Chemical composition and antimicrobial activity of essential oils from six lavender (Lavandula angustifolia Mill.) cultivars

The present study aimed to determine the chemical composition and in vitro antimicrobial potential for the first time of essential oils (EOs) from six cultivars (Druzhba, Raya, Hebar, Hemus, Yubileina, Sevtapolis) of lavender (Lavandula angustifolia Mill.) cultivated in Türkiye (Tekirdağ) against a panel of pathogenic and non-pathogenic microorganisms. The chemical composition of EOs, analysed using gas chromatography/mass spectrometry (GC/MS), revealed 34 different components in the six cultivars. The results indicate that the main major constituents of all EOs were monoterpenoid linalool (47.60-64.13%) and linalyl acetate (12.92-26.08%). Based on principal component analysis (PCA) cvs. Druzhba, Raya and Hebar were situated in the centre right quadrant of the plot and were characterised by linalool and linalyl acetate in subgroup one. The results of antimicrobial assays revealed that lavender EOs were active against all strains of bacteria tested. For bacteria, the strongest activity of cv. Hemus was observed against Enterococcus faecalis (IZ = 19 ± 0.10 mm, MIC = MMC = 6.25 (µg/mL), while the weakest potency was seen against the gram-negative Salmonella enterica (IZ = 21 ± 1.00 mm, MIC = MMC = 31.25 (µg/mL). Based on PCA, the first subgroup of cvs. Hebar and Raya was characterised by Lactobacillus rhamnosus, E. faecalis and Lactobacillus pentosus and was situated in the bottom right quadrant of the plot.