• BMB Reports
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• v.34 no.1
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• pp.28-32
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• 2001

The Fos-Jun heterodimers are part of the regulatory network of gene expression and nuclear proteins encoded by proto-oncogenes. The activation of Fos-Jun is important in the transmission of the tumor-promoting signal from the extracellular environment to the nuclear transcription mechanism. To search for the inhibitors of the Fos-Jun DNA complex formation, several natural products were screened and water-soluble paeoniflorin reduced the binding activity of the Fos-Jun heterodimer. This active compound was purified by silica gel column chromatography and HPLC. The electrophoresis mobility shift assay and reverse-phase HPLC test showed that paeoniflorin reduced the AP-l function. The cytotoxic effect of paeoniflorin was observed in HL-60. These results indicate that paeoniflorin blocks the Fos-Jun heterodimer-binding site of the AP-l DNA and it also has cytotoxic effects on human leukemia cell lines.

• Journal of Microbiology and Biotechnology
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• v.9 no.1
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• pp.56-61
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• 1999

Pseudomonas sp. SW1 grew and produced biosurfactants on 3% hexadecane as the energy and carbon source. As a result of biosurfactant synthesis, the surface tension of the medium was reduced from 72 dyne/cm to 30 dyne/cm. The properties of biosurfactants that were purified from Pseudomonas sp. SW1 were investigated. The purification procedure included acid precipitation from culture supernatant, silica gel G60 column chromatography, and Sephadex G-150 gel filtration. The biosurfactants were separated into two different types, viz., types I and II. Biosurfactant type Isignificantly reduced the surface tension of water from 72 to 27 dyne/cm at concentration levels above 30 mg/l. The surface tension of water was reduced to a minimum of approximately 30 dyne/cm by biosurfactant type II at concentration levels over 80 mg/l. The biosurfactants were effective in a wide range of pHs, at NaCl concentrations of up to 4%, at $CaCl_2$ concentration up to 100 mM, and at temperatures up to $200^{\circ}C$ for 8 h.

• YAKHAK HOEJI
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• v.49 no.2
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• pp.122-127
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• 2005

Dental caries is one of the most common oral diseases in the world. Glucosyltransferase (Gtase) of Streptococcus mutans (S. mutans) plays an important role in the develo pment of dental caries. For the purpose to develop anti- caries, we examined the effect of metabolites isolated from Streptomyces sp. M-20 on Gtase and the growth of S. mutans. Streptomyces sp. M-20 isolated from Mongolian soil showed 95~96% sequence homology with that of Streptomyces lin- colnensis. The metabolites of Streptomyces sp. M-20 were partially purified by extraction with ethyl acetate, silica gel column chromatography and preparative TLC. Partially purified metabolite, red colored component (MR-20) in ethyl acetate fraction showed potent antibacterial activitiy against S. mutans and inhibitory activity against Gtase purified from S. mutans, while another isolated yellow component (MY-20) showed no activity against S. mutans. The inhibitory activity of MR-20 against Gtase was confirmed by activity staining on SDS-polyacrylamide gel electrophoresis. The concentration of MR-20 for 50% inhibition $(IC_{50})$ against Gtase activity was $60{\mu}g/ml$. These results suggest that MR-20 can be developed for antibacterial agent and anticaries.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.136-141
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• 2011

This study was conducted to confirm the application as ingredients of cosmetics through an examination of the function for anti-cancer and anti-microbial of the fraction isolated from Pyrus ussuriensis leaves. The dried leaf of P. ussuriensis were extracted with acetone-$H_{2}O$ (6:4, v/v), concentrated and fractionated with the upper layer of acetone on a separatory funnel. Each fraction was freeze dried, then a portion of acetone soluble powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol as eluents and also used the MIC-gel using a series of aqueous methanol as developing solvent. The isolated compounds were identified by silica-gel TLC. The growth inhibition activity was measured using the MTT assay by the mouse meltioma (B16F10) cell. The cancer cell growth inhibition rate of fractions isolated from P. ussuriensis leaf was 80%. In anti-microbial activity test, the fraction of P. ussuriensis with 0.25 mg/disc resulted in the clear zone of 1.3 cm and 2 cm for Staphylococcus aureus and S. epidermidis of gram positive bacillus, respectively. In Escherichia coli of gram negative bacillus, the fraction with 0.5 mg/disc resulted in the clear zone of 1.1 cm~1.5 cm each fraction. From these results, we confirmed that acetate fraction of P. ussuriensis has a great potential as a natural ingredients with a anti-cancer and anti-microbial source.

• Journal of Microbiology and Biotechnology
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• v.6 no.3
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• pp.184-188
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• 1996

The Acinetobacter sp. BE-254 isolated from soil sources produced a bioemulsifier in the medium supplemented with n-hexadecane. This bioemulsifier was purified by the procedures of fractionation (ammonium sulfate and chilled acetone), extraction by hexane, and column chromatography on silica gel 60. The results from various color reactions indicated that the bioemulsifier was a glycolipid. The purified emulsifier was very stable at pHs ranging from 4 to 10 and under heat treatment at $100^{\circ}C$ for 30 min. Emulsification activity was also hardly influenced by pH. The critical micelle concentration (CMC) and surface tension at the point ($\gamma_{cmc}$) of the bioemulsifier were approximately 35 mg/l and 30 mN/m, respectively. The bioemulsifier showed a fairly good emulsification activity and stability in comparison with other commercial emulsifiers in the basic formula composed of emulsifier, oil, and water.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.04a
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• pp.122-127
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• 1996

In this paper, the effects of the film tinckness, pre-treatment and testing load on. the tribological characteristics have been studied. During the "Ring on-Disk" testing period silica-gel was used to remove the effect of humidity. As a result, increasing the film thickness revealed prolonged wear life, in the case or reasl the testing loads the dynamic friction coefficient was decreased gradually but in regarding the wear life, an intermideate contact pressure (4kgf/mm${2}$) revealed the maximum value. In regarding the surface protuberance friction an intermediate value of area fraction (60%) revealed maximum wear life. In this paper, the qualitative model in regarding the variation of the friction coefficient andworn depth was presented.presented.

• YAKHAK HOEJI
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• v.31 no.2
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• pp.60-63
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• 1987

The effect of manufacturing and packaging conditions on the stability of effervescent tablets has been studied. Mixtures of sodium bicarbonate and tartaric acid were compressed at tabletting forces of 3,6, and 9 ton force. Tablets were more than simple physical mixture but the effect of tabletting force has not been found in this force range. "Curing" the tablet by heating it to $90^{\circ}C$ was effective on increasing the stability and the silica gel in the aluminium pouch stabilized the system. The equipment measuring the carbon dioxide pressure in this experiment was very useful in evaluation of the effervescent tablets.t tablets.

• YAKHAK HOEJI
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• v.40 no.2
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• pp.149-154
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• 1996

A high-performance liquid chromatographic method for the determination of ${\beta}$-sitosterol in the unsaponifiable fraction of Zea mays L. and its related drug preparations using a cholesterol as an internal standard was investigated. They were saponified with 20% methanolic KOH solution. Phytosterols in the reaction mixture were extracted with diethyl ether and separated on silica gel TLC plate with n-hexane-diethyl ether(40:60) as the solvent and then were scraped off. They were separated by reversed phase high perfomance liquid chromatography on Inertsil ODS-2 column with detection at 205nm. Cholesterol and ${\beta}$-sitosterol were resolved from interferences by adjusting the acetonitrile content in the MeOH-tetrahydrofuran-$H_2O$ eluent. The detection limit of ${\beta$-sitosterol was 0.43${\mu}$g.

• Microbiology and Biotechnology Letters
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• v.29 no.1
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• pp.25-30
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• 2001

A strain of Actinomycetes producing cathepis B inhibitor was isolated from soil and identified as Streptomyces misakiensis. The product of S. misakiensis inhibited effectively cathepsis B proteinases as well as trypsin and papain. The cathepsin B inhibitor were largely produced with incubation for 4 days. The S. misakiensis was the most growth with incubation for 5 days. The cathepsin B inhibitor was isolated from the extraction of both with ethanol, ethanol and chlorofrom, and following several column chromatography such as sephadex G-15, silica gel 60 and sephadex LH-20 chromatography. The moleculer weight of purfied inhibitor was 138 dalton.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.110.2-111
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• 2003

삼백초 지상부를 탈지후 60% acetone으로 추출하고 이를 극성에 따라 diethyl ether, ethyl acetate, aqueous fraction과 같이 용매분획하였다. 각 fraction의 superoxide anion, hydrogen peroxide, hydroxyl radical, DPPH radical 에 대한 소거활성을 측정하였다. Diethyl ether fraction의 ROS 소거효과가 비교적 강하였으며 superoxide anion 소거활성은 100ppm에서 86.88%였고, hydroxyl radical 소거활성은 1ppm에서 85.3%로 나타났다. Hydrogen peroxide, DPPH radical 소거활성은 ethyl acetate fraction이 강하게 나타났다. Diethyl ether fraction으로부터 silica gel column chromatography, sephadex LH-20 column chromatography, preparative HPLC에 의하여 수 종의 성분을 분리하였으며 현재 구조동정과 이들의 LDL산화억제 효과 시험 중에 있다.