柳杉精油及成分抗細菌活性之研究

Abstract

本研究目的為評估柳杉材部、葉子、樹皮與枝條精油的抗細菌活性，分離及鑑定精油中之抗細菌活性成分。利用水蒸餾法萃取柳杉各部位精油，精油收率的順序為葉部( 1.42 % ) > 材部( 0.38 % ) > 枝條( 0.05 % ) > 樹皮( 0.03 % )。比較四部位精油的抗細菌活性得知，以材部精油的活性最佳，對於金黃色葡萄球菌（Staphylococcus aureus）和抗藥性金黃色葡萄球菌(Methicillin-resistant Staphylococcus aureus)的最低抑制濃度均為1 mg/mL，而對於糞腸球菌(Enterococcus faecalis)的MIC則為0.5 mg/mL。進一步由柳杉材部精油活性分離部中分離出epi-Cubebol、Cubebol、β-Elemol、δ-Cadinol、α-Cadinol、α-Calacorene與Sandaracopimarol，而從葉部精油活性分離部中分離得到cis-Sabinene hydrate、γ-Eudesmol、β-Eudesmol、β-Elemol、α-Cadinol、Cryptomeridol與ent-Kaur-16-ene。總計分離出1個單

The objectives of this paper were to evaluate the antibacterial activities of essential oils from Cryptomeria japonica wood, leaves, bark and twigs, and to isolate the antibacterial compounds from active oils. Essential oils were prepared by water distillation, and the yield of essential oils was in the decreasing order of leaves (1.42 %) > wood (0.38 %) > twigs (0.05 %) > bark (0.03 %). Among these oils, wood oil possessed the strongest activity against tested bacteria, the MIC values obtained ranged from 1 mg/mL against S. aureus and MRSA to 0.5 mg/mL against E. faecalis. In addition, compounds were isolated from active fractions of wood oil, including epi-cubebol, cubebol, β-elemol, δ-cadinol, α-cadinol, α-calacorene and sandaracopimarol. cis-Sabinene hydrate, γ-eudesmol, β-eudesmol, β-elemol, α-cadinol, cryptomeridol and ent-kaur-16-ene were isolated and identified from active fractions of leaf oil. All twelve compounds including one monoterpenoid, nine sequiterpenoids and two diterpenoids were obtained from wood and leaf oils. According to the antibacterial tests, cubebol, α-cadinol, α-calacorene and sandaracopimarol exhibited inhibitory effects against bacteria. The MIC values of these compounds were 0.5, 0.25, 0.25 and 0.25 mg/mL against S. aureus, respectively; 0.25, 0.25, 0.5 and 0.5 mg/mL against E. faecalis; and 0.5, 0.25, 0.125 and 0.5 mg/mL against MRSA. The results indicated that these terpenoids possessed superior antibacterial activities. Based on the above results, four antibacterial compounds were obtained from wood and leaf essential oils of C. japonica. It is worth further investigations and utilization in the future.