• Journal of the Korean Wood Science and Technology
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• v.45 no.1
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• pp.116-125
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• 2017

In this study, natural extract of Ouercus mongolica by steaming explosion treatment were tested for antioxidant activity and safety. To determine the antioxidative properties of the hot water extracts, experiments were carried out by dividing into four groups (10 mice per group) of four-week-old B6C3F1 male mice from Air Logistics, Japan. As safety test, cell viability test, oral toxicity test were done. The activity of peroxidase was increased by more than 29% in the group treated with hydrothermal extract. From 4 kinds of safety tests, toxicity was not observed. From experimental results, natural extract of Ouercus mongolica by steaming explosion treatment showed superb safety and antioxidant effect.

• Journal of the Korean Wood Science and Technology
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• v.43 no.2
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• pp.274-285
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• 2015

In view of the environmental and health hazards posed by synthetic insecticides, the use of plant products as botanical insecticides has gained increasing in recent years. In this study, we reported the insecticidal activity of extracts isolated from Coptis chinensis. On crude extraction, among the various solvent types tested (water, 1% (w/v) of sodium hydroxide, 70% ethanol), the 70% ethanol extract showed the best insecticidal activity (36.5%). Three different fractions (n-hexane, chloroform and ethyl acetate) were obtained from crude extract (70% ethanol) of the chloroform fraction and found to have noteworthy insecticidal activity (62.9%) by filter paper contact bioassay. Their chemical structures were identified as 2-methoxy-4-vinylphenol and aniline by head space-GC-MS analysis. Both compounds displayed a dose-dependent insecticidal activity of Myzus persicae (Sulzer). Insecticidal activity at the lowest concentration tested (500 ppm) approached 85.4% in the aniline compared with 79.9% in the 2-methoxy-4-vinylphenol. The insecticidal activity was greater for the aniline than 2-methoxy-4-vinylphenol. It is believed that the insecticidal activity is due mainly to the presence of aniline.

• Journal of the Korean Wood Science and Technology
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• v.48 no.2
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• pp.166-180
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• 2020

Rhododendron schlippenbachii have been used as a medicine because of their various biological activities. In this study, R. schlippenbachii ethanol extract was evaluated for the treatment of vitiligo. The R. schlippenbachii ethanol extract did not show any cell cytotoxicity. The effect on mushroom tyrosinase and cellular tyrosinase activities were further assessed. In addition, the determination of melanin content in melanocytes was measured using both the B16 melanoma cells and C57BL/6J Ler-vit/vit mice. Finally, the existence of quercetin in R. schlippenbachii was confirmed by qualitative analysis using HPLC. The results clearly demonstrated the R. schlippenbachii extract enhanced melanogenesis and also increased tyrosinase activity in cultured melanoma cells and C57BL/6J Ler-vit/vit mice. In addition, treatment with R. schlippenbachii extract led to a higher content of melanin and eumelanin in C57BL/6J Ler-vit/vit mice hair than in control (untreated) mice, which demonstrated the therapeutic effect of hair-graying associated with vitiligo. Finally, we confirmed a notable increase in melanocytes in the skin of C57BL/6J Ler-vit/vit mice treated with R. schlippenbachii extract compared with the control. Extracts of R. schlippenbachii was shown to be potent tyrosinase and melanin synthesis activator in B16 melanoma cells. The R. schlippenbachii extract have significantly higher melanin content than the untreated control in C57BL/6J Ler-vit/vit mice hair. The results suggest that R. schlippenbachii extract might be considered as an alternative treatment for improvement of vitiligo.

• The Korean Journal of Mycology
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• v.42 no.1
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• pp.40-49
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• 2014

The mycelial growths of wood-decaying mushroom strains collected from Korean forests were investigated on solid media under different culture media and temperatures. Most of strains showed the higher mycelial growth on potato dextrose agar (PDA) than malt extract agar (MEA) or sabouraud dextrose agar (SDA) plates. Except for a few strains, they grew well on PDA at $25^{\circ}C$ and showed a poor growth at low temperature ($10^{\circ}C$) than high temperature ($30^{\circ}C$). All strains showed the carboxymethylcellulase (CM-cellulase) and laccase activities on solid media containing the specific substrates for two different enzymes.

• Journal of the Korean Wood Science and Technology
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• v.26 no.4
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• pp.71-77
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• 1998

To elucidate chemical structure of the wood extractive, wood meal of Larix leptolepis Gorden was extracted with 95% ethanol for 72 hours. The extract was fractionated with organic solvents such as n-hexane, chloroform, diethylether, and ethyl acetate. From the hexane somble fraction of the extractives, a new diterpene compound was isolated and identified as 6-acetoxymanool or 13-hydroxy-8(17), 14-labddienyl-6-acetate by IR, $^1H(^{13}C)$-NMR and Mass spectrometry.

• 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.41 no.5
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• pp.447-455
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• 2013

Hemicellulose extract obtained by pre-pulping extraction of woodchips, is very diluted acidic in nature. The major component responsible for this weak acidity is acetic acid, present in levels up to 5~10 g/L. Here, we report an exploratory study on the extract upgrading by reactive solvent extraction of acetic acid as well as ASPEN simulation. In this study, liquid-liquid equilibria for the ternary systems (water + acetic acid + ethyl acetate) were measured at the temperature of 298.15 K and 10 (pH = 2.02), 5 (pH = 2.17), and 1 (pH = 2.48) percent of acetic acid samples were used to carry out liquid-liquid extraction studies using ethyl acetate. In a one-stage batch experiment, 96.0% of acetic acid could be extracted for the solvent when the ratio of organic-to-aqueous phases is 4:1. For simulation results, they were used to estimate the interaction parameters between each of the three compounds of the systems studied for the NRTL and UNIQUAC models. The estimated interaction parameters were successfully used to predict the equilibrium compositions by the two models.

• Biomolecules & Therapeutics
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• v.13 no.2
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• pp.107-112
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• 2005

Excessive drinking causes 'alcohol hangover' within 8-16 hours. The cause of 'hangover' has not been elucidated exactly until now, but it is reported that it is caused by the creation of blood ethanol and acetaldehyde as ethanol metabolites. In this study vinegar extract of wood (VE) or OC-1, to which the powder extract of green tea leaves extract is added, was administered to the rats 30 minutes before the oral administration of ethanol (3 g/kg) and the blood ethanol and acetaldehyde concentration was measured in order to evaluate the efficacy of the beverage material for detoxification. As a result, the blood ethanol concentration in the group of the VE-1(vinegar crude extract) and VE-2 (double diluted solution) is statistically lower (P,0.05) than the exclusive alcohol administered control group. The blood acetaldehyde concentration of all groups of VE and OC-2, which is the double dilution of OC-1, is statistically low after 7 hours following ethanol administration. Especially, the AUC value of OC-2 group is statistically low compared to the control group. Accordingly, it indicates the conclusion that VE and OC-1, reducing the blood ethanol and acetaldehyde concentration which are two leading factors of 'hangover' after drinking, and worthwhile to be developed as beverage materials to eliminate 'hangover'.

• 보존과학연구
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• s.29
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• pp.125-136
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• 2008

To investigate bioactive materials for development of natural conservative agent on organic cultural heritage, methanol extracts from 17 medicinal plants were screened for antifungal and insecticidal activity against 6 wood rot fungi and adult of Lasioderma serricorne. Antifungal activity of extracts was tested by using paper disc soaking method against wood-rot fungi. Among these extracts, the most significant antimicrobial activity was observed from the extract of Coptis japonica at 5 mg/disc against all wood rot fungi tested. The insecticidal activity of extracts was examined by topical application against L. serricorne adults. The extracts from Asarum sieboldii gave 83.3 % mortality at $25{\mu}g/adult$ for 24hr. From these result, the methanol extract from C. japonica and A. sieboldii described could be useful for conservation of organic cultural heritage against biological deterioration by wood rot fungi and L. serricorne.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.223-228
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• 2004

Agricultural waste products, beech wood and walnut shells, were hydrolyzed at 40$^{\circ}C$ using mixed crude enzymes produced by Penicillium sp. AHT-1 and Rhizomucor pusillus HHT-1. D-xylose, 4.1 g and 15.1 g was produced from the hydrolysis of 100 g of beech wood and walnut shells, respectively. For xylitol production, Candida tropicalis IFO0618 and the waste product hydrolyzed solutions were used. The effects on xylitol production, of adding glucose as a NADPH source, D-xylose and yeast extract, were examined. Finally, a 50% yield of xylitol was obtained by using the beech wood hydrolyzed solution with the addition of 1% yeast extract and 1% glucose at an initial concentration.