• Korean Journal of Pharmacognosy
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• v.35 no.4 s.139
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• pp.375-379
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• 2004

According to the traditional chinese herbal Cuscuta japonica Choisy and C. australis R.Be (original plant of Semen Cuscutae in Korea) have been used to cure pimple. In order to prove their bacteriostatic effects against Propionibacterium acnes, we performed the micro broth dilution method. The minimal inhibitory concentration (MIC) of C. japonica juice was 27.3 mg/ml, but C. australis juice showed no effect. The MIC of water extracted C. japonica seed and Wontosa and Bupjetosa were $960\;{\mu}g/ml$. The MIC of both water and ethanol extracts of C. australis seed was $9240\;{\mu}g/ml$. But ethanol extracts of C. japonicaseeds, Wontosa and Bupjetosa had no bacteriostatic activity. We also performed the disk diffusion test, C. japonica juice had prominent effect. Water extracts of C. japonica seed, Wontosa and Bupjetosa showed bacterio-static effect in 10 mg/ml, and C. australis seed in 10 mg/ml. The ethanol extract of C. japonica seed, Wontosa and Bupjetosa, and C. australis seed showed bacteriostatic effect in 20 mg/ml.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.286-290
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• 2006

New quaternary ammonium chlorides, [alkyldimethyl-[5-(2-phenylthiazol-4-yl]-1,3,4-oxadizol-2-ylmethyl]quaternary ammonium chlorides (ADOQACs): 6] were obtained with high yields by the reaction of compound 5 with N,N-dimethylalkyl amines in isopropyl alcohol. The structures and physical properties of the synthesized compounds were investigated and those surface-active properties were measured. The surface tension ($\gamma_{cmc}$) and the minimal inhibitory concentration (MIC) of compound 6 were found to be influenced by the number of alkyl chain carbon. Especially, compounds 6c and 6d exhibited high anti-bacterial activities and good surface-active properties.

• The Korean Journal of Mycology
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• v.16 no.1
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• pp.33-40
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• 1988

To investigate the antimicrobial activities and safety of natural naringin, it was isolated with methanol from peels of Citri fructus. Its hydrolysate, naringenin was obtained by hydrolysis of naringin. In the antimicrobial activities of two components against eleven species of bacteria and eleven species of Fungi were examined by serial dilution method. Its result appeared to the minimal inhibitory concentration(MIC) and the antimicrobial activities of naringin and naringenin were compared. Naringenin showed considerably high order of activities against bacteria. There were no effect against Fungi $(MIC>100{\mu}g/ml)$. In the safety tests of naringin, examined for 50% lethal dose, Blood clinical chemical tests and organ tissue tests. The results showed that 50% lethal does in mice was 1,650 mg/kg. The experiments of administration in rats showed that there were no changes in blood clinical chemical future and organ tissue as control.

• YAKHAK HOEJI
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• v.43 no.4
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• pp.419-422
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• 1999

In order to develop a antimicrobial agent, dried Sophora flavescens Ait. was extracted with several solvents, and than antimicrobial activity was investigated. The minimal inhibitory concentration (MIC) of the extracted substance against microorganisms were also examined. Antimicrobial activity of the initial methanol extract from the sample was the strongest compared to those of other solvent extracts such as $H_2O$, n-hexane, chloroform, ethyl acetate and methanol. The methanol extract had strong growth inhibition activity against gram-postive bacteria (MIC, $25~50{\;}{\mu\textrm{g}}/ml$) such as B. subtilis. Among gram-positive bacteria tested, B. subtilis was the most susceptible to the extracted substance. The antimicrobial activity of the methanol extract from the sample had strong growth inhibition activity against gram-negative bacteria such as P. aeruginosa (MIC, $25{\;}{\mu\textrm{g}}$/ml).

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.310-314
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• 2006

Allium fistulosum L. (Welsh onion) is a perennial herb that is widely cultivated throughout the world, especially in China, Japan and Korea. Although, various activities were reported, little is known about antimicrobial activity of A. fistulosum L.. In this study, strong antimicrobial substances, fistuloside A, B, and C were isolated from the edible parts of A. fistulosum L. and their antimicrobial activity was evaluated with pathogenic- or food-spoilage microorganism based on disk-diffusion assay, minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) determination. Fistuloside A and fistuloside C showed strong antifungal activity and anti-Proteus activity, while fistuloside B is effective to only fungi. The fistuloside C showed a prominent antifungal activity with $3.1{\sim}6.2{\mu}g/ml$ of MIC and MFC. Our results indicated that fistuloside C has a prominent antifungal activity and support the use of A. fistulosum to treat microbial infection.

• Mycobiology
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• v.29 no.1
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• pp.11-14
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• 2001

A preparation of water soluble components(EA) was made from carpophores of Elfvingia applanata(Pers.) Karst and its in vitro antibacterial activity on a number of bacterial species was examined by macrobroth dilution assay. Among 16 species of bacteria tested, the most potent antibacterial activity was observed against Staphylococcus epiderrnidis and Proteus vulgaris, of which MICs were 1.25 mg/ml. To investigate the antibacterial effects in combinations of EA with quinolone antibiotics, such as ciprofloxacin, enoxacin, lomefloxacin, norfloxacin, and ofloxacin, the fractional inhibitory concentrations(FICs) and the fractional inhibitory concentration indices(FICIs) for four bacterial strains were determined by macrobroth dilution checkerboard assay. Combinations of EA and quinolones exhibited either additive or indifferent effects of antibacterial activity in most instances. However, both synergistic and antagonistic effects were not observed in any cases.

• Mycobiology
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• v.36 no.4
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• pp.249-254
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• 2008

Minimal growth inhibitory concentrations (MICs) of chitosan acetate (M.W. 60 kDa) on heterotrophic bacteria (strains MK1, S, and R) isolated from the soft-rotten tissues of Neungee mushroom (Sarcodon aspratus) were measured. The slimy substance produced by the MK1 strain was responsible for the diseased mushroom’s appearance. The S and R strains were members of the Burkholderia cepacia complex. These strains showed different levels of susceptibility toward chitosan acetate. The MIC of chitosan acetate against the MK1 and S strains was 0.06%. The MIC against the R strain was greater than 0.10%. Survival fractions of the MK1 and S strains at the MIC were $3\;{\times}\;10^{-4}$ and $1.4\;{\times}\;10^{-3}$ after 24 h, and $2\;{\times}\;10^{-4}$ and $7\;{\times}\;10^{-4}$ after 48 h, respectively. Survival fractions of the R strain after 24 and 48 hr at 0.1% chitosan acetate were $1\;{\times}\;10^{-2}$ and $6.9\;{\times}\;10^{-3}$, respectively. Compared to the MK1 and S strains, the low susceptibility of the R stain towards chitosan acetate could be due to the ability of the R strain to utilize chitosan as a carbon source. Thirty-eight percent of Neungee pieces treated in a 0.06% chitosan acetate solution for $2{\sim}3$ second did not show any bacterial growth at 4 days, whereas bacterial growth around untreated mushroom pieces occurred within 2 days. These data suggest that chitosan acetate is highly effective in controlling growth of indigenous microorganisms on Neungee. The scanning electron micrographs of the MK1 strain treated with chitosan revealed a higher degree of disintegrated and distorted cellular structures.

• The Journal of Korean Medicine
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• v.26 no.3 s.63
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• pp.98-109
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• 2005

Objectives : This study was designed to identify the effects of Salvia Miltiorrhiza or antibacterial activity against Streptococcus pneumoniae ATCC 33400. Methods : The ethanol- and water-extracts of more than 80 oriental herbal medicines were investigated by the Kirby-Bauer method to determine their inhibitory effect on growth of S. pneumoniae ATCC 33400 in vitro. Of thorn, Salvia Miltiorrhiza was selected. Results : The ethanol-soluble extract of Salvia Miltiorrhiza showed relatively high antibacterial activity against S. pneumoniae ATCC 33400. However, the water-soluble extract of Salvia Miltionrhiza showed no antibacterial activity. The ethanolic extract was forker fractionated with organic solvents such as hexane, chloroform, and ethyl acetate in that order. Among the fraction tested, the chloroform fraction showed the highest antibacterial activity, when the ethanol-soluble extract of Salvia Miltiorrhiza minimal inhibitory concentration (MIC) was 25${\mu}g/ml$. Conclusions : Further study should be carried out to identity of the cell growth inhibition effects of S. pneumoniae ATCC 33400.

• YAKHAK HOEJI
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• v.42 no.6
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• pp.639-641
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• 1998

Minimal inhibitory concentrations (MICs) of Bifidobacterium spp. strains (Bifidobacterium breve K-110, B. breve K-111 and B. infantis K-525) isolated from healthy Korean against antituberculosis agents and fluoroquinolones were determined. From the MICs it was found that Bifidobacterium breve K-110, B. breve K-111 and B. infantis K-525 were susceptible to rifampicin and fluoroquinolenes and resistant to other antituberculosis agents.

• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.41-47
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• 2004

This study was performed to investigate the antimicrobial effects of hetero-chitosans and their oligosaccharides on the halophilic bacterium, Vibrio parahaemolyticus. Nine classes of hetero-chitosan oligosaccharides were prepared based on their molecular weights, using an ultrafiltration membrane reactor system with chitosanase and celluase, from partially different deacetylated chitosans, 90%, 75%, and 50% deacetylated chitosan, respectively. Thirty-two strains of V. parahaemolyticus were isolated from various marine organisms such as shellfish, shrimps, octopus, and seabirds. Seventy-five percent deacetylated chitosan showed the highest antimicrobial acitivity. The minimal inhibitory concentration (MIC) was 0.5 mg/ml on 14 strains of V. parahaemolyticus, and MIC of the rest strains (18 strains) was 1.0 mg/ml. In addition, MIC of most hetero-chitosan oligosaccharides was 8.0 mg/ml. The results revealed that the antimicrobial effects of hetero-chitosans and their oligosaccharides against V. parahaemolyticus depend on the degree of deacetylation, their molecular weights, and strains tested.