• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.662-665
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• 2001

Enantioselective production of levofloxacin from ofloxacin butyl ester by porcine liver esterase was enhanced with the addition of ${\alpha}$-cyclodextrin(${\alpha}-CD$) and pH change. The conversion yield was increased from 27 to 64% and 100% with 150 mM substrate when the molar ratio of ${\alpha}-CD$ to substrate was 1 and 2, respectively. When 100 mM of substrate was added with the same molar ratio of ${\alpha}-CD$ at pH 5.6, the solubility was increased 3.8 times and the conversion yield was increased 4.4 times.

• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.274-281
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• 1996

A bacterium producing Cyclodextrin Glucanotransferase (CGTase) and Cyclodextrinase (CDase) was isolated from soil, and named as Bacillus stearothermophilus KJ16. The growth of the isolated strain occurred in two steps, and syntheses of CGTase and CDase were dependedt on the growth cycle of the cell. CGTase was constitutively synthesized during the 1st growing phase, while CDase was synthesized inducibly during the 2nd growing phase. When the midium pH was controlled at 7.0 the maximum enzyme activities of CGTase and CDase were increased by 12-fold (1300 mU/ml) and 2-fold (225 mU/ml), respectively, compared with the pH-uncontrolled batch culture. The CGTase of the isolate converted soluble starch to CDs with the ratio of $\alpha$-CD:$\beta$-CD:$\gamma$-CD=42:46:12 at $55^{\circ}C$.The optimal pH and temperature of CGTase were 6.0 and $60^{\circ}C$, respectively and the optimal pH and temperature of CDase were 6.0 and $55^{\circ}C$. The molecular weights of the purified CGTase and CDase were estimated to be 65, 000 and 68, 000 dalton, respectively. Among several substrates, $\gamma$-CD was most rapidly hydrolyzed by the purified CDase.

• Molecules and Cells
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• v.23 no.1
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• pp.57-63
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• 2007

Leukotrienes (LTs) are produced by several biosynthetic enzymes including cytosolic phospholipase $A_2$ ($cPLA_2$), 5-lipoxygenase (5-LO), and 5-lipoxygenase activating protein (FLAP) in the perinuclear area. In the present study, we showed that pretreatment with methyl-${\beta}$-cyclodextrin (MβCD), a cholesterol-depleting agent, dramatically reduced the synthesis of LTs in response to A23187 in mast cells. A23187-induced LT synthesis was inhibited by pretreatment with M${\beta}$CD, and this effect was reversed when cholesterol was added. In an approach to identifying the $M{\beta}CD$-sensitive protein(s), we observed that FLAP co-localized with flotillin-1, a lipid raft marker protein, in the lipid raft-rich low-density region of sucrose gradients. In addition, electron microscopic analysis revealed that FLAP co-localized with flotillin-1. Together, these results suggest that FLAP is present in cholesterol-rich lipid raft-like domains and that its localization in these domains is critical for LT synthesis.

• The Korean Journal of Food And Nutrition
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• v.33 no.4
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• pp.419-427
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• 2020

The purpose of this study was to investigate the qualitative changes of the citron by identifying the type of solution and addition of the solution to prevent the browning reaction of the citron in a way that inhibits the browning of the citron. The browning inhibitor solution was investigated using the individual and mixture, and the results of the degree of browning and chromaticity showed that vitamin C+NaCl+cyclodextrin (CD) had the lowest browning of 0.52. In chromaticity, the ΔE values indicate that the higher the value, the greater the change in color, and the lowest value of the vitamin C+NaCl+CD mixture was 47.0, indicating that there was minimal browning compared to other treatment. The active change of the polyphenol oxidase (PPO) in the citron increased enzyme activity as the browning progressed, and the vitamin C+NaCl+CD solution was the lowest at 68.40 μ/g among the anti-browning solution. Based on these research results, it seems that the CD mixing solution can be used as a citron browning inhibitor.

• Journal of Dairy Science and Biotechnology
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• v.25 no.1
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• pp.9-13
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• 2007

The present study was carried out to examine the effect of crosslinked ${\beta}$-cyclodextrin(${\beta}$-CD) made by adipic acid on cholesterol removal rate and find the structural change after recycling on SEM observation. The size reduction and morphological changes were found during the recycling process and the profound changes were observed at 8th time reuse. After cholesterol removal in milk, the used crosslinked ${\beta}$-CD was washed for cholesterol dissociation and reused. In recycling study, the cholesterol removal rate at first trial was 92.5% in milk, which was mostly same as that using new crosslinked ${\beta}$-CD(92.4%). With repeated 10th reuse of crosslinked ${\beta}$-CD resulted in 81.4% of cholesterol removal in milk. Similar trend was found in cream and cholesterol removal was 91.5% at 1st trial and 83.4% at 10th trial. In both milk and cream samples, the removal rate at 1st reuse was not significantly different from that at 6th reuse(p>0.05). The present study indicated that crosslinked ${\beta}$-CD made by adipic acid resulted in the effective recycling efficiency, especially up to 6th reuse and morphological modifications were not distinguishable up to 8th reuse.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.632-637
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• 2000

This research was undertaken to restore the biological activity of cyclodextrin glucanotransferase (CGTase) of Bacillus macerans origin expressed as inclusion bodies in recombinant Escherichia coli. The optimum concentration of urea used as a denaturant was 8 M. The supplementation of 0.5 M urea into a dialysis buffer increased the refolding efficiency by preventing any protein aggregation. The influence of the protein concentration, temperature, and pH were also investigated. The protein concentration was found to be the most important factor in the refolding efficiency. The optimum temperature was 15-$25^{\circ}C$ and the optimum pH was 6.0. The maximum specific activity of the CGTase refolded under the optimum conditions was 92.2 U/mg, corresponding to 72% of the native CGTase. A comparison of the secondary structure between the native and the refolded CGTase showed that the relative ratio of the $\alpha$-helix content in the native to the refolded CGTase was 1:0.82.

• Journal of Pharmaceutical Investigation
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• v.20 no.1
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• pp.13-18
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• 1990

Hydrocortisone (HC) sustained-release suppositories were prepared by using a solid matrix of methacrylic acid-methacrylic acid methyl ester copolymer $(Eudragit\;L_{100}^{R}:\;EL)$ as a poorly water soluble carrier and polyethylene glycole 1540 (PEG) as an water soluble carrier. HC release rate was controlled by complexation with ${\beta}-cyclodextrin$ $({\beta}-CyD)$ which was confirmed by X-ray diffractometry, IR-spectroscopy and differential scanning calorimetry. Release rate of HC from the EL-PEG matrix suppositories decreased with increase of EL contents. The release rale from $HC-{\beta}-CyD$ complex decreased in the following order: $HC-{\beta}-CyD/PEG$ > HC/PEG > $HC-{\beta}-CyD/EL_{10%}-PEG$ > $HC/EL_{10%}-PEG$ > $HC-{\beta}-CyD/EL_{15%}-PEG$ > $HC/EL_{15%}-PEG$ > $HC-{\beta}-CyD/EL_{20%}-PEG$ > $HC/EL_{20%}-PEG$. The crystallinity of HC in polymer matrix was identified using X-ray diffractometer and the surface of matrix suppositories after release test was examined by scanning electron microscopy. The sustained release of HC from these matrix suppositories was attributed to the network structure of EL.

• Archives of Pharmacal Research
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• v.27 no.11
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• pp.1183-1187
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• 2004

This study was designed to develop crosslinking of $\beta$-cyclodextrin ($\beta$-CD), and determine the optimum conditions of different factors (mixing time, mixing temperature, and mixing speed) on cholesterol reduction from milk. Crosslinked $\beta$-CD was prepared with epichlorohydrin. When milk was treated with different conditions, the cholesterol removal rate was in the range of 79.4 to 83.3% with 1 % crosslinked $\beta$-CD addition, which were not significantly different among treatments. After cholesterol removal from milk, the used crosslinked $\beta$-CD was washed for cholesterol dissociation and reused. For recycling study, the cholesterol removal rate in first trial was 81.8%, which was mostly same as that using new crosslinked $\beta$-CD. With five trials repeatedly using the same sample, the mean cholesterol removal rate was 81.2%. The present study indicated that the optimum conditions on cholesterol removal using crosslinked $\beta$-CD were 10 min mixing with 400 rpm speed at $5^{\circ}C$ with about 80% cholesterol removal. In addition, crosslinked $\beta$-CD resulted in the effective recycling efficiency almost 100%.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.3
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• pp.409-416
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• 2003

This study was carried out to find a cholesterol removal rate, flavor development and bitter amino acid productions in Cheddar cheese treated with $\beta$-cyclodextrin (CD): 1) Control (no homogenization, no $\beta$-CD), and 2) Milk treatment (1000 psi milk homogenization, 1% $\beta$-CD). The cholesterol removal of the cheese was 79.3%. The production of short-chain free fatty acids (FFA) increased with a ripening time in both control and milk treated cheese. The releasing quantity of short-chain FFA was higher in milk treated cheese than control at 5 and 7 mo ripening. Not much difference was found in neutral volatile compound production between samples. In bitter-tasted amino acids, milk treatment group produced much higher than control. In sensory analysis, texture score of control Cheddar cheese significantly increased with ripening time, however, that in cholesterol-reduced cheese decreased dramatically. Our results indicated that the cheese made by $\beta$-CD treated milk with low pressure homogenization showed an effective cholesterol reduction and a rapid cheese ripening, while no capture of flavor compounds by $\beta$-CD.

• Macromolecular Research
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• v.14 no.4
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• pp.449-455
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• 2006

Ionic cluster mimic, polymer electrolyte membranes were prepared using polymer composites of crosslinked poly(vinyl alcohol) (PVA) with sulfated-${\beta}$-cyclodextrins (${\beta}-CDSO_3H$) or phosphated-${\beta}$-cyclodextrins (${\beta}-CDPO(OH)_2$). When Nafion, developed for a fuel cell using low temperature, polymer electrolyte membranes, is used in a direct methanol fuel cell, it has a methanol crossover problem. The ionic inverted micellar structure formed by micro-segregation in Nafion, known as ionic cluster, is distorted in methanol aqueous solution, resulting in the significant transport of methanol through the membrane. While the ionic structure formed by the ionic sites in either ${\beta}-CDSO_3H$ or ${\beta}-CDPO(OH)_2$ in this composite membrane is maintained in methanol solution, it is expected to reduce methanol transport. Proton conductivity was found to increase in PVA membranes upon addition of ionized cyclodextrins. Methanol permeability through the PVA composite membrane containing cyclodextrins was lower than that of Nafion. It is thus concluded that the structure and fixation of ionic clusters are significant barriers to methanol crossover in direct methanol fuel cells.