Catalytic oxidative coupling of o-phenylenediamine, in-vitro antibacterial and antitumor activities of a gold(III)-bipyridine complex

In the perspective of underdeveloped high-valent late-transition metal complexes mediated homogeneous catalysis in oxidative coupling of substrates and designing of metallo-therapeutics, this research study demonstrates the synthesis, structural description, bio-mimics of phenazine oxidase activity and in-vitro antibacterial as well as antiproliferative activity of a mononuclear aurum(III) complex, [Au(bpy)Cl-2]NO3 (1) [bpy = 2,2'-bipyridine]. The crystal structure analysis of 1 reveals that Au(III) center adopts a nearly perfect square planar geometry and theoretical calculations agree well with the structural features. Examination of the catalytic fate for Au(III) complex towards oxidative coupling of o-phenylenediamine (OPD) in methanol displays a good catalytic activity with high turnover number, k(cat) = 6.75 x 10(2) h(-1). The cytotoxic effect of 1 against human lung cancer cell line (A549) is assessed through changes in morphologies observed in different fluorescent staining methods as well as MTT assay. The experimental outcomes ensure that most of the cell destruction of A549 occurs by apoptosis mode. Antibacterial activity of 1 against pathogenic bacteria is examined through the nature of variation in mitochondrial trans-membrane potential and depolarization pattern which suggests that destruction of mitochondrial membrane drives the development of antibacterial properties. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study demonstrates the synthesis, structural description, bio-mimics, and in-vitro biological activities of a mononuclear aurum(III) complex. The complex showed strong cytotoxic effects against human lung cancer cells and exhibited potent antibacterial activity against pathogenic bacteria by destroying mitochondrial membranes.