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 .