Structural Elucidation of 2-(6-(Diethylamino)benzofuran-2-yl)-3-hydroxy-4H-chromen-4-one and Labelling of Mycobacterium aurum Cells

Trehalose conjugates of 3-hydroxychromone (3HC) dyes have previously been utilized as fluorescence labels to detect metabolically active mycobacteria with a view facilitating point-of-care detection mycobacterial pathogens, especially Mycobacterium tuberculosis. We subjected the 3HC dye 2-(6-(diethylamino)benzofuran-2-yl)-3-hydroxy-4H-chromen-4-one (3HC-2) combined X-ray crystallography and density functional theory (DFT) study, conducted preliminary labelling experiments model organism aurum. In crystal, 3HC-2 exhibits an s-cis conformation chromone benzofuran moieties about central C–C bond. According DFT calculations, conformer is 1.8 kcal mol−1 lower in energy than s-trans conformer. The solid-state supramolecular structure features hydrogen-bonded dimers π…π stacking. Fluorescence microscopy revealed M. aurum cells treated trehalose conjugate 3HC-2-Tre GFP channel. It was concluded that preferred generally considered non-pathogenic can be labelled probe for convenient vitro drug screening new antimycobacterial agents.