• Mycobiology
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• v.47 no.1
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• pp.87-96
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• 2019

Fungi produce various secondary metabolites that have beneficial and harmful effects on other organisms. Those bioactive metabolites have been explored as potential medicinal and antimicrobial resources. However, the activities of the culture filtrate (CF) and metabolites of whiterot fungus (Schizophyllum commune) have been underexplored. In this study, we assayed the antimicrobial activities of CF obtained from white-rot fungus against various plant pathogens and evaluated its efficacy for controlling anthracnose and gray mold in pepper plants. The CF inhibited the mycelial growth of various fungal plant pathogens, but not of bacterial pathogens. Diluted concentrations of CF significantly suppressed the severity of anthracnose and gray mold in pepper fruits. Furthermore, the incidence of anthracnose in field conditions was reduced by treatment with a 12.5% dilution of CF. The active compound responsible for the antifungal and disease control activity was identified and verified as schizostatin. Our results indicate that the CF of white-rot fungus can be used as an eco-friendly natural product against fungal plant pathogens. Moreover, the compound, schizostatin could be used as a biochemical resource or precursor for development as a pesticide. To the best of our knowledge, this is the first report on the control of plant diseases using CF and active compound from white-rot fungus. We discussed the controversial antagonistic activity of schizostatin and believe that the CF of white-rot fungus or its active compound, schizostatin, could be used as a biochemical pesticide against fungal diseases such as anthracnose and gray mold in many vegetables.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.493-497
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• 2002

The polyphenol compounds of Korea ginseng radix were extracted with 60% acetone for 4 days at room temperature and purified using Sephadex LH-20 column chromatography, MCI gel column chromatography, Bondapak $C_{18}$, column chromatography, TLC and HPLC. As a result in three compounds were isolated from Korean ginseng. In the inhibitory activities of angiotensin converting enzyme, compound Ⅱ showed the highest value of 31.86% inhibition at 157 ppm. Compound I showed 19.4% inhibition at 157 ppm. In the inhibitory activities of xanthine oxidase, compound I, II showed complete inhibition at 666 ppm but compound III didn't have inhibitory activity. In the inhibitory activities of tyrosninase, compound III showed 6.1% inhibition at 300 ppm and 28.6% at 400 ppm.

• Journal of Photoscience
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• v.9 no.2
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• pp.421-423
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• 2002

Phellinus linteus mycelia have many pharmacological effects, although their pharmacological efficacy principles have not been known yet. In the course of screening for biological activity of the extracts of Phellinus linteus mycelia, we found strong antioxidative activity in some fraction of water-insoluble. Therefore, we tried to isolate the active principle(s) from the extract. The isolation of the active compound was guided by superoxide anion radical scavenging activity. As a result, caffeic acid was isolated as an active compound. The IC$\_$50/ of the compound was 3.05 $\mu$g/ml (16.9$\mu$M).

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.1
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• pp.85-91
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• 2008

A Boost Power Factor Correction (PFC) Converter employing Zero Voltage Switching (ZVS) based Compound Active Clamping (CAC) technique is presented in this paper. An Electro Magnetic Interference (EMI) Filer is connected at the line side of the proposed converter to suppress Electro Magnetic Interference. The proposed converter can effectively reduce the losses caused by diode reverse recovery. Both the main switch and the auxiliary switch can achieve soft switching i.e. ZVS under certain condition. The parasitic oscillation caused by the parasitic capacitance of the boost diode is eliminated. The voltage on the main switch, the auxiliary switch and the boost diode are clamped. The principle of operation, design and simulation results are presented here. A prototype of the proposed converter is built and tested for low input voltage i.e. 15V AC supply and the experimental results are obtained. The power factor at the line side of the converter and the converter efficiency are improved using the proposed technique.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.3
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• pp.45-50
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• 1998

13 develop an active agent for skin whitening, we examined the inhibitory effects of 285 plant extracts on tyrosinase activity and found some plant extracts have an ability to inhibit tyrosinase activity. Of these plant extracts, ramulus mori extracts showed the highest inhibiting activity on enzyme activity. From these results, we selected ramulus mori as a new active agent for skin whitening. $IC_{50}$/ of this extracts on tyrosinase activity is 12.48$\mu\textrm{g}$/m1. Also, ramulus mori extracts showed inhibitory activity on melanin synthesis in B-16 melanoma cells. We isolated active compound from ramulus mori extracts using various column chromatography and recrystalization and identified its chemical structure using Mass spectroscopy, IR and NMR analysis. So, it is identified as Mulberrin, a maior compound of ramutus mori and turned out that it has potent ability on tyrosinase inhibition. $IC_{50}$/ of this compound for tyrosinase activity is 0.5$\mu\textrm{g}$/ml. Also, this compound showed potent inhibitory activity on melanin synthesis in B-16 melanoma cells. This extracts was turned out to be safe in many safety tests.

• Food Science and Biotechnology
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• v.27 no.6
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• pp.1833-1842
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• 2018

The aim of this study was to identify sleep-promoting substance from Polygonatum sibiricum rhizome extract (PSE) with the regulation of sleep architecture. PSE showed a decrease in sleep latency time and an increase in the sleeping time. In the electroencephalography analysis of rats, PSE (150 mg/kg) showed an increase of non-rapid eye movement by 38% and a decrease of rapid eye movement by 31% compared to the control. This sleep-promoting activity was found to be involved in the $GABA_A$-BDZ receptor. The chemical structure of the pure compound was determined by the $^1H$ and $^{13}C$ nuclear magnetic resonance spectroscopy and gas chromatography mass spectrometry analysis; active compound was glyceryl-1-monolinoleate. The commercial standard glyceryl-1-monolinoleate showed a similar inhibitory concentration on [$^3H$]-flumazenil binding to $GABA_A$-BDZ receptors with final active fraction of PSE. The results indicate that glyceryl-1-monolinoleate is a major active compound responsible for the PSE-derived sleep promotion.

• Journal of Microbiology and Biotechnology
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• v.20 no.8
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• pp.1240-1242
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• 2010

We attempted to identify the compound responsible for the growth inhibition of Microcystis aeruginosa occurring when a culture broth of Bacillus subtilis C1 was added to the medium. The active compound was purified from B. subtilis C1 culture broth by adsorption chromatography and HPLC, and was identified as a type of glycolipid based on $^1H$ NMR and MS analyses. The purified active compound completely inhibited the growth of M. aeruginosa at a concentration of 10 ${\mu}g/ml$. This is the first report of a glycolipid produced by a Bacillus strain that has potential as an agent for the selective control of bloom-forming M. aeruginosa.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1257-1264
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• 2015

Trichoderma strain T-33 has been demonstrated to have inhibitory effect on the fungus species Cytospora chrysosperma. Here, an active antifungal compound was obtained from Trichoderma strain T-33 extract via combined separation technologies, including organic solvent extraction, liquid chromatography, and thin-layer chromatography. The purified compound was further characterized by advanced analytical technologies to elucidate its chemical structure. Results indicated that the active antifungal compound in Trichoderma strain T-33 extract is 2,5-cyclohexadiene-1,4-dione-2,6-bis (1,1-dimethylethyl).

• Journal of Sericultural and Entomological Science
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• v.41 no.3
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• pp.180-184
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• 1999

The insecticidal compound priduced by Streptomyces SS-4993 strain was indicated to be a relatively stable small compound by pancreatin treatment. The active compound was adsorbed on HP20 and eluted with 70% acetone. Then, the eluate was extracted with ethyl acetate. The content of the extract was determined by thin layer chromatography (Silica gel 60 F254, hexane-ethyl ether-acetic acid,80 : 20 :1). Three active bands (Rf 0.08, 0.07, 0.88) were identified by dermal application using Bombyx mori larvae. Electrophoretic analysis revealed that the injection of strain SS-4993 culture broth into B. mori larvae induce the reduction of the hemolymph proteins level. Especially, the level of apolipophorin-I was decreased drastically.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.5
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• pp.1235-1242
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• 2003

This study was performed for the investigation of vasodilatory effects of Crataegus pinnatifida Bunge and for isolation and structure determination of the constituent from the active fraction. The fruits of this herbal drug were extracted with 80% methanol, then fractioned successively with methylene chloride, ethylacetate and n-butanol. Among the fractions, ethyl acetate fraction exhibited the most effective vascular relaxation against phenylephrine-induced arterial contraction. In order to isolate the active constituent by activity-guided fractionation, this fraction was chromatographed on silica gel to yield seven subfractions. Among the subfractions, the active one showing the most potent vascular relaxation activity was further separated by prep. HPLC with reversed phase Microsorb C-18 column using 1 % acetic acid and methanol gradient solvent system to afford one pure compound, which revealed a potent vasodilatory effect. Instrumental analyses (NMR and mass spectrometry) of the isolated constituent indicated this compound to be (-)-epicatechin. The vasodilatory action mechanism of this compound should be further investigated.