 followed hydrolytic cleavage pathway. In vitro cytotoxicity evaluation of complex 3 was tested on a different cancer cell lines showing promising antitumor activity.

Communicated by Ramaswamy H. Sarma

Keywords:

• Heterobimetallic complexes
• DFT
• in vitro DNA interaction studies
• molecular docking
• anticancer activity

Acknowledgement

We are also thankful to the Department of Chemistry, Aligarh Muslim University for providing Instrumentation facility supported by DST–PURSE, DST–FIST programme and DRS–1I (SAP) from UGC, New Delhi, India.

Disclosure statement

The authors declare that there is no conflict of interests.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

The authors are grateful to the Deanship of Scientific Research, King Saud University, for funding through Vice Deanship of Scientific Research Chairs.