• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.3
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• pp.66-73
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• 2005

This study was performed to understand the changes in wood extractives, mainly acetone extracts, in pine woods (Pinus densiflora and Pinus rigida) treated by three blue stain fungi (BSF) such as native BSF in Korea, Leptographium sp., screened Albino strain(BSFcs-1) and commercial Cartapip and fungicide, Wood guard. In addition their pulping and bleaching properties were investigated. BSF treatment has significantly reduced acetone extracts, $25.1{\sim}30.4%$ decreasing in red pine and $22.9{\sim}28.1%$ in pitch pine. Three week aging treatment showed about 20% decreasing in red pine and 19.3% in pitch pine. There were not so significant differences in extracts reduction among native BSF and Albino-type strains (Albino strain, BSFcs-1, and commercial Cartapip). But fungicide, Wood guard, treated wood showed relatively lower decreasing rates of extractives, 14% in red pine and 10.1% in pitch pine. Therefore it is understandable that the fungicide could protect the wood from blue stain fungi attack, but has no effect on its extractive reduction. Concerned to pulping properties of BSF and fungicide treated woods, red pine and pitch pine, optimum pulping condition was 20% active alkali, wood to liquor ratio 1 to 6, $170^{\circ}C$, and 2.5 hr. In the case of BSF woods, optimum pulping condition was same as the sound wood, $43.5{\sim}45%$ of pulp yields and $1.3{\sim}1.45%$ of rejects. Screened pulp yield of fungicide treated wood was lower than those of BSF treated woods. Rejects in pulps were higher in fungicide-treated wood than BSF treated woods. Bleaching pulp yields were ranged of 92 to 93.5%. BSF, Cartapip and fungicide treated woods resulted in lower brightness of $55{\sim}58%$, but Albino-type strain(BSFcs-1) $61.3{\sim}62.3%$, very similar to untreated one. Therefore bleaching chemicals could be saved in the processing of chemical pulping.

• Journal of the Korean Wood Science and Technology
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• v.46 no.6
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• pp.692-702
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• 2018

Streptococcus mutans causes oral diseases, including tooth decay, by producing a biofilm called plaque. Therefore, inhibition of biofilm formation is essential for maintaining oral health. Plants produce a variety of secondary metabolites, which act as starting sources for the discovery of new bioactive chemicals that inhibit biofilm formation of S. mutans. Previous studies have reported on chemicals with antibiotic activity for the inhibition of biofilm formation by S. mutans. In this study, nine plant extracts from Melonis Pedicellus, Agastachis Herba, Mori Cortex Radicis, Diospyros kaki leaves, Agrimoniae Herba, Polygoni Multiflori Radix, Lycopi Herba, Elsholtziae Herba, and Schizonepetae Spica were screened for the inhibition of biofilm formation from a plant extract library. The water-soluble compounds of the extracts did not affect cell growth but selectively inhibited biofilm formation. These results suggest that the selected plant extracts constitute novel biofilm formation inhibitors, with a novel biological mechanism, for improving oral hygiene.

• Journal of the Korean Wood Science and Technology
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• v.50 no.2
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• pp.113-125
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• 2022

This study aimed to explore the biodiversity of chemical compounds found in the bark of Guibourtia tessmannii from Gabon, commonly called Kévazingo, and evaluate their anti-termite activity to determine their potential values as a source of development of anti-termite products that can be valued in the fields of fine chemicals and wood preservation. Extraction of G. tessmannii bark powders was carried out using the cold maceration method with trichloroethylene, acetone, ethanol, and water. Phytochemical screening made it possible to highlight groups of chemical families present in the extracts. Anti-termite activity was tested on the wild termites "Cubitermes sp" of the genus Isoptera. The yield of the extracts were 17.11% for the buttress and 13.42% for the height at 6 m. Phytochemical tests revealed that alkaloids, polyphenols, sterols, tannins, reducing compounds, flavonoids, saponins, and anthraquinones were present in the extracts. Results of anti-termite activity indicated that anti-termite activity varied with the different parts of the bark studied, extraction solvent, and concentration (50/50) and (25/75) of the extracts used. The extracts at 50/50 concentration showed a slightly better anti-termite activity compared to the 25/75 concentration. In addition, the buttress Kévazingo or buttress showed the strongest anti-termite activity for the aqueous extract with a survival rate of 0% after 2 days.

• Journal of the Korean Wood Science and Technology
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• v.47 no.5
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• pp.587-596
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• 2019

This study aimed to determine the antimalarial effect of the Strychnos ligustrina (SLW) wood extracts and to analyze its phytochemicals. The SLW powder samples were macerated with 100% ethanol (E100), 75% ethanol (E75), 50% ethanol (E50), 25% ethanol (E25), and aqueous (A100). The extracts were analyzed by LCMS/MS, and its in-vitro antimalarial activity was tested with Plasmodium falciparum. The results showed that the extract yields of E100, E75, E50, E25, and A100 were 4.3, 5.2, 5.3, 4.7, and 3.6%, respectively. The antimalarial activities of the A100, E25, E50, and E75 extracts were classified as active with $IC_{50}$ values of 38.6, 42.6, 42.9, and $43.7{\mu}g/mL$, respectively. But, the antimalarial activity of the E100 extract was classified as slightly active with $IC_{50}$ values of $87.4{\mu}g/mL$. The dominant compounds contained in the extracts of A100, E25, E50, E75, and E100 was the alkaloid compound, namely brucine with relative concentrations of 24.96, 24.55, 21.33, 11.79, and 11.62%, respectively.

• Journal of the Korean Wood Science and Technology
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• v.42 no.5
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• pp.523-532
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• 2014

This study was done to evaluate the antioxidant effect of oak hot water extracts on the oxidative stress induced by reactive oxygen species (ROS). The cytotoxicity of $H_2O_2$-induced oxidative stress was performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay for the cell viability according to the dose-dependent treatment. Oak extracts demonstrated a dose-dependent ability to inhibit $H_2O_2$-induced apoptosis in cultured tenofibroblasts, as assessed by MTT assay and FACS analysis. $H_2O_2$ increased the phosphorylation of extracellular regulated kinase1/2 (ERK1/2) and of c-Jun N-terminal kinase (JNK) and the production of reactive oxygen species (ROS). In contrast, treatment with oak extracts was decreased this activation of ERK1/2 and JNK, as confirmed by western blot analysis, and reduced the production of ROS, as verified by fluorescent microscopic and flow cytometry (FACS) analyses. These findings suggest that oak extracts, by suppressing JNK, ERK1/2, and intracellular ROS production, have a concentration-dependent antiapoptotic effect on achilles tenofibroblasts exposed to an oxidative stressor, and may have therapeutic potential.

• Journal of the Korean Wood Science and Technology
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• v.47 no.4
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• pp.498-508
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• 2019

This study was carried out to investigate the potential of Korean red pine (Pinus densiflora) inner bark extracts as an antidiabetic agent. The ethyl acetate soluble fraction of the bark extracts was chromatographed on a Sephadex LH-20 column to yield five compounds, which structures were elucidated by NMR spectroscopy. The isolated compounds were (+)-catehin, (-)-epicatechin, taxifolin, taxifolin-3'-O-${\beta}$-D-(+)-glucose and $\tilde{n}$-courmaric acid. The antidiabetic activity of the different fractions, including the crude extracts and isolated compounds, was evaluated by ${\beta}$-cells insulin secretion and glucose uptake in skeletal muscle cells. The insulin secretion was 128% for taxifolin at $25{\mu}g/mL$. However, the other samples had no effect on this test. For the glucose uptake activity assay, $1{\mu}M$ insulin and 2 mM metformin were used as controls. Both the crude extract and taxifolin showed relatively low activity values, but the other samples yielded glucose uptake values over 260%. ${\rho}$-courmaric acid showed the highest uptake (270%). The results confirmed that Korean red pine extracts may be used as a hypoglycemic agent.

• Korean Journal of Medicinal Crop Science
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• v.18 no.3
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• pp.157-167
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• 2010

We investigated a method to improve anticancer activities of Acer mono wood extracts by ultra high pressure extraction process. The A. mono was extracted by water at $40^{\circ}C$ and 300 MPa for 15 min (High Pressure Extraction, HPE). The extraction yield by ultra high pressure extraction process was 5.42%. The cytotoxicity on human normal lung cell (HEL299) of the extracts from HPE showed 21.54% lower than that from conventional water extraction at $100^{\circ}C$ in adding the maximum concentration of 1.0 mg/$m{\ell}$. Ultra high pressure extracts process for 15 minutes extracts (HPE15) showed more potent scavenging effect than the control, BHA. On SOD-like test, the HPE15 showed highest activity as 32.4% at 1.0 mg/$m{\ell}$ concentration. Human stomach adenocarcinoma, liver adenocarcinoma, breast adenocarcinoma and lung adenocarcinoma cell growth were inhibited up to about 67~79%, in adding 1.0 mg/$m{\ell}$ of extracts from HPE. HPE was 20~25% higher than conventional water extraction. It was interesting that, among several cancer cell lines (stomach adenocarcinoma, liver adenocarcinoma), the growth of digestive related cancer cells were most effectively inhibited as about 75~79%. On in vivo experiment using ICR mice, the variation of body weight of mice group treated A. mono wood extracts from HPE of 100 mg/kg/day concentration was very lower than control and other group. The survival times of group treated this extracts was 61.96% longer than that of the control group and this extracts showed the lower tumor weight, which were 10.49 g than positive control as 16.17 g. Based on these results, we could tell that the HPE wood extracts of A. mono had higher anticancer activity than conventional water extraction. The results of HPE showed obvious advantages in higher efficiency, shorter extraction time, at lower energy costs.

• Journal of the Korean Wood Science and Technology
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• v.42 no.5
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• pp.624-633
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• 2014

This study separated the crude extract (70% ethanol) of and its three fractions (hexane, chloroform and ethyl acetate extracts) on the basis of polarity indexes, and examined for their insecticidal activities against aphid (Uroleucon lactucicola). For crude extraction, the 70% ethanol extract showed the best extract yield (58.0%) and insecticidal activity (69.0%) among the various concentrations tested (water, 30% ethanol, 50% ethanol, 70% ethanol and 95% ethanol). The major chemical compounds of different fractions (hexane, chloroform and ethyl acetate extracts) were identified as eugenol by head space-GC-MS analysis. The hexane extract showed the highest eugenol content (43.7%) and insecticidal activity (80.0%). The insecticidal activity is accordingly believed to be attributable to the eugenol component. This may provide a useful starting point for the development of bio-pesticides.

• Journal of the Korean Wood Science and Technology
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• v.47 no.1
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• pp.1-7
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• 2019

Japanese anise (Illicium anisatum L.) leaves 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 concentration. A portion of EtOAc (3.12 g) and $H_2O$ (6.08 g) soluble fractions were chromatographed on a Sephadex LH-20 column with various aqueous MeOH solution to isolate the compounds. Compound 1 ((+)-catechin) was isolated from EtOAc soluble fraction. Compounds 2 (quercetin), 3 (quercitrin) and 4 (2''-O-rhamnosylvitexin) were isolated from $H_2O$ soluble fraction. For the first time, quercitrin (3) and 2''-O-rhamnosylvitexin (4) of the isolated compounds were obtained from the extracts of japanese anise leaves.

• Journal of the Korean Wood Science and Technology
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• v.25 no.1
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• pp.23-27
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• 1997

Alkali-soluble extracts were prepared from barks of Japanese larch(Larix leptolepis). Siberian larch(Larix gmelineii) and Radiata pine(Pinus radiata) The effect of various factors, such as particle size, liquor ratio, extraction temperature, and reaction time, on the extracts yield was investigated. Particle sizes affected the alkali-soluble extracts; the finer the particle size, the higher extracts and extract efficiency. High temperature and high liquor ratio were more effective. In the range of 0.25% to 1% NaOH concentration, alkali extracts were increased with the increasing alkali concentration. However, extract yields were leveled off above 0.5% alkali concentration. Extractions with NaHCO3 were almost equivalent to those of NaOH extraction. 1% NaOH and 1% NaHCO3 resulted in the highest yields of alkaline extracts. Extracts from Japanese larch were lower than those from Siberian larch and Radiata pine barks. Siberian larch bark was the best raw material for tannin adhesives, because its extractive yield was higher than those of the other barks. Concerning pH of alkaline media during extraction, small increases of the extract yields were resulted at range of pH 7 to pH 9, while a large increases from pH 9.0 to pH 12. This phenomenon is attributed to higher alkalinity.