• 한국가구학회지
• /
• 제26권3호
• /
• pp.222-228
• /
• 2015

To evaluate the natural decay durability of valuable domestic softwoods which are used for preservative treatment in our country, we carried out decay test by European standard method. Of all test wood species, Japanese larch (Larix leptolepis) showed slightly high natural decay durability compared to other 4 wood species, Japanese red pine (Pinus densiflora), pitch pine (Pinus rigida), Japanese cedar (Cryptomeria japonica), and scots pine (Pinus sylvestris). However, all of evaluated domestic softwood species in this study caused high weight losses over about 30% in heartwood by test fungus, Poria placenta. We can hardly expect a good natural decay durability from these softwood species. According to the classification of the natural durability of European standard (EN 350-1), they are classified into "Not durable" or "Slightly durable". Therefore, if using these softwoods as exterior materials, we must do preservative treatment to ensure durability.

• 한국가구학회지
• /
• 제18권1호
• /
• pp.39-46
• /
• 2007

This study was carried out to investigate the wood properties for efficient utilization of warm temperate tree species of Quercus acuta Thunb. grown in Korea. Fundamental wood properties in the anatomical, physical, mechanical and chemical characteristics were examined. Quercus acuta Thunb. is a radial-porous, straight grained and fine textured wood. The heartwood is not clearly distinguished from the sapwood. In physical properties, it has a high oven-dry specific gravity of $0.85{\pm}0.02$, and high shrinkage from green to air-dried condition of $7.05{\pm}0.52%$ in radial and $11.13{\pm}0.48%$ in tangential direction. Mechanical properties determined are strong with the MOR of $1,065{\pm}90kgf/cm^2$, and tensile strength parallel to grain of $1,490{\pm}258kgf/cm^2$ and shear strength of $175{\pm}13kgf/cm^2$. Also, this wood has high extractive contents: 11.11% for cold and 13.51% for hot water.

• 한국식품과학회지
• /
• 제47권5호
• /
• pp.545-555
• /
• 2015

Oxyresveratrol (trans-2,3',4,5'-tetrahydroxystilbene) has been receiving increasing attention because of its astonishing biological activities, including antihyperlipidemic, neuroprotection, antidiabetic, anticancer, antiinflammation, immunomodulation, antiaging, and antioxidant activities. Oxyresveratrol is a stilbenoid, a type of natural phenol and a phytoalexin produced in the roots, stems, leaves, and fruits of several plants. It was first isolated from the heartwood of Artocarpus lakoocha, and has also been found in various plants, including Smilax china, Morus alba, Varatrum nigrum, Scirpus maritinus, and Maclura pomifera. Oxyresveratrol, an aglycone of mulberroside A, has been produced by microbial biotransformation or enzymatic hydrolysis of a glycosylated stilbene mulberroside A, which is one of the major compounds of the roots of M. alba. Oxyresveratrol shows less cytotoxicity, better antioxidant activity and polarity, and higher cell permeability and bioavailability than resveratrol (trans-3,5,4'-trihydroxystilbene), a well-known antioxidant, suggesting that oxyresveratrol might be a potential candidate for use in health functional food and medicine. This review focuses on the plant sources, chemical characteristics, analysis, biosynthesis, and biological activities of oxyresveratrol as well as describes the perspectives on further exploration of oxyresveratrol.

• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
• /
• pp.102-102
• /
• 2003

The inhibitors of prostaglandin biosynthesis and nitric oxide production by corresponding inducible isozyme have been considered as potential anti-inflammatory and cancer chemopreventive agents. In our continuous search for cancer chemopreventive agents from natural products, we have evaluated the inhibitory potential of PGE$_2$and NO production in lipopolysaccharide (LPS)-induced mouse macrophage RAW264.7 cells. As a result, pinosylvin (3,5-dihydroxy-trans-stilbene), a stilbenoid, mainly found from the heartwood and leaves of the Pinus sylvestris, showed potential inhibitory activity of LPS-induced PGE$_2$and NO production in a dose-dependent manner. Pinosylvin also suppressed the LPS-induced iNOS protein expression. Further study revealed that pinosylvin exhibited antioxidant activity by the DPPH free radical scavenging potential and inhibitory effect of xanthine oxidase activity. In addition, pinosylvin inhibited COX -2 overexpressed human colon cancer cell (HT-29) growth in a time- and dose-dependent manner. These findings suggest that pinosylvin might be a promising candidate for developing cancer chemopreventive agent.

• Journal of Plant Biotechnology
• /
• 제3권2호
• /
• pp.45-57
• /
• 2001

Trees have the ability to undergo secondary growth and produce a woody body. This tree-specific growth is affected by the secondary vascular system and the developmental continuum of secondary phloem and xylem. Secondary growth is one of the most important biological processes on earth. Considering its economic and environmental significance, our knowledge of tree growth and development is surprisingly limited. Trees have received little attention as model species in plant science, as most Plant biology questions can be best addressed by using herbaceous model species, such as Arabidopsis. Furthermore, tree biology is difficult to study mainly due to the inherent problems of tree species, including large size, long generation time, large genome size, and recalcitrance to biotechnological manipulations. Despite all of this, one must rely on trees as models to study tree-specific questions, such as secondary growth, which cannot be studied effectively in non-woody model species. Recent advances in genomics technology provide a unique opportunity to overcome these inherent tree-related problems. Several groups, including our own, have been successful in studying the biology of wood formation with a variety of hardwood and softwood species. In this article, 1 first review the current understanding of tree growth and then discuss the recent attempts to fully explore and realize the potential of molecular biology as a tool for enhanced understanding of secondary growth.

• Journal of the Korean Wood Science and Technology
• /
• 제23권4호
• /
• pp.1-9
• /
• 1995

This study was carried out to experiment the dimensional stabilization of woods of red pine (Pinus densiflora S. et Z.) and sugi(Cryptomeria japonica D. Don) by vacuum impregnation of polyehtylene glycols(PEG) with mo. wt. 200, 400, 600, 1000; polypropylene glycols (PPG) with mo. wt. 425,725 ; PEG-acryloylates, and PPG-acryloylates synthesized, and then by water soaking. The results obtained are as follows: 1. The density of sapwood and heartwood was different from each other in both species. 2. The PEG and PEG-macromers with lower molecular weight by impregnation has increased the density of wood specimens more higher, thereby caused their higher volume expansion, and those with higher molecular weight than 600 has tended to down their density increment. 3. Before and after water soaking, the density decrease of specimen impregnated was high in woods impregnated with simple PEG and PPG, while lower in specimens impregnated with PEG-macromers and PPG-macromers. 4. So PEG-macromer was expected to hold the original dimension of decayed wood for antiques, but it was necessary to develop another penetration method as well as aqueous solvent.

• Journal of the Korean Wood Science and Technology
• /
• 제23권4호
• /
• pp.18-26
• /
• 1995

국내 합판 산업계는 오랫동안 남양재 활엽수를 주로 사용하여 왔으나, 환경 보존적인 측면에서 열대재의 벌채를 규제하는 등 여러 요인으로 인하여 합판용 원목의 수입이 어려워지고 있다. 이에 대응하기 위하여 합판용 원목을 침엽수재로 대체할 필요가 있으며, 침엽수 합판 제조를 위한 기초 자료를 제공하기 위하여 본 연구를 수행하였다. 공시 수종은 국내에서 조림한 낙엽송과 시베리아산 낙엽송 및 뉴질랜드산 라디에타 소나무였으며, 공시원목으로부터 얻어진 단판의 품질과 이들 단판으로 제조한 합판의 접착력과 휨강도를 조사하였다. 이면 할렬실험에서 시베리아산 낙엽송은 다른 수종에 비해 할렬 밀도가 낮게 나타났다. 단판 품질은 접착력 및 휨강도에 거의 영향을 미치지 않았으나 합판의 휨강도에서는 심재와 변재에 따른 차이가 있음을 알 수 있었다. 이는 합판제조사 심재와 변재를 구별하여 사용할 필요가 있었다. 라디에타 소나무의 변재부로 만든 합판 MOR은 다른 수종에 비해 우수하게 나타났다. 접착력 실험에 있어서는 페놀 접착제를 사용하여 만들어진 합판만이 구조용으로써 사용할 수 있음을 알았다. 목파율은 동일 수종 합판에서는 라디에타 소나무 구성이 가장 높게 나타났으며, 이수종(異樹種) 합판에서는 표판을 국산 낙엽송, 심판을 라디에타 소나무를 사용하여 만든 합판에서 가장 높게 나타났다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2013년도 춘계학술대회 논문집
• /
• pp.760-765
• /
• 2013

Eco-friendly material applied to building would be one of the materials which is must developed for global environmental conservation and reduction of carbon dioxide. For development of eco-friendly material, a cellulose sound-absorbing material has been developed with waste paper through adjustment of various mix proportions. The developed cellulose sound-absorbing material has been tested for its acoustic properties such as acoustic absorptivity and dynamic elastic modulus. The absorptivity was evaluated by developing six samples and using impedance tube and reverberation chamber. As a result of the evaluation, 0.64(NRC) was secured in absorptivity and $4.7MN/m^3$ was indicated in dynamic elastic modulus. Also, for practical use of developed sound-absorbing material as inner heartwood in drywall, comparison test of sound reduction index was performed with existing glass wool sound-absorbing material and constructed drywall of gybsum board. The results have shown 55dB(Rw) of sound reduction index in glass-wool wall and 46dB(Rw) in cellulose.

• 한국소음진동공학회논문집
• /
• 제23권5호
• /
• pp.456-462
• /
• 2013

Eco-friendly material applied to building would be one of the materials which is must developed for global environmental conservation and reduction of carbon dioxide. For development of eco-friendly material, a cellulose absorber has been developed with waste paper through adjustment of various mix proportions. The developed cellulose absorber has been tested for its acoustic properties such as absorption coefficient and dynamic stiffness. The absorption coefficient was evaluated by developing six samples and using impedance tube and reverberation chamber. As a result of the evaluation, 0.64(NRC) was secured in absorption coefficient and 4.7 $MN/m^3$ was indicated in dynamic stiffness. Also, for practical use of developed absorbers as inner heartwood in drywall, comparison test of sound reduction index was performed with existing glass wool absorbers and constructed drywall of gypsum board. The results have shown 55 dB(Rw) of sound reduction index in glass-wool wall and 46 dB(Rw) in cellulose.

• 생약학회지
• /
• 제31권3호
• /
• pp.345-350
• /
• 2000

From the heartwood of Rhus verniciflua, four known flavonoids (1-4) were isolated along with an unknown one (5). Compounds 1-4 were identified to be garbanzol, sulfuretin, fisetin and fustin by NMR data. NMR data of 1-4 were fully assigned by the aids of 2D-NMR spectra. Among these compounds, only sulfuretin had significant cytotoxic and antioxidant ability at high concentrations. In addition, it seems likely that the 5-hydroxy-lacking flavonoids could not influence on the activity of laccase with cofactor of cupric cation, which catalyzes oxidative coupling reaction, in this plant.