柠檬桉叶挥发性成分的提取及成分分析

采用水蒸气蒸馏法从柠檬桉叶中提取挥发油中的油相成分,用乙醚作为溶剂从蒸馏残液中萃取挥发油中的水溶性物质,利用气相色谱-质谱联用(GC-MS)分析二者的化学成分并进行比较。柠檬桉叶挥发油油相成分的得油率为1.36%(以鲜重计),确认了其中的37种成分,占油相成分总量的97.36%,其中有12种碳氢化合物和25种含氧化合物，其主要成分为香茅醛(57.00%),其后依次是香茅醇(15.89%)、乙酸香茅酯(15.33%)。水溶性成分的得油率为0.48%(以鲜重计),确认了其中的10种成分,占水溶性物质总量的82.05%,主要为醇类物质，其主要成分为顺-对烷-3,8-二醇(53.43%)和反-对烷-3,8-二醇(16.48%)。

Extraction and Determination of Volatile Constituents in Leaves of Eucalyptus citriodora

The volatile constituents in leaves of Eucalyptus citriodora,including oil fraction and water-soluble fraction,were extracted and determined.Oil fraction of volatile components was obtained through steam distillation.Ether was used as the solvent to extract the water-soluble fraction of volatile compounds from the liquid left after steam distillation in order to know the quantity and constituents of volatile compounds dissolved in the water phase.The oil yield in the oil fraction was 1.36%,and the oil yield in the water-soluble fraction was 0.48%(both on fresh weight basis).Both oil fraction and water-soluble fraction were analyzed by gas chromatography-mass spectrometry(GC-MS) method.The results showed that 37 compounds(97.36%) in the oil fraction and 10 compounds(82.05%) in the water-soluble fraction were(identified.) There were 12 hydrocarbon compounds and 25 oxygenated compounds identified in oil fraction.The major constituents in oil fraction were citronellal(57.00%),followed by citronellol(15.89%) and citronellyl acetate(15.33%).Alcohols dominated the compounds in water-soluble fraction.cis-p-Menthane-3,8-diol(53.43%) and trans-p-menthane-3,8-diol(16.48%) were found to be the major compounds,which have the activity to repel insects.It is concluded that the comprehensive utilization value of leaves of Eucalyptus citriodora was(enhanced) owing to the extraction of water-soluble volatile components.