• Natural Product Sciences
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• 제12권4호
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• pp.237-240
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• 2006

Paeoniflorin, the major component of the root of Paeonia lactiflora, was quantitatively analyzed using $^1H-NMR$ spectrometry. The quantity of paeoniflorin was calculated by the ratio of the intensity of the signals (H-9, H-10, H-2', 6') to the aldehyde peak of the known amount of internal standard, 2,4,6-trihydroxybenzaldehyde. These results were compared with the conventional HPLC method. The contents of paeoniflorin in P. lactiflora, which were respectively calculated by H-9, H-10, H-2', 6' in the $^1H-NMR$ spectra and HPLC, were determined $2.60{\pm}0.07,\;2.44{\pm}0.09,\;2.77{\pm}0.12\;and\;2.46{\pm}0.16%$. The advantages of quantitative $^1H-NMR$ analysis are that can be analyzed to identify and quantify, and no reference compounds required for calibration curves. Besides, it allows rapid and simple quantification for paeoniflorin with an analysis time for only 20 min without any preprocessing.

• 한국자기공명학회논문지
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• 제6권2호
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• pp.94-102
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• 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
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• 제10권1호
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• pp.96-104
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• 2006

The gene coding for APG8a (At4g21980), a protein from Arabidopsis thaliana, is involved in the autophagy process. The protein is an interesting candidate for structure determination by NMR spectroscopy. Toward this end, APG8a has been produced recombinantly in Escherichia coli and typical NMR experiments such as $^{15}N-HSQC$, HNCA, HN(CO)CA, CBCA(CO)NH, HCCH-TOCSY, HNCO were performed. The backbone resonances, HN, N, CA, CB, and C' were sequence-specifically assigned, and the secondary structures including 3 $\alpha$ helices and $4\beta$ strands were deduced based on the assignments. Due to the intrinsic flexibility or the effect of the denaturant, the backbone resonances were not fully observed. Since the structure calculation by NMR data was not possible, the 3-dimensional model was built based on the sequence homology, and compared with the NMR results. The overall structure of the model could explain and complement the NMR derived secondary structures.

• 한국자기공명학회논문지
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• 제10권1호
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• pp.38-45
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• 2006

The NMR and MS techniques were applied to identification and quantitative analysis of oligomers in a commercialized poly (trimethylene terephthalate). Oligomers in a commercialized poly (trimethylene terephthalate) were extracted via a dissolving and reprecipitation method. Analysis of the components of the extract using NMR and MS revealed that it contained mainly cyclic oligomers with degrees of polymerization of 2, 4 and 5 (dimer, tetramer and pentamer). Trimer and cyclic oligomers with degrees of polymerization of more than 6 were not found in the extract in the present study. Quantitative analysis of dimer was performed by NMR spectroscopy.

• 대한화학회지
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• 제63권2호
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• pp.78-84
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• 2019

High-resolution $^1H$ NMR spectroscopic technique has been widely used as one of the most powerful analytical tools in food chemistry as well as to define molecular structure. The $^1H$ NMR spectra-based metabolomics has focused on classification and chemometric analysis of complex mixtures. The principal component analysis (PCA), an unsupervised clustering method and used to reduce the dimensionality of multivariate data, facilitates direct peak quantitation and pattern recognition. Using a combination of these techniques, the various green teas and black teas brewed were investigated via metabolite profiling. These teas were characterized based on the leaf size and country of cultivation, respectively.

• 한국자기공명학회논문지
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• 제23권2호
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• pp.56-60
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• 2019

Study on the structure and dynamics of molecules at the atomic level is of great significance for understanding their function and stability as well as roles for various chemico-physical and biological processes. $^{17}O$ NMR spectroscopy has appeared as an elegant technique for investigating of the physicochemical and structural properties of oxygen-containing compounds such as metal organic frameworks and nanosized oxides. This method has drawn much attention as it provides unique insights into the properties of targets based on atomistic information of local oxygen environments which is otherwise difficult to obtain using other methods. In this mini review, we introduce and discuss the recent study and developments of $^{17}O$ NMR techniques which are tailored for the investigation on the structure and dynamics of water and inorganic materials.

• 분석과학
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• 제23권1호
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• pp.97-101
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• 2010

(R)-N-3,5-dinitrobenzoyl (DNB) phenylglycinol로 부터 만들어진 키랄 선택제가 라세미 Nacylnaphthylalkylamines의 분리에 HPLC 키랄 정지상으로 이용된 바 있다. 본 연구에서는 (R)-phenylglycinol 유도체 키랄 선택제를 이용하여 키랄 크로마토그래피와 NMR 분광법에 의한 광학순도를 측정하였다. NMR과 HPLC 실험결과를 참값과 비교하여 각 광학순도 측정값의 정확도와 정밀도를 계산하였다. NMR 방법의 오차는 +2.2%, 평균 RSD는 4.54% 이었고, HPLC 방법의 오차는 -3.5%, 평균 상대표준편차는 3.23% 이었다.

• 생약학회지
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• 제19권3호
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• pp.153-169
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• 1988

The combined use of the J-modulated selective INEPT and CSCM 1DNMR techniques is described for the structure elucidation of several new classes of compound including prionitin, the loureirins and larreantin, and for the regiosubstitution of the furanonaphthoquinones. Spectroscopic studies on the conformation of the cytotoxic agent savinin are also described, together with the NMR assignments and preliminary biosynthetic experiments on the antitumor antibiotic staurosporine.

• 약학회지
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• 제26권3호
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• pp.139-148
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• 1982

• 한국재료학회:학술대회논문집
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• 한국재료학회 1993년도 춘계학술발표회
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• pp.116-116
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• 1993