Chemical Constituents in Essential Oils from Elsholtzia ciliata and Their Antimicrobial Activities

Objective To compare the chemical constituents in the essential oils from the leaves, flowers, and seeds of Elsholtzia ciliata and their antimicrobial activities. Methods The chemical constituents in essential oils were extracted by the hydro-distillation method and analyzed by GC-MS. The chemical constituents in essential oils were identified on the basis of comparison on their retention indices and MS spectrum with published data. Moreover, the antimicrobial activities of the chemical constituents in the oils against the growth of six bacteria strains and one pathogenic yeast strain were evaluated by using minimum inhibitory concentration and minimum bactericidal concentration methods. Results A total of 58 compounds were identified, while compounds 31, 35, and 36 were identified in the essential oils from the leaves, flowers, and seeds, respectively. Fifteen compounds were identified as shared constituents in the leaves, flowers, and seeds. The chemical constituents in the essential oils showed the inhibitory activities against the six bacteria strains and the yeast strain. Conclusion The major constituents are different in the essential oils of the leaves, flowers, and seeds. The major chemical constituents in the essential oils are monoterpenoids and sesquiterpenoids. And the chemical constituents in the essential oils obtained from the leaves show higher inhibitory activities especially against Bacillus subtillis CMCC63501 and Escherichia coli ATCC25922.