OBJECTIVETo investigate the antimicrobial activity in vitro and chemical composition of essential oil from lavender extracted by supercritical CO2 extraction (SFE-CO2) process and hydrodistillation.

METHODThe antimicrobial activities against 4 bacteria and 4 fungi strains of these two oils were evaluated by using the agar disc diffusion and agar dilution method to determine the inhibition zone, minimal inhibitory concentration (MIC) and minimal bactericidal/fungicidal concentration (MBC/MFC). A GC-MS method was established to determine the chemical components of essential oils.

RESULTThese two oils presented remarkable antimicrobiat activities against all tested strains in vitro. Compared with the hydrodistillation product, SFE-CO, oil showed better antimicrobial activity against either bacteria or fungi of which MIC values were 0.63-3.33 g x L(-1) and the MBC/MFC values were 1.04-5.00 g x L(-1). By GC-MS analysis, 34 and 29 compounds identified cover 95.51% and 98. 39% of total peak area of substances appeared. The main differences between SFE-CO2 oil and hydrodistillation oil were the amounts of linalyl acetate and 5-methyl-2-(1-methylethenyl)-4-hexen-1-ol acetate.

CONCLUSIONResults presented here may suggest that the essential oil of lavender extracted by SFE-CO2 possesses has better antimicrobial properties, and therefore it is a potential source of antimicrobial ingredients for pharmaceutical industry.