• Food Science and Biotechnology
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• v.18 no.1
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• pp.185-189
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• 2009

Microencapsulation of flavor was carried out by molecular inclusion process using $\beta$-cyclodextrin (${\beta}CD$). ${\beta}CD$-flavor complex was prepared at various flavor-to-${\beta}CD$ ratios (1:6-1:12) to determine the effect of ${\beta}CD$ concentration on the inclusion efficiency. Maximum total oil retention and minimal surface oil content were obtained at flavors to ${\beta}CD$ ratio of 1:10. The physical properties and controlled release pattern of flavors from ${\beta}CD$-flavor complex were measured and compared with spray-dried microcapsules prepared using carbohydrate wall system. ${\beta}CD$-flavor complex showed higher total oil retention and surface oil contents, smaller mean particle size, lower moisture uptake, and higher oxidation stability than spray-dried microcapsule. Oxidative stability of flavor was correlated with hygroscopicity of wall materials. The controlled release mechanism was highly affected by temperature and characteristics of wall materials.

• Applied Chemistry for Engineering
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• v.32 no.5
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• pp.504-508
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• 2021

In this study, the effect of molecular features of guest molecules on the structure, property, and formation of poly(vinyl alcohol) (PVA)/beta-cyclodextrin (bCD) inclusion compound hybrid films was investigated using three types of guest molecules such as hydroquinone (HQ), arbutin (AB), and tranexamic acid (TA). First, the successful formation of inclusion compounds between bCD and the guest molecules, and polymer/inclusion compound hybrid were proved using Raman spectroscopy. The effect of bCD-based inclusion compounds on the structure and property of PVA matrix composites containing inclusion compounds was also studied using X-ray diffraction (XRD) and thermal analyses such as differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). It was notable that the effect of TA to the crystalline structure of the PVA was significantly different from that of using other guest molecules including HQ and AB. It was also supported by a simple molecular simulation result. This article will be a good example for demonstrating the effect of molecular characteristics on the inclusion compound formation in polymer films, which can provide important information for relevant future research.

• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.675-678
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• 2005

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2791-2794
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• 2011

• Bulletin of the Korean Chemical Society
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• v.13 no.5
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• pp.474-479
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• 1992

Molecular interaction between ${\alpha}$-cyclodextrin and aspirin was studied by UV, $^2H$-NMR and $^2H$-NMR spectroscopy analyses for solution complex and by FT-IR analyses for solid complex. The inclusion structure provides a basic understanding of the aspirin and ${\alpha}$-cyclodextrin interaction.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.524-526
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• 2003

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2779-2782
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• 2011

• Bulletin of the Korean Chemical Society
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• v.26 no.8
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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.

• BMB Reports
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• v.34 no.5
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• pp.402-407
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• 2001

Based on the currently proposed toxicity model for the different Bacillus thuringiensis Cry $\delta$-endotoxins, their pore-forming activity involves the insertion of the ${\alpha}4-{\alpha}5$ helical hairpin into the membrane of the target midgut epithelial cell. In this study, a number of polar or charged residues in helix 4 within domain I of the 65-kDa dipteranactive Cry11A toxin, Lys-123, Tyr-125, Asn-128, Ser-130, Gln-135, Arg-136, Gln-139 and Glu-141, were initially substituted with alanine by using PCR-based directed mutagenesis. All mutant toxins were expressed as cytoplasmic inclusions in Escherichia coli upon induction with IPTG. Similar to the wild-type protoxin inclusion, the solubility of each mutant inclusion in the carbonate buffer, pH 9.0, was relatively low When E. coli cells, expressing each of the mutant proteins, were tested for toxicity against Aedes aegypti mosquito-larvae, toxicity was completely abolished for the alanine substitution of arginine at position 136. However, mutations at the other positions still retained a high level of larvicidal activity Interestingly, further analysis of this critical arginine residue by specific mutagenesis showed that conversions of arginine-136 to aspartate, glutamine, or even to the most conserved residue lysine, also abolished the wild-type activity The results of this study revealed an important determinant in toxin function for the positively charged side chain of arginine-136 in helix 4 of the Cry11A toxin.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.3035-3037
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• 2010