Abstract
A series of novel fluorescent 5,7-dihydroxy-4-propyl-2H-chromen-2-one derivatives (2a-j) were synthesized and were found to absorb around 322 and 410 nm. All compounds except the nitro-containing compound exhibited emission wavelengths around 450 nm with good fluorescence quantum yields (Phi(F)). Their antimicrobial activity was investigated and tested against several human pathogen Gram-positive, Gram-negative bacteria and fungi as well as mycobacterium using agar well diffusion method and minimum inhibitory concentrations were reported. All compounds showed significantly potent antimicrobial activities against most bacterial strains compared to reference drugs. Due to their structural similarity to reference drugs clorobiocin and novobiocin, the docking experiments in the ATP binding pocket of DNA gyrase B enzyme revealed that the compounds mostly have the same binding mode as the reference drugs. Moreover, the cytotoxic activity was also evaluated against four different human cell lines and exhibited more potency than the reference drug.