• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 추계 총회 및 학술발표회
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• pp.152-155
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• 2004

• Bulletin of the Korean Chemical Society
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• 제26권8호
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• pp.1203-1208
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• 2005

A computational study based on molecular dynamics (MD) simulations was performed in order to explain the difference in aqueous solubilities of two flavonoid/$\beta$-cyclodextrin ($\beta$-CD) complexes, hesperetin/$\beta$-CD and naringenin/$\beta$-CD. The aqueous solubility of each flavonoid/$\beta$-CD complex could be characterized by complexwater interaction not by flavonoid-CD interaction. The radial distribution of water around each inclusion complex elucidated the difference of an experimentally observed solubility of each flavonoid/$\beta$-CD complex. The analyzed results suggested that a bulky hydrophobic moiety (-$OCH_3$) of B-ring of hesperetin nearby primary rim of $\beta$-CD was responsible for lower aqueous solubility of the hesperetin/$\beta$-CD complex.

• 한국식품영양과학회지
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• 제26권2호
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• pp.351-357
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• 1997

Bacillus firmus가 생산하는 cyclodextrin glycosyltran-sferase(CGTase)를 ammonium sulfate 침전, DEAE-Sephadex A-50 및 Sephdex G-100 column chromatography로 분리, 정제하였다. 이 방법으로 수율은 12%, 정제도는 49배인 SDS-PAGE 상에서 단일 band의 효소 단백질을 얻을 수 있었다. 정제된 CGTase는 Phast system의 SDS-polyacrylamide gel 전기영동에 의하여 분자량은 80,000dalton, isoelectric focusing으로 등전점은 9.6으로 추정되는 단백질이었다. 이 효소의 최적 활성 pH와 온도는 8.0, $65^{\circ}C$이였으며, pH와 열안정성은 $pH\;5.5{\sim}9.0$, $50^{\circ}C$이였다. Soluble starch를 기질로 하여 24시간 효소반응한 액의 ${\alpha}-\;:\;{\beta}-\;:\;{\gamma}-cyclodextrin$의 생성비율은 0.01 : 2.90 : 1.00으로 ${\beta}-$ 및 ${\gamma}-cyclodextrin$을 주로 생산하였다.

• 대한화학회지
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• 제58권2호
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• pp.227-229
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• 2014

• 한국미생물·생명공학회지
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• 제17권4호
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• pp.370-378
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• 1989

토양으로부터 역가높은 CGTase를 분비하는 호알칼리성 미생물을 분리하였으며, 동정 결과 Bacillus circulans로 판정되었다. 배양액 중의 CGTase를 ammonium sulfate 침전, DEAE-Sephadex 그리고 Sephadex G-100 column chromatography로 분리, 정제하여 단일 단백질 band를 얻었다. 정제된 CGTase의 분자량은 약 93,000, 최적 pH와 온도는 6.0, $50^{\circ}C$였으며, pH와 온도안정성은 5.5-11, $65^{\circ}C$까지였다. Soluble starch를 기질로 할 때의 $V_{max}$ 와 $K_{m}$ 값은 각각 0.16$\mu$mole $\beta$-CD/min, 14.3mg soluble starch/mi이였고 24시간 반응액의 $\alpha$-：$\beta$-:${\gamma}$-CD 의 생성비율은 1：8.1：1.9로서 $\beta$-CD를 우선적으로 합성하였다. 기질로 glucose와 maltose를 사용하였을 때 CD합성작용이 없었으며, sweet potato 그리고 cornstarch를 사용하였을 때 가장 높은 CD합성작용을 보였다. 어느 수준 이상의 과다한 CGTase 첨가경우에는 $\alpha$-CD생성이 급격히 증가하였다. 또한 정제된 CGTase는 stevioside에로의 당전이성을 갖고 있었다.

• Journal of Microbiology and Biotechnology
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• 제9권1호
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• pp.62-69
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• 1999

In order to investigate the critical amino acid residues involved in the catalytic activities of $\beta$-cyclodextrin glucanotransferase ($\beta$-CGTase) excreted by Bacillus firmus var. alkalophilus, the amino acid residues in $\beta$-CGTase were modified by various site-specific amino acid modifying reagents. The cyclizing and amylolytic activities of $\beta$-CGTase were all seriously reduced after treatment with Woodward's reagent K (WRK) modifying aspartic/glutamic acid, N-bromosuccinimde (NBS) modifying tryptophan, and diethylpyrocarbonate (DEPC) modifying histidine residues. The roles of tryptophan and histidine residues in $\beta$-CGTase were further investigated by measuring the protection effect of various substrates during chemical modification, comparing protein mobility in native and affinity polyacrylamide gel electrophoresis containing soluble starch, and comparing the $K_m$ and $V_{max}$ values of native and modified enzymes. Tryptophan residues were identified as affecting substrate-binding ability rather than influencing catalytic activities. On the other hand, histidine residues influenced catalytic ability rather than substrate-binding ability, plus histidine modification had an effect on shifting the optimum pH and pH stability.

• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.835-840
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• 2005

The main objective of the present study was to determine the effect of dietary $\beta$-cyclodextrin ($\beta$-CD) on egg laying performance and cholesterol content of egg yolk. Feed intake, egg production and egg weight varied slightly, but not significantly, between hens fed either a control diet or a diet containing one of an increasing series of $\beta$-CD concentrations (2%, 4% or 6%). However, feed intake, egg production and egg weight were all lower in the hens fed on 8% $\beta$-CD (p<0.05). No difference in haugh unit values, egg yolk color and egg shell thickness were found between the different treatments. The cholesterol content of egg yolks (mg/g yolk) was significantly decreased by 0.71, 2.98, 4.00 and 4.24 mg in eggs from hens maintained on 2%, 4%, 6% and 8% $\beta$-CD, respectively (p<0.05). These observations indicate that appropriate supplementation of diets with $\beta$-CD can reduce the cholesterol content of eggyolks, thus raising the prospect of the production of a healthier functional food.

• Archives of Pharmacal Research
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• 제24권4호
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• pp.281-285
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• 2001

Enantiomers of five racemic ${\beta}_2$-agonists were investigated by capillary electrophoresis employing a hydroxypropyl-${\beta}$-cyclodextrin (HP-${\beta}$-CD). The effects of the concentration of HP-${\beta}$-CD added to the background electrolyte and of the pH of the buffer on the effective mobility and resolution of the studied compounds were examined. Very good resolution was achieved for terbutaline and clenbuterol; salbutamol and bambuterol was able to be partially resolved. Enantioselectivity and resolution were influenced by the concentration of the HP-7-CD, buffer composition and pH.

• Journal of Pharmaceutical Investigation
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• 제27권3호
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• pp.165-171
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• 1997

Ibuprofen, a nonsteroidal antiinflammatory, analgesic and antipyretic drug, has several limitations in clinical application because of low solubility in water and gastrointestinal irritation. Effect of ibuprofen/$2-Hydroxypropyl-{\beta}-cyclodextrin\;(HP{\beta}CD)$ inclusion compound on release of suppository was investigated. Complex formation was confirmed by $^{1}H-\;and\;^{13}C-NMR$ spectroscopy. The release of ibuprofen from suppository base in vitro was significantly increased by the complexation with $HP{\beta}CD$. The release of ibuprofen from hydrophilic base was faster than that from hydrophobic base. In vivo studies, the release rate of ibuprofen from suppository was accelerated after rectal administration in complex form. This results suggested that ibuprofen/$HP{\beta}CD$ complex can be practically used for suppository to have faster effect of ibuprofen with reduced side effect.

• Applied Biological Chemistry
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• 제33권1호
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• pp.79-86
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• 1990

Bacillus stearothermophilus KFCC 21203를 배양하여 cyclodextrin(CD)을 분해하는 효소를 분리, 정제하고 정제효소의 몇 가지 특성을 조사하였다. 배양액에서 얻은 조효소를 염석, DEAE-cellulose column chromatography, Ultro AcA 34 gel filtration등의 방법으로 15배 정제하였으며 회수율은 77.2%이었다. 정제효소의 specific activity는 12.30units/mg protein 이었고 분자량은 약 29,500정도였다. 이 효소의 작용최적 PH는 5.5, 작용최적온도는 $55^{\circ}C$였으며 $40^{\circ}C$이하의 온도와 pH $5.0{\sim}8.0$의 범위에서 안정하였고 ${\gamma}-CD$에 대한 Km치는 $3.78{\times}10^{-3}$ M이었다. 정제효소는 ${\beta}-CD$에 대한 활성이 매우 낮았고 ${\alpha}-CD$에는 거의 활성이 없었으나 ${\gamma}-CD$에는 매우 높은 활성을 나타내었으며, 이의 분해산물로는 주로 glucose 및 maltose 그리고 소량의 maltotriose였다. 또한 amylose, potato starch, corn starch, amylopectin 및 maltooligomer등에는 높은 활성을, 그리고 glycogen, dextrin에도 비교적 높은 활성을 나타내었고 분해산물로는 주로 glucose와 maltose였다.