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The effect of methylbenzene/ethanol ratios on chemical composition of extractives from Eucalyptus grandis

Forestry Studies in China 2012年第3期14卷 235-239页

作者： ZHANG Bin WU Shu-bin GUO Da-liang State Key Laboratory of Pulp and Paper Engineering South China University of TechnologyGuangzhou 510640R R.China

Chemical components of methylbenzene/ethanol extractives of Eucalyptus grandis were identified by GC/MS and different methylbenzene/ethanol solutions （9/1, 4/1, 2/1, 1/1, 1/2） were used to describe their distinctions. The distributions of micro particles in each extractive were studied simultaneously. The results show that there were significant differences between the various extrac- tives, although the extractives were essentially the same, i.e., alcohols, alkanes, esters and acids. With the increase of ethanol compo- sition in the solutions, the total amount of extractives increased; in solvent with higher amounts of ethanol, some acidic structures or acids, such as glutaric acid, could be seen. An investigation of micro particles indicated that the distribution of particle size of each sample did not change greatly between the solutions. A slight decrease in size was seen with the reduction in the amount of methylbenzene.

关键词： extractives Eucalyptus grandis micro particles

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Genetic variation of Norway spruce clones regarding their natural durability, physical and chemical properties

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Advances in Bioscience and Biotechnology 2012年第8期3卷 1104-1112页

作者： Ilze Irbe Guna Noldt Uldis Grinfelds Anrijs Verovkins Aris Jansons Gerald Koch Johann Heinrich von Thunen-Institute (vTI)/Federal Research Institute for Rural Areas Forestry and Fisheries Institute of Wood Technology and Wood Biology (HTB) Hamburg Germany Latvian State Forest Research Institute “Silava” Salaspils Latvia Latvian State Institute of Wood Chemistry (LS IWC) Riga Latvia

Genetic variation of ten Norway spruce (Picea abies (L.) Karst.) clones regarding their decay resistance against brown rot fungi, as well as physical and chemical properties of clones were investigated. 31- year-old spruce clones: 26, 31, A10, A15, A7, B10, B15, B6, V7, V9 were selected across Latvia. The stem diameters of spruce clones varied between 13.0 and 20.9 cm. The wood density of clones ranged from 361 to 443 kg/m3. Klason lignin content, depending on the clone, was between 27.0%-28.9%. Cellular UV microspectrophotometry of the non-infected tracheids displayed the typical lignin distribution with highest absorbance values in the cell corners (abs280 nm 0.80) and compound middle lamellae (abs280 nm 0.48), while secondary wall showed lower lignin absorbance values (abs280 nm0.29 - 0.35). The deposition of phenolic extractives in ray parenchyma and epithelial cells of resin canals were emphasized by a significantly higher UV-absorbance (abs280 nm 0.68 to 0.78) when compared to the cell wall associated lignin. The content of acetone-soluble extractives of spruce clones varied between 1.1% - 1.8%. The x-value (natural durability) for all spruce clones after exposure to C. puteana and P. placentawas >0.90 (durability class 5, not durable). Most of clones after degradation by G. trabeum had x-value > 0.90 with exception of clones B15 and V9 that showed x-value ≤ 0.90 (durability class 4, slightly durable). Natural durability of spruce clones did not correlate with stem diameter, density, content of lignin and extractives.

关键词： Norway Spruce Clones Natural Durability Brown Rot Lignin extractives Density UV Microspectrophotometry

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