• Title/Summary/Keyword: H-NMR

Search Result 2,735, Processing Time 0.032 seconds

$^1H$ NMR Study of mono-and di-cyanide ligated Hemin Complexes as Models of Hemoproteins (Heme 단백질의 Model로서의 Hemin 착물에 관한 $^1H$ NMR 연구)

  • Lee, Kang-Bong;Kim, Nam Jun;Kweon, Jeehye;Rhee, Jae-Seong;Choi, Young-Sang
    • Analytical Science and Technology
    • /
    • v.7 no.4
    • /
    • pp.505-515
    • /
    • 1994
  • $^1H$ NMR spectra for monocyanide ligated ferriprotoporphyrin(hemin) complex and dicyanide coordinated hemin complex in dimethylsulfoxide(DMSO-$d_6$) solution have been recorded and analyzed. NMR spectra of hemin-cyanide complexation in DMSO-$d_6$ exhibit that the cyanide ligation to hemin is temperature-dependent. Thermodynamic parameters for the monocyanide ligated hemin to dicyanide ligated hemin are consistent with endothermic process with ${\Delta}H^{\circ}=736.6cal/mol$ and ${\Delta}S^{\circ}=16.4eu$. Detailed analysis of the anomalous deviation from Curie behavior for CN/DMSO coordinated hemin complex demonstrates the presence of a high spin character, and this weaker axial field relative to the purely low-spin dicyanide hemin complex is supposed to attribute to instantaneously ruptured iron-DMSO bond. This complex may serve as a useful model to characterize electronic/molecular structure of hemoproteins, which one of axial ligands is weak.

  • PDF

Reaction of lithiated pyridine with $Me_2RSiCl$ and its identification with NMR spectroscopic methods(R=Me, $^tBuCH_2CHSiMe_3$) (리튬화된 Pyridine과 $ME_2RSiCl$의 반응생성물의 NMR 분광학적 연구 (R=Me, $^tBuCH_2CHSiMe_3$))

  • Kim, Duk-Mook;Son, Byung-Yung
    • Analytical Science and Technology
    • /
    • v.7 no.2
    • /
    • pp.187-191
    • /
    • 1994
  • A reactive intermediate 1,2-dihydropyridine derivative 2 has been prepared and isolated from the reaction of pyridine with $^tBuLi$ and trimethylchlorosilane in nonpolar condition at low temperature 2 has characterized by $^1H-NMR$ fine structure analysis with SPINX3. The mechanistic information of formation of 2 was obtained from synthesized 2,5-disubstituted pyridine derivatives 3 and 4.

  • PDF

Solid-State High-Resolution 1H-NMR Study for Ammonia Borane of Hydrogen Storage Material

  • Han, J.H.;Lee, Cheol-Eui;Kim, Se-Hun;Kim, Chang-Sam;Han, Doug-Young
    • Journal of the Korean Magnetic Resonance Society
    • /
    • v.14 no.1
    • /
    • pp.38-44
    • /
    • 2010
  • In liquids NMR, $^{1}H$ is the most widely observed nucleus, which is not the case in solids NMR. The reason is due to the strong homo-dipolar interactions between the hydrogen atoms which mask the useful chemical shift information. Therefore we must remove the strong homo-dipolar interactions in order to get structural information, which can be investigated by the isotropic chemical shift. There are two ways of obtaining it. One is the ultra-fast MAS of ca. 70 kHz spinning speed, which has become available only recently. The other way is devising a pulse sequence which can remove the strong homo-dipolar interaction. In the latter way, MAS with a moderate spinning rate of a few kHz, is enough to remove the chemical shift anisotropy. In this report, 1D-CRAMPS and 2D MASFSLG techniques are utilized and their results will be compared. This kind of highresolution $^{1}H$ NMR for solids, should become a valuable analytical tool in the understanding and the developing of a new class of hydrogen storage materials. Here ammonium borane $-NH_{3}BH_{3}$, whose hydrogen content is high, is used as a sample.

A NMR Study on the Micellization of Sodium Dodecyl Sulfate in ω-Phenylalkylammonium Salt Solution (1H NMR을 이용한 ω-Phenylalkylammonium Salt의 수용액에서 Sodium Dodecyl Sulfate의 미셀에 관한 연구)

  • Oh, Jung Hee
    • Applied Chemistry for Engineering
    • /
    • v.10 no.4
    • /
    • pp.628-634
    • /
    • 1999
  • The orientational binding of ${\omega}$-phenylakylammonium ions to the sodium dodecyl (SDS) micellar interface has been studied from $^{1}H\;NMR$ chemical shift data. The NMR resonaces of the methylene protons of SDS and aromatic protons embedded into the micellar interior have shown the upfield shift. The aromatic induced chemical shifts of the alkyl chain methylene protons of SDS demonstrate the deep penetration into the palisade layer by these organic salts. Alkylammonium groups have been considered to be oriented toward outside of the micellar interface. Aromatic rings have been thought to be oriented toward the micellar core. The depth of penetration by organic salts has been observed to increase with the length of alkyl chain.

  • PDF

One-pot Synthesis of 5,7-Diaryl-3,4,6-trihydronaphthalen-2-ones (5,7-Diaryl-3,4,6-trihydronaphthalen-2-ones의 One-pot 합성)

  • Gopalakrishnan, M.;Manikandan, H.;Sureshkumar, P.;Thanusu, J.;Kanagarajan, V.
    • Journal of the Korean Chemical Society
    • /
    • v.51 no.4
    • /
    • pp.356-360
    • /
    • 2007
  • 5,7-Diaryl-3,4,6-trihydronaphthalen-2-ones have been synthesized from 3,5-diaryl-cyclohex-2-en-1- ones and methyl vinyl ketone in the presence of sodium ethoxide. The products were characterized by IR, UV-Visible, 1H-NMR, 13C-NMR and mass spectral techniques. To confirm 1H and 13C signals, HSQC spectrum was recorded and analyzed.

Expression and Purification of the Helicase-like Subdomains, H1 and H23, of Reverse Gyrase from A. fulgidus for Heteronuclear NMR study

  • Kwon, Mun-Young;Seo, Yeo-Jin;Lee, Yeon-Mi;Lee, Ae-Ree;Lee, Joon-Hwa
    • Journal of the Korean Magnetic Resonance Society
    • /
    • v.19 no.2
    • /
    • pp.95-98
    • /
    • 2015
  • Reverse gyrase is a hyperthermophile specific protein which introduces positive supercoils into DNA molecules. Reverse gyrase consists of an N-terminal helicase-like domain and a C-terminal topoisomerase domain. The helicase-like domain shares the three-dimensional structure with two tandem RecA-folds (H1 and H2), in which the subdomain H2 is interrupted by the latch domain (H3). To understand the physical property of the hyperthermophile-specific protein, two subdomains af_H1 and af_H23 have been cloned into E. coli expression vector, pET28a. The $^{15}N$-labeled af_H1 and af_H23 proteins were expressed and purified for heteronuclear NMR study. The af_H1 protein exhibits the well-dispersion of amide signals in its $^1H/^{15}N$-HSQC spectra and thus further NMR study continues to be progressed.

Structure and Hydrolysis Study of Inclusion Complex of Cyclodextrin and Aspirin (시클로덱스트린과 아스피린의 포접화합물의 구조와 가수분해에 관한 연구)

  • 최희숙;김경순
    • Journal of Life Science
    • /
    • v.10 no.1
    • /
    • pp.86-93
    • /
    • 2000
  • Specific molecular recognition of cyclodextrin and aspirin was determined. A stable 1:1 inclusion complex was established in solution. The distinct structure of inclusion complex was elucidated by FT-IR, FAB-MS, UV, 1H NMR, and 13C NMR spectroscopy. Based on the 1H NMR data, a time-averaged conformation of $\alpha$-cyclodextrin exhibited significant catalytic activity toward the hydrolysis of aspirin in alkaline solution.

  • PDF

Application of Deuterium NMR Analysis for the Differentiation of Korean and Foreign Liquors (중수소 핵자기 공명을 이용한 외국 술과 국산 술의 비교 분석)

  • Han, Gee-Chung;Lee, Sueg-Geun
    • Analytical Science and Technology
    • /
    • v.13 no.1
    • /
    • pp.127-129
    • /
    • 2000
  • The $^2H$ NMR analysis was used to determine the relative deuterium contents at the position of methyl and methylene in ethyl alcohols. Four different liquors manufactured in Korea clearly showed different R values from those of foreign liquors. These R values for the Korean liquors could be used to distinguish adulteration.

  • PDF

Purification and Backbone Assignment of the Hypothetical Protein MTH1821 from Methanobacterium Thermoautotrophicum H

  • Kwak, Soo-Young;Lee, Woong-Hee;Shin, Joon;Ko, Sung-Geon;Lee, Weon-Tae
    • Journal of the Korean Magnetic Resonance Society
    • /
    • v.11 no.2
    • /
    • pp.73-84
    • /
    • 2007
  • MTH1821 (UniProtKB/TrEMBL ID O27849) is a 96-residue hypothetical protein from the open reading frame of Methanobacterium thermoautotrophicum H one of the target organisms of structural genomics pilot project. Proteins which contain conserved sequence compared with MTH1821 have not been discovered yet and the functional and structural information for MTH1821 is not available. Here, we present the sequence-specific backbone resonance using multidimensional heteronuc1ear NMR spectroscopy and propose the secondary structure using GetSBY software. The backbone resonances of N, HN, $C_{\alpha}$, $C_{\beta}$, CO and $H_{\alpha}$ which are necessary for a prediction of secondary structure by GetSBY were assigned about 98% (557/568). The secondary structure of MTH1821 confirmed that it is comprised of four strand regions and two helical regions. This report will provide a valuable resource for the calculation solution structure of MTH1821 and for the other hypothetical protein that is targeted for structural-based functional discovery.

  • PDF

Phenolic Compounds from Acer tegmentosum Bark (산겨릅나무 수피의 페놀성 화합물)

  • Kwon, Dong-Joo;Bae, Young-Soo
    • Journal of the Korean Wood Science and Technology
    • /
    • v.35 no.6
    • /
    • pp.145-151
    • /
    • 2007
  • To investigate the chemical constituents of Acer tegmentosum, the bark were collected, air-dried and extracted with 70% aqueous acetone. Then it was successively partitioned with n-hexane, $CH_2Cl_2$, EtOAc and $H_2O$. Repeated Sephadex LH-20 column chromatography on the EtOAc soluble fraction gave five phenolic compounds. Their structures were elucidated as (+)-catechin (1), (-)-epi-catechin (2), Q-epicatechin-3-O-gallate (3), gallic acid (4) and 6'-0-galloylsalidroside (5) on the basis of spectroscopic evidences using $^1H-NMR$, $^{13}C-NMR$, 2D-NMR and MS spectroscopy, (-)-epicatechin-3-Ogallate (3), gallic acid (4), 6'-Ogalloylsalidroside (5) have not been reported in this plant yet.