Antimicrobial activity of Thuja occidentalis essential oils and extracts

The steam distillation method was used to obtain samples of essential oil of cultivars with a columnar and spherical shape of the crown Thuja occidentalis introduced in the Republic of Belarus. More than 26 components have been identified and determined in the essential oil of Thuja occidentalis by gas-liquid chromatography. The dominant components are α-thujone (∼55–60 %), β-thujone (∼10–12 %), fenchone (∼8–16 %), sabinene (∼1–5 %), camphor (∼1–4 %), bornylacetate (∼1–3 %). Distributions of terpenoid enantiomers in the essential oil of Thuja occidentalis cultivars are shown. The antimicrobial activity of Thuja occidentalis essential oils was detected in relation to test cultures of gram-positive and gram-negative bacteria. Bacterial cultures were more sensitive to the inhibitory effect of essential oil samples from plants with a spherical crown shape. The influence of the optical activity of camphor on the essential oil antimicrobial properties is shown. It has been established that alcohol extracts of Thuja occidentalis are inferior to essential oils in terms of antimicrobial activity. The effect of the crown shape and the color of the studied cultivar needles on their antioxidant properties is shown.