Chemical Composition, Antibacterial Activity of the Essential Oil from Roots of <i>Radix aucklandiae</i> against Selected Food-Borne Pathogens

Radix aucklandiae from Yunnan Province in China is a significant medicinal plant. In the present study, the essential oil composition from Radix aucklandiae roots was investigated by gas chromatography-mass spectrometry (GC-MS). A total of 23 compounds representing 57.95% of the essential oil were tentatively identified. The main constituents were eremanthin (12.74%), d-Guaiene (6.26%), ζ-Himachalene (6.16%) and l-Caryophyllene (4.84%). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the essential oil from R. aucklandiae were evaluated against three Gram-positive bacteria (Staphylococcus aureus, Staphylococcus albus and Bacillus subtilis) three Gram-negative bacteria (Salmonella typhimurium, Escherichia coli and Shigella dysenteriae). Results revealed that the essential oil exhibited significant in vitro antimicrobial property. Among all the tested microorganisms, the essential oil showed the strongest inhibitory effect against S. typhimurium. The data of this study suggests that the essential oil from Radix aucklandiae has great potential for application as a natural antimicrobial agent to preserve food.