Extraction Technology And Bioactivity Research Of Volatile Components From E.urophylla×E.Gr-Andis(Guanglin9)

There are large area of E. Urophylla×E. Grandis（Guanglin9） plantation growing innorth and central of Guangxi province because of its fast-growing, straight trunk and coldtolerance. The antibacterial activity, antioxidant activity and repellent activity of essentialoils were investigated. The chemical composition and biological activity of essential oilsat different period in distillation process were also investigated.（1） The antibacterial activities of essential oil from leaves of Eucalyptusurphylla×E.grandis（Guanglin9） against bacteria （Staphylococcus aureus, Bacillussubtilis, Escherichia coil）, filamentous fungi （Aspergillus flavus, Aspergillus niger,Penicillum citrinum） was tested using a paper disk method and agar dilution method. Theresult indicated that the essential oils have moderate activity against the examinedpathogens. The minimum inhibitory concentrations （MICs） of essential oil was rangedfrom10²0mg/mL for bacteria and5¹0mg/mL for fungi. The data obtained from discdiffusion method（DDs） were ranged from9.5mm to16.8mm for bacteria and9.7¹7.5mm for fungi. Penicillum citrinum was the most sensitive fungi tested with thelowest MIC value,5mL/L.The essential oil showed stronger activity against the testedfungi. than the bacteria.（2） The antioxitive activity of the essential oil from leaves of Eucalyptusurophylla×E.grandis（Guanglin9） was assessed by DPPH· radical scavenging assays.IC₅₀value of scavenging ability on DPPH· radical for the essential oil was17.66mg/mL.IC₅₀value of scavenging abilities on DPPH· of α-Pinene, β-Pinene and1,8-Cineole were5.00mg/mL,77.18mg/mL and241.0mg/mL.（3） The essential oil from Eucalyptus urophylla×E.grandis（Guanglin9） was testedfor repellenency against Culex pipiens quinquefasciatus according to the nationalstandard of GB/T131917.9-2009. The effective protection time for human body againstCulex pipiens quinquefasciatus of essential oil9were7.5min,30min and135min withthe concentrateon of oil being12.5%,25.0%and50.0%.（4） Depending on the use, the essential oils from Eucalyptus urophylla×E.grandis，（Guanglin9） at0¹0min,10⁶0min in distillation process when the total distillation time1h were collected and analyzed. The yield of essential oil from the air-dried leaves at0¹0min was0.28mL/100g and the yield at10⁶0min was0.34mL/100g. Thecomposition of essential oil varied greatly with the distillation time. The relative contentof1,8-Cineole in the0¹0min oil fraction was54.892%and in the10⁶0min oil fractionwas34.506%.（5） The antibacterial activity, antioxidant and repellent activity of10⁶0min oilfraction was better than0¹0min oil fraction. The data obtained from disc diffusionmethod of0¹0min oil fraction against Bacillus subtilis, Staphylococcus aureus,Escherichia coil, aspergillus niger, penicillum citrinum, aspergillus flavus were12.9mm, 10.1mm,8.4mm,11.1mm,9.7mm and8.5mm while the result of10⁶0min oil fractionwere14.0mm,13.4mm,8.6mm,14.9mm,10.5mm and9.0mm. The MICs of0¹0min oilfraction and10⁶0min oil fraction were ranged from5mL/L to40mL/L for the examinedpathogens. The antioxidant capacity of10⁶0min oil fraction (IC₅₀=16.74mg/mL) wassignificantly higher than that of0¹0min oil fraction (IC₅₀=49.87mg/mL), which wasprobably due to the percentage of α-pinene in the composition. The effective protectiontime for human body against Culex pipiens quinquefasciatus of0¹0min oil fraction was48min with the concentration of essential oil being25.0%and143min with theconcentration of oil being50.0%. The effective protection time for human body againstCulex pipiens quinquefasciatus of10⁶0min oil fraction was60min with theconcentration of essential oil being25.0%and180min with the concentration of oilbeing50.0%.