A phytochemical investigation of Leucas aspera involved the isolation of flavones and steroids, along with triterpenoids. The identified chemical constituents were characterized as baicalein, baicalein-7-O-β-D-glucuronide, lup-20(29)-ene-3α,23-diol, β-sitosterol, and stigmasterol. Notably, baicalein (4) and baicalein-7-O-β-D-glucuronide (5) demonstrated significant antimicrobial activity at a low minimum inhibitory concentration against Staphylococcus aureus, Pseudomonas fluorescens, and Escherichia coli. Meanwhile, lup-20(29)-ene-3α,23-diol, β-sitosterol, and stigmasterol displayed moderate antimicrobial activity against all the screened microorganisms. Further analysis showed that baicalein-7-O-β-D-glucuronide had a strong docking score of -5.78 kcal/mol, indicating its robust interaction with E. coli DNA gyrase, which aligns with the in vitro findings. Additionally, baicalein-7-O-β-D-glucuronide exhibited in silico ADME (absorption, distribution, metabolites, and excretion) properties similar to those of tetracycline.
Keywords: Antimicrobial activity; Baicalein-7-O-β-D-glucuronide; lup-20(29)-ene-3αc23-diol.