[feed] Atom [feed] RSS 1.0 [feed] RSS 2.0

Bera, Pradip and Brandão, Paula and Mondal, Gopinath and Santra, Ananyakumari and Jana, Abhimanyu and Mokhamatam, R.B. and Manna, S.K. and Mandal, T.K. and Bera, Pulakesh (2019) An unusual iminoacylation of 2-amino pyridyl thiazole: Synthesis, X-ray crystallography and DFT study of copper(II) amidine complexes and their cytotoxicity, DNA binding and cleavage study. Polyhedron, 159. pp. 436-445. ISSN 0277-5387

[img] Text
Polyhedron 159 p436.pdf
Restricted to Repository staff only

Download (1656Kb) | Request a copy

Abstract

Insertion of acetonitrile in the exocyclic NH2 group of the thiazole unit of 2-amino-4-(2-pyridyl)thiazole (HL) in the presence of copper chloride results in the formation of the monomeric amidine complex [Cu{LC(Me)=NH)}Cl2] (1). The same reaction of HL and copper(II) perchlorate yields the complex [Cu(HL)2](ClO4)2 (2), without acetonitrile insertion. However, the presence of a spacer donor, e.g. pyrazine, in the reaction medium results in the formation of a dinuclear amidine derivative, [(ClO4){LC(Me)=NH}Cu(μ-pyrazine)Cu{LC(Me)=NH}(ClO4)] (ClO4)2 (3). Complexes 1 and 3 are the first examples of copper assisted iminoacylation of 2-amino pyridylthiazole derivatives, confirming a nitrile to amidine transformation. The new complexes were characterized by single crystal X-ray crystallography, cyclic voltammetry and a DFT study. The complexes have a potential cytotoxic effect in human monocytic cells (U937) with IC50 values ranging from 0.84 to 4.5 μM. Significant necrotic activities are ascertained by a lactate dehydrogenase (LDH) enzyme release assay. The interaction with calf thymus (CT) DNA shows the binding constant (Kb) values are ∼ 104 M−1. The chemical nuclease activity of 1, 2 and 3 result in 65, 99 and 80% relaxation of supercoiled DNA at 10 μM in the presence of glutathione (GSH, 1 mM), respectively. The study with radical scavengers proved that a hydroxyl or singlet oxygen-like species is responsible for the DNA degradation.

Item Type: Article
Depositing User: Dr P Divakar
Date Deposited: 28 Dec 2018 07:00
Last Modified: 22 Jan 2019 05:36
URI: http://cdfd.sciencecentral.in/id/eprint/875

Actions (login required)

View Item View Item