• Title/Summary/Keyword: complexation

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Synthesis of 4o-vinylbenzo-15-crown-5 and its copolymerization behavior with Di(ethylene glycol) ethyl ether acrylate (4′-vinylbenzo-15-crown-5의 합성과 Di(ethylene glycol) ethyl ether acrylate와의 라디칼 공중합)

  • Soukil Mah;Jin, Long-Yi;Kyuchan Han
    • Proceedings of the Korean Fiber Society Conference
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    • 2002.04a
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    • pp.195-198
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    • 2002
  • Poly(crown ether)s as a functional polymer materials have powerful and selective complexation properties with a large number of metal cations and have advantage of facility of their recovery and modification of their complexation properties in contrast to their monomeric analogues. Poly(crown ether)s having pendant macrocyclic groups can easily form 2:1-type crown ether ring-to-cation complexes with particular metal ions which are a little larger than the cavity of the crown ether ring. (omitted)

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A Study on Complexation of Dowelling Environment - Focused on environment-friendly and ubiquitous home - (주거환경의 복합화에 관한 연구 - 친환경과 유비쿼터스 홈을 중심으로 -)

  • Lee, Sang-Hoon;Jun, Han-Jong
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2006.05a
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    • pp.154-157
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    • 2006
  • With the sustainable development theory introduced, some planning factors, such as how to minimize bad effects on the environment and how to be more environmentally friendly, have been Integrated in planning the residential development. In addition, a new residential space concept, the ubiquitous home, arouse the interest of architects and residents. Although there have been many efforts to achieve the environment-friendly and convenient residence, the problem is that the environment-friendly architecture's many of the efforts have been primarily focused on the outside of the apartment units. Thus, the purpose of this study is to show possibilities of housing model not only being applied the environment-friendly construction concept to the inside of the apartment units, but also being integrated the ubiquitous home model inside.

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Solubility Enhancement of Flavonoids by Cyclosophoraose Isolated from Rhizobium meliloti 2011

  • Kang Si-Mook;Lee Sang-Hoo;Kwon Chan-Ho;Jung Seun-Ho
    • Journal of Microbiology and Biotechnology
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    • v.16 no.5
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    • pp.791-794
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    • 2006
  • Cyclosophoraose (cyclic $\beta-(1,2)-glucan$, Cys) isolated from Rhizobium meliloti, a soil microorganism, was used as a solubility enhancer for flavonoids. The complexes of the cyclic oligosaccharide with flavonoids were confirmed through $^1H$ nuclear magnetic resonance (NMR) spectroscopic analysis. Flavonoids solubilized by Cys were quantitatively analyzed through high-performance liquid chromatography (HPLC). Among the flavonoids tested, the solubility of naringenin was greatly enhanced by Cys, compared with other compounds. The solubility of naringenin was enhanced about 7.1-fold by adding 10 mM Cys, compared with a control. $^1H$ NMR spectroscopic analysis indicated that the H-6 and H-8 protons, which are located on the A ring of naringenin, were greatly shifted upfield upon the complexation with Cys. This result suggested that Cys showed a regioselective interaction with the naringenin molecule upon the complexation, resulting in the solubility enhancement of naringenin.

Optimum Concentration of the Cd(II)-Quercetin Complexation Reaction (Quercetin의 카드뮴 착물반응에 대한 최적농도)

  • Lee, Jeong-Ho;Shin, Sun-Woo;Baek, Seung-Hwa
    • YAKHAK HOEJI
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    • v.53 no.5
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    • pp.235-240
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    • 2009
  • The interaction of cadmium (II) ion with quercetin was investigated in aqueous solution at different pH. The quercetin/cadmium stochiometries for cadmium (II) binding have been determined by UV-vis spectrophotometric method. The complexation of Cd(II) ion with 54.72 ${\mu}M$ quercetin (A=1.00793) was formed in 0.2 M $NH_3-0.2$ M $NH_4Cl$ (pH 8.0) buffer solution. 1:1 Cd(II)-complex had a maximum absorbance and showed the bathochromic shift of the long-wavelength band of the UV-vis spectra in the alkaline pH when interacted with quercetin in buffer solution. These results suggest that Cd(II)-quercetin complex has the optimal condition of chelation in basic buffer solution.

Kinetics of the Formation of Metalloporphyrins and the Catalytic Effect of Lead Ions and Hydrogen Ions

  • Qi, Yong;Pan, Ji Gang
    • Bulletin of the Korean Chemical Society
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    • v.35 no.11
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    • pp.3313-3318
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    • 2014
  • The reaction mechanism of Lead ions catalyzing complexation reactions between TIPP and metal ions was investigated by researching the kinetics of the formation of metalloporphyrins by UV/Vis-spectra, and verified by exploring the formation of metalloporphyrins catalyzed by acetic acid. Kinetics studies suggested that the fluctuations of reaction rate indicated the formation of metalloporphyrin was step-wise, including the pre-equilibrium step (the coordination of the pyrrolenine nitrogens to $Mn^+$) and the rate-controlling step (the deprotonation of the pyrrole proton). In the pre-equalization step, a sitting-atop (SAT) structure formed first with the complexation between larger radius of $Pb^{2+}$ and TIPP, changed the activation, then $Pb^{2+}$ left with the smaller radius of metal ions attacking from the back of the porphyrin ring center. In the rate-controlling step, two pyrrole protons dissociated to restore a stable structure. This was verified by adding acetic acid at different reaction times.

Effect of ion-pair complexation with bile acids on the bilary excretion and systemic distribution of organic drugs

  • Shim, Chang-Koo
    • Archives of Pharmacal Research
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    • v.9 no.1
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    • pp.49-54
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    • 1986
  • Effect of sodium taurodeoxycholate (TDC) infused intravenously on the pharmacokinetics of methylene blue (MB) was studied in the rat to investigate the role of ion-pair complexation in the body on drug elimination and disposition. Distribution volume (Vd) of MB was increased significantly (p< 0.05) by TDC infusion. Considering together with the fact that apparent partition coefficient (APC) of MB between phosphate buffer (pH 7.4) and n-octanol was increased markedly by TDC, the increase in Vd seemed to be the result of decreased polarity of MB by ion-pair formation with TDC. But total body clearance (CLt) and biliary excretion clearance (CLbil) of MB were not increased significantly by TDC.

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Fast-Curing of Phenol·Formaldehyde Resin Adhesives for Plywood (합판용 페놀수지 접착제의 속경화)

  • Roh, Jeang-Kwan
    • Journal of the Korean Wood Science and Technology
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    • v.23 no.3
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    • pp.33-39
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    • 1995
  • To accelerate the cure of phenolic resin adhesives for plywood, the complexation with melamine resin and the addition of cure-accelerating agents were discussed. The hot-pressing temperature and time of phenol resin could be decreased by complexation with melamine resin. but the wet glue-joints strength of phenol melamine resin was lower than that of ordinary phenol resin in case of plywood using spruce veneer at core layer. Among the tested cure-accelerating agents. the sodium carbonate showed the greatest effect on shortening gelation time of phenolic resin. In addition, in the manufacturing scale test, the hot-pressing time of phenol resin with the addition of 5 parts sodium carbonate could be shortened about 20% compared with ordinary phenol resin which had same glue-joints properties.

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Inclusion Complexation of Chlorpropamide with Cyclodextrins (클로로프로파미드와 싸이클로덱스트린과의 포접 화합물에 관한 연구)

  • 정경혜;김길수;구영순
    • YAKHAK HOEJI
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    • v.30 no.2
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    • pp.87-95
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    • 1986
  • Inclusion complexation of $\alpha$-cyclodextrin($\alpha$-CD), $\beta$-cyclodextrin($\beta$-CD) and tri-O-methyl-$\beta$-cyclodextrin(tri-O-methyl-$\beta$-CD) with chlorpamide(CPA) in aqueous solution and in the solid state were studied by the solubility method, spectroscopy (UV, IR), differential scanning calorimetry (DSC) and powder X-ray diffractometry, and all their molar ratios were found to be 1:1. The solid complexes of CPA with three kinds of cyclodextrins were prepared by a freezedrying method, and their dissolution behaviors were examined. As a result, the release of CPA from the inclusion complexes was significantly improved. The intrinsic dissolution rate of CPA in cyclodextrin inclusion complexes was about 51 times ($\alpha$-CD inclusion complex) and 12 tmies ($\beta$-CD inclusion complex) larger than that of intact CPA.

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Preparation of Mucoadhesive Chitosan-Poly(Acrylic acid) Microspheres by Interpolymer Complexation and Solvent Evaporation Method II

  • Cho, Sang-Min;Choi, Hoo-Kyun
    • Archives of Pharmacal Research
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    • v.28 no.5
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    • pp.612-618
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    • 2005
  • A mucoadhesive microsphere was prepared by an interpolymer complexation and solvent evaporation method, using chitosan and poly(acrylic acid) (PAA), to prolong the gastric resid ence time of the delivery system. The Fourier transform infrared results showed that microspheres were formed by an electrostatic interaction between the carboxyl groups of the PAA and the amine groups of the chitosan. X-ray diffraction and differential scanning calorimetry analysis showed that the enrofloxacin in the chitosan-PAA microsphere was molecularly dispersed in an amorphous state. Scanning electron microscopy of the surface and the quantity of mucin attached to the microspheres indicated that chitosan-PAA microspheres had a higher affinity for mucin than those of chitosan alone. The swelling and dissolution of the chitosan-PAA microspheres were found to be dependent on the pH of the medium. The rate of enrofloxacin released from the chitosan-PAA microspheres was slower at higher pH; therefore, based on their mucoadhesive properties and morphology, the chitosan-PAA microspheres can be used as a mucoadhesive oral drug delivery system.

Complexation Studies for Cadmium (II) with Quercetin and (+)-Catechin (Quercetin과 (+)-Catechin의 카드뮴(II)에 대한 착물반응)

  • Lee, Jeong-Ho;Shin, Sun-Woo;Baek, Seung-Hwa
    • YAKHAK HOEJI
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    • v.53 no.6
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    • pp.342-350
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    • 2009
  • The interaction of cadmium (II) ion with quercetin and (+)-catechin was investigated in aqueous solution at various pH. The flavonoid/cadmium stochiometries for cadmium (II) binding to quercetin and (+)-catechin have been determined by UV-vis spectroscopy. 1 : 1 Cd (II)-Flavonoid complex had a maximum absorbance and showed the bathochromic shift of the long-wavelength band of the UV-vis spectra in the alkaline pH, that occurs upon complexation, due to a ligandto-metal charge transfer. These results suggest that Cd (II)-flavonoid complex has the optimal condition of chelation in 0.2 M $NH_3$ - 0.2 M $NH_4Cl$ (pH 8.0) solution.