Physicochemical investigation and fluorescence quenching of biologically active pyrrole-containing push-pull chromophore by Ag nanoparticles

An efficient, one pot, multicomponent synthesis of 4-[(1- methyl -1 H - pyrrol -2- yl ) methylidene ]-2-phenyl-1,3oxazol-5(4 H )-one (MPMO) from 1-methylpyrrole-2-carbaldehyde, hippuric acid ( N -Benzoylglycine), and NaOAc in acetic anhydride has been developed. The solvatochromic properties viz . Stokes shift, excitation coefficient, and fluorescence quantum yield for MPMO has been explored by recording its absorption and emission spectra in solvents of varied polarities. When the solvent polarity varies from less-polar (n-hexane) to highly polar (dimethyl sulfoxide, DMSO), the emission and absorption maximum show red shift. Interaction of MPMO with the CTAB and SDS could be used for the determination their critical micellar concentration (CMC). Further, fluorescence quenching of MPMO with colloidal silver nanoparticles (AgNPs) was observed and the Stern-Volmer quenching rate constant (K sv ) in ethanol and ethane-1,2diol (glycol), was determined to be 1.43 x 10 8 M - 1 and 1.32 x 10 8 M - 1 respectively. The antibacterial activity of MPMO was evaluated against Gram-positive and Gram-negative bacterial strains and results showed the compound MPMO good antibacterial agent against Gram-negative bacteria. (c) 2022 Published by Elsevier B.V.

Automated summary

An efficient one-pot synthesis of MPMO was developed using 1-methylpyrrole-2-carbaldehyde, hippuric acid, and NaOAc. The solvatochromic properties of MPMO were investigated by studying its absorption and emission spectra in solvents of different polarities. MPMO showed a red shift in emission and absorption maximum as the solvent polarity increased. The interaction of MPMO with CTAB and SDS was used to determine their critical micellar concentration. Additionally, fluorescence quenching of MPMO by AgNPs and its antibacterial activity against Gram-negative bacteria were observed.