The antibacterial activity of the synthesized dyes 3a–e was evaluated
using Staphylococcus aureus (SA), Micrococcus luteus (ML), Escherichia
coli (EC) and Pseudomonas aeruginosa (PS). The bacteria were grown
on nutrient agar plates and aseptically transferred to 3 mL of nutrient
broth. After overnight growth at 37 °C, 50 μL of the suspension was
transferred on to nutrient agar plates and spread on the surface using
a sterile spreader. Wells were bored in to the agar using sterile Pasteur
pipette ends. Concentrations of 30 μg/mL of synthesized compounds
were prepared in DMF. To each well 40 μL of the sample solution
(12 μg/well) was added. After incubation overnight at 37 °C, zones of
inhibition were measured. Penicillin and tetracycline disks were used
as positive controls.