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In this study antitermitic activities of essential oils from different tissues of Chinese cedar (Cryptomeria fortunei Hooibrenk) against Reticulitermnes chinensis were investigated. In addition, the yields of essential oils obtained by water distillation were compared and their constituents determined by GC-MS analyses. The yields of bark, sapwood, heartwood, and leaf essential oils of Chinese cedar were 0.9, 0.4, 1.0, and 1.5%, respectively. GC-MS analyses showed that the major compounds of bark, sapwood, heartwood, and leaf essential oils of Chinese cedar were ferruginol (30.6%), y-cadinene (18.3%), y-cadinene (31.0%), and kaurene (30.6%), respectively. Bioactivity tests against R. chinensis demonstrated that the leaf and heartwood essential oils had an excellent effect, and the LC) values after 5 days were 0.9 and 1.8 microL/mL (LC90=1.4 and 2.9 microL/mL), respectively. The results of this study showed that the leaf and heartwood essential oils of Chinese cedar might be considered as a potential source of a fine natural termiticide.

The persistent use of synthetic termiticides is at present of environmental concern and has resulted in the need to search for plant-derived compounds as an alternative for termite control. Antitermitic activity of Chinese cedar (Cryptomeria fortunei Hooibrenk) against Reticulitermes chinensis was demonstrated in laboratory tests. Bioactivity tests against the termite R. chinensis demonstrate that the lethal concentration (LC50) value of leaf essential oil is 2.80 mg/mL. Furthermore, α-terpineol, which was responsible for the antitermitic property and isolated from Chinese cedar that exhibited very strong antitermitic activity, was found to be significantly effective against R. chinensis with median LC50 values of 0.86 mg/mL. The findings suggested that the essential oil from Chinese cedar leaf and α-terpineol might be considered as a potent source for the production of effective, environmentally friendly and safe termiticides.

The essential oils of composition obtained from the leaves ofCryptomeria fortunei, collected at different seasons in Wuhan (China), were analyzed by gas chromatography (GC) GC–mass spectrometry (GC–MS). Fifty constituents were identified, constituting 92.3–97.7% of the essential oils. Our results showed that seasonal differences did not have an effect on the composition of oils but on the amount of oil components. The main components of the oil were kaur-16-ene (30.9–42.4%), elemol (16.8–18.9%), α-eudesmol (7.4–13.6%), α-pinene (1.9–8.0%) and γ-eudesmol (4.0–7.5%). On the basis of the results obtained, some suggestions are made concerning the optimal season for theC.fortuneioils. [ABSTRACT FROM PUBLISHER]

Abstract: Essential oils were extracted by hydrodistillation from the leaves of Cryptomeria fortunei from the principal habitats in China. The essential oil yields of samples from various locations ranged from 0.61 to 1.66% (w/w). GC–MS analysis revealed eighty-seven compounds, constituting 85.89–94.75% of the total essential oils. The main constituents were kaurene (0–44.69%), phyllocladene (0.07–32.98%), kaur-16-ene (0–32.28%), elemol (5.28–18.92%), α-cadinol (0–11.39%), α-eudesmol (0–11.21%), α-pinene (2.32–9.15%). The samples were separated into 3 chemotypes by hierarchical cluster analysis, according to the composition of the corresponding essential oils. Chemical composition of essential oils was significantly related to nine geographic distributions among populations. Our results revealed chemical polymorphism in the essential oils of the C. fortunei leaf in China. The chemical variability could be attributed to genetic and environmental factors. The chemical diversity of the oils offers opportunity to choose C. fortunei leaves and essential oils with preferential compound for green plant protection, pharmaceutical, perfume and food industries. [Copyright &y& Elsevier]

Abstract: The essential oils obtained by hydrodistillation from leaves of Chinese native Cryptomeria japonica and Cryptomeria fortunei were analyzed by GC and GC–MS. Fifty-seven compounds were identified in the essential oils of C. japonica with α-elemol (20.12%), kaur-16-ene (14.84%), β-phellandrene (5.97%), β-elemene (5.87%), α-eudesmol (5.62%) and β-eudesmol (5.03%) as main constituents. Forty components were identified in the oil of C. fortunei with kaurene (34.04%), α-elemol (13.34%), γ-eudesmol (10.80%), β-eudesmol (10.16%), α-pinene (2.75%) and γ-cadinene (1.92%) as the most abundant components. This study demonstrated the occurrence of α-elemol chemotype in C. japonica and kaurene chemotype in C. fortunei from China. The essential oil compositions of two Cryptomeria samples were shown that they can be used for green plant protection, pharmaceutical, perfume and food industries. [Copyright &y& Elsevier]