• Title/Summary/Keyword: ligand selectivity

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Response Characteristics of Ligand Free PVC Membranes (이온운반물을 사용치 않은 이온 선택성 막의 특성)

  • Kim, Young-Hak;Lee, Ji-Yeun;Jung, Moon-Mo;Kim, Eu-Jung;Hur, Moon-Hye;Ahn, Moon-Kyu
    • Analytical Science and Technology
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    • v.10 no.6
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    • pp.453-458
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    • 1997
  • Many polymeric poly(vinyl chloride) membrane electrodes have been developed for the determination of basic drugs. But relatively little has been roported concerning the behavior of ligand free PVC memebranes. In connection with the evaluation of various ionophores, we bave evaluated a near-Nernstian response and selectivity of these ligand-free PVC electrodes towards basic drugs such as alverine, chlorpromazine and promazine. The electrode membranes were constructed with only several plasticizer and poly (vinyl chloride) matrix. The plasticizer studied were dioctyl phenylphosphonate, 2-nitrophenyl octyl ether, isododecyl phenylphosphate and dioctyl maleate.

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Adsorption Characteristics of U ranium (VI) Ion on Cryptand Synthetic Resin Adsorbent

  • Kim, Hae-Jin
    • Journal of Integrative Natural Science
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    • v.10 no.4
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    • pp.225-231
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    • 2017
  • Cryptand resins were synthesized by mixing 1-aza-18-crown-6 macrocyclic ligand with styrene divinylbenzene copolymer having 1%, 2%, 5%, and 10% crosslink by a substitution reaction. These synthetic resins were confirmed by chlorine content, elementary analysis, SEM, surface area, and IR-spectrum. As the results of the effects of pH, crosslink of synthetic resin, and dielectric constant of a solvent on uranium ion adsorption for resin adsorbent, the uranium ion showed high adsorption at pH 3 or over. Adsorption selectivity for the resin in methanol solvent was the order of uranium ($UO_2{^{2+}}$) > calcium ($Ca^{2+}$) > neodymium ($Nd^{3+}$) ion, adsorbability of the uranium ion was the crosslink in order of 1%, 2%, 5%, and 10% and it was increased with the lower dielectric constant.

Efficiency of Lamarckian Genetic Algorithm in Molecular Docking of Phenylaminopyrimidine (PAP) Derivatives: A Retrospect Study

  • Ratilla, Eva Marie A.;Juan, Amor A. San
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2004.11a
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    • pp.203-209
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    • 2004
  • Molecular docking using Lamarckian genetic algorithm of AutoDock 3.0 (AD3) was employed to understand in retrospect the selectivity of phenylaminopyrimidine (PAP) derivatives against the kinase domain c-Abl, implicated in chronic myelogenous leukemia (CML). The energetics of protein-ligand complex was scored using AD3 to identify active drug conformations while Ligplot and ligand protein contact (LPC) programs were used to probe schematic molecular recognition of the bound inhibitor to the protein. Results signify correlation between model and crystal structures of STI-571 compound or Imatinib (IM), a PAP derivative and now clinically proven for its efficacy in CML. A prospect active form Abl inhibitor scaffold from matlystatin class of compounds will be published elsewhere.

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Adsorption of Metal Ions on Cryptand Synthetic Resin (Cryptand 합성수지에 위한 금속 이온들의 흡착)

  • Lee Chi-Young;Kim Joon-Tae
    • Journal of environmental and Sanitary engineering
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    • v.20 no.4 s.58
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    • pp.38-44
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    • 2005
  • Cryptand resins were synthesized with 1-aza-15-crown-5 macrocyclic ligand attached to styrene divinylbenzene (DVB) copolymer with crosslink of $1\%,\;2\%,\;5\%\;and\;10\%$ by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of uranium$(UO_2^{2+})$ ion were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium$(UO_2^{2+})$ > zinc$(Zn^{2+})$ > samarium$(Sm^{3+})$ ion. The adsorption was in order of $1\%>2\%>5\%>10\%$ crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvents.

Adsorption Characteristic of Mg(II), Al(III), Pb(II) Metal Ions on Cryptand Ion Exchange Resin from Water Fire Extinguishing Agent (물 소화약제로부터 Cryptand 이온교환수지의 Mg(II), Al(III) 및 Pb(II) 흡착특성)

  • Kim, Joon-Tae;Kim, Kwan-Chun
    • Journal of environmental and Sanitary engineering
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    • v.23 no.1
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    • pp.57-65
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    • 2008
  • Resins were synthesized with 1-aza-15-crown-5 macrocyclic ligand attached to styrene(dangerous matter) divinylbenzene(DVB) copolymer with crosslink of 1, 2, 6 and 15% by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time and crosslink on adsorption of metal ion from water fire extinguishing agent by the synthetic resin adsorbent were investigated. The metal ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in water was in increasing order of $Mg^{2+}>Al^{3+}>Pb^{2+}$. The adsorption was in the order of 1, 2, 6, and 15% crosslink resin.

Adsorption and Separation of U (VI), Co (II), and Dy (III) Metal Ions on Crown Synthetic Resin

  • Kim, Joon-Tae
    • Journal of Integrative Natural Science
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    • v.10 no.1
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    • pp.43-50
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    • 2017
  • Synthetic resins were combined 1-aza-12-crown-4 macrocyclic ligand with styrene divinylbenzene copolymer having 1%, 2%, 8%, and 16% crosslink by a substitution reaction. These synthetic resins were confirmed by chlorine content, elementary analysis, SEM, surface area, and IR-spectrum. As the results of the effects of pH, crosslink of synthetic resin, and dielectric constant of a solvent on metal ion adsorption for resin adsorbent, the metal ions showed high adsorption at pH 3 or over. Adsorption selectivity for the resin in ethanol solvent was the order of uranium ($UO_2{^{2+}}$) > cobalt ($Co^{2+}$) > dysprosium ($Dy^{3+}$) ion, adsorbability of the metal ion was the crosslink in order of 1%, 2%, 8%, and 16% and it was increased with the lower dielectric constant. In addition, theses metal ions could be separated in the column with 1% crosslink resin by using nitric acid (pH 2.0) as an eluent.

Potentiometric Characteristics of Nitroso.R-Salt-Metal Complex Based Basic Drug Selective Electrodes (금속 니트로소 R염 착물을 이용한 염기성 의약품 선택성 전극의 특성)

  • 이미나;안문규
    • YAKHAK HOEJI
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    • v.47 no.6
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    • pp.356-360
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    • 2003
  • Nitroso-2-naphthol-3,6-disulfonic acid, disodium salt (NRS) was used as an organic ligand to prepare basic drug-selective polymeric membrane electrode. The sensing membrane of the electrode consited of basic drug-meta1(II)-NRS as an ion-exchanger site in a poly(vinyl chloride) matrix plasticized with 2-nitrophenyl octyl ether (NPOE). The metal ions used were Fe$^{2+}$, Co$^{2+}$, Ni$^{2+}$ and Cu$^{2+}$. The electrodes exhibited fast and wide linear response in the basic drug concentration of 10$^{-5}$ ∼10$^{-3}$ mol/l with a response slope of 50∼60 mV/decade in a buffer solution of pH 4∼8. The electrodes exhibited good selectivity for many basic compounds.mpounds.

Adsorption of Uranium (VI) Ion on 1-Aza-12-Crown-4 Synthetic Resin with Styrene Hazardous Material

  • Kim, Joon-Tae
    • Journal of Integrative Natural Science
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    • v.6 no.2
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    • pp.104-110
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    • 2013
  • 1-Aza-12-crown-4 macrocyclic ligand was combined with styrene (2th petroleum in 4th class hazardous materials) divinylbenzene copolymer having 1%, 2%, 3%, and 6% crosslinks by a substitution reaction, in order to synthesize resin. These synthetic resins were confirmed by chlorine content, elementary analysis and IR-spectrum. As the results of the effects of pH, equilibrium arrival time, crosslink of synthetic resin, and dielectric constant of a solvent on uranium ion adsorption for resin adsorbent, the uranium ion showed high adsorption at pH 3 or over and adsorption equilibrium of uranium ion was about 2 hours. In addition, adsorption selectivity for the resin in methanol solvent was the order of uranium ($UO_2{^{2+}}$) > iron ($Fe^{3+}$) > lutetium ($Lu^{3+}$) ions, adsorbability of the uranium ion was in the crosslinks order of 1%, 2%, 3%, and 6% was increased with the lower dielectric constant.

Separation Characteristics of Alkali and Alkaline Earth Metal Ions Using Novel HDBPDA Ion Exchanger (새로운 HDBPDA 이온교환체를 사용한 알칼리 및 알칼리 토금속 이온들의 분리특성)

  • Kim, Dong Won;Kim, Chang Suk;Choi, Ki Young;Jeon, Young Shin;Hong, Choon Pyo
    • Analytical Science and Technology
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    • v.6 no.5
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    • pp.471-477
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    • 1993
  • The novel macrocylic ligand {(4, 5):(13, 14)-dibenzo-6, 9, 12-trioxa-3, 15, 21, -triazabicyclo [15. 3. 1]heneicosa-(1, 17, 19)(18, 20, 21) triene: HDBPDA} was synthesized, and protonable constants of the ligand and the complex stability constants with alkali metals alkaline earth metals were determined. We evaluated the resolution factor(${\Delta}$) from equation that inducing from stability constants(pK). Also, this ligand was grafted on chloromethylated styrene-divinyl benzene(Merrifield resin) for HDBPDA, ion exchanger. Alkali and alkaline earth metal ions were separated using water by the column chromatography with this ion exchanger. Selectivity(${\alpha}$) and resolution(Rs) of alkali and alkaline earth metal ions were measured from the elution curves chromatogram. The selectivity and resolution values of the various ions calculated from the elution curves were compared with those abtained from pK values. The results were in a good agreement between tow methods. Ion exchange capacity of the resin were determined using the alkali and alkaline earth metal ions and pH dependence of capacity was also discussed.

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Characterization and Transcriptional Activity of a Vitamin D Receptor Ortholog in the Ascidian Halocynthia roretzi (멍게(Halocynthia roretzi) 비타민 D 수용체 상동체 동정 및 전사활성)

  • Lee, Jung Hwan;Sohn, Young Chang
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.6
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    • pp.913-919
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    • 2015
  • In vertebrates, the vitamin D receptor (VDR), a member of the nuclear receptor superfamily, binds the biologically active ligand $1{\alpha},25-(OH)_2$-vitamin $D_3$ (1,25 $D_3$). Nearly all vertebrates, including Agnatha, possess a VDR with high ligand selectivity for 1,25 $D_3$ and related metabolites. Although a putative ancestral VDR gene is present in the genome of the chordate invertebrate Ciona intestinalis, the functional characteristics of marine invertebrate VDR are still obscure. To elucidate the ascidian Halocynthia roretzi VDR (HrVDR), we cloned full-length HrVDR cDNA and investigated the transcriptional activity of HrVDR in HEK293 cells. HrVDR consists of 1,680 nucleotides (559 amino acids [aa]), including a short N-terminal region (A/B domain; 26 aa), DNA-binding domain (C domain; 72 aa), hinge region (D domain; 272 aa), and C-terminal ligand-binding domain (E domain; 161 aa). The amino acid sequence identity of HrVDR was greatest to that of C. intestinalis VDR (56%). In the luciferase reporter assays, the transcriptional activity of HrVDR was not significantly increased by 1,25 $D_3$, whereas the farnesoid X receptor agonist GW4064 increased the transactivation of HrVDR. These results suggest the presence of a novel ligand for and a distinct ligand-binding domain in ascidian VDR.