Components of Cunninghamia lanceolata Heartwood Extracts

摘要

China-fir (Cunninghamia lanceolata) has a reputation for producing naturally durable heartwood. This species is native in China and has been extensive planted there. Mainly, extractives are responsible for the wood resistance to decay fungi. Compared with the number of studies on China fir focused only on essential oil, studies on other China fir wood extracts is few. In this report, different Cunninghamia lanceolata heartwood extracts were studied. Ground wood was sequentially extracted by solvents with different polarities, hexane, ethyl acetate and methanol. The components of the extracts were identified by Gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared spectroscopy (FTIR) and high performance liquid chromatography (HPLC). Both of FTIR and HPLC revealed that the hexane extract was primarily aliphatic compounds, the methanol extract was rich in phenols in nature and the ethyl acetate extract contained phenols and aliphatic compounds. The GC-MS analysis of the hexane extract and the ethyl acetate extract led to the identification and quantification of a total of 16 components accounting for 48.29% of the hexane extract and 18 components accounting for 66.06% of the ethyl acetate extract. Total phenolic contents (TPCs) and antioxidant capacity of the ethyl acetate extract and the methanol extract were evaluated using the Folin-Ciocalteau colorimetric method and DPPH- assay, respectively. TPCs analysis showed that phenols took up 6.66 % of the ethyl acetate extract and 22.8% of the methanol extract. ED50 values of the ethyl acetate extract and the methanol extract were 4.25 mg mL"' and 0.19 mg mL"', respectively. When the methanol extract of 0.145 mg mL"1, its percent DPPH- remaining at steady state (57.92%) was close to that of butylated hydroxytoluene (BHT) (48.5%).