• 한국식품과학회지
• /
• 제34권6호
• /
• pp.1062-1066
• /
• 2002

참깨의 원산지를 판별하기 위하여 일반성분 및 low field NMR을 이용하여 relaxation time을 측정하였다. 일반성분으로는 한국산, 중국산 및 수단산간의 유의적인 차이는 없었으나 NMR 데이터 중 CPMG를 제외한 나머지 측정항목인 $T_1-IR,\;T_1-SR,\;T_2-SE,\;SFC$는 원산지별 유의적인 차이를 보였다. 가장 유의적인 차이가 높았던 SFC, IR, SR을 이용하여 정준 판별분석을 시행한 결과 수단산은 100% 판별이 가능하였고, 한국산 및 중국산은 각각 80%, 90%의 정확성을 나타내었으며, 5가지 NMR 측정항목을 모두 사용하여 판별한 결과 한국산, 중국산, 수단산이 각각 95%, 90%, 100%의 원산지 판별이 가능하였다.

• 한국자기공명학회논문지
• /
• 제6권2호
• /
• pp.94-102
• /
• 2002

An interesting recent application of intermolecular NOE experiment is the saturation transfer difference NMR(STD-NMR) method that is useful in screening compound libraries to identify bio-active ligands. This technique also identifies the group epitopes of the bound ligand in a reversibly forming protein-ligand complex. We present here a complete relaxation and conformational exchange matrix (CORCEMA) theory (Moseley et al., J. Magn. Reson. B, 108, 243-261 (1995)) applicable for the STD-NMR experiment. Using some ideal model systems we have analyzed the factors that influence the STD intensity changes in the ligand proton NMR spectrum when the resonances from some protons on the receptor protein are saturated. These factors will be discussed and some examples of its application in some model systems will be presented. This CORCEMA theory for STD-NMR and the associated algorithm are useful in a quantitative interpretation of the STD-NMR effects, and are likely to be useful in structure-based drug design efforts. They are also useful in a quantitative characterization of protein-protein (or protein-nucleic acid) contact surfaces from an intermolecular cross-saturation NMR experiment.

• 한국자기공명학회논문지
• /
• 제21권1호
• /
• pp.1-6
• /
• 2017

Enhancements in NMR sensitivity have been the main driving force to extend the boundaries of NMR applications. Recently, techniques to shift the thermally populated nuclear spin states are employed to gain high NMR signals. Here, we introduce a technique called photochemically induced dynamic nuclear polarization (photo-CIDNP) and discuss its progresses in enhancing the solution-state NMR sensitivity.

• Journal of Ginseng Research
• /
• 제21권2호
• /
• pp.104-108
• /
• 1997

(20S)-ginsenoside $Rs_3$ and its isomers were chemically prepared from diol ginseng saponins by partial acid hydrolysis and acetylation. The characteristics of $^{1}H-NMR$ and $^{13}-NMR$ data were compared with each other and fully assigned.

• Journal of Ginseng Research
• /
• 제20권1호
• /
• pp.111-112
• /
• 1996

The chemical shifts of C-21 and C-23 in the $^{13}C$-NMR for (20R)-protopanaxatriol, (20R)-ginsenoside $Rh_1$ and (20R)-ginsenoside $Rg_3$ were revised by employing some extensive 2D-NMR techniques.

• 한국자기공명학회:학술대회논문집
• /
• 한국자기공명학회 2002년도 International Symposium on Magnetic Resonance
• /
• pp.69-69
• /
• 2002

• 한국자기공명학회논문지
• /
• 제12권2호
• /
• pp.89-95
• /
• 2008

Function of protein is frequently related with tautomeric states of histidine sidechains. Thus, several NMR experiments were developed to determine the tautomeric states of histidines. However, poor sensitivity of these experiments caused by long duration of magnetization transfer periods is unavoidable. Here, we alleviate the sensitivity of HCN experiment for determining the tautomeric states of histidine residues using TROSY principle to suppress transverse relaxation of $^{13}C$ spins during long polarization transfer delays involving $^{13}C-^{15}N$ scalar couplings. In addition, this experiment was used to assign the sidechain resonances of histidines. These assignments can be used to follow the pH-titration of histidine sidechains.

• 한국자기공명학회논문지
• /
• 제21권3호
• /
• pp.96-101
• /
• 2017

Metabolomics is one of latest '-omics', which is to analyze metabolome in cells, tissues and biofluids and to study metabolisms. It has become increasingly popular since 1990. The first goal of metabolomics is to analyze metabolites in a technical aspect. The major two analytical platforms in metabolomics are NMR spectroscopy and mass spectrometry (MS). MS is superior to NMR for detecting many more metabolites. That is one of the most important factors in metabolomics. However, NMR also has several advantages over MS. In this review, I firstly introduced metabolomics by comparing NMR-based metabolomics and MS-based metabolomics. Second, I explored technical issues on sample preparation and NMR experiments for metabolite identification and quantification.

• 한국고분자학회지:고분자과학과기술
• /
• 제4권3호
• /
• pp.211-225
• /
• 1993

• 한국고분자학회지:고분자과학과기술
• /
• 제4권4호
• /
• pp.287-304
• /
• 1993