Antimicrobial Properties of Essential Oils of the Monarda Genus Plants Cultivated in Belarus

The essential oils obtained by hydrodistillation from the Monarda genus plants cultivated in Belarus were investigated. Using the technique of gas-liquid chromatography, essential oil components were identified and quantified. The dominant components of the essential oils were thymol (up to 27%), carvacrol (up to 29%), γ-terpinene (up to 22%), and p-cymene (up to 35%). The distribution of dominant components of Monarda essential oil depending on the plant chemotype and the method of plant material preparation was shown. Antimicrobial activity of Monarda essential oil against Gram-positive and Gram-negative bacteria test cultures was revealed. Gram-positive bacterial cultures were more sensitive to the inhibitory effect of Monarda essential oils. Antimicrobial properties of dominant components (thymol, carvacrol, γ-terpinene, and p-cymene) were investigated. The effect of dominant component concentration on the antimicrobial properties of Monarda essential oils was established.