• KSBB Journal
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• v.13 no.3
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• pp.244-250
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• 1998

Flow-injection analysis (FIA) for on-line monitoring of glucose and acetate are described and employed in E.coli fermentation process. Glucose oxidase (GOD) for the detection of glucose is immobilized on epoxy polymer support, which is packed in a small cartirdge, and applied to a GOD-FIA system. The detection of acetate is based on the inhibition of acetate to the oxidation of sarcosine by sarcosine oxidase (SOD). SOD is also immobilized on epoxy polymer support and used for a SOD-FIA system. GOD-FIA system is characterized as well as SOD-FIA system by the investigation of the effects of pH, temperature and metabolites in samples on the peak height. GOD-FIA and SOD-FIA systems were also applied for on-line On-line measurements buy FIA measurements by FIA were in god agreement with off-line measurements.

• Textile Coloration and Finishing
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• v.28 no.4
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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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• v.11 no.1
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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.

• Korean Journal of Pharmacognosy
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• v.50 no.4
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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.

• Korean Journal of Pharmacognosy
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• v.42 no.4
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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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1268-1272
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• 2004

The 70% ethanol extract from cactus Chounnyouncho (Opuntia humifusa) was fractionated subsequently by hexan, chloroform, ethyl acetate, buthanol and water. The ethyl acetate fraction exhibited strong antimicrobial activities by paper disk diffusion method on the five strains of food born bacteria Bacillus subtilis, Staphylococcus aureus subsp. aureus, Escherichia coli, Salmonella typhimurium and Pseudomonas fluorescens. It has a heat resistance to show inhibitory effect after heat treatment at 11$0^{\circ}C$ for 1 hr. The ethyl acetate fraction showed almost perfect growth inhibition at over 700 ppm on the tested strains.

• Biomedical Science Letters
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• v.6 no.3
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• pp.181-186
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• 2000

Asadisulphide were purified from Ferrula assafoetida by organic solvent extraction and chromatography. Its inhibitory effects on the TPA-induced adherence of HL-60 cells was analyzed. Since ethyl acetate extracts of F. assafoetida has the strongest inhibitory effect on adherence of HL-60 cells, it was re-extracted with ethyl acetate, hexane, and ethyl ether and chromatographed three times to isolate asadisulphide. At the minimum concentration of 2 $\mu\textrm{g}$/ml, asadisulphide inhibited adherence of 98% of HL-60 cells that have been treated with TPA. It also showed anti-cancer effect with no cytotoxity in the ED$_{50}$ value of 20 $\mu\textrm{g}$/ml.

• Journal of the Korean Society of Safety
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• v.25 no.3
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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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• v.23 no.11
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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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• v.15 no.6
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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.