• 제목/요약/키워드: COSY NMR spectroscopy

검색결과 22건 처리시간 0.028초

Analysis of in vitro 2D-COSY on Human Brain Metabolites for Molecular Stereochemistry

  • Kim, Sang-Young;Woo, Dong-Cheol;Bang, Eun-Jung;Kim, Sang-Soo;Lim, Hyang-Sook;Choi, Chi-Bong;Choe, Bo-Young
    • 한국자기공명학회논문지
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    • 제12권1호
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    • pp.14-25
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    • 2008
  • To investigate the 3-bond connectivity of human brain metabolites by scalar coupling interaction through 2D-correlation spectroscopy (COSY) techniques using high field NMR spectroscopy. All NMR experiments were performed at 298K on Unity Inova 500 or 600 (Varian Inc.) equipped with a triple resonance probe head with z-shield gradient. Human brain metabolites were prepared with 10% $D_2O$. Two dimensional 2D COSY spectra were acquired with 4096 complex data points in $t_2$ and 128 or 256 increments in $t_1$ dimension. The spectral width was 9615.4 Hz and solvent suppression was achieved using presaturation using low power irradiation of the water resonance during 2s of relaxation delay. NMR data were processed using VNMRJ (Varian Instrument) software and all the chemical shifts were referenced to the methyl resonance of N-acetyl aspartate (NAA) peak at 2.0 ppm. Total 10 metabolites such as N-acetyl aspartate (NAA), creatine (Cr), choline (Cho), glutamine (Gln), glutamate (Glu), myo-inositol (Ins), lactate (Lac), taurine (Tau), ${\gamma}$-aminobutyricacid (GABA), alanine (Ala) were included for major target metabolites. Symmetrical 2D-COSY spectra were successfully acquired. Total 14 COSY cross peaks were observed even though there were parallel/orthogonal noisy peaks induced by water suppression. Except for Cr, all of human brain metabolites produced COSY cross peaks. The spectra of NAA methyl proton at 2.02 ppm and Glu methylene proton ($CH_2(3)$) at 2.11 ppm and Gln methylene proton ($CH_2(3)$) at 2.14 ppm were overlapped in the similar resonance frequency between 2.00 ppm and 2.15 ppm. The present study demonstrated that in vitro 2D-COSY represented the 3-bond connectivity of human brain metabolites by scalar coupling interaction. This study could aid in better understanding the interactions between human brain metabolites in vivo 2D-COSY study. Also it would be helpful to determine the molecular stereochemistry in vivo by using two-dimensional MR spectroscopy.

산호로부터 2개의 푸란노세스키테르펜의 분리와 구조 결정 (Isolation and Structure Determination of Two Furanosesquiterpenes from the Soft Coral Sinularia lochmodes)

  • 박선구
    • 대한화학회지
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    • 제38권10호
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    • pp.749-752
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    • 1994
  • 하와이 Pohnpei에서 채집한 soft coral Sinularia lochmodes로부터 2개의 furanosesquiterpenes인 (5'E)-5-(2',6'-dimethylocta-5',7'-dienyl) furan-3-carboxylic acid (1)와 (1'E,5'E)-5-(2',6'-dimethylocta-l',5',7'-trienyl) furan-3-carboxylic acid (2)가 검출되었다. 이들의 구조를 $^1H$ , $^{13}C$ NMR, Homo-COSY, $^1H$-$^{13}C$ (1 bond) Heteronuclear Multiple Quantum Coherence Spectroscopy (HMQC), $^1H$-$^{13}C$ (2 and 3 bond) Heteronuclear Multiple Bond Coherence Spectroscopy (HMBC), Electron Impact Mass Spectroscopy (EI-ms) 및 Infrared Spectroscopy (IR)에 의해 밝혔다.

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Isolation of Dineolignans, Saucernetin-7 and -8, with Nitric Oxide Inhibitory Activity and NMR assignment from Saururus chinensis

  • Lee, Kyung-Tae;Jung, Hyun-Ju;Park, Hee-Juhn
    • 한국자원식물학회지
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    • 제19권6호
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    • pp.655-659
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    • 2006
  • Two dineolignans (1,2) with nitric oxide inhibitory activities were isolated from Saururus chinensis (Saururaceae) using silica gel column chromatography. Although the structures, saucernetin-7 (1) and -8 (2), have been already reported, NMR assignment of the two compounds was completed aided by 2D-NMR spectroscopy including $^1H-^1H$ COSY, $^1H-^{13}C$ COSY, HMBC and NOESY NMR spectra. Compounds 1 and 2 exhibited significant nitride oxide inhibitory activity in LPS-induced RAW 264.7 cells with $IC_{50}$ values of $11.3{\mu}M\;and\;7.1{\mu}M$, respectively.

몇가지 페닐 알카놀의 Sodium Dodeylsulfate 수용액 미셀내에서의 가용화 위치 (The Solubilization Site of Some Phenyl Alkanols in Aqueous Sodium Dodecylsulfate Micelle)

  • 정종재;강정부;이경희
    • 대한화학회지
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    • 제38권3호
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    • pp.194-199
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    • 1994
  • Sodium dodecylsulfate(SDS) 0.2M수용액 미셀내에 몇 가지 페닐 알카놀$[C_6H_5(CH_2)_nOH;$ 페놀(n=1), 벤질 알코올(n=1), 펜에틸 알코올(n=2), 3-페닐-1-프로판올(n=3)]이 가용화(solubilization)될 때 이들의 가용화 위치를 이차원 이핵 상관 NMR분광법(Two dimensional heteronuclear correlation spectroscopy (2D C-H COSY)으로 조사하였다. 실험 결과 $^1H$-NMR 신호의 적분에 의하여 조사한 이전의 연구결과보다 훨씬 정량적이며 정확한 가용화 위치를 알 수 있었다. 이들이 SDS 미셀 중심의 중간부 메틸렌기에 침투하는 깊이는 ${\alpha}$메틸렌기로부터 6.5~7.0 단위까지 임을 알았다.

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Intramolecualr cyclization of a dipyrromethane by an electrophilic aromatic substitution reaction producing a new chiral compound

  • Kim, Seung Hyun;Kim, Sung Kuk
    • 한국자기공명학회논문지
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    • 제22권4호
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    • pp.115-118
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    • 2018
  • Dipyrromethane 2 functionalized with 3-chloropropyl group on the meso carbon undergoes an unusual intramolecular electrophilic aromatic substitution reaction in the presence of $NaN_3$ instead of a simple nucleophilic substitution reaction. As a result, a new chiral dipyrromethane 1 was synthesized. In this reaction, the ${\beta}$-carbon of the pyrrole ring functions as a nucleophile while the carbon next to the chlorine atom acts as an electrophile. Interestingly, this reaction progresses even in the absence of an acid catalyst. Compound 1 was fully characterized by $^1H-^1H$ and $^1H-^{13}C$ COSY NMR spectroscopic analyses and the high resolution EI mass spectrometry.

Complexation between Venlafaxine Hydrochloride and β -Cyclodextrin:Structural Study by Nuclear Magnetic Resonance Spectroscopy

  • Ali, Syed Mashhood;Koketsu, Mamoru;Asmat, Fahmeena
    • Bulletin of the Korean Chemical Society
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    • 제27권9호
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    • pp.1397-1400
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    • 2006
  • A detailed spectroscopic study ($^1H$ NMR, COSY, ROESY) of complexation of venlafaxine hydrochloride (VEN) with $\beta$-cyclodextrin ($\beta$--CD) was carried out in solution. The stoichiometry of the complex was determined to be 1 : 1 and penetration of aromatic ring into $\beta$-Cyclodextrin cavity was confirmed from primary rim side, with the help of ROESY spectral data. The structure of the venlafaxine hydrochloride-$\beta$-CD complex has been proposed. The association constant was determined to be 234 $M^{-1}$.

Electron Withdrawing Group을 함유한 Polythiophene의 합성과 특성에 관한 연구 (Synthesis and Characteristic of Polythiophene Containing Electron Withdrawing Group)

  • 홍혁진;한신호
    • 공업화학
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    • 제23권6호
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    • pp.539-545
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    • 2012
  • 전자를 끌어당기는 benzotriazole을 vinylene으로 thiophene과 연결한 3-(2-benzo-triazolovinyl)thiophene (BVT)을 합성하고, FT-IR 및 $^1H$-NMR, $^{13}C$-NMR, 2D hetero-cosy spectra로 구조분석을 하였다. 합성한 BVT와 3-octylthiophene (OT)을 공중합 하였다. 공중합체들은 수평균 분자량 12000 (PDI 2.67)과 15000 (PDI 2.55)을 나타내었으며, THF, TCE와 chloroform 등의 유기용매에 잘 용해되었다. 공중합체들의 BVT와 OT의 공중합된 비율은 $^1H$-NMR spectra에 의하여 BVT : OT = 1 : 1.8과 1 : 2.8 (mol/mol)로 확인되었다. 파장 470 nm와 465 nm에서 UV-vis 최대 흡수를 나타내었고, photoluminescence (PL)는 각각 ${\lambda}_{max}$ = 662 nm와 641 nm로 나타나 적색계로 관찰되었다. 공중합체의 band gap은 각각 1.96 eV, 2.02 eV로 poly(3-octylthiophene)보다 더 증가하였다. 또한, poly(3-octylthiophene)에 비해서 HOMO 에너지 준위는 모두 낮아졌으나, LUMO 에너지 준위는 모두 높아졌다.

Revision of Structures of Flavanoids from Scutellaria indica and Their Protein Tyrosine Phosphatase 1B Inhibitory Activity

  • Min, Byung-Sun
    • Natural Product Sciences
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    • 제12권4호
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    • pp.205-209
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    • 2006
  • The structures of flavonoids, 2(S)-5,7-dihydroxy-8,2'-dimethoxyflavanone (1), wogonin (2), 2(S)-5,7, 2'-trihydroxy-8-methoxyflavanone (3), and 2(S)-5,2',5'-trihydroxy-7,8-dimethoxyflavanone (4), isolated from Scutellaria indica were revised on the basis of 2D NMR spectroscopy, including to gCOSY, gHSQC, and gHMBC. Compounds 1-4 were tested in vitro protein tyrosine phosphatase 1B (PTP1B) inhibitory activity. Compounds 2 and 4 exhibited weak PTP1B inhibitory activity with $IC_{50}$ values of 208 and $337{\mu}M$, respectively.

Bacillus subtilis KS1이 생산하는 항진균물질의 정제 및 특성 (Purification and characterization of antifungal compounds produced by Bacillus subtilis KS1)

  • 류승우;맹학영;맹필재
    • 한국균학회지
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    • 제24권4호통권79호
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    • pp.293-304
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    • 1996
  • 인삼포 토양으로부터 강력한 항진균력을 보이는 KS1 균주를 분리하고 Bacillus subtilis로 동정하였다. 온상시험에서 B. subtilis KS1의 배양액은 오이잿빛곰팡이병, 밀붉은녹병 등의 진균성 농작물병에 대하여 탁월한 방제효과를 나타내었다. 또한, B. subtilis KS1 배양액의 butanol 분획은 Botrytis maydis, Chytridium lagenarium, Candida albicans 등 식물 또는 사람의 병원성 진균을 비롯한 몇몇 진균류에 대하여 억제효과를 나타내었다. 이 균주가 생성하는 항진균물질을 pep-RPC reverse phase column과 ${\mu}$ Bondapak $C_{18}$ reverse phase column을 이용하여 분리 정제하였다. 정제된 항진균물질의 열안정성 및 pH 안정성을 조사한 결과, $-20-121^{\circ}C$와 pH 4.0-10.0의 범위에서 안정하였다. 이 물질의 조성 및 구조적 특징을 HPLC와 $^1H-,\;^1H-^1H-$, COSY, NOESY, COSY-NOESY 및 HOHAHA NMR spectroscopy를 통하여 각각 분석한 결과, B. subtilis가 생산하는 고리형 peptide 중 iturin A에 속하는 물질로 확인되었다. 그러나, 지금까지 알려진 iturin A계 물질들의 ${\beta}$-아미노산에 붙어 있는 탄화수소 사슬이 곁가지가 없거나 terminus 또는 subterminus에 1개의 $CH_3$ 곁가지를 갖는 것과는 달리, SW1의 ${\beta}$-아미노산은 2개의 $-CH_3$ 곁가지가 붙어 있는 탄화수소 사슬을 가짐이 확인되었다.

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화살나무(Euonymus alatus)로 부터 α-glucosidase 저해 물질의 분리 및 동정 (Isolation and Characterization of α-glucosidase Inhibitors from Euonymus alatus)

  • 김신덕
    • 한국미생물·생명공학회지
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    • 제45권4호
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    • pp.311-315
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    • 2017
  • 화살나무 가지로부터 activity based fractionation에 의해 ${\alpha}$-glucosidase 저해 활성 물질 compound 1-4을 분리하였고, $^1H$ NMR, $^{13}C$ NMR, $^1H-^1H$ COSY와 HMBC 등의 spectral data에 의해 구조를 결정하였다. Compound 1-4는 모두 flavonol 물질로 ${\alpha}$-glucosidase에 대해 $IC_{50}$ 값이 각각 25.3, 17.1, 47.3과 $35.1{\mu}M$로 positive control로 사용한 acarbose 보다 강한 활성을 나타내었다. 화살나무의 혈당 저하 기능의 유효성분으로 처음 동정된 Compound 1-4는 ${\alpha}$-glucosidase에만 특이적 활성을 갖는 물질로 당뇨병 치료제로의 개발 가능성이 높은 물질로 사료된다.