茉莉酸甲酯對紅檜葉子揮發成分含量之影響

Effect of Methyl Jasmonate on the Amounts of Volatile Compounds Emitted from Chamaecyparis formosensis Matsum. Leaves

紅檜為台灣特有樹種，木材具有極佳的耐久性並具特殊的香味。為瞭解紅檜葉子的揮發性成分組成，本研究除利用水蒸氣蒸餾法製備精油外，並利用固相微萃取技術收集葉子的揮發性成分，續以氣相層析質譜鑑定成分。此外，本研究並以茉莉酸甲酯模擬葉子受到機械創傷或是昆蟲、真菌的侵害後，其揮發性成分的變化。由分析結果可知，共108種紅檜葉子之化合物被鑑定出，在揮發性成分中以α-Pinene為最主要成分，佔30.29%，而在精油中則是以β-Myrcene為主成分，佔 22.45%。紅檜葉子在茉莉酸甲酯處理後，其揮發性成分之釋出量大幅提高，揮發量為未以茉莉酸甲酯處理的葉子的1.92倍；而在茉莉酸甲酯處理後對於時間上的影響上，在施加10 mM茉莉酸甲酯經過5 hr後，其揮發量增加最多，之後揮發量就開始減少。 Chamaecyparis formosensis is an endemic tree grown in Taiwan. The durability of C. formosensis wood is excellent and with fragrance odor. In order to analysis the volatile compounds of C. formosensis, in addition to the essential oil of leaves was prepared by water distillation, the solid phase micro extraction technology was also conducted to collect the compounds emitted from leaves. Moreover, the leaves of C. formosensis were treated by methyl jasmonate (MeJA) to mimic it wounded or attacked by fungus or insects. According to the results obtained in our study, totally 108 compounds were identified from C. formosensis, the amount of α-Pinene is 30.29% is the most dominant compound in the volatile compound emitted from leaves; however, β-Myrcene (22.45%) is the most dominant compound in the essential oil. After MeJA treatment, the amount of volatile compound was increased to 1.92-fold. Meanwhile, we also found that the amount of volatiles would reach to the highest concentration after 5 hr treatment at the dosage of 10 mM MeJA.