• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.200-204
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• 1991

Certain parts of 36 kinds of plant were extracted by 75% ethanol and water. The extracts were tested their microbial inhibition activities against several food spoilage microorganisms, Bacillus subtilis, Lactobacillus plantarum, Leuconostoc mesenteroides, Pseudomonas fluorescens, Bacillus cereus and Saccharomyces cerevisiae. The ethanol extract of amur cork was shown inhibitory effect on all 6 species of the microorganisms tested. Chinese pepper, sesame cake, gromwell and oak were on 5 species except S. cerevisiae or P. fluorescens and bamboo leaves, lycopi herba, paulownia and rigida were on 4 species. In general amur cork exhibited the strongest inhibition with a few exceptions on certain species. By disc diffusion method, the ethanol extract of leaf mustard showed the highest inhibition effect on B. subtilis, amur cork on L.plantarum, L. mesenteroides and B. cereus, and amur cork and gallnut on P. fluorescens. Mostly the ethanol extracts in comparison with water extracts showed higher inhibition in most of plants but a few exhibited higher in water extracts.

• The Korean Journal of Mycology
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• v.46 no.1
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• pp.51-57
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• 2018

We investigated the antioxidant activities of nine Lentinula edodes varieties cultivated on oak log. The total polyphenol content (TPC), total flavonoid content (TFC), and antioxidant properties of L. edodes (varieties: Dasanhyang, Chunbaegko, Poongnyunko, Soohyangko, Baekwhahyang, Chunjang 1ho, Chunjang 2ho, Sanlim 5ho, and Sanlim 7ho) were evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay and the ferric reducing antioxidant power (FRAP) assay. The TPC and TFC of mushroom extracts ranged from 5.10 to 10.88 mg gallic acid equivalent (GAE)/g and 0.76 to 5.78 mg quercetin equivalent (QE)/g, respectively. In addition, mushroom extracts exhibited DPPH radical scavenging activity of 24.22~90.41%, 2.0 mg/mL and FRAP of 0.056~0.231, 2.0 mg/mL. The Chunbaegko variety showed the highest TPC (10.88 mg GAE/g), TFC (5.78 mg QE/g), DPPH activity (38.19~90.11%, 0.2~2.0 mg/mL), and FRAP (0.075~0.231, 0.2~2.0 mg/mL).

• Culinary science and hospitality research
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• v.23 no.8
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• pp.137-144
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• 2017

This study examined the components and physicochemical properties of Lepidium meyenii as a natural health food source. To accomplish this objective, the general and antioxidative contents of Lepidium meyenii were measured. Total contents of carbohydrates, crude protein, crude lipid, and ash were 56.04%, 33.77%, 1.49%, and 3.7%, respectively(dry wright basis). Total phenol contents of the 70% ethanolic extracts of Lepidium meyenii were 189.9 mg/g, 152.5 mg/g. Total flavonoid contents of the 70% ethanolic extracts were 166.0 mg/g, 78.2 mg/g. The antioxidative activities of Lepidium meyenii were significantly increased in a dose dependent manner on DPPH(1,1-diphenyl-2-picrylhydrazyl) radical scavenging, ABTS (2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) radical scavenging, FRAP(ferric reducing antioxidant power) activity, reducing power. The general nutrients and other antioxidant bioactive materials in Lepidium meyenii were also potential materials for good health food.

• Journal of Life Science
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• v.29 no.2
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• pp.164-172
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• 2019

In Korea, shiitake mushroom, Lentinula edodes, is cultivated on artificial medium containing oak sawdust and wheat bran. The annual production of spent mushroom substrate (SMS) of shiitake, a byproduct of the mushroom industry, is estimated to reach over 50,000 tons per year. This study aimed to improve the use of SMS as a novel bioresource. Hot water extracts of SMS after the first and third harvest were prepared and their bioactivities evaluated. Hot water extracts of uninoculated medium and shiitake were used as controls. Extracts of SMS showed higher radical scavenging of DPPH anions, ABTS cations, nitrites, and a higher reducing power than those of shiitake or medium extracts. After the first and third harvests at 0.5 mg/disc, SMS extracts showed no antibacterial or antifungal activities against the pathogenic and food-spoilage bacteria and fungi. However, they showed good inhibitory activities against ${\alpha}$-glucosidase at 0.5 mg/ml. In addition, SMS extracts had strong anti-coagulation activities via their inhibition of thrombin, prothrombin, and blood coagulation factors without platelet aggregation activity. Our results suggested SMS should no longer be perceived as a useless byproduct but should be understood as a novel bioresource, the extracts of which could be developed as antioxidant, antidiabetic, and antithrombosis agents.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.672-676
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• 2006

The aim of this study is to evaluate the antioxidant, antimicrobial, and antitumor activities of various concentrations of partially purified substance(s) from green tea seed (Camellia sinensis L.). The total polyphenol contents of each fraction (non-adsorption fraction: F-1, fraction eluted with 40% methanol: F-2, and fraction eluted with 100% methanol: F-3) purified by Diaion HP-20 column chromatography were, in the increasing order: F-1 (3.7 mg tannic acid equivalents, TAB/g) < F-3 (23.2 mg TAB/g) < seed extracts (26.2 mg TAB/g) < F-2 (42.7 mg TAB/g). The scavenging activities toward the 1,1-diphenyl-2-picyrylhydrazyl (DPPH) radical were, in decreasing order: F-2 (93.3%) > butylated hydroxytoluene (BHT; 89.8%) > ascorbic acid (89.3%) > leaf extracts (70.3%) > F-3 (15.9%) > seed extracts (15.8%) > F-1 (14.8%) at a 0.1% concentration. In studies on antimicrobial activities, the results indicate that the growth of yeast (Candida albicans KCCM 11282 and Cryptococcus neoformans KCCM 50544) was inhibited more so than that of other fungi (Alternaria alternate KCTC 6005 and Rhizoctonia solani). In addition, it appears that the antitumor activities of the F-1, F-2, and F-3 fractions at a concentration of $50\;{\mu}g/mL$ showed 6, 7, and 23% growth inhibition of the HEC-1B cell line, 14, 11, 82% inhibition of the HEP-2 cell line, and 8, 16, and 81% inhibition of the SK-OV-3 cell line, respectively. Overall these results indicate that the antioxidant activity is greatest in the F-2 fraction, and the antimicrobial and antitumor activities are greatest in the F-3 fraction.

• Journal of the Korean Wood Science and Technology
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• v.52 no.5
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• pp.405-422
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• 2024

This study investigated the resistance of domestic wood species used as wood members in general wood construction and Korean wood cultural properties to the termite Reticulitermes speratus using no-choice and two-choice tests. The results of the no-choice experiment confirmed that hardwood has higher termite resistance than that of softwood. In addition, R. speratus prefers softwood, including Abies holophylla, which has low density, is easy to feed on, and does not contain repellent extracts. In a two-choice test, Zelkova serrata was found to be the most termite-resistant wood species used in wooden cultural buildings. In addition, we investigated the effects of different wood extraction methods and their components on termite resistance. The cold-water extraction of softwood increased the feeding activity of termites; however, the cold-water extraction of hardwood had little effect on the feeding activity of termites. In natural environments with repeated exposure to moisture, such as rainfall, water-soluble extracts present in wood species are relatively more likely to dissolve and removed, making softwood more likely to be damaged by termites than hardwood. Untreated Quercus variabilis showed an extremely weak feeding activity of termites compared with that in other wood species; however, feeding termites with the alcohol-benzene extract of Q. variabilis had no inhibitory effect on their feeding activity. Therefore, we believe that the high density of Oriental cork oak wood inhibits the feeding activity of R. speratus. In contrast, the alcohol-benzene extracts of Z. serrata, Prunus sargentii, and Castanea crenata showed a strong inhibition of the feeding activity of termites.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.271-274
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• 2011

Pepper mild mosaic virus (PMMoV) and cucumber mosaic virus (CMV) are important pathogens in various vegetable crops worldwide. We have found that methanol extracts of Quercus dentate (Oaimyo Oak) gal/nut strongly inhibit PMMoV and CMV infection. Based on this result, the inhibitor named as "KN0912" formulated from the extract of Q. dentate gallnut was tested for its inhibitory effects on PMMoV or CMV infection to each local lesion host plant (Nicotiana glutinosa; PMMoV, Chenopodium amaranticolor; CMV). Pre-treatment effect of KN0912 against infections of each virus to local host plant was measured to be $75.1{\pm}0.5{\sim}97.5{\pm}1.5%$ to PMMoV and $70.6{\pm}2.2{\sim}99.0{\pm}1.0%$ to CMV in 1~10mg/ml conc. and the absorption effect of the antiviral composition of KN0912 to the inside of tobacco leaves tissue, was inhibited by 55.7% to PMMoV and 63.8% to CMV. The persistence of KN0912 treatment was maintained until after the 3 days high inhibitory effect by 98% to PMMoV and by 95.1% to CMV. Inhibitory effects on systemic host plants of KN0912 were measured to be 80~90% to PMMoV and 60~75% to CMV. From the change of morphological characteristics of PMMoV particles under EM, we are tentatively suggested that one mode of action of KN0912 is inactivation due to the destruction of virus particles.

• Journal of the Korean Wood Science and Technology
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• v.17 no.3
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• pp.52-60
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• 1989

This study was carried out to know the possibility of simultaneous utilization of laccase from white-rot fungus with cellulase on enzymatic hydrolysis of cellulosic substrate from autohydrolyzed oak wood. Laccases from 3 white-rot fungi, Pleurotus ostreatus. Ganoderma lucidum, and Phanerochaete chrysosporium, were isolated, purified and measured their activities. The highest activity was shown in Pleurotus ostreatus and the lowest in Phanerochaete chrysosporium. Laccase from Pleurotus ostreatus has optimum pH of 5.94, Km value of 3.209 mM and appeared to be stable at relatively wide pH range, 4.7-8.72. Temperature stability showed that 60% activity was preserved after 40 minutes at $50^{\circ}C$. Laccase from Ganoderma lucidum reached to the maximum activity during 15-20 day incubation. This enzyme has optimum pH of 6.45, Km value of 6.71 mM and pH range of 5.0-9.0 for stabilization. 95% activity was preserved at $30^{\circ}C$ and 58% activity at $50^{\circ}C$. Concerned to the enzymatic hydrolysis of cellulosic substrate with both enzymes, cellulase and laccase, simultaneously, mixed culture filtrates and mycellium extracts were shown higher hydrolysis rates than those of Trichoderma viride. There were no significant differences in the extent of hydrolysis among various mixed culture filtrates and mycellium extracts.

• Korean Journal of Pharmacognosy
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• v.25 no.2
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• pp.132-139
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• 1994

To investigate the effect of Korean mistletoe on stimulation of macrophage, the activity to induce interleukine-1(IL-1) and tumor necrosis factors-${\alpha}(TNF-{\alpha})$ from murine peritoneal macrophage by its extracts originated from oak was examined. From in vitro analysis of the cytokines using the culture supernatants of macrophages stimulated with its extracts for 1hr, it was found that Korean mistletoe induces IL-1 and $TNF-{\alpha}$ from murine macrophage. Furthermore, both extracts of Korean mistletoes that were extracted with distilled water and 2% acetic acid exhibited a significant activity to induce two cytokines. In the stimulation for 30 min, Korean mistletoe at concentration of $1{\sim}100\;\mu/ml$ showed a significant induction of IL-1 from macrophage until 24 hrs after stimulation, showing maximal activity on $5{\sim}10\;hrs\;at\;10{\sim}100\;\mu/ml$. On the other hand, $TNF-{\alpha}$ was induced on the early period, 2 hrs, after stimulation at a wide range of concentration, $1{\sim}500\;\mu/ml$. In addition, the fraction of Korean mistletoe from 80% saturated ammonium sulphate precipitation showed a significant activity to induce both cytokines from macrophage. The present study demonstrates that Korean mistletoe contains immunoregulatory factors responsible for stimulating murine macrophage to secrete IL-1 and $TNF-{\alpha}$ which play an important role in immune responses, and suggests that the activity of Korean mistletoe to induce two cytokines is functioned by a possible independent stimulation manner.

• Korean Journal of Plant Resources
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• v.32 no.6
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• pp.698-704
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• 2019

Quercus mongolica (QM), which belongs to fagaceae, is one of the oak native to Korea. We evaluated the anti-inflammatory effect of branches extracted with 70% ethanol of QM (QM-B) and elucidated the potential signaling pathway in LPS-induced RAW264.7 cells. The QM-B showed anti-inflammatory activity through inhibition of NO production. The QM-B dose-dependently suppressed NO production by inhibiting iNOS, COX-2 and IL-6 expression in LPS-induced RAW264.7 cells. The QM-B inhibited the degradation and phosphorylation of IκB-α and NF-κB activation. The QM-B suppressed the phosphorylation of p38 and ERK1/2. Also, the QM-B increased HO-1 expression. These results suggested that QM-B may utilize anti-inflammatory activity by suppressing NF-κB and MAPK signaling pathway and inducing HO-1 expression indicated that the QM-B can be used as a natural anti-inflammatory drugs.