• 한국수산과학회지
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• 제49권5호
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• pp.678-682
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• 2016

Antibacterial activity of 80% methanol extract from 13 commercial herb medicines was measured against fish pathogens Streptococcus iniae, causing several diseases in various kind of fish. Siegesbeckia pubescens showed the strongest antibacterial activity against S. iniae. Methanol extract of S. pubescens was further extracted using several organic solvents having different polarity. Extract from n-hexane and ethyl acetate fraction showed strong activity. Minimal inhibitory concentration, MIC of S. pubescens extract was measured and resulted showing 8 μg/mL with n-hexane fraction and 32 μg/mL with ethyl acetate fraction against S. iniae. The growth of S. iniae was fully inhibited by adding 50 μg/mL (final concentration) of n-hexane or ethyl acetate fraction in the liquid media. It is needed that, from these results, purification and isolation of responsible active compound(s) of these activities and further study on the synergy effect using combination with commercial antibiotics against fish pathogenic bacteria.

• Journal of Microbiology and Biotechnology
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• 제34권8호
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• pp.1642-1652
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• 2024

Arctium lappa (Burdock) root is used in various culinary applications especially in Asian Cuisine. Arctigenin (ARC) is a polyphenolic compound abundant in the roots of the burdock plant from which it derives its name. The emergence of bacterial resistance is a growing global worry, specifically due to the declining availability of new antibiotics. Screening for the antibacterial candidates among the safe natural products is a promising approach. The present study was aimed to assess the antibacterial activity of ARC against Pseudomonas aeruginosa exploring its effect on the bacterial cell membrane. Furthermore, the anti-virulence activities and anti-quorum sensing (QS) activities of ARC were in vitro, in vivo and in silico assessed against P. aeruginosa. The current results showed the ARC antibacterial activity was owed to its disruption effect of the cell membrane. ARC at sub-MIC significantly decreased the formation of biofilm, motility, production of extracellular enzymes and in vivo protected mice against P. aeruginosa. These anti-virulence activities of ARC are owed to its interference with bacterial QS and its expression. Furthermore, ARC showed mild effect on mammalian erythrocytes, low probability to induce resistance and synergistically combined with antibiotics. In summary, the promising anti-virulence properties of ARC indicate its potential as an effective supplement to conventional antibiotics for treating severe P. aeruginosa infections.

• 약학회지
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• 제21권4호
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• pp.211-213
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• 1977

Since ampicillin, one of the important semi-synthetic derivatives of penicillins, is restricted in use because of its unfavorable physico-chemical and pharmacological properties, the author synthesized a new derivative, methampicillin lysinate and its physical and characteristics were determined. The antibacterial activity of this compound against ten species of Gram positive and negative bacteria in vitro showed that it was more active to Gram negative bactria than the positive and that was three times more potent than ampicillin trihydrate.

• 한국환경보건학회지
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• 제24권1호
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• pp.47-53
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• 1998

5.7-Dichloro-8-hydroxyquinaldyl-N-ethylcarbamate, one of the carbamate derivative which are generally used as insecticide, was newly synthesized. Its physical properities were determined and chemical structure was indentified by means of I.R., nmr in addition to elemental analysis. The yield of addition, using triethylamine as catalyst, 5.7-dichloro-8-hydroxyquinaldine and isocyanate was better than that of condensation of 5.7-dichloro-8- hydroxyquinaldine with carbamoylchloride. The effect of the cornpond on rabbit's ileum, and antibacterial activity against Staphylococcus aureus, Salmonella typhi, Escherichia coli, and Pseudomonas aeruginosa were examined. It was observed that the dosage over 100 $\mu$g/ml of the compound relaxed rabbit's ileum and the same dosage of the compound inhibited growth of the above strains of bactera.

• Journal of Applied Biological Chemistry
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• 제49권2호
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• pp.51-56
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• 2006

Metanolic root extract of Glycine max (L.) Merr. was chromatographed, affording three triterpenoids 1-3. The compound 3 was isolated from microorganism called Fusarium sporotrichioides but never been isolated from any plant sources. Compounds 1-3 showed cytotoxic activity against HT-59 human cancer cell line with $IC_{50}$ values of 62.9, 20.0, and $44.2{\mu}M$, respectively. Compound 3 showed significant activities against Gram-positive bacterial such as Bacillus cereus, Bacillus subtilis, and Staphylococcs aureus.

• Archives of Pharmacal Research
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• 제28권8호
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• pp.889-891
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• 2005

Two ergosterins and two triterpenoids were isolated from the dried fruit bodies of Ascomyce Bulgaria inquinans. By means of chemical (hydrolysis) and spectroscopic methods (NMR, EIMS), their structures were established as betuinic acid (1), cerevisterol (2), (24R)ergosta-7, $22E­diene-3\beta,\;5\alpha,\;6\beta-triol-3-O-palmitate$ (3) and ursolic acid (4). Compound 3 is a new compound.

• Bulletin of the Korean Chemical Society
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• 제22권1호
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• pp.59-62
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• 2001

The dried fruit-body of Daedaleopsis tricolor was extracted by the petroleum ether. The extracts were purified by liquid-liquid extraction, column chromatography, and recrystallization. The purified compound was a colorless orthorhombic crystal form. Its melting point, molecular weight and molar extinction coefficient $(\varepsilon)$ were estimated $168-170^{\circ}C$, 424 and 3,935 at 208 nm, respectively. Its structure was elucidated to be 20(29)-lupen-3-one by UV-Vis, FT-IR, NMR and X-ray crystallographic analysis. It showed antifungal activities against Saccharomyces cerevisiae and Microsporum gypseum, and antibacterial activities against Escherichia coli, Proteus vulgaris, Pseudomonas pyocyanea, Bacillus subtilis, and Staphylococcus aureus. In addition, this compound showed an antioxidative activity on lipid-peroxidation by 6.4%.

• 한국자원식물학회지
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• 제21권6호
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• pp.431-434
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• 2008

Dental caries is the destruction of the enamel of teeth by Streptoccus mutans. S. mutans has been isolated from human dental plaque and is associated with the initial development of enamel lesions. We have studied the antibacterial action of the fruit of Callistemon citrin us against a cariogenic bacterium, S. mutans. From the fruit of C. citrinus, piceatannol (3,3',4',5-tetrahydroxystilbene) was isolated by repeated column chromatography with $SiO_2$ and Sephadex LH-20. Its structure was elucidated by instrumental analysis using 1D-NMR, 2D-NMR and EI-MS. This compound was isolated from the fruit of C. citrin us for the first time. The anticarcinogenic activity of this compound was determined by using agar well-diffusion method and minimal inhibition concentration (MIC).

• ALGAE
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• 제29권1호
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• pp.47-55
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• 2014

To develop effective and safe acne vulgaris therapies with a continuing demand for new solutions, we investigated unique efficacy of an antibacterial agent from marine brown alga Eisenia bicyclis in treating acne vulgaris. The methanolic extract of E. bicyclis exhibited potential antibacterial activity against acne-related bacteria. The ethyl acetate fraction showed the strongest antibacterial activity against the bacteria among solvent fractions. Six compounds (1-6), previously isolated from the ethyl acetate fraction of E. bicyclis, were evaluated for antibacterial activity against acne-related bacteria. Among them, compound 2 (fucofuroeckol-A [FF]) exhibited the highest antibacterial activity against acne-related bacteria with a minimum inhibitory concentration (MIC) ranging from 32 to $128{\mu}g\;mL^{-1}$. Furthermore, FF clearly reversed the high-level erythromycin and lincomycin resistance of Propionibacterium acnes. The MIC values of erythromycin against P. acnes were dramatically reduced from 2,048 to $1.0{\mu}g\;mL^{-1}$ in combination with MIC of FF ($64{\mu}g\;mL^{-1}$). The fractional inhibitory concentration indices of erythromycin and lincomycin were measured from 0.500 to 0.751 in combination with 32 or $64{\mu}g\;mL^{-1}$ of FF against all tested P. acnes strains, suggesting that FF-erythromycin and FF-lincomycin combinations exert a weak synergistic effect against P. acnes. The results of this study suggest that the compounds derived from E. bicyclis can be a potential source of natural antibacterial agents and a pharmaceutical component against acnerelated bacteria.

• 폴리머
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• 제26권3호
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• pp.389-399
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• 2002

단파장 자외선을 이용하여 폴리에틸렌테레프탈레이트(PET) 섬유 표면의 화학적 성질을 개질 하였다. 자외선 조사에 의하여 PET 섬유의 화학결합이 절단되어 섬유표면에 COOH기가 생성되고 자외선 조사시간에 비례하여 COOH기가 증가함을 FT-IR과 XPS 분석에 의하여 확인하였으며 XPS측정을 통하여 PET 섬유 표면에 생성된 COOH기가 12개월후에도 변화가 없음을 알 수 있었다. 또한 자외선 조사 PET 섬유에 기능성을 부여하기 위하여 사용한 친수성의 양이온성 천연화합물이, 자외선 조사 PET 섬유에 용이하게 흡착되는 현상으로부터 자외선 조사에 의하여 PET 섬유표면에 음이온성을 나타내는 COOH기가 존재함을 흡착실험을 통하여 확인하였다. 항균성 및 소취성을 측정한 결과 자외선 조사시간이 30분 이상인 경우에 99% 이상의 항균성과 75% 이상의 소취성을 나타내는 기능성 PET 섬유의 제조가 가능하였다.