Background: In previous reports, the antibacterial properties of certain tetrazole derivatives
have been described. We have previously reported the antibacterial properties of aryl 1Htetrazole
Objective: To study the antibacterial activity of 5-substituted heteroaryl, vinyl, benzyl, and alkyl
Methods: The antibacterial properties of heteroaryl, vinyl, benzylic, and aliphatic tetrazole derivatives
were investigated against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.
The activity was assessed by determining the minimum inhibitory concentration of these
tetrazole derivatives and comparing them to the known antibiotics amoxicillin, trimethoprim and
Results: The tetrazole compounds were prepared utilizing cerium(III) chloride heptahydrate catalysis
at 160 °C for 1-4 h in a microwave reactor using an aqueous solvent mixture. The most active
derivatives exhibited minimum inhibitory concentration values between 125-250 µg/mL
against Escherichia coli. More importantly, these compounds were considerably more active when
used in combination with trimethoprim and a significant synergistic effect was observed (MIC =
0.98-7.81 µg/mL) against E. coli and S. aureus.
Conclusion: The tetrazole derivatives were synthesized in high yield and short reaction times in
water. Several of the tetrazole compounds showed a significant synergistic antibacterial effect
when used with trimethoprim.