• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.179.2-179.2
• /
• 2003

The cytotoxic activity of 13(E)-Labd-13-ene-8$\alpha$, 15-diol(1), isolated from the ethanol extract of Brachyglottis monroi was evaluated against tumor cell lines such as P388, SNU-C4 MDA-MB231, B 16 melanoma and A549 in vitro. By mean of spectral analysis particularly by the aid of various two dimensional NMR experiments, 1H-NMR and 13C-NMR signals of (1) was completely assigned, and thus the structure of (1) was established unambiguously. (omitted)

• Journal of the Korean Magnetic Resonance Society
• /
• v.16 no.2
• /
• pp.162-171
• /
• 2012

SAV2228 has an OB (Oligomer-Binding)-motif which is frequently used for nucleic acid recognition. To characterize the activity of translation initiation factor-1 (IF-1) from Staphylococcus aureus, SAV2228 was expressed and purified in Escherichia coli. We acquired 3D NMR spectra showing well dispersed and homogeneous signals which allow us to assign 94.4% of all $^1HN$, $^{15}N$, $^{13}C{\alpha}$, $^{13}C{\beta}$ and $^{13}CO$ resonances. We could predict a secondary structure of SAV2228 using TALOS and CSI from NMR data. SAV2228 was consisted of one ${\alpha}$-helix and five ${\beta}$-sheets. The predicted secondary structure, ${\beta}-{\beta}-{\beta}-{\alpha}-{\beta}-{\beta}$, was similar to other bacterial IF-1, but it was not completely same to the eukaryotic one. Assigned NMR peaks and secondary structre prediction can be used for the study on interaction with nucleic acid in the future.

• Journal of Sericultural and Entomological Science
• /
• v.38 no.2
• /
• pp.180-185
• /
• 1996

Biosynthesis tracing of the silk fibroin in Bombyx mori silkworm was examined in vivo with isotopic [1-13C] Gly. labeling by nuclear magnetic resonance method. The [1-13C] Gly. labeled silk fibroin yielded very sharp 13C NMR signal in the posterior silk gland as well as in aqueous solution and the amound of [1-13C] Gly. labeled signal in the silkworm increased gradually and rapidly to 5-th day of fifth instar. However, the decomposition or decrease of the [1-13C] Gly. labeled signal occured from 5-th to 9-th day of fifth instar unexpectedly. These findings suggest that a relative amount of ${\alpha}$-helical portion or amorphous silk II portion was formed without any further signal from 6-th day of fifth instar to pupation. Through peak separation of orientation spectrum, between the fiber axis and the molecular bond direction, N-H bond in Bombyx mori silk fiber as well as the orientation distribution around the silk fibroin axis were determined and two kinds of peaks were also obtained from this orientation spectrum.

• Analytical Science and Technology
• /
• v.10 no.2
• /
• pp.139-145
• /
• 1997

Alkylbenzenes used as synthetic lubricant base oils have been analyzed to find the quantity of mono- and di-substituted alkyl aromatic hydrocarbon compositions and the number of carbon atoms in alkyl chains by $^{13}C$-NMR, near-infrared, and UV-Vis spectroscopy. Also, linear long chain alkylated benzene in the engine lubricants was analyzed quantitatively by infrared spectroscopy.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1993.04a
• /
• pp.85-96
• /
• 1993

합성세제의 주원료로 많이 사용되고 있는 알킬벤젠 생산시 발생되는 부산물은 극한지 및 특수 산업용 윤활유의 합성 윤활기유로서 좋은 효과를 갖는다는 사실은 잘 알려져 있다. 알킬벤젠은 여러가지 방향족 화합물들의 혼합물로써 이루어져 있으며 그 조성은 그들을 기유로한 윤활유의 품질에 많은 영향을 미친다. 그러므로 그 조성분석을 위한 신속, 정확한 방법은 대단히 중요하다. 본 연구에서는 합성기유로서 사용될 수 있는 몇가지 알킬벤젠들에 대하여 $^{13}C-NMR$을 이용하여 그 조성을 분자구조적인 측면에서 구조파라미터에 따라서 관찰하고 그들의 윤활기유로서의 산화안정성 및 열안정성에 대하여 비교 관찰하였다.

• Analytical Science and Technology
• /
• v.15 no.1
• /
• pp.36-42
• /
• 2002

The dissolved organic carbon extracted from groundwater is separated into humic acid and fulvic acid. They are characterized for their chemical composition, spectroscopic characteristics using UV/VIS, IR and solid state $^{13}C-NMR$ spectroscopy, proton exchange capacity and molecular size distribution. The results are comparable with the literature data. The study explains that the aquatic humic and fulvic acid in this experiment are site-specipic and polydisperse natural organic matter with considerable proton exchange capacity.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2006.04a
• /
• pp.16-19
• /
• 2006

Humin is the insoluble fraction of humic materials and play an important roles in the irreversible sorption of hydrophobic organic contaminants onto soil particles. However, there have been limited knowledge about the sorption and chemical properties of humin due to the difficulties in its separation from the inorganic matrix(mainly clays and oxides). In this study, do-ashed humin was isolated from a soil sample after removing free lipid and alkali-soluble humic fractions followed by dissolution of mineral matrix with 2% HF, and characterized by elemental analysis, C-13 NMR spectroscopic method. Sorption behavior of 1-naphthol with humin was also investigated from aqueous solution. C-13 NMR spectra indicate that humin molecules are mainly made up of aliphatic carbon including carbohydrate, methylene chain etc.. Sorption intensity for 1-naphthol was increased as organic carbon content of humin increased and log Koc values for the 1-naphthol sorption were determined to be ${\sim}3.12$

• Journal of the Korean Wood Science and Technology
• /
• v.29 no.3
• /
• pp.83-91
• /
• 2001

This paper examines the structural characteristics of fern lignins (deer fern (Blechnum spicant), sword fern (Polystichum munitum) and maidenhair fern (Adiantum pedatum)) by chemical degradation methods of thioacidolysis and nitrobenzene oxidation as well as 13C NMR. Phloroglucinol-HCI staining indicates that the lignins are specifically accumulated at the sclerenchyma cells beneath the epidermis and vascular bundles. The fern lignins consist of only guaiacyl units. Remarkably, the frequency of the -O-4 linkages is extremely low in fern lignins (only 9 to 11 %). Furthermore, the presence of lignin is ambiguous in maidenhair fern, due to very rare amount of -O-4 linkage. Biphenyl (5-5) and 1,2 bis arylpropane (-1) are main condensed dimeric substructures in fern lignins over 70%. In addition, 13C NMR analysis strongly evidenced the integration of phenolics or their derivatives into the fern lignins.

• Bulletin of the Korean Chemical Society
• /
• v.13 no.2
• /
• pp.135-139
• /
• 1992

The mono(aryl)cyanoplatinum(II) complex $[Pt(CN)(C_6H_3{CH_2NMe_2}_2-26)]$, reacts with the dihalogens to yield the mono(aryl)cyanoplatinum complexes $[PtX_2(CN)(C_6H_3{CH_2NMe_2}_2-26)]$, (X = Cl, Br, I). The structural configuration of the two halogen atoms for a square planar platinum complex was studied by 1H-NMR spectroscopy and led to a mixture of trans and cis orientation. The trans orientation was found to be more stable in energy (1.33 kcal/mol) than the cis orientation by means of Extended H ckel calculations. On the base of a combination of the analysis of $^1H-NMR$, $^{13}C-NMR spectra and computational calculations it is assumed that the intermediate consists of an initial attack in the linear transition state, leading to the $S_{N}2$ type mechanism.

• Natural Product Sciences
• /
• v.4 no.3
• /
• pp.153-157
• /
• 1998

The aqueous ethanolic leaf extract of Ailanthus altissima was found to contain the new natural product, $luteolin\;7-O-{\beta}-(6"-galloylglucopyranoside)$, 13, along with fourteen known phenolic metabolites (1-12, 14 and 15). Structures of all compounds (1-15) were established by conventional methods of analysis and confirmed by FAB-MS, $^1H-\;and\;^{13}C-NMR$ spectral analysis.