• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.6
• /
• pp.901-905
• /
• 1995

Three flavonoid compounds, astragalin(1), isoquercitrin(2) and quercetin $3-O-{\beta}-D-xylopyranosyl(1-2)-{\beta}-D-glucopyranoside(3)$ isolated from the leaves of Eucommia ulmoides were identified and quantified by HPLC. All flavonoids were well separated on a ${\mu}-Bondapak\;C_{18}$ column with a mobile phase composed of THF-dioxane-MeOH-HOAc-5% $H_3PO_4-H_2O$(145 : 125 : 50 : 20 : 2 : 658). The contents of compound 1 in the methanol extract and n-butanol fraction were 0.09%(w/w) and 0.46%(w/w), of compound 2 were 0.08%(w/w) and 0.48%(w/w), and of compound 3 were 0.40%(w/w) and 1.22%(w/w), respectively.

• Analytical Science and Technology
• /
• v.20 no.5
• /
• pp.448-451
• /
• 2007

A new bis(dicyclohexylammonium) chromate dihydrate complex, $[(C_6H_{11})_2NH_2]_2[CrO_4]{\cdot}2H_2O$, (I), has been synthesized and its structure analyzed by FT-IR, EDS, elemental analysis, ICP-AES, and single crystal X-ray diffraction methods. The Cr(VI) complex (I) is tetragonal system, I${\bar{4}}$2d space group with a = 12.5196(1), b = 12.5196(1), c = $17.3796(3){\AA}$, a = ${\beta}$ = ${\gamma}$ = $90^{\circ}$, V = $2724.09(6){\AA}^3$, Z = 4. The crystal structure of complex (I) consists of tetrahedral chromate $[CrO_4]^{2-}$ anion, two organic dicyclohexylammonium $[(C_6H_{11})_2NH_2]^+$ cations and two lattice water molecules. The chromate anion and protonated dicyclohexylammonium cation is mainly constructed through the ionic bond. The cyclohexylammonium rings of the dicyclohexylammonium cation take the chair form and vertical configuration with each other. The N-H${\cdot}$O and O-H${\cdot}$O hydrogen bond networks between the $N_{dicyclohexylammonium}$, $O_{water}$ and $O_{chromate}$ atom lead to self-assembled molecular conformation and stabilize the crystal structure.

• KSBB Journal
• /
• v.21 no.1 s.96
• /
• pp.16-19
• /
• 2006

Oxidative modification of nucleoside diphosphate kinase (NDPK) is identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometer. The quaternary structure of NDPK appears to be regulated by cross-linking with an oxidant, $H_2O_2$. We compared roles of NDPK in each of wild type and ynk mutant against oxidative stress. Six specific proteins changed by $H_2O_2$ were identified using two-dimensional electrophoretic analysis. YNK regulated several proteins, related to $H_2O_2$ signaling functions. These results suggest that one of the important functions of NDPK is the regulation of cellular redox state.

• Journal of the Korean Wood Science and Technology
• /
• v.34 no.3
• /
• pp.73-83
• /
• 2006

The dried needles (1.5 kg) of Abies koreana and Abies holophylla were ground, extracted with acetone-$H_2O$ (7:3, v/v), concentrated, and fractionated with a series of hexane, methylene chloride, ethyl acetate and water on a separatory funnel. Each fraction was freeze dried, then a portion of ethyl acetate soluble powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. The isolated compounds were identified by cellulose TLC, $^1H$, $^{13}C-NMR$, COSY, HETCOR, FAB and EI-MS. The needles of Abies koreana and Abies holophylla contained a large amount of aromadendrin-7-O-${\beta}$-D-glucopyranoside (compound III), polydatin (compound VI), (-)-rhododendrol-2-O-${\beta}$-D-glucopyranoside (compound VII), in addition to a small amount of (+)-catechin (compound I), kaempferol-3-O-${\beta}$-D-glucopyranoside (compound IV), myricetin-3-O-${\beta}$-D-glucopyranoside (compound V), naringenin-7-O-${\beta}$-D-glucopyranoside (compound II). DPPH analysis was also tested to investigate the antioxidative effects on the isolated compounds and (+)-catechin and polydatin were effective.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.34D no.12
• /
• pp.46-53
• /
• 1997

The TMA gas sensors are fabricated with the ZnO-based thin films grown by a RF magnetron sputtering method. The hall effect measurement and AES analysis are carried out to investigate the effects of the sputtering gases and dopants which effect on the electrical resistivity and sensitivity to TMA gas. We measure the cfhanges of the surface carrier concentration, haall electron mobility, electrical resistivity, surface condition, and depth profile of the films. The ZnO-based thin film sensors sputtered in oxygen, or added with dopants showed a high sruface carrier concentration, film sensors sputtered in oxygen and doped with 4.0 wt.% $Al_{2}$O$_{3}$, 1.0 wt.% TiO$_{2}$, and 0.2 wt% v$_{2}$O$_{5}$ showed the highest surface carrier concentration of 5.952 * 10$^{20}$ cm$^{-3}$ , hall electron mobility of 176.7 cm$^{2}$/V.s, lowest electrical resistivity of 6*10$^{-5}$ .ohm.cm and highest sensitivity of 12. These results were measured at a working temperature of 300.deg. C to 8 ppm TMA gas.

• Korean Journal of Ichthyology
• /
• v.22 no.3
• /
• pp.201-205
• /
• 2010

One specimen of a natural hybrid of an Oplegnathus (Oplegnathus fasciatus $\times$ Oplegnathus punctatus) was found in Tongyeong, Korea in August 2008. We, herein, describe its morphological and genetic characteristics and compare them with those of O. fasciatus and O. punctatus. In morphology, the hybrid showed many distinctive black rounded blotches on body sides and four faint vertical bars, being in those features similar to O. punctatus. Although the counts and measurements of the hybrid mostly overlapped between O. fasciatus and O. punctatus, the Oplegnathus hybrid resembled O. punctatus in the ratio of pelvic-fin length in standard length: Oplegnathus hybrid (26.7%) was closer to O. punctatus (26.4%) than to O. fasciatus (17.2~23.6%). In genetics, as a result of analysis of 510 base pair sequences of mitochondrial DNA 16S rRNA, the hybrid was closer to O. fasciatus (d=0.000~0.010) than to O. punctatus (d=0.020). Our results suggest that the natural hybridization represented by the subject specimen occurred between an O. fasciatus female and an O. punctatus male.

• Fisheries and Aquatic Sciences
• /
• v.18 no.2
• /
• pp.131-135
• /
• 2015

Two new bitter-tasting cyclic peptides comprising six amino acids, namely gamakamide C and D, were isolated from cultured oysters Crassostrea gigas. Dimethylaminoazobenzene sulfonyl-amino acid analysis detected Val and Leu in gamakamide C and Ile and Leu in gamakamide D. The molecular formula of gamakamide C was determined as $C_{43}H_{60}N_{7}O_8S$ by high-resolution fast atom bombardment mass spectroscopy (HR FAB-MS) ($[M+H]^+m/z822.4200{\Delta}-2.4mmu$), and that of gamakamide D was determined as $C_{43}H_{62}N_7O_8S$ by HR FAB-MS ($[M+H]^+m/z836.4379{\Delta}-2.0mmu$). Comparison of amino acid analyses and fragment ions by MS/MS among gamakamide C, D, and E (known), the structures of gamakamide C and D were confirmed $as-{\small{L}}-Val-{\small{L}}-Met(SO)-{\small{L}}-NMe-Phe-{\small{L}}-Leu-{\small{D}}-Lys-{\small{L}}-Phe-$ and $-{\small{L}}-Ile-{\small{L}}-Met(SO)-{\small{L}}-NMe-Phe-{\small{L}}-Leu-{\small{D}}-Lys-{\small{L}}-Phe-$, respectively.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.911-913
• /
• 2004

This paper presents characteristic analysis of claw-pole type generator. The analysis is performed using 2D equivalent model by 2D FEM. 3D FEM is used to check whether 2D equivalent model reflects the magnetic characteristics of the actual machine. Initially, 2D equivalent model of the claw-pole type generator is designed only by 3D geometry. Using 2D equivalent model, back emf characteristics are estimated and compared to measurements. The analysis results agree with measurements well and take less time comparing to 3D FEM.

• Journal of the Korean Chemical Society
• /
• v.18 no.4
• /
• pp.267-271
• /
• 1974

The tetradentate schiff base, N,N'-bis(salicylaldehyde)-ethylene diimine has been reacted with a series of Mo(IV), Mo(V), Mo(IV), and Mo(III) oxidation states to form new Complexes; $[MoO_2(C_{16}H_{14}O_2N_2)], (MoO(C_{16}H_{14}O_2N_2)]_2O, (Mo(SCN)(C_{16}H_{14}O_2N_2)]_2O, and (Mo(H_2O)(C_{16}H_{14}O_2N_2)]_2O.$ These complexes have hexa coordinated configurations and the mole ratio of these ions to the ligand was 1:1. These complexes have been identified by visible spectra, infrared specra, T.G.A., D.T.A., and elemental analysis.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.5
• /
• pp.1361-1367
• /
• 2010

A series of O,O-dialkyl-1-phenoxyacetoxy-1-methylphosphonate analogues (1~22) as a new class of potent inhibitors of pyruvate dehydrogenase were synthesized and 3D-QSARs (three dimensional qantitative structure-activity relationships) models on the pre-emergency herbicidal activity against the seed of cucumber (Cucumus Sativa L.) were derived and discussed quantitatively using comparative molecular field analysis (CoMFA) and comparative molecular similarity indeces analysis (CoMSIA) methods. The statistical values of CoMSIA models were better predictability and fitness than those of CoMFA models. The inhibitory activities according to the optimized CoMSIA model I were dependent on the electrostatic field (41.4%), the H-bond acceptor field (26.0%), the hydrophobic field (20.8%) and the steric field (11.7%). And also, it was found that the optimized CoMSIA model I with the sensitivity to the perturbation ($d_q{^{2'}}/dr^2{_{yy'}}$ = 0.830) and the prediction ($q^2$ = 0.503) produced by a progressive scrambling analyses were not dependent on chance correlation. From the results of graphical analyses on the contour maps with the optimized CoMSIA model I, it is expected that the structural distinctions and descriptors that subscribe to herbicidal activities will be able to apply new an herbicide design.