Compositions and Antioxidant Activities of Essential Oils of Different Tissues from Cryptomeria japonica D. Don

柳杉（Cryptomeria japonica D. Don）各部位精油組成分及抗氧化活性之探討

Both hydrodistillation and headspace-GC methods were applied to extract essential oils from leaves, heartwood, sapwood, twig, and bark of Cryptomeria japonica D. Don and their chemical compositions determination and oil yields were analyzed. The antioxidant activities of these oils were also evaluated. The hydrodistillated leaves, heartwood, sapwood, twig, and bark essential oils contained 53, 44, 50, 87, and 60 identified compounds, respectively. Whereas the headspace methods separated from those parts 38, 35, 46, 61 and 46 identified compounds, respectively. Both methods showed similar main components and yields. The main composition of leaf essential were kaurene (19.1%), α-pinene (16.5%) and elemol (16.3%). Its heartwood oil had 1-epi-cubenol (18.9%), δ-cadinene (17.2%), andcubenol (14.9%) as the main ingredients; the sapwood oil contained cubebol (19.5%), cubenol (13.3%), 1-epi-cubenol (12.5%) and ferruginol (10.8%) as the main components; the bark oil, however, contained camphor (46.5%) and α-pinene (16.2%) etc.; and α-eudesmol (25.2%), γ-eudesmol (11.8%) in the twig oil. Essential oils from the leaves, heartwood, sapwood, and twigs of the species were predominately oxygenated sesquiterpenes, while the bark oil was mostly oxygenated monoterpenes. The antioxidant activities of these oils in a decreasing order was sapwood ＞ twig ＞ heartwood ＞ bark ＞ leaves. After TLC fractionation of the sapwood oil, we found that ferruginol processed the highest antioxidant activity, and may be applicable as a natural antioxidant. 本研究探討以水蒸餾法及頂空間氣相層析（Headspace-GC）等二方法萃取柳杉（Cryptomeria japonica D. Don）各部位精油，分析其組成化合物及收率，並評估各精油之抗氧化活性。由水蒸餾法取得之葉、心材、邊材、枝條及樹皮精油，分別鑑定出53、44、50、87及60個化合物，而以Headspace-GC取得之各部位揮發性化合物，分別鑑定出38、35、46、61及46個化合物，且其主成分及收率均與水蒸餾法所得之精油相若。葉精油主要組成分為kaurene（19.1%）、α-pinene（16.5%）、elemol（16.3%）等。心材精油主要組成分為1-epi-cubenol（18.9%）、δ-cadinene（17.2%）、cubenol（14.9%）等。邊材精油主要組成分為cubebol（19.5%）、cubenol（13.3%）、1-epi-cubenol（12.5%）及ferruginol（10.8%）等。樹皮精油主要組成分為camphor（46.5%）、α-pinene（16.2%）等。柳杉枝條精油主要組成分為α-eudesmol（25.2%）、γ-eudesmol（11.8%）等。柳杉葉、心材、邊材及枝條之精油均以倍半含氧化合物量為最多，而樹皮為以單含氧化合物為主。柳杉各部位之抗氧化能力依序為邊材＞枝條＞心材＞樹皮＞葉，於邊材部位精油成分中，以TLC分離各區段後，證實ferruginol有最佳之抗氧化活性，推論柳杉邊材精油，可做為天然抗氧化劑之應用。

本研究探討以水蒸餾法及頂空間氣相層析（Headspace-GC）等二方法萃取柳杉（Cryptomeria japonica D. Don）各部位精油，分析其組成化合物及收率，並評估各精油之抗氧化活性。由水蒸餾法取得之葉、心材、邊材、枝條及樹皮精油，分別鑑定出53、44、50、87及60個化合物，而以Headspace-GC取得之各部位揮發性化合物，分別鑑定出38、35、46、61及46個化合物，且其主成分及收率均與水蒸餾法所得之精油相若。葉精油主要組成分為kaurene（19.1%）、α-pinene（16.5%）、elemol（16.3%）等。心材精油主要組成分為1-epi-cubenol（18.9%）、δ-cadinene（17.2%）、cubenol（14.9%）等。邊材精油主要組成分為cubebol（19.5%）、cubenol（13.3%）、1-epi-cubenol（12.5%）及ferruginol（10.8%）等。樹皮精油主要組成分為camphor（46.5%）、α-pinene（16.2%）等。柳杉枝條精油主要組成分為α-eudesmol（25.2%）、γ-eudesmol（11.8%）等。柳杉葉、心材、邊材及枝條之精油均以倍半含氧化合物量為最多，而樹皮為以單含氧化合物為主。柳杉各部位之抗氧化能力依序為邊材＞枝條＞心材＞樹皮＞葉，於邊材部位精油成分中，以TLC分離各區段後，證實ferruginol有最佳之抗氧化活性，推論柳杉邊材精油，可做為天然抗氧化劑之應用。