杨梅树叶、皮、根部精油成分及其抗氧化活性物质

Chemical Composition and Antioxidant Components of Essential Oils from Leaves,Bark and Root of Myrica rubra

采用GC-MS技术结合Kovats保留指数(KI)对比法分析鉴定了采自南岭自然保护区的乌杨梅(Myrica rubravar.astropureaTsen.)叶、皮和根部芳香精油的成分,同时运用薄层层析(TLC)筛分法对其抗氧化活性物质进行了对比分析。杨梅树根和树皮精油的主要成分为5-羟基菖蒲烯(相对含量分别为74.66%和60.32%)和油酸(7.74%和11.39%),而树叶精油的主体成分为5-羟基菖蒲烯(30.44%)、石竹烯(11.61%)、异石竹烯(10.17%)、(E)-橙花叔醇(9.57%)和油酸(4.40%)。树根、树皮到树叶部位的次生代谢物明显出现越来越复杂的分化特性。5-羟基菖蒲烯是3个部位精油的主要抗氧化活性物质,但叶部精油中的倍半萜烯类物质也表现出一定的二苯代苦味酰(DPPH)自由基清除活性。

Essential oils from leaves, bark and root of Chinese waxmyrtle （Myrica rubra var. astropurea Tsen）, growing wild in Nanling National Nature Reserve, have been analyzed for their chemical composition and investigated for their antioxidant components. The GC-MS analysis as well as comparison of the Kovats retention indices （K/） of elution peaks with literature data were used for compound identification of the essential oils; TLC-screening method was used for analysis of antioxidant components in the oils. The essential oils of M. rubra bark and root are both dominated with 5-hydroxycalamenene （74.66% and 60.32% ） and oleic acid （7. 74% and 11. 39%）, respectively, whereas, the leaves oil is constituted mainly by 5-hydroxycalamenene （30.44%）, caryophyllene （ 11.61% ）, isocaryophyllene （ 10. 17% ）, （ E）-nerolidol （9.57%） and oleic acid （4.40%） , respectively. The composition matrixes of the essential oils of M. rubra leaves, bark and root express the differential complexity of secondary metabolites in this species. 5-Hydroxycalamenene is identified as the principal antioxidant in all three essential oils. However, the sesquiterpenes in leaves oil also show positive 2,2-diphenyl-l-picrylhydrazyl （DPPH） radical scavenging activity in certain extent.