Process Optimization Of Solvent-free Microwave Extraction Of Essential Oil From The Leaves Of Eucalyptus Globulus And Research On Its Antifungal And Antioxidant Activity

In this study, the leaves of Eucalyptus globulus as raw materials, studying the extraction technology of E. globulus’s leaves essential oil to optimize the extraction process. Then, GC-MS was used to analyze the component of the essential oil and the relative content of each component. On such basis, its antioxidant capabilities were detected in terms of 1,1-Diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and β-Carotene, linoleic acid bleaching assay. The antibacterial activities of the essential oil were evaluated against the three species of Fusarium. According to MTT method, research the inhibition of essential oils on the proliferation of murine macrophages Raw264.7. At the same time, in order to achieve efficient use of waste, to optimization of the extraction conditions of the active ingredients (Gallic acid and Ellagic acid). The primary coverage was as follows.1.The use of solvent-free microwave extraction (SFME) method for the essential oil of E. globulus’s leaves, through kinetic model to compared with other traditional method. In addition, solvent-free microwave-assisted screening of single factor experiment, by the Response Surface Analysis to optimum extracting conditions. The extraction condition was developed for the essential oil of E.globulus’s leaves with solvent-free microwave extraction method:moisture content 59.7%, extraction time 22 min and microwave power 575 W. Under the optimum conditions, the maximum extraction yield of 6.6 ml/kg.2. GC-MS methods to determinate the chemical component from the essential oil of E. globulus’s leaves, and the results of chemical component analysis. GC conditions:a capillary column(30mx0.25mmcx0.25 μm), manual injection 1μl; injector temperature,270℃;carrier gas (He) flow 1ml/min; splitless; oven temperature programmed 40℃ to 165℃ at a rate of 10℃/min, from 165℃ to 200℃ at a rate of 5℃/min and 200℃ to 250℃ at a rate of 10℃/min. The detector temperature was 280℃.The MS was operated under 70 eV, scan range 15-500 amu, scan-TIC.The chemical compositions of essential oils were identified by direct comparison of their mass spectral pattern in NIST02 Mass Spectral Library. The main components of the essential include 1,8-cineole, a-terpineol and a-terpineol acetate.3.DPPH radical scavenging experiments, iron reduction ability test and β-carotene and linoleic acid bleaching experiments were investigated to study the antioxidant activity of essential oil extracted from different extraction methods, and compared with the natural antioxidants Vc and Ve.The antioxidant activity of essential oil extracted from SFME was better than that from HD.4. The antimicrobial activity of the essential oil from E. globulus’s leaves against Fusarium culmorum, F. avenaceum, F. solani var coeruleum was investigated. Two of the more sensitive strains are F.sporotrioides and F. culmorum, the minimum inhibitory concentration (MIC) are 1.25μl/mL and 0.75μl/mL. The killing curve reflects the antibacterial effect of the essential oil within the concentration-dependent relationship.5. Test the inhibition rate of the essential oil on the proliferation of cell by the method of MTT. The proliferation rate of the cell is lower after the affection of the essential oil, the essential oil caused the inhibition of cell proliferation in the selected concentration range, and the inhibition increased as the mass increased, cell viability (67.18±0.06)%.6.The residue extracted with Microwave-assisted extraction of Gallic acid and Ellagic acid to optimize the best conditions:ethyl alcohol absolute 40%, liquid-solid ratio 40:1mL·g-1, soaking time 2h, microwave irradiation power 385W, microwave irradiation time 30 min and the extraction 1 times. These conditions, the Gallic acid and Ellagic acid content of 3.15mg/g and 3.44mg/g.