• Journal of the Korean Wood Science and Technology
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• v.34 no.5
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• pp.1-10
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• 2006

The objective of this study was to elucidate the microscopic patterns of decay caused by brown-rot fungi of Tyromyces palustri and Gloeophyllum trabeum in Korean red pine (Pinus densiflora) and radiata pine (Pinus radiata) woods through light and electron microscopies. The ultrastructural changes of cell walls attacked by the two brown-rot fungi were compared in this respect. Macroscopically, radiata pine showed more ring and radial checks than Korean red pine. Microscopically, with the progress of decay, spiral checks associated with cross-field pits and bore holes in the cell wall were more remarkably numerous in the radiata pine than in the Korean red pine. In the radiata pine, G. trabeum produced more spiral checks in the cell wall than T. palustris. In the advanced stages of decay by G. trabeum, the erosions of ray cell walls were identified both in the Korean red pine and radiata pine but $S_3$ layers of tracheid walls were eroded only in the Korean red pine.

• Journal of the Korean Wood Science and Technology
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• v.39 no.4
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• pp.311-317
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• 2011

The mechanical properties of heat-compressed Radiata pine (Pinus radiata D.Don) by compression set were investigated. Heat-compression condition was temperature at $180^{\circ}C$ and press time for 60 minutes. The mechanical properties of heat-compressed wood increased with increasing compression set. Increase of the specific gravity has led to increase in mechanical properties. The maximum compression set of Radiata pine was investigated approximately 65%. It was almost same result with porosity 68% of Radiata pine in specific gravity 0.48.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.424-430
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• 2006

Low molecular weight polyphenols were isolated from hot water extracts of radiata pine (Pinus radiata) bark using a Sephadex LH-20 column and characterized by $^1H$ and $^{13}C$ NMR, UV, FT-IR, and GC-MS analyses. Major compounds isolated and identified were protocatechuic acid, trans-taxifolin, and quercetin. Trans-taxifolin, an important intermediate in biosynthetic route of proanthocyanidin (PA), was isolated in large quantities and indicates that PA is a major component of radiata pine bark. Small amounts of polyphenols were identified by GC-MS analysis. The presence of p-hydroxybenzoic acid, vanillic acid, protocatechuic acid, cis- and trans-feruic acid, p-coumaric acid, trans-caffeic acid, (-)-epicatechin, (+)-catechin, trans- and cis-taxifolin, (+)-gallocatechin, and quercetin was confirmed by comparison of mass fragmentation patterns and retention times (RT) with authentic samples. In addition, the presence of astringenin, astringenin glycoside, trans- and cis-leucodelphinidin was strongly assumed from characteristic mass fragment ions due to their conjugated structure and retro Diels-Alder reaction, and also from biosynthetic route of PA. GC-MS analysis allowed us to detect small amounts of phenolic acids and flavonoids and eventually discriminate trans- and cis-configuration in the identified polyphenols.

• Journal of the Korean Wood Science and Technology
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• v.35 no.2
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• pp.1-8
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• 2007

Frost ring formed in the secondary xylem of Pinus radiata was examined using various microscopic techniques. Cell walls in a frost ring were poorly developed, lacking in the proportion of wall components. Formation of secondary cell wall was imperfect and thickness of secondary wall was varied. Cytochemical examinations provided the evidence that the synthesis of structural polysaccharides and lignin was inhibited, resulting in the malformation of secondary cell walls. Judging by the highly irregular nature of the cell wall, it appears that cellulosic/hemicellulosic framework was affected and the template for lignification by frost.

• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.720-727
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• 2017

Antioxidants are known to affect the feeding habits of termites and a good source is pine bark which contains high levels of antioxidants which can be extracted with neutral solvents. In this study procyanidins (PCs)-rich MeOH-extract and a hot-water extract (HWE) were prepared from Pinus radiata bark. HWE was further separated into crude PCs (CPCs), polymeric PCs (PPCs), and low-molecular-weight PCs (LMWPCs) fractions. The MeOH extract and these fractions were examined for termite (Reticulitermes flavipes Kollar) antifeedant activities using a no-choice test. Catechin was used as a positive control. The LMWPCs was found to be the most effective deterrent to termite feeding. The comparative efficiency of the compounds tested were LMWPCs > PPCs > CPCs > MeOH extract, with the latter being more dependent on molecular weight than on its antioxidant activity.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.861-868
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• 2020

The use of polyphenol extracts from radiata pine (Pinus radiata) bark as raw materials for bio-foams was investigated along with the optimal NaOH extraction conditions. The targeted yield of alkaline extracts was 60%, and the targeted pH was 11 to 12. The radiata pine bark was composed of 70% of a 1% NaOH extract, which contained mainly polyphenols, such as proanthocyanidin (PA). As the particle size of the bark decreased, the yield of the 1% NaOH extracts increased from 57 to 87%. A range of NaOH concentrations, liquor ratios, and extraction times were explored to establish an economic polyphenol extraction method. More than 60% of the alkaline extract was extracted, and the pH of the extract was approximately 12 when the optimum extraction conditions were employed, i.e., a liquor to bark ratio of 5:1, a NaOH dosage of 17 to 18% based on the bark weight, and a 1 h extraction time. Following neutralization of the alkaline extract, structural analysis indicated severe structural changes in the PA during the alkaline extraction. Because the alkaline extract was barely soluble in the solvent used for the structural analyses, it is assumed that chemical modification is required to increase the solubility of the alkaline extract for the production of bio-foams.

• Plant Biotechnology Reports
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• v.5 no.2
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• pp.177-186
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• 2011

This study describes for the first time in Pinus genus a plant regeneration system via a combined pathway of somatic embryogenesis and organogenesis from immature seeds of radiata pine. Somatic embryos were obtained from embryogenic line 2162 of Pinus radiata D. Don on EDM basal medium containing $60{\mu}M$ ABA and 6% sucrose. The explants used for organogenesis experiments were either freshly collected somatic embryos or somatic embryos germinated for 1 week. Germination medium was half-strength LP medium, supplemented with 0.2% activated charcoal. Different induction periods and BA concentrations were assayed for shoot induction. After induction treatments, explants were elongated on the same medium used for germination stage. Rooting medium was quarter-strength LP medium supplemented with three different auxin treatments: $1.5mg\;L^{-1}$ 1-naphthalene acetic acid (NAA), $1.5mg\;L^{-1}$ indole-3-butyric acid (IBA) and $1mg\;L^{-1}$ IBA with $0.5mg\;L^{-1}$ NAA (MIX). The effect of the photon flux ($120mmol\;m^{-2}\;s^{-1}$ and darkness) in the first week of the explants in the rooting media was also tested. This methodology could offer an alternative to overcome some problems associated with somatic embryogenesis such as the seasonality of embryogenic tissue (ET) initiation or a low embryo production from the ET, a particularly important issue in the case of genetically transformed ETs.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.878-887
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• 2020

A neutral extract (NE), that is soluble in cold water and has excellent antioxidant activity, from Pinus radiata pine bark was prepared by sodium bicarbonate treatment, and its chemical characteristics were investigated. NE was prepared by treating P. radiata bark with 0.8% NaHCO₃ aqueous solution with a 5 : 1 liquor-to-bark ratio at boiling temperature for 1 h, resulting in 44% yield and final pH of 6.66. The yield of NE was 11% higher than that of the hot water extract (HWE) due to the increase in the solubility of polyphenols, the main component in the bark, by NaHCO₃ treatment. NE was characterized through FT-IR, NMR, and MALDI TOF MS analyses. The results indicated that NE is mostly composed of proanthocyanidins (PAs) consisting of procyanidin (PC) units. The acetylated neutral extract (Ac-NE) had weight average molecular weight (${\bar{M}}w$) of 5,300 Da. The Ac-NE had wide molecular weight distribution and its polydispersity (${\bar{M}}w/{\bar{M}}n$) was 6 times higher than that of pure PA. The antioxidant activity of NE was determined by 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and showed that NE had comparable antioxidant activity with pure PA.

• Journal of the Korean Wood Science and Technology
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• v.39 no.4
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• pp.303-310
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• 2011

The mechanical properties of heat-compressed Radiata pine (Pinus radiata D.Don) by compression temperature and time were investigated. The compressive strength and bending strength of heat-compressed wood increased with increasing compression temperature and time. But the compressive strength and bending strength decreased with press temperature $220^{\circ}C$. It was considered due to thermal degradation during high temperature conditions. The surface hardness of heat-compressed wood increased with increasing compression temperature. However, the effect of compression time was negligible. The nail holding power was not affected by compression temperature and time.

• Korean Journal of Human Ecology
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• v.18 no.6
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• pp.1315-1321
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• 2009

The chemical composition of natural powder dye $Pinux^{TM}$ manufactured from Pinus radiata bark and dyeability of dyed silk fabrics with $Pinux^{TM}$ were examined. It is made up of the optimum dyeing condition of silk fabric according to the dyeing concentration, dyeing time, and dyeing temperature. Also, we examined the colorfastness and antibiosis of dyed silk fabrics to washing, rubbing, perspiration and light. For the analysis of the chemical composition of $Pinux^{TM}$, the total contents of phenolic compound, proanthocyanidin(PA) and anti-oxidative activities of the dye were analyzed. As a result, it was found that the main components of the $Pinux^{TM}$ manufactured from Pinus radiata bark is proanthocyanidin, mostly a flavonoid containing a procyanidin structure, and it consists of approximately 63% phenol. As a result of examining the dyeability of silk fabrics with $Pinux^{TM}$, it showed that the dyeability was best under the conditions of the concentration of dye $1{\sim}1.5%$(wt/v%), dyeing time of 90 minutes, and dyeing temperature at $90^{\circ}C$. It was found that the colorfastness of dyed silk fabrics, colorfastness to washing, perspiration for acidic and rubbing were as good as grade 4 or 4-5. However, the colorfastness to light was low at grade 1, the same as the results of other natural dyed fabrics. As a result of the antibiosis measurement for the $Pinux^{TM}$-dyed silk fabrics, it showed high antibacterial properties to Staphylococcus sureus at 99.6%.