香茅叶挥发油的化学成分及其体外抗氧化活性

Chemical constituents and their antioxidant activities in vitro of volatile oil from leaves of Cymbopogon Citratus

目的研究香茅Cymbopogen citratus(DC.)Stapf叶挥发油的化学成分及其体外抗氧化活性。方法水蒸气蒸馏法提取香茅叶挥发油,气相色谱-质谱(GC-MS)法分析其化学成分,Folin-Ciocalteau比色法测定总多酚含有量。通过铁还原抗氧化能力(FRAP)和1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除法研究其体外抗氧化活性。结果最佳提取时间为5 h,提取率为1.30%。挥发油中共鉴定出17种成分,以开链单萜类化合物为主,醇类占76.98%,总多酚含有量为70.72 mg/g(没食子酸当量)。而且,挥发油对DPPH自由基的清除活性明显优于其5种主要单体成分(香茅醇、香叶醇、香茅醛、芳樟醇和乙酸香叶酯)。结论香茅叶挥发油主要由开链单萜类化合物组成,并且具有较好的体外抗氧化活性。

AIM To study the chemical constituents and their antioxidant activities in vitro of volatile oil from leaves of Cymbopogon Citratus（ DC.） Stapf. METHODS The volatile oil from leaves of Cymbopogon Citratus was extracted by steam distillation,whose chemical constituents were analyzed by GC-MS. The content of total polyphenols was determined by Folin-Ciocaheu colorimetry. Then the antioxidant activities in vitro were studied by ferric reducing antioxidant power（ FRAP） and 1,1-diphenyl-2-picrylhydrazyl（ DPPH） radical scavenging. RESULTS The best extraction time was 5 h with the yield of 1. 30%. Seventeen constituents were identified in volatile oil,most of which were open-chain monoterpenes,and alcohol compounds accounted for 76. 98%. The content of total polyphenols was 70. 72 mg/g. In addition,the volatile oil exhibited significantly higher scavenging activity against DPPH· than five main monomer components（ citronellol,geraniol,citronellal,linalool and geranyl acetate） in it. CONCLUSION The volatile oil from leaves of Cymbopogon Citratus is mainly consisted of openchain monoterpenes,having good antioxidant activities in vitro.