• Journal of the Korean Wood Science and Technology
• /
• v.47 no.1
• /
• pp.8-20
• /
• 2019

This study was conducted to analyze the pore structure of Yellow poplar. Cross-sectional surfaces of heartwood and sapwood of Yellow poplar (Liriodendron tulipifera) were observed by SEM, and the true density of the heartwood, intermediate wood and sapwood were measured by gas pycnometery, while gas permeability and pore size of heartwood, intermediate wood and sapwood were measured by capillary flow porometery. The pores were classified as through pore, blind pore and closed pore. It was determined that the permeability was increased due to the content and size of through pore being increased although the total porosity of specimen showed slight difference from pith to bark. The content of through pore porosity was 33.754 % of heartwood and 47.810 % of sapwood, showed an increasing trend from pith to bark, however, those for the blind pore porosity and closed pore porosity were 27.890 % and 19.492 % for heartwood and 19.447 % and 4.660 % for sapwood, showed a decreasing trend from pith to bark. The max pore size of specimens was increased by about 5 times from $5.927{\mu}m$ to $31.334{\mu}m$, and mean flow pore size was increased by about 315 times from $0.397{\mu}m$ to $12.437{\mu}m$ from pith to bark.

• Journal of Korean Society of Forest Science
• /
• v.4 no.1
• /
• pp.30-32
• /
• 1965

Many kind tree species are growing in Korea. However most of them are inferior in wood qualities and production for commercial utilization except several species. Among the useful several species Red Pine (Pinus densiflora S. et. Z.) is growing in main tree species and most generally utilizing wood in korean forest. It is used widely as mine timbers, cross ties, boxes, floorings, pulpwoods, constructions and engineerings. Although this species is most useful and economical in this country, the basical properties on relation between wood and relative humidities were not studied certainly. This study was performed by need of inspection the hygroscopic and swelling properties to be apllied for physical manufacturing. According to the results the Equilibrium Moisture Contents of each relative humidity conditions are as table (3), and the swelling values of sap and heartwood are as table (4) and (5) in text. In this study sapwood moisture contents are higher than heartwood in each relative humidities conditions. Tangential and radial ratios of average swelling values are 1:1.971 in sapwood and 1:2.178 in heartwood.

• Journal of the Korean Wood Science and Technology
• /
• v.19 no.4
• /
• pp.27-33
• /
• 1991

Three kinds of specimens(radiata pine sapwood, radiata pine heartwood and whemlock heartwood) were dried at four temperature levels (30, 40, 50 and $60^{\circ}C$) in an emvironmental chamber. Unsteady-state diffusion coefficients were calculated from obtained drying fates by using infinite slab equation for first half of sorption and interval diffusion equation for second half of sorption. Activation energies for moisture diffusion in wood were calculated from the diffusion coefficients obtained at four temperatures. In most cases diffusion coefficients for radial movement were higher than those for tangential movement. Activation energy differences between sapwood and heartwood weren't significant for radial movement, but were significant for tangential movement. Most activation energies calculated from drying rates were lower than heat of water condensation(about 11,000cal/mole). Specially the avenge activation energy for sapwood tangential movement was only 5,000cal/mole.

• Journal of the Korean Wood Science and Technology
• /
• v.28 no.4
• /
• pp.25-28
• /
• 2000

Two flavan 3,4-diol derivatives were isolated from the heartwood of Robinia pseudoacacia and characterized by spectroscopic methods including $^1H$ and $^{13}C$ NMR and positive FAB-MS. The structures were identified as 2,3-trans-3,4-cis-3,4,7,3',4',5'-hexahydroxy flavan, one of isomeric leucorobinetinidins, and 4'-methoxy-2,3-trans-3,4-cis-3,4,7,3',5'-pentahydroxy flavan.

• Journal of the Korean Wood Science and Technology
• /
• v.28 no.2
• /
• pp.42-48
• /
• 2000

Two stilbenoids and two flavonoids were isolated from ethylacetate fraction of ethanol extract of Morns bombycis heartwood. These four compounds were identified 2',3,4',5-tetrahydroxystilbene(oxyresveratrol), 3,4',5-trihydroxystilbene (resveratrol) as stilbenoids, and 2',3,4',5,7-pentahydroxyflavone(morin), 3,4',5,7-tetrahydroxyflavan((+)-afzelechin) as flavonoids by Mass and NMR spectroscopic analysis.

• Journal of the Korean Wood Science and Technology
• /
• v.31 no.4
• /
• pp.16-23
• /
• 2003

Four flavonoids were isolated from the heartwood of Prunus sargentii. The structures were identified by NMR spectroscopic analysis: prunetin as isoflavone, angophorol, and sakuranetin as flavanone, and isosakuranin as flavanone glycoside. However, these compounds indicated low antifungal and antioxidative activities. In this regard, it could suggest that high antifungal and antioxidative activities of extractives of P. sargentii have no ralationship with these compounds.

• Natural Product Sciences
• /
• v.28 no.3
• /
• pp.115-120
• /
• 2022

Ten compounds, consisting of neoflavonoids (1-5), isoflavonoids (6 and 7), flavanone (8), and chalcones (9 and 10) were isolated from the ethyl acetate and n-butanol-soluble fractions of the heartwood of Dalbergia melanoxylon. The chemical structures were identified on the basis of spectroscopic evidence and compared to previously reported spectra. Compounds 1-10 were evaluated for cytotoxicity against HCT116 human colorectal cancer, MDA-MB-231 human metastatic breast cancer, and A2058 human melanoma cell lines. Among them, compounds 3 and 10 showed the strongest cytotoxic activity with IC₅₀ values of 11.92±1.07 μM, 10.83±1.02 μM, and 14.37±1.02 μM, 13.62±1.09 μM against HCT116 and MDA-MB-231 cell lines, respectively. Compounds 9 and 10 also had cytotoxic activity with IC₅₀ values of 13.49±1.18 μM and 9.82±0.91 μM against A2058 cell lines, respectively. To the best our knowledge, compounds 2 and 5-10 were isolated from this source for the first time.

• Journal of the Korean Wood Science and Technology
• /
• v.43 no.2
• /
• pp.248-257
• /
• 2015

This research focused on the natural durability of twenty one lesser known tropical wood species planted in West Java, Indonesia against subterranean termite (Coptotermes curvignathus). It was observed that both heartwood and sapwood of Kiara payung (Filicium decipiens); heartwoods of Nangka (Arthocarpus heterophyllus), Mahoni (Swietenia macrophylla) and Simpur (Dillenia grandifolia); and sapwood of Bungur (Lagerstroemia speciosa) were rated as resistant (natural durability class II) according to Indonesian standard SNI 01.7207.2006 (BSN 2006). Both heartwood and sapwood of Salam (Syzigium polyanthum), Pasang (Lithocarpus sundaicus), Bisbul (Diospyros discolor), Rukam (Flacourtia rukam) and Trembesi (Samanea saman); heartwood of Puspa (Schima walichii), Bungur, Tanjung (Mimusops elangi) and Angsana (Pterocarpus indicus) were rated as moderately resistant (natural durability class III). Both heartwood and sapwood of Sungkai (Peronema canescens), Pine (Pinus merkusii), Mangium (Acacia mangium) and Afrika (Maesopsis eminii); sapwoods of Mahoni, Puspa and Tanjung were rated as poorly resistant (natural durability class IV). Both heartwood and sapwood of Agathis (Agathis dammara), Durian (Durio zibethinus), Ki sampang (Evodia latifolia) and Jabon (Anthocephalus cadamba); sapwoods of Nangka and Angsana were rated as very poorly resistant (natural durability class V). This reserach showed that woods with lower resistance against C. curvignathus attack (natural durability class IV and V) tend to have lower termite mortality values compared to woods with higher resistance against C. curvignathus attack (natural durability class II and III). Results of the study will provide some valuable information on termite resistance of twenty one lesser known tropical wood species planted in Indonesia.

• Journal of Korean Society of Forest Science
• /
• v.79 no.4
• /
• pp.419-423
• /
• 1990

This study was carried out to investigate the cause of pith-damaged wood formation, the state of growth, and difference of chemical composition of Japanese Larix(L. leptolepis Gorden). 1. Larix grew normaly to 10 years, and the volume increment was 32.4%. But it was gradually decreased to 19.4% from 11 to 13 years that the heartwood damage was occurred. Therefore, the volume increment was decreased 13%. The decayed wood was formed from fire wound portion of bark by forest fire. The volume loss from pith-dagmaged wood occurred by forest fire was more than 20%. 2. On the ash content, heartwood(0.05%) and pith-damaged wood(0.08%) was lower than sapwood(0.29%). The difference of extractive contents are considered the reason. It is considered that this ash content difference is depend upon the extractive contents among sap, heart and decayed wood parts. Holocellulose contents were from 54.3% to 59.3% and there were no difference among heartwood, pith-damaged wood, and sapwood, On the pentosan contents, heartwood(6.3%) and pith-damaged wood(6.6%) were higher than sapwood. Lignin contents of pith-damaged wood was tower than heartwood (34.4%). This seems to weaken all kinds of wood strength.

• Natural Product Sciences
• /
• v.6 no.2
• /
• pp.96-101
• /
• 2000

The ethanolic extract of the heartwood of Taxus baccata L. afforded six taxoids, belonging to the skeletally three different groups, $2{\alpha},\;5{\alpha},\;10{\beta}-triacetoxy-14{\beta}-(2-methyl)-butryloxy-4(20)$,11-taxadiene (1), taxusin (2), baccatin VI (3), baccatin III (4), $1{\beta}-hydroxybaccatin$ I (5) and taxol (6). The isolation and structure elucidation of three taxoids (3-5) have been presented in this study. This is the first report for the presence of these taxoids in Taxus baccata L. growing in Turkey.