• Title/Summary/Keyword: Proton-NMR

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Solid State NMR Studies of Proton Conducting Polymer, Poly(vinyl phosphonic) acid

  • Lee, Young-Joo;Bingol Bahar;Murakhtina Tatiana;Sebastiani Daniel;Ok, Jong-Hwa;Meyer Wolfgang H.;Wegner Gerhard;Spiess Hans Wolfgang
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.347-347
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    • 2006
  • Polymers containing poly(vinyl phosphonic) acid segments are promising candidates to be used as proton conducting membranes. Solid state NMR spectroscopy represents an ideal probe of proton motion on the molecular level, because it allows us to selectively detect the nuclei of interest. In this paper, we apply solid state NMR methods to poly(vinyl phosphonic) acid in order to demonstrate that the proton conduction of poly(vinyl phosphonic acid) results from P-OH proton through hydrogen bonding and that the condensation of phosphonic acid leads to decrease in proton conductivity. $^{1}H\;and\;^{31}P$ solid state NMR experiments are supported by quantum chemical computation of NMR parameters.

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Practical Guide to NMR-based Metabolomics - II : Metabolite Identification & Quantification

  • Jung, Young-Sang
    • Journal of the Korean Magnetic Resonance Society
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    • v.22 no.1
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    • pp.10-17
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    • 2018
  • Metabolite identification and quantification are one of the foremost important issues in metabolomics. In NMR based metabolomics, mainly one-dimensional proton NMR spectra of biofluids, such as urine and serum are measured. However, it is not always easy to identify and quantify metabolites in one-dimensional proton NMR spectra. This article introduces useful public metabolite databases, metabolic profiling software, and articles.

The Development of Quantification Technique for Brain In vivo Proton NMR Spectroscopy (뇌의 양성자 핵자기공명 분광학을 위한 정량화 방법 개발)

  • 강해진
    • Progress in Medical Physics
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    • v.12 no.1
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    • pp.31-39
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    • 2001
  • NMR spectroscopy enables us to measure the molar concentration of the metabolites in the organisms, and this technique is the only method to measure the concentration non-invasively. The proton NMR spectroscopy has been used to study the biochemical changes in human as well as in animal brain. MRI uses the proton densities and its relaxation times for reconstructing images, but MRS gives the biochemical changes inside the body. NMR spectroscopy could provide the information which MRI and CT could not, and this makes NMR spectroscopy more useful in diagnosing diseases. This study was tried to develop the quantitation of the molar concentration of the metabolites in the brain using the proton MR spectroscopy. The spectra of each metabolites was obtained, and the proton MR spectra was obtained from the insula gray matter areas of the 16 volunteers. And this spectra was analyzed to estimated the molar concentrations of the metabolites in the region. The results showed the very similar to those of the others.

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NMR Spectroscopy and Mass Spectrometry of Benzyl Alcohol Galactoside synthesized using β-Galactosidase (베타-갈락토시데이즈를 이용하여 합성된 Benzyl Alcohol Galactoside의 NMR Spectroscopy 및 Mass spectrometry)

  • Lee, Hyang-Yeol;Jung, Kyung-Hwan
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.1
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    • pp.84-89
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    • 2019
  • To characterize the molecular structure of BzO-gal synthesized using Escherichia coli ${\beta}$-gal, NMR ($^1H$- and $^{13}C$-) spectroscopy and mass spectrometry of BzO-gal were conducted. $^1H$ NMR spectrum of BzO-gal showed multiple peaks corresponding to the galactosyl group, which is an evidence of galactosylation on BzOH. Five proton peaks around the aromatic region at ${\delta}_H$ 7.43 ~ 7.24 ppm and 2 peaks from ${\delta}_H$ 4.93 and 4.67 ppm were evidence of the presence of the benzyl group. Seven proton peaks at ${\delta}_H$ 4.32 ~ 3.46 ppm showed the presence of a monosaccharide and were indicative of galactosylation on BzOH. $^{13}C$ NMR spectrum also revealed the presence of 11 carbons suggestive of BzO-gal. The mass value (sodium adduct ion of BzO-gal, m/z = 293.0994) from mass spectrometry analysis of BzO-gal, and $^1H$ and $^{13}C$ NMR spectral data were in good agreement with the expecting structure of BzO-gal. We are expecting that through future study it will eventually be able to develop a new additive of low cytotoxicity.

Solid-state NMR Studies of Phenethyl Sulfonic Acid-functionalized MCM-41

  • Chul Kim
    • Journal of the Korean Chemical Society
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    • v.68 no.2
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    • pp.74-81
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    • 2024
  • A sulfonic acid-water-silanol system in SO3H-functionalized MCM-41 was investigated using solid-state nuclear magnetic resonance techniques. The proton exchange rate between a water molecule and a silanol group in the S-PE-MCM-41 was determined by analyzing the 1D proton spectra, the proton EXSY spectrum, and 2H spin-lattice relaxation data under various hydration levels. Two kinds of water-bounding sites were found in the S-PE-MCM-41: weakly and strongly bound sites. Over several hours, water molecules bound to the weakly bound sites at the low hydration level migrated to the strongly bound sites. At high temperature, the S-PE-MCM-41 easily lost water molecules weakly bound to the silanol, while the strongly bound water molecules survived. Water molecules that participated in the hydration of the phenethyl sulfonate were involved in the hydrogenbonded silanol mechanism of proton conductivity. This phenomenon contributes higher proton conductivity to the S-PE-MCM-41 by the cooperation of sulfonyl and silanol groups in the proton transfer process, even at higher temperature.

Development of NMR Based Prototype Sensor for Non-destructive Sugar Content Measurement in Fruits. (수소 핵자기공명을 이용한 과실의 비괴적 당도측정 시작기의 개발)

  • 조성인;정창호
    • Journal of Biosystems Engineering
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    • v.21 no.3
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    • pp.336-342
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    • 1996
  • A 4.1MHz$1^H$ Nuclear Magnetic Resonance(NMR) sensor was designed and manufactured to evaluate the internal quality of fruits. The magnet console having 963gauss magnetic field induction was used for the NMR sensor. To optimize and evaluate the NMR sensor, glycerol and sugar-water solutions were used. $^1$H(proton) resonance signals were used to estimate the sugar contents in fruits. Artificial neural network models were developed to predict sugar contents in fruits from the proton resonance signals. The standard errors of prediction(SEP) were 0.565(apple), 0.394(pear) and 0.415(kiwi), respectively. The result implied that it was possible to evaluate apple, pear and kiwi into 3 grades using the NMR sensor.

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Prototype of NMR Based Sensor For Non-Destructive Sugar Content Measurement in Fruits

  • Cho, Seoung-In;Chung, Chang-Ho
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1996.06c
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    • pp.305-312
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    • 1996
  • A 4.1MHz 1H Nuclear Magnetic Resonance (NMR) sensor was designed and manufactured to evaluate the internal quality of fruit. The magnet console having 963 gauss magnetic field induction was used for the NMR sensor. To optimize evaluate the NMR sensor, glycerol and sugar-water solutions were used. 1H(proton) resonance signals were use of to estimate the sugar contents in fruits the proton resonance signals and were validated . The standard errors of predictions(SEP) were 0.565(apple) , 0.394(pear) and 0.415(kiwi) respectively. The result implied that is possible to evaluate apple , pear and kiwi into 3 grades using the NMR sensor.

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Ferroelectric-Paraelectric Phase Transition of CsH2PO4 studied by Static NMR and MAS NMR

  • Lim, Ae Ran;Lee, Kwang-Sei
    • Journal of the Korean Magnetic Resonance Society
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    • v.19 no.1
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    • pp.29-35
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    • 2015
  • The microscopic dynamics of $CsH_2PO_4$, with two distinct hydrogen bond lengths, are studied by static nuclear magnetic resonance (NMR) and magic angle spinning (MAS) NMR. The proton dynamics of the two crystallographically inequivalent hydrogen sites were discussed in terms of the $^1H$ NMR and $^1H$ MAS NMR spectra. Although the hydrogen bonds have two inequivalent sites, H(1) and H(2), distinct proton dynamics for the two sites were not found. Further, the $^{133}Cs$ spectrum is more or less continuous near $T_{C1}$ (=153 K). Finally, the phase transition mechanism of $T_{C1}$ in $CsH_2PO_4$ is related to the ordering of protons.

NMR Studies of the Conformation and Stability of the 4' - Aminomethyl - 4,5',8 - Trimethylpsoralen (AMT) Cross - Linked DNA Octamer Duplex, $d(GGGTACCC)_2$

  • Lee, Joon-Hwa;Hwang, Geum-Sook;Choi, Byong-Seok
    • BMB Reports
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    • v.30 no.6
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    • pp.421-425
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    • 1997
  • The 4'-aminomethyl-4,5',8-trimethylpsoralen (AMT) has been used as intercalating DNA binding drugs in the photo-chemotherapy of skin diseases. The conformation and stability of DNA octamer duplex, $d(GGGTACCC)_2$, cross-linked with AMT has been studied by NMR spectroscopy. All the proton resonances of the psoralen cross-linked octamer were assigned and meting temperature studies were carried out based on the assignment of the proton resonances. The aromatic proton chemical shift data suggest that the conformation of the helix cross-linked with psoralen is destabilized more to furanside of the psoralen. possibly due to the protrusion of the aminomethyl side chain of the psoralen.

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