超临界CO_(2)萃取条件下4种杜鹃枝叶总挥发油的GC-MS分析

GC-MS Analysis of Total Volatile Oil from Branches and Leaves of Four Rhododendron Species Under Supercritical CO_(2)Extraction

目的明确烈香杜鹃、头花杜鹃、千里香杜鹃、陇蜀杜鹃4种杜鹃植物枝叶部位挥发油成分。方法利用超临界CO_(2)萃取法分别得到4种植物叶部位及枝部位总挥发油,应用GC-MS分析鉴定所得总挥发油的化合物组成,并对不同部位、不同品种含量进行比较。结果结果表明叶部位出油率最高的为千里香杜鹃(6.97%),枝部位出油率最高的为烈香杜鹃(20.53%)。分别在烈香杜鹃、头花杜鹃、千里香杜鹃、陇蜀杜鹃枝油中检测出35、80、58、40种化合物,以头花杜鹃化合物种类较为丰富;叶油中分别检测出48、57、62、50种化合物,以千里香杜鹃化合物种类较为丰富。烈香杜鹃枝、叶油中含量最高的均为角鲨烯(34.92%、26.90%),头花杜鹃枝油中含量最高的是1-二十醇(26.79%),叶油中含量最高的是乙酸十八酯(42.32%),千里香杜鹃枝、叶油中含量最高的为甜没药-3,10-二烯-2-酮(34.66%、28.20%),陇蜀杜鹃枝、叶油中含量最高的为15-oxo ETE(38.20%、40.40%)。可见,不同部位挥发油中,以头花杜鹃枝油、叶油含量差异较大。而不同品种挥发油中,4种杜鹃含量最高的化合物则不尽相同。结论可以依照不同种、不同部位杜鹃挥发油成分含量的差异,有目的性地进行开发利用,本研究结果可为杜鹃资源合理开发利用提供科学依据。

OBJECTIVE To clarify the components of volatile oil in branches and leaves of Rhododendron anthopogonoides,Rhododendron capitatum,Rhododendron thymifolium and Rhododendron przewalskii.METHODS The total volatile oil in leaves and branches of these plants were obtained by supercritical CO_(2)extraction.After that,the chemical composition of the total volatile oil was analyzed and identified by GC-MS,and the contents of different parts and varieties were compared.RESULTS The results showed that the highest oil yield of leaves was Rhododendron thymifolium(6.97%),and the highest oil yield of branches was Rhododendron anthopogonoides(20.53%).Thirty-five,eighty,fifty-eight and forty compounds were detected in the branch oil of Rhododendron anthopogonoides,Rhododendron capitatum,Rhododendron thymifolium and Rhododendron przewalskii respectively,among which Rhododendron capitatum was rich in compounds.Forty-eight,fifty-seven,sixty-two and fifty compounds were detected in the leaf oil,among which the compounds of Rhododendron anthopogonoides were the richest.Among the detected components,squalene(34.92%,26.90%)was the highest content in the branches and leaves of Rhododendron anthopogonoides.1-Eicosanol(26.79%)was the highest content in the branch oil of Rhododendron capitatum,and octadecyl acetate(42.32%)was the highest content in the leaf oil.The highest content of bisabola-3,10-diene-2-one(34.66%,28.20%)was found in the branches and leaves of Rhododendron thymifolium,and 15-oxoETE(38.20%,40.40%)was the highest content in the branches and leaves of Rhododendron przewalskii.The results showed that the contents of oil in branches and leaves of Rhododendron capitatum were quite different in different parts.In the comparison of different varieties,the compounds with the highest content of four rhododendrons were all different.CONCLUSION According to the difference of the content of active components of different rhododendrons and parts,the appropriate species and parts for purposeful development and utilization should be selected.The research results can provide scientific basis for rational development and utilization of Rhododendron resources.