• YAKHAK HOEJI
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• v.58 no.1
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• pp.58-61
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• 2014

The essential oil was extracted from the roots of Angelica dahurica Bentham et Hooker f. by steam distillation and its composition was analyzed by GC-MS. The antifungal activities were evaluated by micro-dilution method against five Aspergillus and three Trichophyton species. The most abundant component was ${\alpha}$-pinene (17.21%) among 40 compounds identified in this oil. The essential oil fraction of A. dahurica and ${\alpha}$-pinene exhibited marked inhibiting activities against the tested Aspergillus and Trichophyton species with MICs (minimum inhibitory concentrations) between 0.12 mg/ml and 8 mg/ml.

• YAKHAK HOEJI
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• v.18 no.4
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• pp.243-248
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• 1974

Nine benzoxazolin-2-thione derivatives were sunthesized as the potential antimicrobial substances. These compounds were tested for the antimicrobial activities using Staphylococcus aureus and Escherichia coli by way of tube dilution method. The three compounds of I, II and VII omjoboted the growth of S.aureus at the concentration of 1${\mu}$g/ml, and III,VI,VIII and IX exhibited considerable antimicrobial activities against S. aureus at the concentration of 10.m.u.g/ml. As to the growth of E. Coli, VII VII and VIII inhibited at the concentration of 1${\mu}$g/,l. II,III and IV exhibited considerable antimicrobial activities against E. coli at the concentration of 10${\mu}$g/ml.

• Archives of Pharmacal Research
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• v.26 no.5
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• pp.389-393
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• 2003

The essential oils from Cedrus atlantica, Styrax tonkinensis, Juniperus communis, Lavandula angustifolia, Melaleuca alternifolia, Pelargonium graveolens, Pogestemon patchouli and Rosmarinus officinalis were analyzed by GC-MS. Antifungal activities of the oils were investigated by disk diffusion assay and the broth dilution method against Aspergillus niger and A. flavus. The effects of geraniol and the essential oil fraction from P. graveolens on the antifungal activity of amphotericin Band ketoconazole were examined using a checkerboard microtiter assay against both Aspergillus fungi. Most of the tested essential oils, with the exception of C. atlantica, J. communis, and P. patchouli, significantly inhibited growth of A. niger and to a lesser extent that of A. fIavus, with MICs (minimal inhibitory concentrations) in the range 0.78-12.5 mg/mL. The essential oil fraction of P. graveolens and its main components, geraniol and citronellol, exhibited additive effects with amphotericin B and with ketoconazole against both Aspergillus species, resulting in fractional inhibitory concentration (FIC) indices ranging from 0.52 to 1.00.

• International Journal of Oral Biology
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• v.39 no.2
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• pp.115-120
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• 2014

Minimal inhibitory concentration (MIC) is the lowest concentration of antibiotics that inhibits the visible growth of a microorganism. It has been reported that sub-MIC of antibiotics may result in morphological alterations along with biochemical and physiological changes in bacteria. The purpose of this study was to examine morphological changes of periodontal pathogens after treatment with sub-MIC antibiotics. Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis were used in this study. The MIC for amoxicillin, doxycycline, metronidazole, penicillin, and tetracycline were determined by broth dilution method. The bacterial morphology was observed with bright field microscope after incubating with sub-MIC antibiotics. The length of A. actinomycetemcomitans and F. nucleatum were increased after incubation with metronidazole; penicillin and amoxicillin. P. gingivalis were increased after incubating with metronidazole and penicillin. However, F. nucleatum showed decreased length after incubation with doxycycline and tetracycline. In this study, we observed that sub-MIC antibiotics can affect the morphology of periodontal pathogens.

• YAKHAK HOEJI
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• v.43 no.5
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• pp.566-571
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• 1999

(1H-1,2,4-Triazolyl) methy-4-(sub). phenyl-5-methyl-1,3-dioxolan-2-yliden (3) derivatives were synthesized and tested for their antifungal activities. The designed compounds with a 1,2,4-triazolylmethyl group at the 4-position of 1,3-dioxolan-2-yliden moiety were synthesized by reaction of difluorinated olefins(2) with (2R, 3R)-2-(2,4-dihalophenyl)-1-(1H-1,2,4-triazol-l-yl) butane-2,3-diol (1). These compounds were tested for in vitro antifungal activities against 16 fungi species. The MIC values were determined by the micro broth dilution method. In general, 1,3-dioxolan-2-yliden derivatives showed antifungal activities in vitro. Among them, (4R, 5R)-4-(2,4-difluorophenyl)-5-methyl-2-[1-(3,4-methylenedioxypheny)meth-ylidene)-1,3-dioxolon-4-yl(1H-1,2,4-triazollyl)methane showed superior antifungal activities to fluconazol and ketoconazol.

• YAKHAK HOEJI
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• v.54 no.2
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• pp.122-125
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• 2010

The essential oil fraction was extracted from the aerial parts of the plant by steam distillation method and its composition was analyzed by GC-MS (gas chromatography-mass spectrometry) which led to the identification of 43 compounds. Dehydroelsholtzia ketone (56.81%) and elsholtzia ketone (30.05%) were identified as the predominant components of this oil. The antibacterial activities of the essential oil fraction were assessed by micro-dilution tests against antibioticsusceptible and -resistant strains of Streptococcus pneumoniae, Staphylococcus aureus, Salmonella enteritidis, and S. typhimurium. The oil inhibited most of the tested strains significantly resulting MICs (minimum inhibiting concentrations) between 2 mg/ml and >16 mg/ml. In most cases of this study Streptococcus pneumoniae and Staphylococcus aureus showed higher sensitivity to this oil than Salmonella strains.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.58.1-58.1
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• 2011

We present elemental abundances of 95 blue compact dwarf galaxies (BCDs) at z=0.2~0.35 using the Sloan Digital Sky Survey (SDSS) DR7. We derived element abundances using Te method. We found that nitrogen abundance of merging BCDs are more enriched than normal BCDs by fast rotating young massive star. On the other hand, neon and oxygen abundances for merging BCDs are slightly lower than the normal BCDs. This might be result from the dilution by metal-poor gas infall during the interaction. This means that merging BCDs undergone star formation event for a long time than normal BCDs and we trying to explain using STARLIGHT code and various star formation rates (SFRs) ratios. At a result, merging BCDs have older stellar population (>10 Myr) more than normal BCDs and have clear distinction in elements abundances versus Ha/UV diagram. We also discuss the characteristics of post merger candidate using FUV to NUV ratios.

• Journal of Welding and Joining
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• v.28 no.3
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• pp.36-41
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• 2010

High Mn steel has been developed for automotive applications since the steel has an excellent combination of strength and ductility. However, from the viewpoint of welding, high Mn steel has a few problems related to its chemical composition. This paper describes characteristics of dissimilar $CO_2$ laser welding for expanding application of high Mn steel. From this work it was cleared that dissimilar laser welded joint between high Mn steel and carbon steel had poor formability due to the formation of martensite within weld metal. In order to improve ductility of welded joint, the method of controlling the dilution ratio of high Mn steel was suggested.

• Archives of Pharmacal Research
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• v.16 no.2
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• pp.161-163
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• 1993

In order to evaluate the antimicrobial effect of 2,3-disubstituted-1,4-naphthalenedione derivatives, we synthesized several 2-chloro, 2-bromo and 2-hydroxy-3(substituted)-1, 4-naphthalene-diones (1-25). These derivatives were tested for antifugal and antibacterial activities, in vitro, against Candida albicans 10231 and local, Aspergillus niger KCTC 1231, Tricophyton mentagrophytes KCTC 6085, Baciilus subtilis ACTT 6633, Pseudomonas aeruginsa NCTC 10490, Staphylococcus aureus ATCC 6538P, Escherichia coli NIHJ. The MIC values were determined by the two-fold agar dilution/strea method. Among these derivatives, 4, 5 and 6 showed the potent antifungal activities. Also 5 and 6 had the antibacterial activities. 5 with (1,2,4-triazolyl)-amino moirty was the most effective in preventing the growth of fungi, such as Candida albicans, Aspergillus niger and Tricophyton mentagrophytes.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.6
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• pp.598-605
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• 2017

To isolate rhizobacteria exhibiting antifungal activities for for five pathogenic fungi (Sclerotinia sclerotiorum, Fusarium solani, Collectotricum gloeosporides, Fusarium oxysporum, and Botrytis cinerea) which cause damage to Ginseng root in Ginseng grown fields, four soils were collected from Cheorlwon gun, in Korea. From 4 soils, a total of 160 bacterial strains were isolated by dilution plate method. Among 160 strains, 32 strains showed antifungal activities for one or more pathogens. From 32 strains, three strains exhibited antifungal activities for all pathogens. These are two Burkholderia cepacia (ATCC 25416 and ET 13) and one Paenibacillus polymyxa (ATCC 842). These potent antifungal strains showed high identities (99% using 16S-rRNA sequencing).