• Journal of the Korean Wood Science and Technology
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• v.31 no.6
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• pp.8-14
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• 2003

This study was carried out identify extractives of Amorpha fruticosa. In this study, one flavonoid glycoside, one ester and two rotenoids were isolated from fruits of A. fruticosa. The structures were determined as: kaempferol 7-O-α-L-rhamnopyranoside (I), methyl 3, 4, 5-trihydroxybenzoate (methyl gallate, II), tephrosin (III) and dalbinol (IV), respectively, on the basis of spectroscopic data.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.1
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• pp.83-91
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• 2011

Hemicelluloses are useful materials for papermaking and other biotechnological applications. To recover and further utilize the hemicelluloses, this study carried out the pre-extraction of the hemicelluloses from Korean mixed hardwoods chips using hot water and sodium hydroxide solution at various temperature and time conditions. Through the hot water pre-extraction, the wood components of 22% was extracted and the 35% of the hemicelluloses which were contained in the original wood chips were dissolved into the pre-extractives. The yield of the pre-extractives was more significantly influenced by the pre-extraction temperature than the time. The pre-extractives with the yield of 30% could be obtained by alkali pre-extraction and alkali concentration was the most important factor. It had lower hemicellulose content but high molecular weight, compared with the hot water pre-extractives.

• Journal of the Korean Wood Science and Technology
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• v.31 no.1
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• pp.32-40
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• 2003

Antimicrobial and antioxidative activities of heartwood extractives of domestic species were investigated to develop a natural fungicide or preservative. Four lignan derivatives and one taxane were isolated from heartwood of Taxus cuspidata which has been selected due to its high antioxidative activity among the tested species. The chemical structures were identified as : taxusin, isolariciresinol (4, 4', 9, 9'-tetrahydroxy-3', 5-dimethoxy-2, 7'-cyclolignan), lariciresinol (4, 4', 9-trihydroxy-3, 3'-dimethoxy-7, 9'-epoxylignan), taxiresinol (3, 4, 4', 9-tetrahydroxy-3'-methoxy-7, 9'-epoxylignan) and isotaxiresinol (3', 4, 4', 9, 9'-pentahydroxy- 5-methoxy-2, 7'-cyclolignan) on the basis of spectroscopic data and their chemical correlations. According to the results of free radical scavenging activity, isolariciresinol, lariciresinol and isotaxiresinol showed higher radical scavenging activity than those of 𝛼-tocopherol and butylated hydroxytoluene (BHT), the strongest natural and synthetic antioxidants. However, taxusin did not show any free radical scavenging activity. In this regard, it could inferred that high antioxidative activity of extractives of T. cuspidata was derived from isolariciresinol, lariciresinol and isotaxiresinol.

• Journal of the Korean Wood Science and Technology
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• v.24 no.3
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• pp.51-56
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• 1996

The Bark lignin(alkali- and acid lignin), bark extractives(hot water-and $Na_2SO_3$ extractives) of Quercus acutissima and Pinus densiflora, and flavonoids were used to detect heavy metal adsorption. The adsorption ratio of heavy metals by lignin was assigned for 40 to 50%, but was not dependent on lignin kinds. However, in case of the addition of light metals such as $Ca^{++}$ and $Mg^{++}$ to lignin the adsorption ratio was increased by 20 to 40%, and $Pb^{++}$ was almost completely adsorbed. On hot water extractives, the adsorption ratio was very low because the substrate was water-soluble, so the substrate should be water-insoluble to adsorb the heavy metals. However, the adsorption ratios of $Cd^{++}$ and $Pb^{++}$ on $Na_2SO_3$ extractives were significantly increased, while those of $Zn^{++}$ and $Cu^{++}$, were similar to lignin. When four kinds of heavy metals were treated to $Na_2SO_3$ extractives together, more than 97% of $Pb^{++}$ and $Cu^{++}$ was adsorbed_ and $Zn^{++}$ was more adsorbed by 40%, and $Cd^{++}$ was not changed, comparing with the case that on kind of heavy metal was treated. There were differences between adsorption ratio of the kinds of flavonoids and heavy metals, and the adsorption ratio of heavy metals was assigned to 20 to 45% per 0.1g flavonoid.

• Journal of the Korean Wood Science and Technology
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• v.28 no.2
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• pp.66-74
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• 2000

Wood of black locust(Robinia pseudoacacia) and bark of poplar(Populus alba x glandulosa), ash(Fraxinus rhynchophylla) and elm(Ulmus davidiana var. japonica) trees were collected, extracted with acetone-$H_2O$(7:3. v/v), fractionated with hexane, chloroform, ethylacetate and $H_2O$. then freeze dried to get some dark brown powder for bioactive tests. Decay-resistant activity was tested using wood block specimens from the hardwood trees and expressed by weight loss rate. Black locust specimens indicated the best anti-decaying property and poplar blocks were the worst. Antimicrobial and antioxidant activities were also investigated against each wood or bark extractives. Antifungal and antibacterial activities did not indicate any significant differences among the tested fractions. In antioxidant activity. ${\alpha}$-tocopherol one of natural antioxidants. and BHT, one of synthetic antioxidants, were used as references to compare with the antioxidant activities of the extracted fractions. Ethylacetate fraction of ash bark indicated the highest activity besides BHT in this test and all fractions of black locust extractives also indicated higher activities compared with the other fractions.

• Journal of Korea Foresty Energy
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• v.24 no.2
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• pp.16-23
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• 2005

The air dried of Epimedium koreanum Nakai was extracted with MeOH and its extractives were concentrated with a vacuum evaporator. The extractives were fractionated with a series of n-hexane, chloroform (${CHCl}_3$), butanol (BuOH), ethyl acetate (EtOAc) and water on a separately funnel. Each fraction was freeze dried to give some dark brown powder. The EtOAc and BuOH soluble fractions were chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-n-hexane mixture as eluents. The isolated compounds were tested with a cellulose TLC developed with TBA and 6% acetic acid and then visualized on UV lamp or sprayed with vanillin-HCl-EtOH. The purified compounds were flavonoids and their glycosides, and organic acid as follows : (+)-catechin, icariin, hyperoside, Ikarisoside A and caffeic acid. The structures of each compounds were confirmed by $^1H-NMR,\;^{13}C-NMR$ and Mass spectra. Also, executed qualitative analysis as use GC/MS(Libraries search) about ${CHCl}_3$ soluble compounds of each part.

• Journal of the Korean Wood Science and Technology
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• v.28 no.3
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• pp.52-61
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• 2000

Black locust(Robinia pseudoacacia) and poplar(Populus alba ${\times}$ glandulosa) trees were collected, extracted with acetone-$H_2O$(7:3, v/v) after drying, fractionated with hexane, chloroform and ethylacetate, and freeze dried to get some brown powder. Each fraction of the powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluting solvents. The wood extractives of black locust contained (+)-leucorobinetinidin as flavan, robtin as flavanone and dihydrorobinetin as flavanonol, and robinetin as flavonol. The poplar bark extractives contained various kinds of phenolic compounds : (+)-catechin as flavan, naringeoin, eriodictyol, sakuranetin, aromadendrin and taxifolin as flavanonol, salireposide as salicin derivative, and minor compounds such as aesculin and p-coumaric acid. However, aesculin has not been reported as a constituent of the poplar bark in Korea yet. NMR and FAB-MS analyses were done to elucidate the structures of isolated phenolic constituents.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.11b
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• pp.204-208
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• 1999

Friction was measured on filter paper sheets impregnated with model compounds representing wood extractives using an apparatus based on the horizontal plane principle. The best lubrication of paper surfaces was achieved when they were completely separated by a densely packed film of saturated long-chain amphophilic molecules, such as fatty acids. The fatty acids adsorbed with their polar ends on the paper surface, causing their hydrocarbon chaine to be orientated perpendicularly to the paper surface. The saturated C18-acid, stearic acid, was an efficient lubricator for paper surfaces. The introduction of a double bond in stearic acid eliminated its lubricating ability. The spatial length of the lubricating fatty acid thereby decreases from 24${\AA}$ to 11${\AA}$. However the transisomer of oleic acid, elidic acid, had the ability to lower friction due to an increased spatial length of the fatty acid. Both the spatial length of the hydrocarbon chain and the number of lubricating chains may be of importance for the paper-to-paper friction caused by wood extractives. A hydrophilic head-graup in the wood extractive and an ordered molecular layer of lubricating molecules seems also to be prerequisites for efficient lubrication. A chemical weak boundary layer between the paper sheets was suggested to cause the low friction when long chain saturated fatty acids were deposited on paper.

• Journal of the Korea Furniture Society
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• v.13 no.2
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• pp.19-28
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• 2002

This study was carried out to investigate the wood properties for efficient utilization of warm temperate tree species. The tested species were Actinodaphne lancifolia Meisn. grown in Korea. Fundamental wood properties such as anatomical, physical and mechanical properties and chemical components were examined. This species was diffuse porous, straight grained and fine textured wood. The heartwoods of this species was not distinguished clearly to the sapwoods. This species had moderate specific gravity, shrinkage, and mechanical properties. And this species had high content of the extractives by organic solvent.

• Journal of the Korean Wood Science and Technology
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• v.22 no.1
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• pp.28-33
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• 1994

The chemical compositions of pine bark from mechanical pulp industry were determined, and effect of Ca base acid sulfite on bark cooking was investigated under various conditions. The pine bark was composed of 39.5 % alkali extractives, 50.3 % lignin, and a small amount of carbohydrate. The contents of alkali extractives and lignin were remarkably higher than those of pine wood. The bark was composed of high content of arabinose and xylose, while the wood was composed of high content of mannose. When pine bark was cooked with 75 % free acid at 145 $^{\circ}C$, the rate of cooking and delignification was improved with the increase of total acid, but it was very difficult to delignify the bark by 50 % and over under these conditions. In the presence of 60~65 % free acid and at 155~165 $^{\circ}C$, initial cooking rate, delignification, and delignification selectivity were considerably increased, but condensation reaction of lignin was considerable at the end of cooking. Therefore, it was shown that pine bark was very difficult to delignify by the Ca-base acid sulfite cooking.