• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.116-116
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• 1997

Complex formation of practically insoluble dexamethasone dipropionate (DDP) with ${\beta}$-cyclodextrin (${\beta}$-CD), dimethyl-${\beta}$-cyclodextrin (DMCD), trimethyl-${\beta}$-cyclodextrin (TMCD), 2-hydroxypropyl-${\beta}$-cyclodextrin (HPCD) and sulfobutyl ether ${\beta}$-cyclodextrin (SBCD) in water was investigated by solubility method at various temperatures. Water solubility of DDP was found to be 1.78 $\mu\textrm{g}$/$m\ell$ at 37$^{\circ}C$. Propylene glycol (PG)-water cosolvent increased the solubility of DDP, but the solubilization was not sufficient (8.93 $\mu\textrm{g}$/$m\ell$ in 20% PG). The addition of CD markedly increased the solubility of DDP in water, and A$\sub$L/ type phase solubility diagrams were obtained with ${\beta}$-CD, TMCD, HPCD and SBCD, where the apparent stability constants of the soluble complexes at 25$^{\circ}C$ were determined to be 1388, 216, 1054, and 1992 M$\^$-1/, respectively. However, DMCD remarkably increased the solubility of DDP, and showed an A$\sub$P/ type diagram, suggesting that DMCD forms a soluble complex of high order with DDP. The stability constant for the DDP-DMCD complex at 25$^{\circ}C$ was determined to be 19132 M$\^$-1/. The thermodynamic parameters were calculated for the inclusion complex formation in aqueous solution. CD (1${\times}$10$\^$-2/M) remarkably decreased the partition coefficients of DDP between isopropyl myristate/water in the order of TMCD < ${\beta}$-CD < HPCD < SBCD < DMCD, and in squalane/water system in the order of HPCD < TMCD < ${\beta}$-CD < DMCD < DMCD $\leq$ SBCD. This finding represents that, in a o/w type cream, cyclodextrin complexation with DDP may result in high concentration of DDP in aqueous phase. The permeation of DDP through a cellophane membrane was highly suppressed by the addition of CD, and the degree of suppression was different among CDs, indicating that CD may control the skin permeation of DDP. The dissolution rates of solid dispersions with CDs were much faster than those of drugs alone and corresponding physical mixtures. All DDP-CD solid dispersions exceeded the equilibrium solubility. Consequently these results suggest that complex formation of DDP with CDs may provide useful means to markedly enhance the solubility, and CDs are useful in the semi-solid preparations such as creams and gels for topical application.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.495-500
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• 1997

To isolate a gene for cyclodextrin glycosyltransferase (CGTase) from alkalophilic Bacillus sp. E1, polymerase chain reaction (PCR) amplification was carried out. Direct molecular cloning of 1.2 kbp fragment and partial nucleotide sequence analysis of the PCR amplified clone, pH12, showed close homology with CGTases from Bacillus species. To investigate the genomic structure of the gene, Southern blot analysis of genomic DNA was carried out with the clone pH12 as a molecular probe. It showed that 5.3 kbp XbaI fragment was hybridized with the probe pH12. To isolate a genomic clone, genomic DNA library was constructed and a genomic clone for CGTase, pCGTE1, was isolated. Nucleotide sequence analysis of the clone pCGTE1 revealed that BCGTE1 contained 2,109 bp open reading frame encoding a polypeptide of 703 amino acids and showed over 94.3% amino acid sequence homology with CGTase of ${\beta}-cyclodextrin$ producer, Bacillus sp. KC201.(Received October 7, 1997; accepted October 20, 1997)

• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.310-316
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• 2002

Extracellular cyclodextrin glucanotransferase (CGTase) from Paenibacillus sp. JK-12 was purified through sev-eral purification steps consisting of ammonium sulfate precipitation and chromatographies on DEAE-sephadex A-50 and Mono QIM HR5/5. The purified CGTase exhibited a single band on SDS-PAGE and was estimated to be approximately 82 kDa. The isoelectric point of the enzyme was 7.2 as determined by isoelectric focusing. The CGTase from Paenibacillus sp. JK-12 had a transglucosylation activity at the C-2 position of L-ascorbic acid. The optimum pH and temperature for the CGTase activity were 8.0 and 5$0^{\circ}C$, respectively. The enzyme activity was stable from pH 6.0 to 9.() and at temperatures up to 55$^{\circ}C$ at pB 8.0, having 80% residual activity. The activity of the CGTase was strongly resistant to metals such as A $g^{+}$ and $Ba^{2+}$ but slightly inhibited by H $g^{+}$, N $i^{2+}$ and $Mg^{2+}$. The enzymeproduced $\alpha$ -cyclodextrin ($\alpha$-CD) and $\beta$-CD as the main products from starch, but not ${\gamma}$-CD.X>-CD.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2016-2022
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• 2013

Ionically modified ${\beta}$-cyclodextrins, which have excellent water-solubility, have been interested in purification technology as well as drug carrier system. The present study summarizes the synthesis and characterization of cationic and anionic ${\beta}$-cyclodextrin (${\beta}$-CyD) products using by polycondensation. The oligo (${\beta}$-CyD)s are synthesized from ${\beta}$-CyD, epichlorohydrin (EP) and choline chloride (CC; for cationic polymer) or chloroacetic acid (CAA; for anionic polymer) through one step polycondenstaion process. Unlike the previous studies, we successfully purified the ionic ${\beta}$-CyD condensation products from the ${\beta}$-CyD reaction mixtures and accomplished a great level of structural analysis. The detailed structural analysis of these ionic ${\beta}$-CyD compounds is done by $^1H$ NMR, MALDI-TOF as well as GPC analysis and confirms the formation of oligomers with a few units of ${\beta}$-CyD. We found that the sequence of reactant addition also could effect on the molecular weight of the resulting product as well as the molar ratio of the reactants. Finally, we used the cationic and anionic ${\beta}$-CyD oligomers for fabricating multilayer films by layer-layer process.

• Korea-Australia Rheology Journal
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• v.12 no.2
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• pp.93-100
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• 2000

The interactions between methylated $\beta$-cyclodextrin (CD) and hydrophobically modified alkali-soluble associative polymers (HASE) were examined by a rheological technique. The effect of "capping" of hydrophobes by methylated $\beta$-cyclodextrin on the viscosity and modulus was evaluated. Model HASE polymers with $C_1$to $C_{20}$ alkyl hydrophobic groups ethoxylated with~10 moles of ethylene-oxide (EO 10) and at concentrations up to 3 wt% were examined. With the addition of methylated $\beta$-CD, the steady shear viscosity profiles shift from a Newtonian profile to one that display a shear-thinning characteristic. Significant "capping" of the hydrophobes occurs for HASE polymers with $C_{l2}$, $C_{16}$ and $C_{20}$ hydrophobes as reflected by the large reduction in the viscosity. However, the steady shear viscosity remains constant when the concentration of $\beta$-CD exceeds 1 wt%, suggesting that $\beta$-CD is not able to fully encapsulate the hydrophobes of the HASE polymer. The temperature variation plots indicate that the activation energy of the HASE-EO10-$C_{20}$ system and $\beta$-CD is dependent on the magnitude of the applied shear stress. These results further reinforce the hypothesis that $\beta$-CD is not able to completely remove all the hydrophobic associations.phobic associations.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.411-416
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• 2002

Bacillus macerans cyclodextrin glucanotransferase (CGTase) was expressed on the cell surface of Saccharomyces cerevisiae by fusing with Aga2p linked to the membrane-anchored protein, Aga1p. The surface display of CGTase was confirmed by immunofluorescence microscopy and its enzymatic ability to form ${\alpha}$-cyclodextrin from starch. The maximum surface-display of CGTase was obtained by growing recombinant S. cerevisiae at $20^{\circ}C$ and pH 6.0. S. cerevisiae cells displaying CGTase on their surface consumed glucose and maltose, inhibitory byproducts of the CGTase reaction, to enhance the purity of produced cyclodextrins. Accordingly, the experimental results described herein suggest a possibility of using the recombinant S.cerevisiae anchored with bacterial CGTase on the cell surface as a whole-cell biocatalyst for the production of cyclodextrin.

• Journal of Pharmaceutical Investigation
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• v.13 no.1
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• pp.10-22
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• 1983

The interactions of ${\alpha}-cyclodextrin({\alpha}-CyD)$ and ${\beta}-cyclodextrin({\beta}-CyD)$ with several non-steroidal antiinflammatory drugs were studied on the effects of ${\alpha}-$ and ${\beta}-CyD$ on the solubility of the drugs in aqueous medium. Indoprofen, niflumic acid, alclofenac, and naproxen were chosen as representatives of antiinflammatory drugs. The solubility of all drugs studied increased with the addition of ${\beta}-CyD$, while not with glucose or ${\alpha}-CyD$. The increase of the solubility with ${\beta}-CyD$ was considered due mainly to the formation of inclusion complexes between ${\beta}-CyD$ and drugs. From the solubility data, the apparent stability constants K of the complex could be calculated. Ultraviolet absorption and circular dichroism confirmed the inclusion of indoprofen, niflumic acid and naproxen with ${\beta}-CyD$ in the molar ratio of 1 : 1. Inclusion complexes in solid powder form were obtained by the freeze-drying method and the inclusion formation was confirmed again by infrared, diffential thermal analysis, and X-ray diffraction measurements.

• Journal of Microbiology and Biotechnology
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• v.9 no.2
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• pp.230-233
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• 1999

A plasmid vector was constructed for the expression and secretion of Bacillus macerans cyclodextrin glucanotransferase (CGTase) in Bacillus subtilis. The vector, pUBACGT, was composed of the ribosome-binding sequence, signal sequence, and cgt gene from B. macerans under the control of amyR2, the promoter of amyE gene coding for $\alpha$-amylase from B. subtilis var. natto. Bacillus subtilis LKS88, a mutant strain lacking genes for an amylase and two proteases, was used as a host for the transformation of the plasmid vector. The transformants were selected on kanamycin-containing Luria-Bertani plates. The starch hydrolyzing activity was observed on the starch-containing plates by the iodine method and cyclodextrin-forming activity was detected in the culture medium. A SDS-PAGE analysis showed that most of the expressed CGTase in the recombinant B. subtilis was secreted into the medium at a high expression level.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.191-193
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• 2000

A whole-cell biocatalyst was constructed by immobilizing an enzyme on the surface of the yeast Saccharomyces cerevisiae. The gene encoding Bacillus macerans cyclodextrin glucanotransferase(CGTase) was fused with the AGA2 gene encoding a small peptide disulfide-linked to the aga1, a cell wall protein of a-agglutinin. The plasmid was introduced S. cerevisiae and expressed in the medium consisting of 10g/L yeast extract, 20g/L peptone, and 20g/L galactose. The activity was detected with the formation of cyclodextrin(CD) from 10g/L soluble starch. Surface display of CGTase was also verified with the halo-test, flow cytometry, and immunofluorescence microscopy. The recombinant S. cerevisiae produced ${\alpha}-cyclodextrin$ more efficiently than the free CGTase by simultaneous fermentation and cyclization as yeast consumes glucose and maltose which are inhibitors for CD synthesis.

• Food Science of Animal Resources
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• v.26 no.4
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• pp.540-547
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• 2006

This review highlights areas of interest in the cholesterol removal of milk and dairy products. The demand for cholesterol removal has increased due to consumer demand for cholesterol-reduced products. At present the best method for producing without changing flavor, taste and texture of the products is entrapping cholesterol by ${\beta}-cyclodextrin({\beta}-CD)$. Especially, crosslinking of ${\beta}-CD$ is important due to recycling that could be separated the ${\beta}-CD$ from treated cream or milk. The recycling can be up to 10 times with keeping the rate of cholesterol removal. Various functional milk and dairy products can be produced in this manner. This report reviews general information including methods of cholesterol removal, crosslinking of ${\beta}-CD$, and recycling of the ${\beta}-CD$ in milk and dairy products.