Cytotoxic profile study, DNA and protein binding activity of a new dinuclear nickel(II) thiocyanato complex

Abstract

One new binuclear Ni(II) complex with the molecular formula [Ni₂(L)₂(SCN)₂(μ-SCN)₂] (1) has been synthesized using a tridentate Schiff base ligand (L), formed by the condensation between quinoline-2-carboxaldehyde and N,N-dimethylethylenediamine. Complex 1 was characterized by FT-IR, UV-vis, and ESI-mass spectroscopy techniques, as well as elemental analysis, cyclic voltammetry, and single-crystal X-ray crystallography. The X-ray diffraction analysis of 1 indicated a centrosymmetric complex with nickel(II) centers in a distorted octahedral geometry and double bridged by thiocyanate anions via end-to-end (μ-1,3) fashion. The interaction of 1 with CT-DNA was explored by UV-vis and fluorescence spectroscopy, viscosity and cyclic voltammetry which indicated a moderate intercalation of the complex with CT-DNA. The protein binding study of 1 with BSA and HSA was investigated by various spectroscopic methods and indicated a static quenching process. In addition, 1 showed prominent in vitro cytotoxic activity against human melanoma (A375) and human breast carcinoma (MDA-MB-231) cell lines under the identical condition with IC₅₀ value of 149.06 and 124.22 µM, respectively.

Graphical Abstract

Keywords:

• Nickel(II)
• Schiff base complex
• X-ray crystal structure
• DNA/protein binding
• cytotoxicity

Supplementary data

CCDC 2132600 contains the supplementary crystallographic data for 1. These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html, or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; Fax: [phone]; or E-mail: [email protected]. Supplementary data associated with this article can be found in the online version.

Acknowledgements

N. Biswas acknowledges CSIR, New Delhi, Govt. of India, for awarding junior research fellowship (Project No. 01/2537/11-EMR-II).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

C. Roy Choudhury acknowledges DST-FIST (Project No. SR/FST/CSI-246/2012) New Delhi, Govt. of India for instrumental support under capital heads.