• KSBB Journal
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• 제13권3호
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• pp.244-250
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• 1998

글루코스와 초산을 온라인 모니터링 하기위한 흐름주입분석기 술이 개발되었고 대장균발효공정에 이용되었다. 또한, Epoxy 고 분자 담체에 고정화된 GOD와 SOD 를 이용한 GOD-FIA와 SOD-FlA의 특성을 연구했다. 즉, FIA 의 조작온도, 운반용액 속의 첨 가제 (Triton, EDTA, natrium azid 등), 분석 시 료에 용 해된 신진대사물의 농도, pH, 초산측정시 사코진 농도 등에 따 라 고정화된 GOD와 SOD의 활성도, 즉 검출신호의 높이변화를 고찰했다. 최소배양액 과 복합배양액을 사용한 대장균 발효공정 에서 달루코스와 초산을 동시에 온라인 모니터링 하였으며 그결 과는 오프라인 분석결과와 잘 일치 하였다,

• 한국염색가공학회지
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• 제28권4호
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• pp.299-307
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• 2016

In order to clarify the availability of heat treatment for catechu dyeing, effect of color developing by heating process on cotton fabrics dyed with catechu extract was investigated. Dyed fabrics were heated various time(min) at $150^{\circ}C$. The cases of non-mordanting and mordanting were compared, and examined the effect of sodium acetate as an agent to promote the color developing to fabrics. Experiments with after-mordanting method showed that various colors can be obtained using catechu. K/S values of dyed fabrics with Al, Cu, Fe mordant were higher than the case of no mordant. The fabric by Cu mordanting showed 3 times to the case of no mordant. Fabrics dyed with catechu by mordanting lowered $L^*$ value while there was little change in $a^*$, $b^*$ value as the heating process progressed. Therefore, K/S values were increased due to heating process. The effects of adding sodium acetate in dyeing bath on dyed fabrics were shown higher K/S values, and the $L^*$ values were lower than those without sodium acetate according to heating time increase. The result show sodium acetate had a promoting effect on the color developing to the fabrics by heating process, it was very effective.

• Toxicological Research
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• 제11권1호
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• pp.57-62
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• 1995

To investigate the ultrastructural changes of kidney and clarify to a cause of its changes in lead intoxicated rats, the 0.5% lead acetate administed orally to the rats and those were sacrifled at 2 day, 1, 2, 4, 6 and 8 week after the treatment of lead acetate. Each extirpated kidney was histopathologically examined under the electron microscopy and histochemical examination was also carried out. Concomitantly, the activity of free radical metabolizing enzyme was determined. The blood levels of lead concentration showed a gradual increase from the first group reaching the plateau at the one or two week group with the slightly decreasing value throughout the whole course of the experiment. And the urinary ALA concentration showed a gradual increase from the first group to the 8 week group. In the kidney tissue of rat sacrified at 6 week, the proximal tubular cells showed dilatation of endoplasmic reticulum, mitochondrial swelling, increased numbers of secondary lysosomes and myelin figure-like residual bodies on electron microscope and oxygen free radicals are identified by histochemistry on light microscope whereas there were no differences in the activity of catalase and glutathione peroxidase between the lead acetate treated group and control group. But the activity of xanthine oxidase was more increased in lead acetate treated rats than control group. Furthermore, the superoxide dismutase activity was significantly increased in the experimental group than the control group. In conclusion, it is assumed the kidney damage in lead intoxicated rat may be induced by free radicals.

• 생약학회지
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• 제50권4호
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• pp.299-304
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• 2019

In order to research the anti-oxidative activity of methanol extract of Phellinus baumii Pilat (Hymenochaetaceae), Caenorhabditis elegans model system was used. Ethyl acetate soluble fraction of the methanol extract showed the most potent DPPH radical scavenging activity. The ethyl acetate fraction was measured on its activities of superoxide dismutase (SOD), catalase, and oxidative stress tolerance with reactive oxygen species (ROS) level in C. elegans. Furthermore, to see if regulation of stress-response gene is responsible for the increased stress tolerance of C. elegans which treated by the ethyl acetate fraction, we checked SOD-3 expression using a transgenic strain. Consequently, the ethyl acetate fraction of P. baumii increased SOD and the catalase activities in a dose-dependent manner in C. elegans, reduced ROS accumulation dose-dependently. Besides, the ethyl acetate fraction-treated CF1553 worms showed higher SOD-3::GFP intensity than the control worms.

• 생약학회지
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• 제42권4호
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• pp.323-328
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• 2011

We investigated antioxidative activity, tyrosinase inhibitory activity, and melanin production inhibitory activity of the methanol extract of Paeoniae Radix and its fractions. The total polyphenol content of the extract was 73.45 mg/g, and content of the ethyl acetate fraction was 514.50 mg/g as the highest content of fractions. In DPPH radical scavenging ability, $SC_{50}$ values of the ethyl acetate was 3.86 ${\mu}g/ml$ as a result of greater activity in the positive control (ascorbic acid). Moreover, tyrosinase inhibitory activity of the ethyl acetate fraction showed higher activity than arbutin used as a positive control. In the cytotoxicity measurement by MTT assay, the extract and fractions were exhibited cell viabilities of 76.96~157.26% against Raw 264.7 and B16F10 cell in concentration of 10~100 ${\mu}g/ml$. In nontoxic concentration range, the ethyl acetate fraction showed strong melanin production inhibitory effect in ${\alpha}$-melanocyte stimulating hormone (${\alpha}$-MSH)-stimulated B16F10 cell. As a result, the ethyl acetate fraction of the methanol extract from Paeoniae Radix could be applicable to functional materials for skin-whitening agents.

• 한국식품영양과학회지
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• 제33권8호
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• pp.1268-1272
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• 2004

본 연구에서는 천년초 손바닥 선인장 유기용매 추출물의 항균성을 비교, 검토하고자 하였다. 70% ethanol로 추출하여 hexan, chloroform, ethyl acetate, buthanol, water로 순차 분획하여 ascorbic acid, benzoic acid와 항균효과를 비교하여 보았다. Escherichia coli 등 Gram positive bacteria 2종, Gram negative bacteria 2종, yeast 1종 등 총 6개의 병원성 식중독 미생물에 대해 항균효과를 검토한 결과 ethyl acetate 분획물이 가장 우수한 항균효과를 나타내었고 이는 동량의 benzoic acid보다 월등히 우수하였다. Gram positive bacteria와 Gram negative bacteria에 대해 유의적 차이가 없는 비슷한 항균효과를 보여주었으나 bacteria에 비해 yeast에서 항균효과는 낮게 나타났다.

• 대한의생명과학회지
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• 제6권3호
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• pp.181-186
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• 2000

항암제로 사용되어 온 아위를 사용하여 극성에 따른 용매추출 분획을 얻고 TPA로 처리된 HL-60 세포를 사용하여 기질부착 억제실험을 수행한 결과, ethyl acetate (EA) 층에서 가장 강한 부착억제효과가 있음을 알아 내었기에 ethyl acetate (EA)층을 다시 ethyl acetate (EA), hexane (HEX), ethyl ether (EE)로 추출한 뒤 3회 chromatography하여 아위 순수활성물질인 asadisulphide를 분리해 내었다. 이 순수활성물질을 가지고 HL-60 암세포에 대한 부착 억제실험을 수행한 결과 asadisulphide는 최소농도 2 $\mu\textrm{g}$/ml에서 HL-60 세포의 부착을 98%억제하였다. 또한 assdisulphide는 HL-60 세포에 대해 ED$_{50}$값은 2.6 $\mu\textrm{g}$/ml이었으며, 20 $\mu\textrm{g}$/ml 농도 이하에서 세포독성이 없고 항암효과가 있다는 사실을 규명하였다.

• 한국안전학회지
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• 제25권3호
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• pp.61-65
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• 2010

Most of the chemical reactions performed in the chemical industry are exothermic, meaning that thermal energy is released during the reaction. It is also important to understand the thermal hazards such as thermal stabilities and runaway reactions, which are governed by thermodynamics and reaction kinetics of the mixed materials. The paper was described the evaluation of thermal behavior caused by an exothermic batch process in manufacture of the vinyl acetate resin. The aim of the study was to evaluate the thermal stabilities of raw materials with operating conditions such as a reaction inhibitor, heating rate, reaction atmosphere and the mount of methanol charged in the vinyl acetate polymerization process. The experiments were performed in the differential scanning calorimeter(DSC), C 80 calorimeter, and thermal screening unit($TS^u$). It was suggested that we should provide the thermal characteristics for raw materials to present safe precautions with operating conditions in the vinyl acetate polymerization process.

• Journal of Microbiology and Biotechnology
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• 제23권11호
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• pp.1544-1553
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• 2013

Despite the importance of acetate kinase in the metabolism of bacteria, limited structural studies have been carried out on this enzyme. In this study, a three-dimensional structure of the Escherichia coli acetate kinase was constructed by use of molecular modeling methods. In the next stage, by considering the structure of the catalytic intermediate, trifluoroethanol (TFE) and trifluoroethyl butyrate were proposed as potential inhibitors of the enzyme. The putative binding mode of these compounds was studied with the use of a docking program, which revealed that they can fit well into the enzyme. To study the role of these potential enzyme inhibitors in the metabolic pathway of E. coli, their effects on the growth of this bacterium were studied. The results showed that growth was considerably reduced in the presence of these inhibitors. Changes in the profile of the metabolic products were studied by proton nuclear magnetic resonance spectroscopy. Remarkable changes were observed in the quantity of acetate, but other products were less altered. In this study, inhibition of growth by the two inhibitors as reflected by a change in the metabolism of E. coli suggests the potential use of these compounds (particularly TFE) as bacteriostatic agents.

• Macromolecular Research
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• 제15권6호
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• pp.565-574
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• 2007

In this study, five representative, commercially available polymers, Ultem 1000 polyetherimide, Kapton polyimide, phenolic resin, polyacrylonitrile and cellulose acetate, were used to prepare pyrolyzed polymer membranes coated on a porous {\alpha}-alumina$ tube via inert pyrolysis for gas separation. Pyrolysis conditions (i.e., final temperature and thermal dwell time) of each polymer were determined using a thermogravimetric method coupled with real-time mass spectroscopy. The surface area and pore size distribution of the pyrolyzed materials derived from the polymers were estimated from the nitrogen adsorption/desorption isotherms. Pyrolyzed membranes from polymer precursors exhibited type I sorption behavior except cellulose acetate (type IV). The gas permeation of the carbon/{\alpha}-alumina$ tubular membranes was characterized using four gases: helium, carbon dioxide, oxygen and nitrogen. The polyetherimide, polyimide, and phenolic resin pyrolyzed polymer membranes showed typical molecular sieving gas permeation behavior, while membranes from polyacrylonitrile and cellulose acetate exhibited intermediate behavior between Knudsen diffusion and molecular sieving. Pyrolyzed membranes with molecular sieving behavior (e.g., polyetherimide, polyimide, and phenolic resin) had a $CO_2/N_2$ selectivity of greater than 15; however, the membranes from polyacrylonitrile and cellulose acetate with intermediate gas transport behavior had a selectivity slightly greater than unity due to their large pore size.