Isolation, characterization, and antibacterial activities of bioactive compounds from the methanolic leaf extracts of Thymus vulgaris

Thymus vulgaris L. (Lamiaceae) is cultivated in Ethiopia and is traditionally used to treat ailments such as gonorrhoea, cough, and hypertension. This study investigated the methanolic leaf extract of T. vulgaris for phytochemicals and antibacterial activity. Preliminary screening revealed the presence of tannins, phenols, flavonoids, steroids, and terpenoids. A triterpenoid compound was isolated and structurally characterised using IR, 1H NMR, 13C NMR, and DEPT-135 techniques. The compound was identified as Betulin (lup-20(29)-ene-3,28-diol), which is being reported here for the first time from T. vulgaris. Antibacterial activity of the crude extract, assessed via agar-well diffusion, showed dose-dependent inhibition against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive), with higher efficacy against E. coli. These findings support the plant’s traditional use and suggest that T. vulgaris may serve as a promising source of natural antimicrobial agents.