Chemical composition and antibacterial activity of Tussilago farfara (L.) essential oil from Quebec, Canada

The chemical composition of Tussilago farfara L. essential oil from the Saguenay-Lac-St-Jean region of Quebec, Canada was analyzed by gas chromatography-flame ionisation detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS), and the antibacterial activity of the oil was tested against Escherichia coli and Staphylococcus aureus. Forty-five (45) compounds were identified from the GC profile. The main components were 1-nonene (40.1%), α-phellandrene (26.0%) and ρ-cymene (6.6%). The essential oil demonstrated antibacterial activity against E. coli (MIC₅₀ = 468 µg·mL^-1; MIC₉₀ = 6869 µg·mL^-1) and S. aureus (MIC₅₀ = 368 µg·mL^-1; MIC₉₀ = 773 µg·mL^-1). Dodecanoic acid was found to be active against both bacteria having a MIC₅₀ and MIC₉₀ of 16.4 µg·mL^-1 and 95 µg·mL^-1, respectively for E. coli and a MIC₅₀ and MIC₉₀ of 9.8 µg·mL^-1 and 27.3 µg·mL^-1, respectively for S. aureus. In addition, 1-decene and (E)-cyclodecene were also found to be active against E. coli.