Chemical Composition and Antibacterial Activity of Essential Oils from Six Lamiaceae Species Native to the Republic of Tatarstan

Lamiaceae plants are valued for their organoleptic and biological properties, with extensive use in food, fragrance, and pharmaceutical sectors. The escalating spread of antibiotic resistance threatens global public health, stimulating the search for novel antimicrobial agents, particularly plant-derived essential oils. This study analyzes essential oils obtained by hydrodistillation from six Lamiaceae species native to the Republic of Tatarstan: Betonica officinalis L., Clinopodium vulgare L., Lamium maculatum L., Salvia tesquicola Klokov & Pobed., Salvia verticillata L., and Stachys sylvatica L. Gas chromatography–mass spectrometry (GC–MS) revealed significant sesquiterpenoid diversity, with concentrations up to 45% in S. tesquicola. Dominant constituents were caryophyllene oxide (18.2%) and fatty acids (38.5%) in S. tesquicola; hexadecanoic acid (20.6%) and β-caryophyllene (4.63%) in S. verticillata; hexadecanoic acid (27.9%) and 1-octen-3-ol (8.6%) in C. vulgare; methyl salicylate (22.2%) in L. maculatum; 1-octen-3-ol (13.6%) in B. officinalis; and 1-octen-3-ol (35.8%) in S. sylvatica. All oils exhibited antibacterial activity against pathogenic microorganisms. Notably, L. maculatum oil showed the highest activity against Staphylococcus aureus (MIC 1.25 mg/mL), whereas C. vulgare oil was potent against the Gram-negative bacterium Pseudomonas aeruginosa (MIC 1.25 mg/mL). These results confirm the significant antibacterial potential of the studied essential oils. The unique chemical profile and pronounced efficacy of C. vulgare oil against P. aeruginosa underscore its promise for novel, plant-based antiseptic formulations.