Design of a mononuclear copper(II)-phenanthroline complex: Catechol oxidation, DNA cleavage and antitumor properties. (26th February 2016)

• Record Type: Journal Article
• Authors: Dey, Dhananjay; Das, Subrata; Yadav, Hare Ram; Ranjani, Anandan; Gyathri, Loganathan; Roy, Sanjay; Guin, Partha Sarathi; Dhanasekaran, Dharumadurai; Choudhury, Angshuman Roy; Akbarsha, Mohammad Abdulkader; Biswas, Bhaskar
• Is Part Of: Polyhedron. Volume 106(2016)
• Page Start: 106
• Page End: 114
• Publication Date: 2016-02-26
• Subjects: Copper(II) -- Crystal structure -- Catecholase activity -- DNA cleavage -- Antitumor activity; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2015.12.055
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: A mononuclear copper(II) complex [Cu(phen)(OH2 )2 (NO3 )](NO3 ) (1 ) has been evaluated as model system for the catechol oxidase enzyme by using 3, 5- di -tert-butylcatechol (DTBC) as the substrate in methanol medium, revealing that1 exhibits greater catalytic activity with K cat value 3.91 × 10 3 h −1 . The complex cleaves the double strand of pBR 322 plasmid DNA in a concentration-dependent manner and is cytotoxic to the human hepatocarcinoma cell HepG2. Abstract: A mononuclear copper(II) complex [Cu(phen)(OH2 )2 (NO3 )](NO3 ) (1 ) [phen = 1, 10-phenanthroline] has been synthesized and structurally characterized by different spectroscopic characterization methods including single crystal X-ray diffraction study. X-ray crystal structure analysis shows that1 adopts square pyramidal geometry with CuN2 O3 chromophore and the molecule crystallises in P 21 / n space group.1 has been evaluated as model system for the catechol oxidase enzyme by using 3, 5 -di -tert-butylcatechol (DTBC) as the substrate in methanol medium, revealing that1 exhibits greater catalytic activity with K cat value 3.91 × 10 3 h −1 compared to a few copper(II) complexes of the same class. Electrochemical analysis suggests that the mononuclar Cu(II) complex mimics the catechol oxidase enzyme in methanolic medium through radical pathway. The complex cleaves the double strand of pBR 322 plasmid DNA in a concentration-dependent manner so as for the DNA to change from super coiled form to both nicked circular and linear forms. The complex is cytotoxic to the human hepatocarcinoma cell HepG2, as revealed in MTT assay. AO/EB and Hoechst 33528 fluorescent staining techniques were used to find the mode of cell death. Interestingly, AO/EB and Hoechst stained cells observed at IC50 concentration shows that1 brings about conformational change on DNA to induce apoptosis which would be the basis underlying its cytotoxic property.