• Journal of the Korea Furniture Society
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• v.11 no.1
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• pp.69-74
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• 2000

Pinus $rigida{\times}taeda$ and Liriodendron tulipifira have been planted in this country for about 20 years. They are known as a relatively 13st-grown and useful species. The physical properties such as green moisture contents, specific gravities and dimensional shrinkages were examined with natively grown timbers. The kiln-dry schedules were developed with 30m thick boards by using an oven-fast-drying method. In both species the green MC's of sapwoods were higher than those of heartwoods, but their discrepancies were small. The green specific gravities of Pinus $rigida{\times}taeda$ and Liriodendron tulipifera were 0.48 and 0.41~O.42, respectively. The developed kiln-dry schedules were proven to minimize drying defects for the hoards of 30mm thickness and various width.

• Journal of Korean Society of Forest Science
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• v.83 no.1
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• pp.25-31
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• 1994

This study was conducted to investigate sensitivity of woody plants growing in urban and industrial regions of Seoul and Taejon, Korea. Malondialdehyde(MDA) contents were analyzed in tree foliage of Pinus densiflora, Pinus koraiensis, Ginkgo biloba, Liriodendron tulipifera and Platanus occidentalis. In addition, MDA contents were analyzed in the foliage of tree seedlings, i.e. Pinus densiflora. Pinus koraiensis, Ginkgo biloba and Liriodendron tulipifera, with the fumigation of $SO_2$ in gas chamber 4 hours a day for six days. MDA contents of leaves in Ginkgo biloba, Platanus occidentalis and Liriodendron tulipifera in polluted regions were higher than those in unpolluted region and among them Liriodendron tulipifera had the highest. MDA contents of Pinus densiflora and Pinus koraiensis increased with the increase of needle age. MDA contents of Liriodendron tulipifera seedlings were increased with the higher concentrations of $SO_2$ but MDA contents in other seedlings showed no changes with $SO_2$ treatment concentrations. MDA contents in all species were increased with the passage of exposure day. Especially. Liriodendron tulipifera had higher MDA content than other species. In Liriodendron tulipifera the MDA production increased with the passage of exposure day until the fourth day after that decreased.

• Journal of Korean Society of Forest Science
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• v.95 no.2
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• pp.216-219
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• 2006

After long exposure to low-density $SO_2$ the five tree species showed different changes in their visible damage: Ailanthus altissima showed no visible damage; Acanthopanax sessiliflorus, Populus alba ${\times}$ Populus glandulosa, and Platanus orientalis showed typical damage of yellow spots on their leaves; and Liriodendron tulipifera showed serious damage on the end of leaf tip. The photosynthesis rate of Liriodendron tulipifera and Acanthopanax sessiliflorus was usually lower than the control group: Ailanthus altissima, Populus alba ${\times}$ Populus glandulosa, and Platanus orientalis showed no difference from the control group, while Acanthopanax sessiliflorus and Liriodendron tulipifera showed large changes. In regard to the light compensation points, Ailanthus altissima showed similar values, Populus alba ${\times}$ Populus glandulosa and Platanus orientalis exposed to $SO_2$, showed 3 to $5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ higher values than the control group, and Acanthopanax sessiliflorus and Liriodendron tulipifera exposed to $SO_2$ showed approximately twice higher light compensation points.

• Natural Product Sciences
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• v.26 no.2
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• pp.171-175
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• 2020

Liriodendron tulipifera, belonging to the family Magnoliaceae, is commonly called tulip tree. Four N-acetylated aporphine alkaloids, N-acetylnornuciferine (1), N-acetylanonaine (2), N-acetyl-3-methoxynornuciferine (3), and N-acetyl-3-methoxynornantenine (4) were isolated from the roots of L. tulipifera. Although the purity of each compound (1 - 4) was determined to be 97, 96, 99, and 98%, respectively, the ¹H and ¹³C NMR spectroscopic data of the aporphine alkaloids 1 - 4 displayed all signals in duplicate, indicating the presence of two rotamers due to restricted rotation of N-COCH₃ functionality in solution status. The absolute configurations of 1 - 4 w ere established by measuring specific rotation and comparison with the reported data. This is the first report on the ¹H and ¹³C NMR assignments of N-acetyl-3-methoxynornuciferine (3) and N-acetyl-3-methoxynornantenine (4). This study provides advanced NMR spectroscopic data for the structure determination of rotameric aporphine alkaloids.

• Journal of the Korean Wood Science and Technology
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• v.32 no.6
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• pp.43-49
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• 2004

Three flavonoids, quercetin, taxifolin, and kaempferol were isolated from the woods of Liriodendron tulipifera. Their structures were determined by spectral analysis. Based on 1, l-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity method, the antioxidative activities of three isolated compounds and their acetates were measured in order to search for natural antioxidants. The IC₅₀ of quercetin (1), taxifolin (2), and kaempferol (3) were 3.6, 3.9, and 4.1 ㎍/㎖, respectively.

• Proceedings of the Korea Forestry Energy Research Society Conference
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• 2011.02a
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• pp.41-44
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• 2011

• Korean Journal of Pharmacognosy
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• v.18 no.1
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• pp.1-4
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• 1987

The methanol and benzene extracts of the leaves of 55 higher plants in Korea were tested for their antibacterial activity against three Gram positive bacteria, Streptococcus mutans, Staphylococcus aureus and Bacillus subtilis, and one Gram negative bacterium Escherichia coli. Among them, the methanol extract of the leaves of Liriodendron tulipifera showed remarkably potent antibacterial activity against both Gram positive and negative bacteria.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.1
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• pp.61-66
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• 2009

Effects of aqueous ammonia soaking treatments to yellow poplar (Liriodendron tulipifera L.) were investigated to focus on chemical compositional changes and enzymatic hydrolysis characteristics changes by this treatment. Treatment temperature and time were main variables. At 3 different levels of aqueous ammonia soaking temperature and time ($145^{\circ}C$ -1 h, $90^{\circ}C$ -16 h and $45^{\circ}C$ - 6 days), lower temperature and longer soaking time led to more xylan removal based on carbohydrate compositional analysis. However, at higher temperature treatment led to more enzymatic saccharification of cellulose to glucose by commercial cellulose mixtures (Celluclast 1.5L and Novozym 342 from Novozyme, Denmark). Cellulose hydrolysis was gradually increased with increasing enzymatic hydrolysis time but xylan hydrolysis was leveled out at early stage (less than 10 h) of enzymatic hydrolysis.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.3
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• pp.22-27
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• 2010

Pulping properties of the imported mixed eucalyptus chips and the domestic yellow poplar chips were investigated for comparing two chips as the raw materials for the hardwood chemical pulp. Soda-AQ (anthraquinone) pulping was applied for this study. The pulp from yellow poplar showed higher pulp yield than pulp from mixed eucalyptus, which comes from the lower hot-water soluble extractives and the higher polysaccharides in yellow poplar chips than those of the mixed eucalyptus chips. The yellow poplar pulp had higher average fiber length and fiber width than those of the mixed eucalyptus pulp, which led to the better respond to beating and the higher tear strength than those of the pulp from the mixed eucalyptus chips.

• YAKHAK HOEJI
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• v.34 no.2
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• pp.106-111
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• 1990

The isolation and identification of an antibacterial component, from the leaves of Liriodendron tulipifera. K. Kotch against a cariogenic bacterium Streptococcus mutans OMZ 176, were carried out for developing of anticariogenic agents. The bioactive component was elucidated as ${\beta}-liriodenolide$, which was isolated newly from the leaves of L. tulipifera. The minimal inhibitory concentration (MIC) of ${\beta}-liriodenolide$ was $100\;{\mu}g/ml$ and the antibacterial activity was stronger than that of berberine. ${\beta}-Liriodenolide$ inhibited ${\beta}-lactamase$ activity, 50, 100 and $200\;{\mu}M$ ${\beta}-liriodenolide$ did ${\beta}-lactamase$ activity as 0.7, 3.5 and 19.7%, respectively. The toxicity of ${\beta}-liriodenolide$ was not found with the method of photohemolysis.