In vitro antibacterial activity of betulinic acid from Psidium guajava L

Abstract

Utilizing chromatography and spectroscopic methods, 3-hydroxy-lup-20(29)-ene-28-oic acid or betulinic acid was isolated from Psidium guajava leaf extract and its structure was identified by spectroscopic methods. The minimum inhibitory concentration (MIC), was determined in vitro against Klebsiella pneumoniae, Bacillus pumilus, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa by a microdilution method. Betulinic acid showed MIC of 0.025 and 0.056 mg/ml against Staphylococcus aureus and P. aeruginosa and this was comparable to the standard drug neomycin with an MIC of 0.072 mg/ml.