The volatile oils from leaves of Michelia chapensis Dandy and M. foveolata Merr.ex Dandy were isolated by organic solvent extraction and their components were analyzed and quantified by GC/MS. Then, the total anti-oxi...The volatile oils from leaves of Michelia chapensis Dandy and M. foveolata Merr.ex Dandy were isolated by organic solvent extraction and their components were analyzed and quantified by GC/MS. Then, the total anti-oxidation capacity and simulated SOD activity were tested. Forty-four compounds in M. chapensis were identified and the main constituents are aromatic (11.057%), ester (5.041%) and terpenoid compounds (19.772%). Fifty-two compounds in M. foveolata were identified, and their main constituents are aromatic (21.293%), alcohol (17.403%), alkene (6.909%), ester (5.657%) and alkane compounds (5.134%). The results showed that the two oils have strong anti-oxidation capacity and simulated SOD activity. The total anti-oxidation capacities were the highest when the volatile oil from M. foveolata was diluted by 50 times and that from M.chapensis by 100 times. The simulated SOD activity of volatile oil from M. chapensis was higher than that from M. foveolata, and CuZn-SODs in the two oils held 73%-74% of the total SOD. These results will provide scientific foundation for the exploration of the bioactivity of M. chapensis and M. foveolata.展开更多
Nanoindentation technique is a technique that determines the mechanical properties of a material in sub-micron scale. The technique involves penetrating a sample material using an indenter, while the penetration depth...Nanoindentation technique is a technique that determines the mechanical properties of a material in sub-micron scale. The technique involves penetrating a sample material using an indenter, while the penetration depth and load are recorded so that stiffness and hardness of the indented location can be subsequently calculated. The micron spatial resolution in nanoindentaion tests renders the technique very useful in the investigation of the wood cell-wall level and polymer interphase. This review mainly discussed the principle of nanoindentation and its current applications in wood science field.展开更多
基金"Research and demonstration of ‘dot’ of ecological network of Chinese urban forest"(2001BA516A15-07) of China scientific andtechnological key projects in "tenth five-year" and "Regional test of arbor and ecological function trees afforested in city and town" (2002-17A)sponsored by State Forestry Administration.
文摘The volatile oils from leaves of Michelia chapensis Dandy and M. foveolata Merr.ex Dandy were isolated by organic solvent extraction and their components were analyzed and quantified by GC/MS. Then, the total anti-oxidation capacity and simulated SOD activity were tested. Forty-four compounds in M. chapensis were identified and the main constituents are aromatic (11.057%), ester (5.041%) and terpenoid compounds (19.772%). Fifty-two compounds in M. foveolata were identified, and their main constituents are aromatic (21.293%), alcohol (17.403%), alkene (6.909%), ester (5.657%) and alkane compounds (5.134%). The results showed that the two oils have strong anti-oxidation capacity and simulated SOD activity. The total anti-oxidation capacities were the highest when the volatile oil from M. foveolata was diluted by 50 times and that from M.chapensis by 100 times. The simulated SOD activity of volatile oil from M. chapensis was higher than that from M. foveolata, and CuZn-SODs in the two oils held 73%-74% of the total SOD. These results will provide scientific foundation for the exploration of the bioactivity of M. chapensis and M. foveolata.
文摘Nanoindentation technique is a technique that determines the mechanical properties of a material in sub-micron scale. The technique involves penetrating a sample material using an indenter, while the penetration depth and load are recorded so that stiffness and hardness of the indented location can be subsequently calculated. The micron spatial resolution in nanoindentaion tests renders the technique very useful in the investigation of the wood cell-wall level and polymer interphase. This review mainly discussed the principle of nanoindentation and its current applications in wood science field.
