• BMB Reports
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• v.50 no.10
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• pp.522-527
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• 2017

A large number of transcriptional activation domains (TADs) are intrinsically unstructured, meaning they are devoid of a three-dimensional structure. The fact that these TADs are transcriptionally active without forming a 3-D structure raises the question of what features in these domains enable them to function. One of two TADs in human glucocorticoid receptor (hGR) is located at its N-terminus and is responsible for ~70% of the transcriptional activity of hGR. This 58-residue intrinsically-disordered TAD, named tau1c in an earlier study, was shown to form three helices under trifluoroethanol, which might be important for its activity. We carried out heteronuclear multi-dimensional NMR experiments on hGR tau1c in a more physiological aqueous buffer solution and found that it forms three helices that are ~30% pre-populated. Since pre-populated helices in several TADs were shown to be key elements for transcriptional activity, the three pre-formed helices in hGR tau1c delineated in this study should be critical determinants of the transcriptional activity of hGR. The presence of pre-structured helices in hGR tau1c strongly suggests that the existence of pre-structured motifs in target-unbound TADs is a very broad phenomenon.

• Journal of radiological science and technology
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• v.44 no.3
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• pp.239-245
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• 2021

Since the side effects of contrast agents occur in many ways, hospitals must clearly identify the contrast agents and know how to manage them. Storage of contrast media It is common practice to store contrast media in a warm room to reduce viscosity and improve patient comfort. However, it is important to recognize that long-term storage at high temperatures can shorten the shelf life of a product. Therefore, in this study, the presence or absence of chemical changes according to the storage period after using the contrast medium was analyzed. As the analysis equipment, a 500 MHz Nuclear Magnetic Resonance Spectrometer of Bruker Avance (Germany) possessed by Korea Basic Science Institute (KOREA BASIC SCIENCE INSTITUTE; KBSI) was used. For the X-ray iodide contrast medium, Pamiray contrast medium of Iopamidol and Optiray contrast medium of Ioversol, samples remaining after 7 days, 20 days, 30 days, and 1 year were collected, By acquiring the spectrum from the 1H-NMR spectrometer of the contrast medium stimulated by It was compared and analyzed with the standard sample. In conclusion, depending on the storage period of the contrast medium, no peaks of physical and chemical changes were observed in both the Pamiray contrast medium of Iopamidol and the Optiray contrast medium of Ioversol after 7 days, 20 days, 30 days, and 1 year after use.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.223-226
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• 1995

Polymers have been developed and applied in many biomedical areas as well as engineering and industrial fields. The first essential to achieve successful development and applications is that properties of such polymer materials would be investigated. In many cases, such investigations are accomplished by observing polymeric behavior arising from the environmental changes such as pH, temperature, and ionic concentration. It has long been known that NMR is extremely sensitive to many biochemical and physical changes occurring in the polymer samples. In the present study we focus our study on NMR Microimaging, which is one of the important NMR applications, to characterize the swelling effect by observing the time dependent spatial variations of polymer specimens. For the samples three kinds of polyvinyl alcohol (PVA) specimens are prepared with different degrees of cross linking density. $^1H$ NMR microimages are acquired as a function of time to visualize the swelling behavior as well as volumetric changes occurring in the specimens. From the acquired time dependent images, the swelling process is exploited.

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.815-818
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• 2010

Free base meso-tetraarylporphyrins ($H_2T(X)PP$) react with tellurium(IV) chloride ($TeCl_4$) in mild conditions for formation sandwich intermediate sitting-atop (i-SAT) complexes, [$TeCl_4(H_2T(X)PP)_2$]. $^1H$ NMR, $^{13}C$ NMR, UV-vis, FT-IR and elemental analysis were used for characterization of the products. In the proposed structure of the i-SAT complexes, four pyrroles of each porphyrin ring are tilted alternatively up and down and this appropriates suitable orientation of lone pairs of two pyrrolenine nitrogens for electron donation to a tellurium center. $^1H$ NMR and FT-IR results showed that in the produced complex, hydrogen atoms of porphyrin macrocycles remained on the pyrrole nitrogens.

• Microbiology and Biotechnology Letters
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• v.33 no.2
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• pp.123-129
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• 2005

Isolation and identification of pathogens from slaughter and meat processing plant were investigated. Antimicrobial activity of Amaranthus lividus against isolated pathogens such as Aeromonas sobria, Escherichia coli, Escherichia coli O157, Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus was investigated. Among the chloroform, ethyl acetate and buthanol fraction of amaranthus lividus showed inhibitory effect against Aeromonas sobria CLFM1 and Escherichia coli CLFM2. Antimicrobial substance in chloroform fraction was isolated by silica gel adsorption column chromatography, sephadex LH-20 column chromatography and silica gel partition column chromatography. The antimicrobial compound of amaranthus lividus was identified as diethyl phtalate by HPLC, GC-MS, H-NMR and C-NMR.

• Applied Chemistry for Engineering
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• v.10 no.4
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• pp.599-602
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• 1999

Chitosan was depolymerized by using nitrous acid. In order to synthesize new fluorinated chitosan oligomer(FCO) derivative, free amine groups of resulting low molucular weight chitosan oligomers were reacted with trifluoroacetic anhydride. The structure changes in the samples were conformed by using FT-IR, $^{1}H\;NMR$, $^{13}C\;NMR$ and $^{19}F\{^{1}H\}NMR$. Antiviral activity of FCO was studied by measuring DAN amounts of the replication viruses at 36 hr after the cells were infected with the viral solution containing FCO of various concentrations. The viral replications in the cells infected with the viral solution containing FCO were proportionally decreased with the FCO does, compared to those of the control groups, indicating that FCO efficiently inhibits viral infection. In particular, viral replication was decreased to 40% in the 1% FCO-treated cells.

• Korean Journal of Medicinal Crop Science
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• v.14 no.4
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• pp.212-216
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• 2006

Root of Scutellaria baicalensis G. was extracted with methanol and water to give the yield of 30.0% in order to find the antioxidant substance. The extract was fractionated with diethyl ether, n-butanol and water to test the inhibitive activity against xanthine oxidase. Three fractions inhibited the activities of xanthine oxidase by 48.2%, 10.2% and 2.8%, respectively, at the amount of $0.1\;{\mu}g$. A component that exhibited strong inhibition of xanthine oxidase was isolated from diethyl ether fraction (SE Fr.) by silica gel column chromatography and HPLC, and then identified by $^1H-NMR$, $^{13}C-NMR$ and MS spectrophotometry. EDA (Electron Donating ability) of the compound was 28.5% at the concentration $100\;{\mu}g/3\;ml$. That was identified to be 3,5,7-trihydroxy-2'-methoxyflavanone by spectrophotometric analysis using $^1H-NMR,\;^{13}C-NMR$ and Mass spectrophotometry.

• The Korean Journal of Food And Nutrition
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• v.27 no.3
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• pp.532-537
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• 2014

Cortex Phellodendri (CP) is derived from the dried bark of Phellodendron amurense. It has been widely used as a drug in traditional Korea medicine for treating diarrhea, jaundice, swelling pains in the knees and feet, urinary tract infections, and infections of the body surface. Many analytical methods have been used to study oriental herbal medicines, such as thin-layer chromatography, column liquid chromatography, and high performance liquid chromatography (HPLC). In this study, preparative centrifugal partition chromatography (CPC) was successfully carried out in order to separate pure compounds from a CP methanol extract. The optimum two-phase CPC solvent system was composed of n-butanol: acetic acid: water (4:1:5 v/v/v). The flow rate of the mobile phase was 3 mL/min in ascending mode with rotation at 1,000 rpm. The CPC-separated fraction and purification procedures were carried out by preparatory HPLC. The $^1H$ NMR spectrum revealed that the resonances at ${\delta}$ 4.10 and 4.20 ppm corresponded to three protons ($-OCH_3$), whereas those at ${\delta}$ 6.10 ppm corresponded to two protons ($-OCH_2O-$). Further, two aromatic protons (H-11 and H-12) conveys a doublet-doublet pattern. The H-11 doublet and H-12 doublet appear at ${\delta}$ 7.98 and 8.11, respectively. The $^{13}C$ NMR. spectrum showed a tetrasubstituted with a methylenedioxy group at C2 and C3, and two methoxy groups at C9 and C10. The chemical structure of the berberine was identified by $^1H$, $^{13}C$-nuclear magnetic resonance and electrospray ionization-mass spectroscopy spectral data analysis.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.347-347
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• 2006

Polymers containing poly(vinyl phosphonic) acid segments are promising candidates to be used as proton conducting membranes. Solid state NMR spectroscopy represents an ideal probe of proton motion on the molecular level, because it allows us to selectively detect the nuclei of interest. In this paper, we apply solid state NMR methods to poly(vinyl phosphonic) acid in order to demonstrate that the proton conduction of poly(vinyl phosphonic acid) results from P-OH proton through hydrogen bonding and that the condensation of phosphonic acid leads to decrease in proton conductivity. $^{1}H\;and\;^{31}P$ solid state NMR experiments are supported by quantum chemical computation of NMR parameters.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.22-28
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• 2003

Antimicrobial effect of Dansham (Saliuia miltiorrhiza Bunge) was investigated. Methanol extract of dried Dansham was fractionated to hexane, chloroform, ethylacetate, butanol and aqueous fraction. Chloroform fraction showed the highest inhibitory effect on the microorganisms such as B. subtilis, S. aureus, E. coli, L. monocytogenes and V. parahaemolyticus at 250 $\mu\textrm{g}$/disc. Chloroform fraction was further fractionated by silica gel column and thin layer chromatography (TLC). The antimicrobial compound was isolated from their fractions and its chemical structure was identified as a cryptotanshinone by GC-MS and $^1$H-NMR, $^{13}$ C-NMR.