• YAKHAK HOEJI
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• v.18 no.4
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• pp.249-254
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• 1974

Eighteen 2-aryl-3-(5-nitro-2-furyl) acrylamides were synthesized as antimicrobial agent, by the condensation of 2-(p-sulbstituted phenyl)-3-(5-nitro-2-furyl) acryloyl chloride with amino component, such as sulfisozxazole, sulfamethoxypyridazine and sulfadimethoxine. All compounds showed fair bacteriostatic activity against staphylococcus aureus 6538p, Bacillus subtilis, Escherichia coli, and Klebsiella pneumoniae. 2-(p-Hydroxyphenyl)-and 2-(p-acetoxyphenyl) compounds also showed antimicrobial activity against Saccharomyces cerevisiae 396 and Aspergillus oryzae.

• Journal of fish pathology
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• v.5 no.1
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• pp.9-18
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• 1992

In order to know the defense mechanism of fish, bactericidal activity was examined into the sera of carp Cyprinus carpio, tilapia Oreochromis niloticus and flounder Paralichthys olivaseus. Each examined normal serum of fishes showed the bactericidal activity against avirulent Escherichia coli but it wasn't appeared against virulent Edwardsiella tarda. When the normal serum of each fish was treated with zymosan, it lost the bactericidal activity completely. After addition of EGTA into the normal serum of each fish, the sera of tilapia and flounder still exhibited the bactericidal activity but the serum of carp lost it. In the presence of specific antibody and complement, bactericidal activity of each antiserum was exhibited high level with in one hour incubation. On the other hand, heat inactivated antiserum showed bacteriostatic reaction. From the above results, although the activity of alternative or classical pathway of each fish complement is different, it is an important function in fish defense mechanism.

• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.572-575
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• 1999

Miconazole was estimated to have a minimum inhibitory concentration of 0.78 ㎍/㎖ against the methicillin-resistant strains of Staphylococcus aureus (MRSA). The antibacterial activity of miconazole against MRSA was bacteriostatic in cation-adjusted Mueller-Hinton broth, but bacteriocidal in saline solution. The anti-MRSA activity of miconazole did not show a significant change under the susceptibility-testing conditions such as various inoculum sizes, pHs, or cations (Ca/sup ++/ or Mg/sup ++/) which was added to the medium. However, the anti-MRSA activity of miconazole was completely suppressed by lipophilic a-tocopherol (50 ㎍/㎖), but definitely not by water-soluble ascorbic acid.

• Korean Journal of Microbiology
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• v.12 no.2
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• pp.77-84
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• 1974

In order to study 5-nitro-2-furaldehyde derivatives having more effective antibacterial activity, four new $N^4$-(5-nitro-2-furfurylidene)-$N^1$-substituted sulfanilamides$N^1$-3,4-dimethyl-5-isoxazoyl-$N^4$-5-nitro-2-furfurylidene sulfanilamide, $N^1$-4,6-dimethyl-2-pyrimidyl-$N^4$-5-isoxazoyl-$N^4$-5-nitro-2-furfurylidene sulfanilamide, $N^1$-6-methoxy-3-pyridazinyl-$N^4$-5-nitro-2-furaldehyde with sulfa drugs such as sulfisoxazole, sulfamethazine, sulfamethoxypyridazine, and sulfadimethoxine. All compounds were tested for antibacterial activity in vitro on the following micro-organisms : Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Proteus vulgaris. Each compound exhibited a fair bacteriostatic activity against each microorganism. Above all, sulfisoxazole derivatives showed higher activity than the others. Each compound was most active against Staphylococcus aureus, whereas least active against proteus vulgaris.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1706-1712
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• 2006

Because of the need for new antimicrobial substances with novel mechanisms of action, we report here the use of an Acinetobacter reporter system for high-throughput screening of active antimicrobial agents. The bioreporter Acinetobacter strain DF4/PUTK2 carrying luciferase genes luxCDABE was chosen because of its ecological importance and it is widespread in nature. This bioreporter is genetically engineered to emit light constitutively that can be measured in real time by luminometry. Hence, this reporter system was employed to determine the bacteriostatic actions of spent-culture supernatants derived from twelve bacterial isolates. Out of the results, the strongest bioluminescence inhibitory effect of the supernatants was recorded with Bacillus cereus strain BAC (S5). Subsequently, ethyl acetate extracts of extracellular products of strain BAC (S5) were separated by a thin-layer chromatography (TLC). Based on the bioluminescence inhibitory assay, three fractions were found to have antimicrobial activity. One fraction (C) having the strongest antimicrobial activity was further purified using TLC and characterized by IR, $^1H$ NMR, mass spectrometry, SDS-PAGE, and amino acid composition analysis. The results predicted the presence of 2-pyrrolidone-S-carboxylic acid (PCA) and the octadeconic-acid-like fatty acid. Fraction C also demonstrated a broad inhibitory activity on several Gram-negative and Gram-positive bacteria. In conclusion, the Acinetobacter reporter system shows great potential to be a reliable, sensitive, and real-time indicator of the bacteriostatic actions of the antimicrobial agents.

• YAKHAK HOEJI
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• v.10 no.2_3
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• pp.15-19
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• 1966

In order to find 2-(5-nitro)furylacrylic acid derivatives possessing antimicrobial activity, nine new 2-(5-nitro)furylacrylamino acids were synthesized which were obtained by the action of 2-(5-nitro)furylacryla chloride on amino acids, such as $_{L}$-phenylalanine, glycine, $_{L}$-isoleucine, $_{L}$-glutamic acid, $_{DL}$-methionine, $_{L}$-threonine, $_{L}$-valine, $_{L}$-tryptophan and $_{DL}$-alanine, according to Schotten-Baumann method. These compounds generally showed a good bactericidal and bacteriostatic activity against Bacillus subtilis but were less effective against staphylococcus aureus, Proteus vulgaris and Escherichia coli. Of the above nine compounds, 2-(5-nitro)furylacryl glycine exhibited a good bactericidal activity.

• Journal of Food Hygiene and Safety
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• v.10 no.1
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• pp.23-28
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• 1995

The effect of the ethanol extract from salviae miltiorrhizae radix (Salvia miltiorrhiza) on the microbial growht and the stability of the extracted antimicrobial material were investigated. The ethanol extract had strong growth inhibition activity (MIC, 3.13~50.0 $\mu\textrm{g}$/ml) against Gram-positive bacteria such as B. subtilis, L. monocytogenes and S. aureus. Among Gram-positive bacteria tested, B. subtilis was the most susceptible to the extracted substance. While the antimicrobial activity of the ethanol extract was weak (MIC, 400~800 $\mu\textrm{g}$/ml) to E. coli and yeasts (C. albicans, Sacch. diastaticus). The ethanol extract had bactericidal action at higher concentration than MIC against B. subtilis, while the extract had only bacteriostatic action against S. aureus. The extracted antimicrobial substance was stable in the pH range of 4.0 to 10.0, heat treatment at 121$^{\circ}C$ for 15 min, and freezing and thawing

• Journal of Environmental Health Sciences
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• v.24 no.1
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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.

• Food Science of Animal Resources
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• v.36 no.4
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• pp.452-457
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• 2016

Lactoferrin is a glycoprotein with various biological effects, with antibacterial activity being one of the first effects reported. This glycoprotein suppresses bacterial growth through bacteriostatic or bactericidal action. It also stimulates the growth of certain kinds of bacteria such as lactic acid bacteria and bifidobacteria. In this study, Asn-Leu-Asn-Arg was selected and chemically synthesized based on the partial sequences of bovine lactoferrin tryptic fragments. Synthetic Asn-Leu-Asn-Arg suppressed the growth of Pseudomonas fluorescens, P. syringae and Escherichia coli. P. fluorescens is a major psychrotrophic bacteria found in raw and pasteurized milk, which decreases milk quality. P. syringae is a harmful infectious bacterium that damages plants. However, synthetic Asn-Leu-Asn-Arg did not inhibit the growth of Lactobacillus acidophilus. It is expected that this synthetic peptide would be the first peptide sequence from the bovine lactoferrin C-lobe that shows antibacterial activity.

• YAKHAK HOEJI
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• v.57 no.2
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• pp.95-100
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• 2013

This study was performed to analyze in vitro and in vivo activities of LCB01-0183, a new oxazolidinone, against clinical isolates of bacteria. In vitro antibacterial activity of LCB01-0183 was tested by the two fold agar dilution method. In vivo activity of LCB01-0183 was determined against systemic infections in mice. LCB01-0183 showed most potent activity among the test compounds against clinical isolates of Gram-positive bacteria. Furthermore, the protective activity of LCB01-0183 was very effective against systemic infections in mice by oral or subcutaneous administration. In time kill study, LCB01-0183 showed a bacteriostatic activity during 24 hours. LCB01-0183 had potent in vitro and in vivo activity against Gram-positive bacteria including drug-resistant strains.