• Korean Journal of Microbiology
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• v.52 no.3
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• pp.327-335
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• 2016

A novel Amycolatopsis strain KCTC 29142 was isolated and characterized based on the polyphasic taxonomic analysis including morphological observation, phylogenetic analysis, physiological and chemotaxonomic characteristics. The ethyl acetate extract of strain KCTC 29142 culture broth showed strong antibacterial activity and the active compound was identified as siderochelin A, a ferrous-ion chelating compound. In this study, siderochelin A showed good activity against multi-drug resistant pathogens, including Acinetobacter baumanii, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Staphylococcus aureus (VRSA), and Escherichia coli (E. coli). The minimum inhibitory activity against clinical isolates was also determined.

• Analytical Science and Technology
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• v.23 no.4
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• pp.405-413
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• 2010

A new method for the simultaneous determination of six glucocorticoids (betamethasone, dexamethasone, prednisone, prednisolone, methylprednisolone, and flumethasone) in meats (bovine muscle, bovine liver) were established. Samples were effectively extracted using C18 cartridge with ethylacetate. Chromatographic separation was achieved using C18 column and negative electrospray ionization mass spectrometry was performed in the Multiple Reaction Monitoring mode for the effective quantitation and qualification of glucocorticoids. Acetonitrile and water (0.1% formic acid) were used as mobile phase and additive for effective electrospray ionization, and gave good chromatographic separation and mass spectrometric sensitivity. The limit of detection (LODs) and the limit of quantitation (LOQs) in spiked blank samples depending on types of matrix and pharmaceuticals were ranged from 0.2 to $1.0\;{\mu}g$/kg and 0.8 to $3.4\;{\mu}g$/kg, respectively. And the recoveries were between 89.5 to 119.6%. The established method showed good recoveries, accuracies, precisions and fast sample preparation and it will be applied to assay of glucocorticoids residues in meat.

• Polymer(Korea)
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• v.26 no.1
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• pp.37-44
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• 2002

The polymer blends of waste polyvinyl chloride (RPVC) and waste polyethylene(RPE) were prepared by melt mixing, and their morphology and tensile properties were evaluated after the copolymers having an ethylene group in backbone and ester group in side position were added as comptatibilizers. The blend compositions were varied as follows ; RPVC/RPE 85/15 wt%, where RPVC formed a continuous phase : 50/50, mid composition : 15/85, RPE a continuous phase. The blends revealed a very low compatibility between component polymers because they showed domain sizes greater than $10\mu\textrm{m}$ over all compositions, especially the worst compatibility around mid composition. The blends showed higher compatibility when ethylene vinylacetate copolymer(EVA) and ethylene ethylacrylate-graft-methyl methacrylate copolymers(EEA-MMA) were added.

• Korean Journal of Medicinal Crop Science
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• v.16 no.2
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• pp.74-78
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• 2008

Liquiritin in licorice (Glycyrrhiza uralensis Fisch) extract was treated with three different plant crude enzymes (Prunus dulcis enzyme; PDE, P. armeniaca enzyme; PAE and P. persica enzyme; PPE) for biotransformation. The resulting product of liquiritin was analyzed by TLC and HPLC. The ${\beta}glucosidase$ activities of crude enzymes were 259.6 U/g (PDE), 407.6 U/g (PAE) and 445.8 U/g (PPE), respectively. The liquiritin was converted to liquiritigenin after 12 hours of incubation with the crude enzymes. Liquiritigenin content reached its maximum level after the treatment with PPE at $37^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.421-427
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• 1996

Ethyl carbamate is an animal carcinogen and a suspected human carcinogen found in fermented foods and beverages. For the determination of ethyl carbamate in typical Korean diet, an analytical method was established for the food as complex as Kimchi. Kimchi samples collected from various locations in the country were homogenized and extracted four times with ethyl acelate. Following concentration and reconstitution with water, the extract was loaded onto $C_{18}$ column. Fraction containing ethyl carbamate was eluted with methanol, while most of the red pigment of the sample was retained on the column. The eluent was further purified with alumina, followed by Florisil column. The final eluent was analyzed by gas chromatography mass spectrometry in the selected ion monitoring mode. None of the twenty Kimchi samples showed ethyl carbamate level higher than 4.6 ppb without correction for the recovery. The concentration of ethyl carbamate in Kimchi increased as pH decreased, suggesting fermentation dependent formation of ethyl carbamate.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.651-655
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• 2001

To investigate the antimutagenic effect of Platycodon grandiflorum DC, methanol extract of Platycodon grandiflorum DC was investigated. In Ames test, the methanol extract showed inhibitory effects of 80-90% on the mutagenicity induced by indirect mutagen of IQ(2-amino-3-methylimidazo[4,5-f]quinoline) and direct mutatgen of MNNG(N-methyl-N'-nitro-N-nitrosoguanidine) in Salmonella typhimurium TA 98 and TA 100. And then the methanol extract was further fractionated. Among the solvent extracted fractions from the methanol extract, the ethyl acetate fraction and butanol fraction exhibited the greatest antimutagenic effect suppressing the mutagenicity IQ and MNNG with inhibition rate of 99% and 98%.

• Journal of Applied Biological Chemistry
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• v.61 no.3
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• pp.283-290
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• 2018

In this study, we verified the 1-1-diphenyl-2-picryl-hydrazyl radical scavenge, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenge, elastase, tyrosinase inhibitory effect by using the solvent fractions of Maekmoondong-tang hot water extract. As a result, the ethyl acetate fraction (MW-EA) showed the highest inhibitory activity. In cell-based assays, MW-EA treatment confirmed a 34% ($100{\mu}g/mL$) efficacy in reactive oxygen species inhibitory activity, and at the same concentration, MMPs showed more than 50% inhibition and tyrosinase inhibited 25% ($50{\mu}g/mL$). Therefore Maekmoondong-tang is considered high development potential as a material to improve the skin.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.249-257
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• 2020

This study investigated whether the extracts from cosmos flowers exhibit antibacterial activities and identified which components were ascribed to the antibacterial effects. The antibacterial effects of extracts from white, pink, and violet cosmos flowers were observed for 24 h after inoculation with four kinds of bacteria, including Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli. Among the three fractions of cosmos flower extracts, the best antibacterial activity against the four bacteria was observed in the extracts isolated from the EtOAc layer. However, the extracts from the CHCl₃ layer were also effective against S. aureus. Moreover, the first of white, second of pink, and first of violet silica gel fractions (Fr.) isolated from the EtOAc layer exhibited minimal inhibition at a concentration of 0.1 mg/mL. Comparison of NMR and High-Pressure Liquid Chromatography results between silica gel Fr. and apigenin suggested that the effective fractions can contain a component including apigenin moiety.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.226.1-226
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• 2003

최근 쌀 소비량이 감소되고 쌀중심 식생활의 영양적 우수성을 인식하지 못하여 쌀은 주식으로서 위치가 흔들리고 있다. 그동안 쌀의 영양특성에 관한 연구로서 주로 탄수화물 급원으로서의 당질에 관한 연구와 미강을 중심으로한 식이섬유, 미강유등에 관한 연구결과들이 발표되었다. 특히 미곡 부산물인 미강으로부터 다양한 유효성분들이 확인되어 그 효능이 보고되고 있으며 일부가 기능성 소재로서 제품화되기도 하였다. 그러나 실제 우리의 식생활에서 섭취되고 있는 백미 또는 현미상태에서의 유효성분의 분포 및 함량에 대한 연구는 미진한 상태이다. 본 연구에서는 쌀의 영양적우수성을 규명하고자 유효성분 중 phenolic acid와 폴리페놀 함량을 품종 및 도정도에 따라 조사하였다. 조생종인 오대와 만생종인 남평 품종으로부터 현미와 7분도, 10분도 및 12분도로 도정도를 달리한 백미, 도정도별 미강을 각각 제조하였다. Ferulic acid 등 쌀과 미강에 존재하는 phenolic acid 는 알칼리로 추출한 후 pH를 조정하고 에틸아세테이트로 반복 추출하여 HPLC로 분석하였다. 현미에 함유된 phenolic acid는 ferulic acid가 가장 많아 50％ 내외를 차지하였으며 p-coumaric acid, benzoic acid, sinapinic acid 순으로 검출되었다. 오대 현미의 총 phenolic acid 함량은 65.9 mg%로서 남평 현미의 57.2 mg%보다 높았으며 도정도가 증가할수록 백미 중의 총 phenolic acid 함량은 감소되었다. 미강 중에는 백미의 10배 량에 해당하는 phenolic acid가 검출되었고 benzoic acid와 m-hydroxy benzoic acid는 미강 시료에서만 검출되었다. 도정한 백미 중의 phenolic acid는 28.8∼51.7 mg%, 미강에서 321.4∼438.4 mg% 범위로 나타났다. 현미, 백미 및 미강에 함유된 총 폴리페놀의 함량을 표준 페놀화합물로 카테친을 사용하고 비색법에 의하여 측정하였을 때 오대 현미의 폴리페놀 함량은 78.4 mg%, 남평 현미 88.8 mg% 였다. 도정한 백미 중의 총 폴리페놀 함량은 30.3∼56.9 mg%, 미강이 541.5∼472.6 mg%의 범위였다. 이상과 같이 쌀에는 phenolic acid 및 총 폴리페놀이 상당량 함유되어 있으며 특히 배유보다는 강층에 많이 존재하므로 이들 성분의 효율적인 이용을 위한 쌀의 섭취방안이 필요한 것으로 나타났다.

• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.680-687
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• 1998

The ethyl acetate fraction from ethanol extract of Glycyrrhiza uralensis FISCH showed growth inhibition on 5 strains of Listeria monocytogenes (ATCC 19111, 19112, 19113, 19114 and 15313) at $50{\sim}100\;ppm$. By silica gel column chromatography twice, antimicrobial active compound G-4-4 was isolated from ethyl acetate fraction of Glycyrrhiza uralensis FISCH. The G-4-4 fraction showed growth inhibition at $10{\sim}50\;ppm$ and confirmed bactericidal effect at 50 and 100 ppm on 5 strains of Listeria monocytogenes. Staphylococcus aureus KFCC 11764 was inhibited at $30{\sim}50\;ppm$ of G-4-4 but Escherichia coli ATCC 25922 was not inhibited at 100 ppm. The antimicrobial active substance G-4-4 was identified as liquiritigenin, a kind of flavanone compound, by IR, MS, $^1H-NMR\;and\;^{13}C-NMR$.