• Journal of the Korean Magnetic Resonance Society
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• v.19 no.2
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• pp.83-87
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• 2015

Syndesmos, which is co-localized with syndecan-4 cytoplasmic domain ($Syn4^{cyto}$) in focal contacts, interacts with various cell adhesion adaptor proteins including $Syn4^{cyto}$ to control cell signaling. Syndesmos consists of 211 amino acids and it exists as a dimer (44kDa) in solution. Recently, we have determined the structure of syndesmos by x-ray crystallography, however, dynamics related to syndecan binding still remain elusive. In this report, we performed NMR experiments to acquire biochemical and structural information of syndesmos. Based on a series of three-dimensional triple resonance experiments on a $^{13}C/^{15}N/^2H$ labeled protein, NMR spectra were obtained with well dispersed and homogeneous NMR data. We present the sequence specific backbone assignment of syndesmos and assigned NMR data with combination structural information can be directly used for the studies on interaction with $Syn4^{cyto}$ and other binding molecules.

• Journal of Pharmaceutical Investigation
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• v.39 no.1
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• pp.43-49
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• 2009

Aspirin or acetylsalicylic acid, a member of the salicylate family, is frequently used as an analgesic, antipyretic, anti-inflammatory and antiplatelet drug. Because aspirin is chemically unstable in water and heat for tablet formulation, additives including lubricants are used in preparing aspirin tablets, using a dry-granulation process. Aspirin tablets are produced by a number of manufacturers which usually use their own unique combination of additives during the manufacturing process. In this study, we employed an NMR based metabolomics technique to identify the manufacturers of various aspirin tablets. Aspirin tablets from six different companies were analyzed by 1H 400 MHz NMR. The acquired data was then integrated and processed by principal component analysis (PCA). Based on the NMR data, we were able to identify peaks corresponding to acetylsalicylic acid in all of the six samples, whereas different NMR patterns were found in the aromatic and aliphatic regions depending on the unique additive used. These observations led to the conclusion that the differences in the NMR patterns among the different aspirin tablets were due to the presence of additives.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.510-514
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• 2013

The structural change of Nafion polymer electrolyte membrane (PEM) induced by hot-pressing, which is one of the representative procedures for preparing membrane-electrode-assembly for low temperature fuel cells, was investigated by $^2H$ nuclear magnetic resonance (NMR) spectroscopy. The hydrophilic channels were asymmetrically flattened and more aligned in the membrane plane than along the hot-pressing direction. The average O-$^2H$ director of $^2H_2O$ in polymer electrolyte membrane was employed to extract the structural information from the $^2H$ NMR peak splitting data. The dependence of $^2H$ NMR data on water contents was systematically analyzed for the first time. The approach presented here can be used to understand the chemicals' behavior in nano-spaces, especially those reshaping and functioning interactively with the chemicals in the wet and/or mixed state.

• YAKHAK HOEJI
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• v.39 no.3
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• pp.268-275
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• 1995

A novel polyacetylene was isolated from Cirsium spp., as well as five known ones, and its chemical structure was determined as heptadeca-1-en-11.13-diyne-8R, 9S, 10R-triol(1) on the basis of spectral data and chemical reactions. $^{1}$H-and $^{13}$C-NMR data of these polyacetylenes were completely assigned by the appfication of 2D-NMR techniques.

• Journal of the Korean Magnetic Resonance Society
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• v.10 no.1
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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.

• Journal of the Korean Magnetic Resonance Society
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• v.20 no.1
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• pp.27-35
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• 2016

NMR spectrometer has been regarded as essential tool for structure elucidation in variable scientific field as like organic synthesis, natural product and macro protein research. Also NMR can be applied for defining dynamic behavior like ligand and receptor binding. One of advantage of research with NMR is that to be great confident to confirm structure and the measured sample could be recovered. Nevertheless NMR also has a weak points than other spectroscopic methods that require a lot of time for interpreting acquired spectrum and running time due to low sensitivity. For last two decade Bruker has developed hardware and software solution for overcome those weak points. In order to overcome low sensitivity Bruker introduced Cryo and Micro diameter probe head technology. And researcher can reduce the time for routine spectrum processing and interpretation works due to lots of introductions in software solutions for quantification, identification and statistics analysis. With four examples, this article describing those new hardware and software solutions in field of recent pharmaceutical research as follows. - New Horizons for NMR in the Biopharmaceutical Industry - The development and application of solid-state NMR spectroscopy (SSNMR) in pharmaceutical analysis - Assisted NMR Data Interpretation in Synthetic Chemistry - Complete Analysis of New Psychoactive Substances Using NMR.

• Analytical Science and Technology
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• v.7 no.1
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• pp.91-102
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• 1994

The monomer compositions in a series of propylene heterophasic copolymer, propylene random copolymer, propylene random terpolymer and ethylene-propylene-ENB terpolymer have been determined from $^{13}C-NMR$ spectra. The simplified and highly resolved $^{13}C-NMR$ spectra made it possible to assign unambiguousely and calculate the monomer composition. A complete sets of NMR chemical shift assignments and the way to measure the quantity of monomer are newly given in diverse polymers. Furthermore complete dyad, triad, tetrad and pentad distributions have been able to be determined. These NMR quantitative analytical results for monomer compostition have consistent with those from Infrared spectral data.

• YAKHAK HOEJI
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• v.49 no.1
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• pp.74-79
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• 2005

Metabonomic analysis has been recognized as a powerful approach for characterizing metabolic changes in biofluids due to toxicity, disease process or environmental influences. To investigate the possibility of relating metabolic changes with $^{1}H-NMR$ spectra, urine samples from Sprague-Dawley rats treated with various dietary restrictions or toxic substances (nicotine) were analysed using $^{1}H-NMR$ spectroscopy and pattern recognition techniques. Dietary restrictions-given to male rats were normal diet and high fat diet and fasting. The nicotine urine samples were collected from SD rats administered with nicotine (25 mg/kg) at the various time intervals. $^{1}H-NMR$ spectra of all urine samples were acquired at 400 MHz on a VARIAN spectrometer. To establish the presence of any intrinsic class-related patterns or clusters in each NMR data, methods of PCA (principal component analysis) and soft independent modeling of class analogy (SIMCA) analysis were used, and the results from these analyses were compared to each other. In all cases of dietary conditions and nicotine treatment, SIMCA analysis gave better results for the discrimination of NMR spectra of urine samples than PCA.

• Journal of Life Science
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• v.10 no.1
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• pp.86-93
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• 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.

• Journal of the Korean Magnetic Resonance Society
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• v.8 no.2
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• pp.115-126
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• 2004

Four secondary metabolites from an unidentified tunicate were isolated by treatment with trichloroethyl chloroformate(TECF) or acetic anhydride in pyridine. Their structures were determined by an extensive NMR analysis and the configuration of diacetyl derivatives(3a, 4a) was assigned by comparing with NMR data of a similar compound. Three new naturally occurring compounds (1, 3, 4) showed potent brine shrimp lethality and antifungal effect against Candia albicans.