Extraction And Antibacterial Effect Of The Essential Oils From Eupatorium Adenophorum Spreng

Objective: Eupatorium adenophorum Spreng is an Eupatoriumjaponicum genus of the tribe Compositae grown in Mexico andJamaica as well as South and Southweast in China,which causedserious harm to agriculture and animal husbandry. Previous studiesshowed that E. adenophorum had a good antibacterial activity onmites, aphids, Ralstonia solanacearum and Candida albicans. However,few studies were reported about antibacterial effect of essential oilsfrom E. adenophorum. This study was designed to extract and separateessential oils from E. adenophorum and primarily observe theantibacterial effect.Methods: The method of steam distillation was used to extractessential oils from the leaf and tender stalk of E. adenophorum.β-elemene was separated by silica gel column chromatography andsilver ion coordination chromatography from essential oils. The level ofβ-elemene was measured by HPLC. The molecular structure ofβ-elemene was validated by the methods of UV，IR，1H-NMR,¹³C-NMR and HRMS.Antibacterial effect of essential oils from E. adenophorum（EAEO）against Staphylococcus aureus, Escherichia coli and Candida albicanswere detected by disk diffusion method. The minium inhibitoryconcentration （MIC） of EAEO against Staphylococcus aureus wasmeasured by tube double dilution method.Electrical conductivity detection, growth curve observation,SDS/PAGE electrophoresis and DAPI staining assay were used toprimarily explore antibacterial mechanism of EAEO againstStaphylococcus aureus.Results: The content of β-elemene in the E. adenophorum isabout0.497%. The antibacterial effect of EAEO againstStaphylococcus aureus was strongest. The antibacterial effect ofEAEO against Candida albicans was stronger than that of Escherichiacoli. The MIC of EAEO against Staphylococcus aureus is200μl/mL.After treated with EAEO, electrical conductivity, growth curve,SDS/PAGE and DAPI staining of Staphylococcus aureus obviouslychanged.Conclusions: The method of steam distillation for extraction ofessential oils from the leaf and tender stalk of E. adenophorum is simple and feasible. Volatile oil from Eupatorium adenophorum hasobvious antibacterial activity against Staphylococcus aureus. Theantibacterial mechanism of EAEO may involve in affecting cellmembrane integrity, soluble protein and nucleic acid synthesis ofStaphylococcus aureus.