Boswellic acids, as novel inhibitor targeting peptidoglycan biosynthetic enzyme UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) in Escherichia coli.

UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) is an essential cytosolic enzyme in the biosynthesis of peptidoglycan. It becomes a potential bacterial target for screening promising antibacterial compounds as it is associated with the early phases of peptidoglycan production. MurA enzyme is conserved and necessary for bacterial viability with no mammalian homolog, which is a well-proven therapeutic research target. The present study reports the natural compounds from Boswellia serrata targeting the MurA enzyme. The identified inhibitors against MurA Escherichia coli (E. coli): β-boswellic acid (IC50 33.65 µM), Acetyl-β-boswellic acid (IC50 30.17 µM), and Acetyl-11-keto-β-boswellic acid (IC50 37.67 µM). Inhibitors showed a fourfold decrease in IC50 values on pre-incubation with substrate-UDP-N-acetyl-glucosamine (UDP-GlcNAc). Mode-of-inhibition studies revealed their uncompetitive nature with both the substrates. Although these boswellic acids have been explored for their pharmacological potential, this is the first study reporting these compounds' E. coli MurA inhibiting potential.