• Title/Summary/Keyword: maleimide

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Binding Capacity of Human Serum Albumin with Estrogen and Other Ligands (Human Serum Albumin이 Estrogen과 기타 Ligands와의 결합력에 관한 연구)

  • Park, Geum-Soon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.23 no.3
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    • pp.414-419
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    • 1994
  • This study was trying to find what physical changes occurred to albumin when it reacted with estrogen and other ligands. Each concentration of human serum albumin with 100$\mu$l estradiol reacted at the highest binding capacity of 280nm. In addition, 1 hr of reaction time showed the highest binding rate. Conformational changes in human serum albumin with dietylstillbesterol and N-ethyl-maleimide produced strong binding capacities. The changes were immediate and they did not increase or decrease over time. Effects of human serum albumin with estriol induced no interaction each other. The binding capacity of human serum albumin with vitamin D$_2$was lower than estradiol. and the highest binding rate showed 1 hr of reaction time. Vitamin D$_2$ was very similar to the binding capacity of estradiol.

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Encapsulation of Plasmid DNA in Pegylated Liposome

  • Jang, Jung-Ok;Gwak, Hye-Sun;Lee, Hwa-Jeong
    • Journal of Pharmaceutical Investigation
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    • v.35 no.5
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    • pp.337-341
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    • 2005
  • The purpose of the study was to prepare the pegylated liposome carrying plasmid DNA with optimal encapsulation efficiency. Plasmid DNA (pCEP4 clone 790, 10.6 kb) was entrapped in the pegylated liposome composed of neutral lipid, POPC (l-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine), cationic lipid, DDAB (dimethyl dioctadecyl ammonium bromide) and anionic lipids, DSPE-PEG 2000 (distearoyl phosphatidyl ethanolamine polyethylene glycol 2000) and DSPE-PEG 2000-maleimide by freezing/thawing method. Free plasmid DNA was separated from the encapsulated one by Sepharose CL-4B column chromatography. The DNA amount encapsulated into the pegylated liposome was increased as cationic lipid concentration, initial amount of plasmid DNA and total lipid amount were increased.

Electrical Properties of LB Films by Using IMI-O Polymer (IMI-O고분자 LB막의 전기적 특성)

  • 정상범;유승엽;박재철;이범종;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.202-205
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    • 1997
  • In this paper, we synthesized poly(N-(2-4-imidazolyl) ethyl) maleimide-alt-1-octadecene(IMI-O) polymer that can have function group and improvement of mechnical strength and then confirmed the possibility of molecular device made by LB method. Evaluation of LB film have been processed such as the technique of EA, $^{1}$H-NMR, FT-IR. Also, the deposition status was observed by SEM and Metal/Insulator/Metal(MIM) device was fabricated for investigation of electric properties. In our experimental results. The surface pressure for the solid state was investigated to 20~35[dyne/cm] by the $\pi$ -A isotherm and the limiting area was about 40 ~45 ($\AA$$^2$/molecule). The deposition status of LB films was confirmed by SEM. The conductivity of LB film was found to be 10$^{-14}$ ~10$^{-13}$ [S/cm] by I-V characteristic.

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The Mitochondrial Tricarboxylate Carrier of Silver Eel: Chemical Modification by Sulfhydryl Reagents

  • Capobianco, Loredana;Impagnatiello, Tecla;Ferramosca, Alessandra;Zara, Vincenzo
    • BMB Reports
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    • v.37 no.5
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    • pp.515-521
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    • 2004
  • The tricarboxylate (or citrate) carrier was purified from eel liver mitochondria and functionally reconstituted into liposomes. Incubation of the proteoliposomes with various sulfhydryl reagents led to inhibition of the reconstituted citrate transport activity. Preincubation of the proteoliposomes with reversible SH reagents, such as mercurials and methanethiosulfonates, protected the eel liver tricarboxylate carrier against inactivation by the irreversible reagent N-(1-pyrenyl)maleimide (PM). Citrate and L-malate, two substrates of the tricarboxylate carrier, protected the protein against inactivation by sulfhydryl reagents and decreased the fluorescent PM bound to the purified protein. These results suggest that the eel liver tricarboxylate carrier requires a single population of free cysteine(s) in order to manifest catalytic activity. The reactive cysteine(s) is most probably located at or near the substrate binding site of the carrier protein.

Electrical Properties of IMI-O Polymer LB Films in Complexed Metal Ion (금속이온 착체에 의한 IMI-O 고분잔 LB막의 전기적 특성)

  • Jung, Sang-Burm;Yoo, Seung-Yeop;Park, Jae-Chul;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 1997.07d
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    • pp.1519-1521
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    • 1997
  • In this paper, poly (N-(2-4-imidazolyl) ethyl) maleimide-alt-1-octadecene (IMI-O) polymer which can complex metal ion was used to confirm the possibility of molecular device made by Langmuir-Blodgett method. Metal/Insulator/Metal (MIM) device was fabricated for investigation of electric properties. In the ${\pi}$-A isotherm, surface pressure at collapse point was different as to the molecular weight of metal ion complexed respectively, In I-V characteristics, currents of MiM devices were different at the same voltage. It was thought that phenomena was occurred by interaction between function group and metal ion.

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Use of Correlation of 1H and 13C Chemical Shifts of N-Arylsuccinanilic Acids,N-Arylsuccinimides, N-Arylmaleanilic Acids, and N-Arylmaleimides with the Hammett Substituent Constants for the Studies of Electronic Effects

  • Lee, Hye-Sun;Yu, Ji-Sook;Lee, Chang-Kiu
    • Bulletin of the Korean Chemical Society
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    • v.30 no.10
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    • pp.2351-2354
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    • 2009
  • A series of N-arylsuccinanilic acids, N-arylsuccinimides, N-arylmaleanilic acids, and N-arylmaleimides was prepared and their NMR spectra were examined by correlating the $^1H\;and\;^{13}C$ chemical shift values with the corresponding Hammett $\sigma$ values. The carbonyl carbons of the amides show a normal correlation with $\sigma$ but those of the imides show an inverse correlation.

Transient Protection of Intramolecular Hydrogen Bonding: A Simple but Elegant Approach for Functional Imaging

  • Kim, Jong-Man;Min, Sung-Jun;Park, Bum-Jun;Lee, Jae-Hyung;Ahn, Kwang-Duk
    • Macromolecular Research
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    • v.12 no.5
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    • pp.493-500
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    • 2004
  • We have developed a novel method for patterning functional images in thin polymer films. The key materials we utilized for the imaging were dihydroxyanthraquinones protected with acid-labile tert-butoxycarbonyl (t-Boc) blocking groups. Among the tested compounds, 1,4-dihydroxyanthraquinone (quinizarin; 1) underwent the most drastic change in terms of its color and fluorescence upon protection. We prepared the t-Boc-protected quinizarin and polymers bearing the protected quinizarins as pendent groups. To investigate the possibility of a single-component imaging system, we synthesized a styrenic monomer 14 incorporating protected quinizarin and a maleimide derivative 15 bearing a photoacid generating group and subjected them to polymerization. Selective removal of the protecting groups of the quinizarin moieties in the exposed area using photolithographic techniques allowed regeneration of quinizarin and patterned fluorescence images in the polymer films.

NMR Signal Assignments of the Stereochemical Cycloadducts of Bicyclolactone via Diels-Alder Reaction

  • Kim, Dae-Sung;Seo, Chan-Woo;Cho, Cheon-Gyu;Won, Ho-Shik
    • Journal of the Korean Magnetic Resonance Society
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    • v.8 no.1
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    • pp.62-69
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    • 2004
  • Bicyclolactones obtained from the Diels-Alder cycloaddition of 3,5-dibromo-2-pyrone can undergo various palladium catalyzed cross coupling reactions to afford aryl bicyclolactones. The resulting coupled products can be readily converted into various 3-OH cyclohexenes via lactone ring openings, while those bearing dienyl units underwent highly diastereoselective Diels-Alder cycloadditions with selected dienophiles to funish multiply functionalized polycarbocycles. Bromo-bicyclic diene furnished two different diastereomers endo-form (62%) and exo-form (38%) upon cycloadditions with N-Et maleimide (NEM), and their stereochemistries were identified with NMR.

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Paeparation and Properties of Epoxy Copolymers Containing Oxime-urethane Groups as Photobase Generators

  • Chae, Gyu Ho;Song, Hye Bong;Seon, Ho Yong;Jang, Ji Yeong
    • Bulletin of the Korean Chemical Society
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    • v.21 no.7
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    • pp.690-696
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    • 2000
  • Epoxy copolymers containing oxime urethane groups were prepared by the polymerization of glycidyl methacrylate and N-[5-(benzophenoneoximinocarbonylamino)pentanyl]maleimide (BOPM). Their physical properties were characterized by GPC, DSC and TGA analyses. Photochemical changes of the copolymers were studied by UV, IR spectroscopy, and contact angle measurements. A photoinduced cross-linking reaction in copolymer films was observed by measuring the insoluble fraction. Irradiation of the copolymers at 254 nm UV light leads to the formation of pendant amino groups by photodissociation of the oxime-urethane groups. Treatment of the amino groups with HCl resulted in the formation of ammonium salts, which changed the polymer surface to be hydrophilic. An insoluble fraction of the copolymers increased with irradiation time, heating time, and heating temperature. Cross-linking of the epoxy resin effectively catalyzed by the photogenerated pendant amines upon heating.

Gas Permeability of Polymeric LB Films Containing Imidazole-Metal Ion Complexes (이미다졸-금속 이온 착체를 포함하는 고분자 LB막의 기체 투과성)

  • 김병주;이범종
    • Polymer(Korea)
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    • v.24 no.4
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    • pp.453-458
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    • 2000
  • The permeability of oxygen and nitrogen was investigated from the polymeric LB films containing imidazole-metal ion complexes and compared with its corresponding cast films on porous membrane filters. The amphiphilic polymer, poly(N- (2-(4-imidazolyl)ethyl)-maleimide-alt-1-octadecene) (IM-O), was synthesized by reaction of poly(maleic anhydride-alt-1-octadecene) with histamine. The IM-O nonolayer showed high stability on Fe (III) ion-containing subphase. The molecular structure in the LB films was investigated by means of FT-IR spectroscopy. The metal ion concentration incorporated into the LB films was determined by means of XPS measurements. The mechanical stability and uniformity of the LB films on porous substrates were indirectly evidenced by SEM observation. The LB and cast films showed more or less higher selectivity toward nitrogen, and high permeability was found to both the oxygen and nitrogen.

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