| Camellia nitidssima has been used for tea by locals due to its medicinal value and no toxic side effect. Essential oil is widely distributed in plants, and it could be used as natural preservative, etc. In order to deeply investigate the C. nitidssima, its essential oil was extracted, and its chemical constituents were also isolated and identified in this dissertation.In this paper, the experiment mainly consists of three parts.In the first part, with C. chrysantha leaves as the research object, extraction technology was measured by essential oil extraction rate. Ultrasonic, vapor distillation and supercritical fluid extraction were explored to extract essential oil from C. chrysantha leaves, taking the influence of factors on the effect into account based on the single factor investigations. Then the optimum level of each factor was etermined, and oil extraction process was screened with high receiving rate. Results showed that the better essential oil extraction rate could be got by supercritical fluid extraction comparing with others. Then the optimum level of each method:(1)Vapor Distillation:Distillation time was 3 h, solid-liquid ratios was1:20, NaCl mass fraction was 4%; essential oil extraction rate was 0.031%; (2) Ultrasonic:the time of ultrasonic was 60 min, the temperature was 40 ℃, the power was 80 W,essential oil extraction rate was 0.039%; (3) Supercritical Fluid Extraction (SFE):the pressure was 15～18 MPa, the temperature was 45℃, the time was 1.5 h, essential oil extraction rate was 0.045%. Three methods were compared, and supercritical fluid extraction was better than the others for essential oil extraction rate. By response surface,the optimum levels of SFE were that the pressure was 18.81 MPa, the temperature was 47.84℃, the time wasl.7h. By GC-MC,10 compounds were identificatiedin essential oil, of with the majority is fatty acids.In the second part, with silica gel as stationary phase, organic extract was separated by column chromatography and detected by thin-layer chromatography. Because of the difficulties to separate the compounds with similar polarities, repeat column chromatography was needed to get pure compounds. Finally,21 compounds were obtained, that 11 compounds were obtained from petroleum ether extract and 10 compounds ethyl acetate extract, respectively.In the third section, pure compounds were detected by nuclear magnetic reso nance (NMR) and mass spectrum (MS). Firstly, the structure types of compounds mentioned above were determined according to MS and NMR spectrum. Next, the functional groups could be defined on the basis of characteristic spectral peaks. Finally, by analyzing data and comparing with the literatures, the structures of the se 21 compounds were identified. They are squalene (1)、cholesterol (2)、24-meth ylene-cholesterol (3)、24-hydroperoxy-24-vinyl-cholesterol (4)、ergosta-4,24(28)-dien-3-one (5)、ergosterol (6)、(24S)-5,28-stigmastadien-3β,24-diol (7)、(3β,5α,8α)-5,8-ep idioxyergost-6,22-dien-3-ol (8)、(3β,5α,8α)-5,8-epidioxyergost-6,24(28)-dien-3-ol (9)、 cholesta-3β-ol-5-en-7-one (10)、germacrene D (11)、a-amuurolene (12)、butyl isobu tyl phthalate (13)、diisobutyl phthalate (14)、trienol acetate (15)、dibutyl phthalate (16)、germacra-4(15)-5,10(14)-trien-1β-ol (17)、alismol (18)、ent-spathulenol (19)、 methyl indole-3-carboxylate (20)、indole-3-aldehyde (21)。... |
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