Synthesis, characterization, antibacterial activity, and molecular docking of novel dicyanodihydrofuran-based push-pull fluorophores.

Abstract

Novel push-pull fluorescent molecules based on dicyanodihydrofuran that had marked molar extinction coefficients were created and described. The fluorophores were synthesized using the Knoevenagel condensation in arid pyridine at room temperature and acetic acid as a catalytic agent. In addition, a condensation reaction was performed for the activated methyl-containing dicyanodihydrofuran with a 3° amine-containing aromatic aldehyde. The molecular structures for the synthesized fluorophores were determined using various spectral techniques such as 1 H or 13 C nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy, and C, H, N analysis. Ultraviolet-visible (UV-vis) absorption and emission spectra of the prepared fluorophores revealed a high extinction coefficient, which was monitored to be affected by the type of the aryl (phenyl and thiophene)-vinyl bridge in conjugation with the 3° amine donor moiety. The substituents bonded to the tertiary amine, aryl, and alkyl groups, were found to affect the maximum absorbance wavelength. In addition, the synthesized dicyanodihydrofuran analogues were investigated to determine their antimicrobial effectiveness. Derivatives 2b, 4a, and 4b showed reasonable activity towards Gram-positive(+ve) bacteria rather than Gram-negative(-ve) bacteria relative to an amoxicillin drug reference. In addition, a molecular docking stimulation was performed to explore the binding interactions (PDB code: 1LNZ).