• Journal of the Korean Wood Science and Technology
• /
• v.19 no.3
• /
• pp.72-76
• /
• 1991

The new preparative separation techneque of dihydroquercetin (2, 3-trans-dihdroxy-3, 3', 4', 5, 7-pentahydroxydihydroflavonol) was investigated by liquid chromatography. Also some typical coniferous wood bark were examined for the sources of dihydroquercetin. The good sources of dihydroquercetin were Douglas-fir[Pseudotsuga menziesii] bark and pitch pine [Pinus rigida] bark. There is no dependance the produced place and species dihyroquercetin which is separated by silica-gel column chromatography was taken with white needle-like crystals. This crystals were very stable in the humidity and on the light. It also can stored very long without derivatives.

• Journal of the Korean Wood Science and Technology
• /
• v.29 no.4
• /
• pp.79-88
• /
• 2001

Lectin was isolated from shiitake mushroom (Lentinula edodes) with 0.15 M NaCl solution, and purified by the following procedures : precipitation by ammonium sulfate, anion exchange column chromatography on DEAE Sephadex A-50 and hydroxyapatite column chromatography. The fresh pileus part of the mushroom contained more than two times of lectin compared to the stipe part, and lectins and its activity were reduced by heating. The extraction yield of crude lectin was 46.03%, 28% yield after purification on on DEAE Sephadex A-50 column chromatography. Some amino acids, aspartic acid, serine, alanine and histidine, were increased by purification process. Relatively low molecular weight parts of lectin had the agglutinating activity for rabbit blood, and its molecular weight was about 23 kDa The molecular weights of purified lectins, LA-a and LB-b, by the hydroxyapatite column chromatography were 24 kDa and 23 kDa, respectively.

• Journal of the Korean Wood Science and Technology
• /
• v.45 no.1
• /
• pp.53-61
• /
• 2017

In this study, specimens were produced with a column member and a wooden gusset only by inserting an wooden gusset which is a substitute for steel plate into the center of a slit-processed column member. The moment resistance performance of the specimens was compared with that of control specimens that used a steel plate. The measured maximum moments of the specimens produced with GFRP-reinforced wooden laminated gussets and pins were lower by 24% on average compared to the steel plate-inserted specimens, but they showed good toughness. The fracture shape suggests that it was fractured along the annual rings between the pin and the end of the column member. The rigid specimen that integrated a laminated wood and a wooden laminated gusset with adhesive showed 2.8 times greater initial rigidity and 40% greater maximum moment on average compared to the control specimen. The rigid specimens mainly fractured on a glulam around glue line.

• Journal of the Korean Wood Science and Technology
• /
• v.34 no.1
• /
• pp.79-85
• /
• 2006

Paulownia coreana Uyeki fruits were collected, extracted with acetone-$H_2O$ (7:3, v /v), fractionated with n-hexane, methylene chloride, and ethyl acetate, then freeze dried to give some dark brown powder. The ethyl acetate soluble mixture was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. Spectrometric analysis such as NMR and MS including TLC were performed to establish the structures of the isolated compounds. From the ethyl acetate fraction, one phenolic acid (I) and five flavonoids (II~VI) and were isolated and elucidated. The antioxidative activities were tested on the isolated compounds, crude and fractionated extractives by DPPH radical scavenging method. The result showed that caffeic acid, kaempferol, luteolin, quercetin and the EtOAc soluble fraction exhibited higher activities than those of ${\alpha}$-tocopherol and BHT.

• Journal of the Korean Wood Science and Technology
• /
• v.37 no.1
• /
• pp.1-11
• /
• 2009

Although the exterior wood such as column may frequently contact with liquid water, little work has been found to measure liquid water absorption in wood. To investigate the moisture diffusivity of wood in the longitudinal direction including bound water and free water movement, liquid water absorption test was conducted at the room temperature. The order of magnitude for absorption coefficient and diffusivity was Japanese elm, horn beam, hemlock, spruce, radiata pine, and painted maple. The Boltzmann transformation method was used to determine the diffusivity from measured moisture content distributions in the absorption test. The shape of the curve representing the dependence of diffusivity with moisture content was similar in test samples. The diffusivity decreased with increasing moisture content until around the fiber saturation point and then increased at the nonhygroscopic region, which ranged from $10^{-10}$ to $10^{-7}m^2/s$.

• Journal of the Korean Wood Science and Technology
• /
• v.24 no.4
• /
• pp.93-99
• /
• 1996

In order to investigate the extent of fixation of new water-borne preservatives in blocks of pinus densiflora sapwoods the streaming potential through the column with preservative treated wood was measured at various conditions. The rates of leachability of ingredients in the treated wood were estimated by the measurement of electric conductivity of the solution with the leached components. The solution was also analyzed by Atomic absorption spectrophotometer (AA). As a results, the experimental data indicated that the fixation of CCB, CCFZ and ACQ in wood were relatively unstable. The fixation rates of CCB, CCFZ were improved by increasing heat and drying time. The amounts of the leached ingredients were apparently higher in CCB and CCFZ than in CCA, while the rate of leaching of ACQ was not changed at various drying temperature.

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.259.2-259.2
• /
• 2003

This study was carried out to isolate and to identify the compounds and to find out antioxidants from the leaf of Distylium racemosum which belongs to Hamamelidaceae family. To isolate compounds, leaf of this plant were extracted with 50％ Acetone and then crude extracts was partitioned with hexane. ether and ethyl acetate (EtOAc) successively. After partitioned, EtOAc fraction was subjected to column chromatography with various solvent systems in silica gel and/or Sephadex LH-20. (omitted)

• Journal of the Korean Wood Science and Technology
• /
• v.36 no.4
• /
• pp.58-65
• /
• 2008

Most connections for the glulam structural members consisted of connector and fastener. The mechanical behaviour of the connection can be occurred by the dowel bearing resistance and wood shear by the fastener. This study aims at the examination of the shear properties for the small specimen with lamination components and for the full-sized pin connection and the moment resisting property for the double shear full-sized pin connection using structural column and beam members. Small specimens including glue line shows greater density and shear strength by the lamination effect than other specimens. It is needed that estimations of double shear property and moment resistance for the pin connections should be adjusted in some degree. For the better and safe estimation of moment resistance strength for the column-beam pin connection, however, the shear strength of small specimens should be deducted by 10%.

• Journal of the Korean Wood Science and Technology
• /
• v.37 no.1
• /
• pp.73-77
• /
• 2009

This study was carried out to investigate the valuable antioxidative compound from extracts of Alnus hirsuta Turcz. which has a nationwide distribution. The bark (2 kg) was extracted with 70% aqueous acetone and fractionated, and the ethyl acetate and $H_2O$ fractions, separately, were chromatographed on a Sephadex LH-20 column to purify the mixture and to give two diarylheptanoid compounds. The isolated compounds were analyzed by NMR spectroscopy, including $^1H$, $^{13}C$ and two-dimensional NMR, and identified as oregonin (1) and 1,7-bis-(3,4-dihydroxyphenyl)-heptane-5-O-${\beta}$-D-xylopyranoside (2). The antioxidative activity was evaluated by DPPH method using two diarylheptanoids and acid-hydrolyzed oregonin derivative which indicated higher activity potential. Of those the acid-hydrolyzed oregonin derivative showed highly active potential with the value of 2.6 of $IC_{50}$.

• Journal of the Korean Wood Science and Technology
• /
• v.45 no.4
• /
• pp.456-462
• /
• 2017

Japanese anise (Illicium anisatum L.) twigs were collected and ground after drying, then immersed with 50% aqueous acetone for 3 days. After filtration, the extracts were fractionated with n-hexane, chloroform ($CHCl_3$), ethylacetate (EtOAc) and $H_2O$, and then freeze-dried after condensation. A portion of EtOAc soluble fraction (5.7 g) was chromatographed on a Sephadex LH-20 column with various aqueous $MeOH-H_2O$. Compound 2 and compound 3 were isolated from fraction 8 and 5, respectively. Compound 1 and compound 4 were isolated after rechromatography of fraction 7. The isolated compounds were elucidated as (+)-catechin (1), taxifolin (2), taxifolin-3-O-${\beta}$-D-(+)-xylopyranose (3) and quercitrin (4) by spectral and literature data, and by comparison with the authentic samples. Of the isolated compounds, taxifolin (2), taxifolin-3-O-${\beta}$-D-(+)-D-xylopyranose (3) and quercitrin (4) were isolated, for the first time, from the extracts of japanese anise twigs.