| Thuja sutchuenensis of Cupressaceae Thuja, evergreen tree, is a living fossil derived from the age of dinosaurs; it is also a Chinese unique world-class rare and endangered plant. According to reports, Thuja sutchuenensis roots, stems, leaves contain thujopsene,α-pinene, limonene terpenoids and other components, most of which have functions like anti-oxidation, antibacterial, anti-cancer, anti-hypertension, expelling insect, diuresis, anti-inflammatory, expectorant and health improving. Thuja sutchuenensis root were chosen as tested materials in this experiment. The extraction methods, chemical composition and biological activity of Thuja sutchuenensis essential oil were studied, aiming at providing a theoretical reference basis for expanding plantation and application of Thuja sutchuenensis. The study results are as follows. 1.Three extraction and process optimization of Thuja sutchuenensis essential oilSD extraction method was applied to extract essential oil from Thuja sutchuenensis and the extraction conditions were optimized by orthogonal tests. The optimization of process were:liquid-to-solid ratio:9:1, soaking time:2h, extracting time:4h, NaCl concentration:4%, essential oil extraction rate is 2.32% under this condition. SFE-CO2 method was applied as well and the optimized process were:filling coefficient:0.68, the extraction pressure and temperature:20MPa and 50℃, dynamic time:60min, static time: 30 min, essential oil extraction rate is 7.26% under this condition. SX extraction method optimized by:solvents:petroleum ether, extracting time:3h, extraction temperature:55℃, ratio between solvent and material:20:1, essential oil extraction rate is 7.83% under this condition.2. Study on the chemical composition of Thuja sutchuenensis essential oilThe effective components from Thuja sutchuenensis essential oil extracted by three methods were determined with GC-MS. The results indicate that by SD,42 kinds of components are separated and 31 components are identified among them. The main chemical constituents are cedrol (62.28%), thujopsene (8.06%), cuparene (6.07%), ethyl vanillate (5.03%). By SFE-CO2 method,55 kinds of components are separated and 36 components are identified among them. The main chemical constituents are cedrol (27.74%), thujopsene (22.41%), longifolene (7.9%), cuparene (7.32%). By SX,37 kinds of components are separated; accordingly 23 components are identified among them, with the main chemical constituents of cedrol (28.45%), thujopsene (28.36%), alloaromadendrene (9.07%) and cuparene (8.83%).3. Study on antimicrobial activity of Thuja sutchuenensis essential oilThe antibacterial experiment in vitro shows that the Thuja sutchuenensis essential oil has inhibitory effete on Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Aspergillum niger, Aspergillus flavus, Penicillium glaucum. The inhibiting order of the Thuja sutchuenensis essential oil was E.coil> B.subtilis> S.aureus> A.niger> A.flavus> P.glaucum. To E.coil, S.aureus, B.subtilis, P.glaucum, A.niger, A.flavus, the minimum inhibition concentrations (MIC) of thuja sutchuenensis essential oil extracted by SD are 2.5, 10,5,20,10, 10μL/mL. By SFE-CO2 are 2.5,5,5,20,10, 10μL/mL and by SX are 5,10, 10,20,10, 10μL/mL, respectively.4. Study on antioxidant activity of Thuja sutchuenensis essential oilAntioxidant activity of Thuja sutchuenensis essential oil was studied by three kinds of models in vitro. Thuja sutchuenensis essential oil has DPPH radical scavenging ability. The tested IC50 of essential oil to DPPH was 5.81mg/mL by SD,4.45mg/mL by SFE-CO2 and 6.85mg/mL by SX. Thuja sutchuenensis essential oil has reducing ability that was assessed by method of potassium ferricyanide. Also, Thuja sutchuenensis essential oil has inhibitory activity of β-carotene bleaching. The tested IC50 of essential oil to P-carotene bleaching inhibitory activity were 2.44mg/mL by SD,1.18 mg/mL by SFE-CO2 and 2.06mg/mL by SX. |
PDF Full Text Request