• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1645-1649
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• 2011

[ ${\beta}$ ]Ketoacyl acyl carrier protein synthase I (KAS I) is involved in the elongation of unsaturated fatty acids in bacterial fatty acid synthesis and a therapeutic target of designing novel antibiotics. In this study, we performed receptor-oriented pharmacophore-based in silico screening of E. coli KAS I (ecKAS I) with the aim of identifying novel inhibitors. We determined one pharmacophore map and selected 8 compounds as candidates ecKAS I inhibitors. We discovered one antimicrobial compound, YKAe1008, N-(3-pyridinyl) hexanamide, displaying minimal inhibitory concentration (MIC) values in the range of 128-256 ${\mu}g/mL$ against MRSA and VREF. YKAe1008 was subsequently assessed for binding to ecKAS I using saturation-transfer difference NMR spectroscopy. Further optimization of this compound will be carried out to improve its antimicrobial activity and membrane permeability against bacterial cell membrane.

• Korean Journal of Pharmacognosy
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• v.34 no.2 s.133
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• pp.142-144
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• 2003

Acetone extracts of 301 strains of marine-derived fungus were tested for antimicrobial activity against three strains of bacteria. The bacteria consisted of three pathogens, Staphylococcus aureus, methicillin-resistant S. Aureus, and multidrug-resistant S. aureus. The acetone extracts of 10 strains (MFA117, MFA130, MFA134, MFA206, MFA217, MFA268, MFA277, MFA291, MFA292, MFA301) showed strong activity, inhibiting 100% of the bacterial growth. These antimicrobial active strains were cultlued in SWS medium on a 1 L scale and the resulting broth and mycelium were extracted to afford mycelium extract (000M) and broth extract (000B), respectively. Antimicrobial activity for all extracts has been tested as the results, the mycelium extract of one strain (217M) and the broth extracts of 9 strains (117B,130B, 134B, 206B, 268B, 277B, 291B, 292B, 301B) exhibited relatively high levels of activity at minimal inhibitory concentration (MIC) values of $500-125\;{\mu}g/mL$ range. Among them, the extracts, 277B, 291B, 292B and 301B showed the most significant antimicrobial activity with $IC_{50}$ values of $125\;{\mu}g/mL$.

• Korean Journal of Veterinary Service
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• v.29 no.2
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• pp.123-128
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• 2006

It's a case of the goat farm reared about 60 heads in Imsil county was outbreak Moniezia expensa infection. And 18 heads of less than 6 month olds goat were died. During the 2005 summer, morbidity and accumulative mortality were more than 60% and 30%, respectively less than 6 month young goat. Most young goat were suffer from diarrhea, severe weight losses, emaciations, and died. In necropsy, there were about 0.7-2.5m of 2-8 adult M expensa in the small intestinal lumen, swollen mesenteric lymph nodes. Slight hemorrhages were seen in lung and moderate hemorrhages were seen in mucous membrane of small intestine. Also various species (Trichostrongylus spp, Haemonchus spp, Eimeria spp) of parasite eggs were seen in fecal test. Pasteurella hemolytica was identified in lung by the API kit (Biomerieux Co. Ltd) for biochemical test. The minimal inhibitory concentration (MIC) results, trimethoprim/sulfamethoxazole, erythromycin, tyrosine, gentamycin, enrofloxacin, and norflocxacin were selected sensitive antibiotics.

• YAKHAK HOEJI
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• v.34 no.2
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• pp.106-111
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• 1990

The isolation and identification of an antibacterial component, from the leaves of Liriodendron tulipifera. K. Kotch against a cariogenic bacterium Streptococcus mutans OMZ 176, were carried out for developing of anticariogenic agents. The bioactive component was elucidated as ${\beta}-liriodenolide$, which was isolated newly from the leaves of L. tulipifera. The minimal inhibitory concentration (MIC) of ${\beta}-liriodenolide$ was $100\;{\mu}g/ml$ and the antibacterial activity was stronger than that of berberine. ${\beta}-Liriodenolide$ inhibited ${\beta}-lactamase$ activity, 50, 100 and $200\;{\mu}M$ ${\beta}-liriodenolide$ did ${\beta}-lactamase$ activity as 0.7, 3.5 and 19.7%, respectively. The toxicity of ${\beta}-liriodenolide$ was not found with the method of photohemolysis.

• Korean Journal of Veterinary Research
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• v.34 no.1
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• pp.153-163
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• 1994

A study on quinolone antibacterial (pefloxacin methanesulfonate) was performed to use for the drug of fisheries. Petloxacin was proved excellent in antibacterial activity and resistance against fish pathogens when compared with the existing antibacterials. And any side effect was not observed during the period of indicated use. An outline of MIC(Minimal Inhibitory Concentration) was $1.6{\sim}6.4{\mu}g/ml$, $TLm_{48h}$ value were 380~420 ppm in Israeli carp(Cyprinus caprio) and 2100~2300 ppm in flounder(Paralichthys olivaceus). The residual time of fish body was less than 15 days. So we can treat some bacterial disease of fish by the dosage of 100 g/day/ton of fish body weight for 3 days and pefloxacin is thought to be used effectively and widely against most bacterial fish pathogens.

• Mycobiology
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• v.28 no.1
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• pp.33-38
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• 2000

Mycelium of Hericium erinaceum isolate KU-1 was cultured in liquid medium (HL medium) and solid medium (Ko medium) at pH 4.0 in $28^{\circ}C$. 1.0% glucose or fructose was the most favorable carbon source, and 0.2% amonium acetate or $NaNO_3$ was an exellent nitrogen source for mycelial growth as well as production of antimicrobial substances. The mixture of saw dust 70% with rice bran 30% (SR medium) was the substrate for formation of sporophores. The active substrates in extracts from mycelium, culture filtrate and fruiting body were separated by TLC. The solvent for TLC was EtOAc: Chloroform: MeOH (10 : 5 : 10). Phenol-like substances appeared at Rf $0.5{\sim}0.9$, and fatty acid-like substances appeared at Rf $0.1{\sim}0.2$. The purified materials from the extracts showed antimicrobial effects to Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Aspergillus niger, Candida albicans and Microsporum gypseum. The S. aureus was the most inhibited. Minimal inhibitory concentration (MIC) of purified white powder and the Hercenone derivatives against S. aureus were $5.65\;{\mu}g/ml$ and $1.85\;{\mu}g/ml$, respectively.

• Journal of Integrative Natural Science
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• v.10 no.3
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• pp.154-161
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• 2017

An antimicrobial peptides-producing Bacillus strain CBS73 was isolated from fermented food (kimchi) that produces low-molecular-weight proteins with broad-spectrum antimicrobial activity. Our goal was to explore the therapeutic potential of antimicrobial substances produced by Bacillus species. Peptide CBS73 was purified from Bacillus subtilis subsp. subtilis with identity of 99.79%. It was found to be stable at pH 4.0-10.0 and temp $20-60^{\circ}C$. A protein band around 5.2 kDa was detected in tricine-SDS-PAGE and band was confirmed by MALDI-TOF test. Peptide CBS73 showed antimicrobial activity against MDR bacteria. The minimal inhibitory concentration (MIC) of peptide CBS73 for vancomycin-resistant S. aureus (VRSA), vancomycin resistant Enterococci (VRE) and Salmonella typhimurium ranged from $10-40{\mu}g/mL$. The antioxidant activity of peptide CBS73 was measured by DPPH scavenging, reducing power activity and total phenolic content. Cell viability and NO production result showed less cytotoxic effect upto $12{\mu}g/mL$. Peptide CBS73 could be a promising antimicrobial agent for clinical application.

• YAKHAK HOEJI
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• v.42 no.1
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• pp.89-94
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• 1998

Propionibacterium acnes is the pharmacological target site of antiacne drugs. We have examined the antiacne activity of ninety seven natural products which have been used as Korean traditional medicines in various skin disorders. The antibacterial activity of extracts from the natural products were evaluated against P. acnes ATCC 9616 by disc method. Twelve natural products showed the potent antibacterial activity against P. acnes, and were, selected for the minimal inhibitory concentration(MC) against P. acnes. MICs of nine extracts were below 0.3% (w/v) and Sophora flavescens showed the most potent activity with a MIC of less than 0.008%(w/v) against P. acnes. Thus, the results suggest that nine natural products including S. flavescens can be developed as sources of promising potent antiacne agents.

• Journal of Animal Science and Technology
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• v.62 no.6
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• pp.864-874
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• 2020

Lactic acid bacteria are well-known probiotics, conferring several health benefits. In this study, we isolated lactobacilli from human breast milk and identified Lactobacillus reuteri LM1071 (RR-LM1071) using 16S rDNA sequencing. We tested the hemolytic activity, biogenic amine production, and antibiotic susceptibility of this strain to assess its safety. RR-LM1071 was found to be negative for hemolytic activity and biogenic amine production, as well as was measured in susceptible level for antibiotics in the minimal inhibitory concentration (MIC) test. The adhesive properties of RR-LM1071 were higher than those of LGG in HT-29 cells, and showed a greater hydrophobicity than LGG in hexadecane solvent. Under inflammatory conditions, RR-LM1071 suppressed the mRNA expression of IL-6, TNF-α, and IL-4 produced in IL-1β-induced HT-29 cells. Our results suggest that RR-LM1071 is a safe and valuable probiotic that can be used for the treatment of inflammatory bowel disease.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.80-91
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• 2003

Mutans streptococci, especially S. mutans and S. sobrinus strongly implicated in pathogenesis of dental caries, the major cause of tooth loss in children. Use of an antibacterial agent controlling dental caries has been rationalized. The present study was performed to observe the antibacterial effect of inorganic polyphosphates (polyP) on S. mutans and S. sobrinus. S. mutans GS5 and S. sobrinus 6715 were grown in brain-heart infusion broth with or without polyP. Minimal inhibitory concentration (MIC) of polyP for S. mutans GS5 was determined to be 0.08% and that for S. sobrius 6715 was 0.17%. PolyP 15 added to the growing culture of S. mutans GS5 and S. sobrinus 6715 at their exponential phase was as effective in inhibiting the growth of S. mutans GS5 and S. sobrinus 6715 as polyP added at the very beginning of the culture. More than 85% of the cells lost their viability determined by viable cell count when polyP 15 was added to the culture of growing S. mutans GS5 at MIC, suggesting that polyP 15 has bacterial effect on the bacterium. And more than 99.9% of the cells lost their viability determined by viable cell count when polyP 15 was added to the culture of growing S. sobrinus 6715 at MIC, suggesting that polyP 15 has bacterial effect on the bacterium. Intracellular nucleotide release from S. mutans CS5 and S. sobrinus 6715 was increased in the presence of polyP 15 for 5h but was not really reversed by the addition of divalent cations like $Ca^{++}\;and\;Mg^{++}$. The majority of the cells appeared to be atypical in their shape, demonstrating accumulation of highly electron-dense granules and ghost cells. The overall results suggest that polyP have a strong bactericidal activity against S. mutans and S. sobrinus in which lysis in relation to chelation may not play the major role but unknown mechanism that possibly affects the viability of the bacterium may be involved. PolyP may be used as an agent for prevention of dental caries.