• Title/Summary/Keyword: 31P NMR

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Syndecan-4 cytoplasmic domain could disturb the multilamellar vesicle

  • Kim, Suhk-Mann
    • Journal of the Korean Magnetic Resonance Society
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    • v.13 no.1
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    • pp.1-6
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    • 2009
  • Syndecan-4 cytoplasmic domain was tested to confirm the interactions with the bilayer membrane using $^{31}P$ solid-state NMR measurements. Syndecan-4 was known as a coreceptor with integrins in the cell adhesion. The syndecan-4 V region is not understood of its functional roles and tested its ability of the interaction with multilamellar vesicles. The $^{31}P$ powder pattern was dramatically changed and showed isotropic peak which imply the bilayer membrane changed its topology to the micelle-like structure. Especially, phosphatidylcholine membrane was affected this effect more than phosphatidylethanolamine membrane.

Mechanistic Investigation in the Oxidation of ${\underline{O}},{\underline{O}}-Diethyl-{\underline{S}}-Phenyl\;Phosphorothiolate-^{18}O$ (O,O-Diethyl-S-Phenyl $Phosphorothiolate-^{18}O$의 산화반응기작)

  • Kim, Jeong-Han
    • Applied Biological Chemistry
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    • v.37 no.3
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    • pp.210-215
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    • 1994
  • ${\underline{O}},{\underline{O}}-Diethyl-{\underline{S}}-phenyl\;phosphorothiolate-^{18}O$ and other related compounds were prepared and oxidized with m-chloroperbenzoic acid (MCPBA). Each reaction was followed by $^{31}P$ NMR and the products were analyzed by GC-MS. ${\underline{O}},{\underline{O}}-Diethyl-{\underline{S}}-phenyl\;phosphorothiolate-^{18}O$ was converted to diethyl methyl phosphate in methanol by MCPBA and it was confirmed to contain $^{18}O$, which proved that the originally proposed mechanism of Segall and Casida operates in the oxidative reaction.

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NMR Study of the Electrooptic Material $KTiOPO_4(KTP)$ (Electrooptic 물질 $KTiOPO_4(KTP)$의 핵자기공명 연구)

  • 한정관;오동근;이창훈;이철의;김정남;김성철
    • Journal of the Korean Magnetics Society
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    • v.6 no.5
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    • pp.294-297
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    • 1996
  • We have carried out a $^{31}P$ nuclear magnetic resonance (NMR) study on the electrooptic material $KTiOPO_{4}(KTP)$. From the spin -lattice relaxation time ($T_{1}$) measurements at 17.9 MHz in the temperature range 77-390 K, two phase transitions associated with the change of the dominant charge carriers were observed and the activation energies were obtained in each phase.

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Structural Analyses of the Novel Phosphoglycolopids Containing the Unusual very Long Bifunctional Acyl Chain, α,ω-13,16-Dimethyloctacosanedioate in Thermoanaerobacter ethanolicus

  • Lee, Sang-Hoo;Kang, Se-Byung;Kim, Jai-Neung;Jung, Seun-Ho
    • Bulletin of the Korean Chemical Society
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    • v.23 no.12
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    • pp.1778-1784
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    • 2002
  • Novel membrane lipids containing the unusual very long chain fatty $acid{\alpha}{\omega}-1316-dimethyloctacosanedioate$, dimethyl. Ester (DME C30) was isolated and purified from thermophilic anaerobic eubacterium, Thermoanaerobacter ethanolicus. Structures of the lipids containing the bifunctional fatty acyl components were proposed by various analyses such as $^1H,\;^{13}C,\;^{31}P$ nuclear magnetic resonance (NMR), Fourier transform infrared(FTIR) spectroscopy, gas chromatography/mass spectrometry (GC/MS) and fast atom bombardment mass spectrometry (FAB/MS). Combined with the GC/MS, $^1H,\;and\;^{13}C$NMR data, we confirmed that the head groups of the lipids contained the glycerol and/or glucosamine molecules. $^{31}P$ NMR spectrum also showed that the lipids contained phosphate in a phosphodiester linkage. The proposed structures of these novel lipid components were the ones in which two head groups were linked by the membrane spanning fatty acyl component(DME C30)and regular chain fatty acids on glycerol moiety of each head group.

Radical Addition Reaction of Phosphorous based Flame Retardant with End Groups of PET (1) - Reaction of Bisphenol A bis(diphenyl phosphate) - (PET 말단에 대한 인계난연제의 라디칼계 부가반응 (1) - 비스페놀에이비스다이페닐포스페이트의 반응 -)

  • Kim, Min-Kwan;Ghim, Han-Do
    • Textile Coloration and Finishing
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    • v.24 no.1
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    • pp.33-38
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    • 2012
  • In this study, to increase flame retardation of poly(ethylene terephthalate) (PET) in burning, bisphenol A bis(diphenyl phosphate) (BDP), a well known flame retardant containing phosphorous, was reacted on end groups of PET by radical pathway. End-capping mechanism of PET with BDP was suggested and confirmed by spectroscopic and thermal analysis. From 400 MHz $^{31}P$ solid state FT-NMR spectrum of end-capped PET (PET-BDP), phosphorus spectra peak in BDP was found at ca. -20 ppm. Furthermore, P-C bond stretching vibration peaks were found ca. $600cm^{-1}$ in FT-IR spectrums of PET-BDP. These results showed that BDP can be chemically added on end groups of PET by our method. Thermal characteristics of pure PET (pPET) and PET-BDP were measured and evaluated by TGA analysis. There was not significant changes in thermal characteristics of PET-BDP compared to that of pPET.

Radical Addition Reaction of Phosphorous based Flame Retardant with End Groups of PET (2) - Reaction of Resorcinol bis(diphenyl phosphate) - (PET 말단에 대한 인계난연제의 라디칼계 부가반응 (2) - 리소시놀비스다이페닐포스페이트의 반응 -)

  • Kim, Min-Kwan;Sohn, Kwang-Ho;Ghim, Han-Do
    • Textile Coloration and Finishing
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    • v.24 no.1
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    • pp.39-44
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    • 2012
  • To improve flame retardation of poly(ethylene terephthalate) (PET) against burning, resorcinol bis(diphenyl phosphate) (RDP), phosphorous containing flame retardant, was incorporated into PET backbone by radical reaction pathway. Radical endcapping of PET with RDP was confirmed by spectroscopic and thermal analysis. From 400 MHz $^{31}P$ solid state FT-NMR spectrum of PET with RDP (PET-RDP), phosphorus spectra peak in RDP was found at ca. -10 ppm. Furthermore, P-C bond stretching vibration peaks were found ca. $530cm^{-1}$ in FT-IR spectrums of PET-RDP. These results indicated that RDP can be chemically bound at the ends of PET by radical addition method. Thermal characteristics of pure PET (pPET) and PET-RDP were measured and evaluated by TGA thermal analysis. There was not significant changes in thermal characteristics of PET-RDP compared to that of pPET.