• 제목/요약/키워드: cycoldextrin

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Pseudomonas stutzeri IAM 12097의 exo-maltotetraohydrolase에 관한 연구(硏究) -제2보(第二報). Exo-maltotetraohydrolase의 특성(特性)- (Studies on the Exo-maltotetraohydrolase of Pseudomonas stutzeri IAM 12097 -Part II. Characteristics of Exo-maltotetraohydrolase-)

  • 이미자;정만재
    • Applied Biological Chemistry
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    • 제27권4호
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    • pp.271-277
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    • 1984
  • Pseudomonas stutzeri IAM 12097이 생산(生産)하는 Exo-maltotetraohydrolase의 gel filtration에 의하여 추정(推定)된 분자량(分子量)은 60,000이었고, SDS-polyacrylamide gel electrophoresis에 의하여 추정(推定)된 분자량(分子量)은 63,000이었으며 등전점(等電點)은 PH 4.8이었다. 최적(最適)pH는 6.6, PH안정(安定)범위는 $6.0{\sim}10.5$, 최적온도(最適溫度)는 $45{\sim}50^{\circ}C,\;40^{\circ}C$이하(以下)에서는 안정(安定)하였으며, $55^{\circ}C$이상(以上)에서는 급격하게 불활성화(不活性化)되었다. 본효소(本酵素)는 $Ag^+,\; Hg^{++},\;I_2,\;{\beta}-cycoldextrin$에 의하여 완전(完全)히 저해(沮害)되었고 EDTA, ${\rho}-CMB$, IAA에 의하여 약간 저해(沮害)되었다. soluble starch, amylopectin, amylose에 대(對)한 Michaelis constant(Km)는 각각(各各) 7.70mg/ml, 6.17mg/ml, 5.56mg/ml이었다.

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Cyclodextrin Glucanotransferase와 Cyclodextrinase를 생산하는 Bacillus 속 세균의 분리와 그 효소들의 특성

  • 권현주;남수완;김광현;곽영규;김병우
    • 한국미생물·생명공학회지
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    • 제24권3호
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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.

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Chiral Separation of ($\pm$)-Higenamine by Capillary Electophoresis

  • Choi, One-Kyun;Jung, Kyo-Soon;Choi, Heisook-Yun;Yang, Deok-Chun
    • Plant Resources
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    • 제6권1호
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    • pp.81-88
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    • 2003
  • Higenamine [1-(4-hydroxy-6, 7-dihydroxy-l, 2, 3, 4-tetrahydroisoquinoline) is a cardiotonic constituent of Aconiti tuber, one of the most widely prescribed oriental medicines. S-(-)higenamine was reported to have a stronger cardiotonic activity than R-(+)-higenamine and known as a central intermediate in the biosynthesis of various benzyl isoquionoline alkaloids in plants. The separation of higenamine enantiomers has been accomplished with capillary electrophoresis using cyclodextrins (CDs) as chiral selectors. Good resolution of this enantiomers was obtained using a 50 mM sodium phosphate buffer containing hydroxypropyl $\beta$-CDs using 27 cm fused silica capillary (50${\mu}{\textrm}{m}$ i.d., 20 cm to detector) at 25 $^{\circ}C$. With the electric field of 340 V/cm, the separation time of higenamine enantiomers was less than 6 min. Under this optimum conditions, the relative standard deviations of migration time and peak area were less than 1.6% and 3.2%. A 512-channel diode array detector was confirmed for the higenamine. The detection limits (S/N = 3) of these enantiomers are $1.5mutextrm{m}$/mL. We confirmed the chiral form of higenamine in medicinal plants.

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Enhancement of Solubility and Disolution Rate of Poorly Water-soluble Naproxen by Coplexation with $2-Hyldroxypropylo-{\beta}-cyclodextrin$

  • Lee, Beom-Jin;Lee, Jeong-Ran
    • Archives of Pharmacal Research
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    • 제18권1호
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    • pp.22-26
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    • 1995
  • The solubility and dissolution rate of naproxen (NPX) complexed with 2-hydroxypropyl-.betha.-cyc-lodextrin (2-HP.betha.CD) using coprecipitation, evaporation, freeze-drying and kneading method were investigated. Solubility of NPX linearly increased (correlation cefficient, 0.995) as $2-HP\betaCD$ concentraction increased, resutling in $A_l$ type phase solubility curve. Inclusion complexes prepared by four different methods were compared by different methods were compared by dfferential scanning calorimetry(DSC). The NPX showed sharp endothemic peak around $156^{\circ}C$ but inclusion complexes by evaporation, freeze-drying and kneading method showed very broad peak without distinct phase transtion temperature. In contrast, inclusion complex prepared by coprecipitation method resulted in detectable peak around $156^{\circ}C$ which is similar to NPX, suggesting incoplete formation of indusion co plex. Dissolution rate of inclusion complexes prepared by evaporation, frezz-drying and kneding except coprecipitation method was largely enhanced in the simultaed gastric and intestinal fluid when compared to NPX powder and commercial $NA-XEN^\registered$tablet. However, about 65% of NPX in gstric fluid. in case of inclusion complex prepared by coprecipitation method, formation of inclusion complex appeared to be incoplete, resulting in no marked enhancement of dissolution rate. From these findings, inclusion complexes of poorly water-soluble NPX with $2-HP\betaCD$ were useful to increase soubility and dissolution rate, resting in enhancement of bioavailability and minimization of gastrointestinal toxicity of drug upon oral administration of inclusion complex.

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