• Title/Summary/Keyword: $^{2}H$-NMR spectra

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The Preparation and its Chemical Properties of Palladium Complexes with a series of Cycloamine (Cycloamine 계의 팔라듐 착물의 합성과 그 화학적 성질)

  • Sang-Oh Oh;Duck-Young Chung
    • Journal of the Korean Chemical Society
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    • v.29 no.4
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    • pp.406-413
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    • 1985
  • We synthesized Pd(II) complexes containing sulfoxide and cycloamine series on the basis of the fact that many workers had the foresight to suggest anticancer activites using Pd(II) complexes with sulfur, nitrogen, or nucleic acid relatives as ligands particulary. The identification and characterization of these complexes are followed; content rates of atoms and molecular weights are confirmed by Elemental Analysis and Mass spectra, bonding of metal and ligands by UV-Vis. spectra and NMR spectra, and donor sites of ligands and configuration of complexes by IR spectra. These are yellow crystals, soluble in methanol and chloroform, and insoluble in H2O and the other common organic solvents.

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Structural and Chemical Characterization of Aquatic Humic Substances in Conventional Water Treatment Processes (재래식 정수처리 공정에서 수질계 휴믹물질의 구조 및 화학적 특성분석)

  • Kim, Hyun-Chul;Yu, Myong-Jin
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.1
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    • pp.11-16
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    • 2005
  • Humic substances(HS) from raw and process waters at a conventional water treatment plant were isolated and extracted by physicochemical fractionation methods to investigate their characteristics. They are characterized for their functionality, chemical composition, and spectroscopic characteristics using FT-IR(Fourier transform infrared) and $^1H-NMR$(proton nuclear magnetic resonance) spectroscopy. Humic fraction gradually decreased from 47.2% to 26.4%(from 0.97 to 0.54 mgC/L) through conventional water treatment processes. Concentration of phenolic groups in the HS fraction gradually decreased from 60.5% to 21.8%(from 12.2 to $6.0\;{\mu}M/L$ as phenolic-OH) through water treatment. In the case of carboxylic groups, the concentration increased from 39.5% to 46.9%(from 7.9 to $10.6\;{\mu}M/L$ as COOH) by pre-chlorination, but gradually decreased to 34.2%($9.4\;{\mu}M/L$ as COOH) through sedimentation and sand filtration. From the results of the FT-IR and $^1H-NMR$ spectra of HS, the content of carboxylic groups increased and ratio of aliphatic protons to aromatic protons($P_{Al}/P_{Ar}$) also increased through water treatment, which indicated the increase of aliphatic compounds.

Preponderant Occurrence of sl natural methane hydrates: Spectroscopic analysis of crystalline structure transition (sI 천연 메탄하이드레이드의 존재 : 결정구조 변화의 분광학적 분석)

  • Yeon, Sun-Hwa;Seol, Ji-Woong;Lee, Huen
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.387-390
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    • 2006
  • We report here that under strong attacksof external $CH_4$ guest molecules the sII and sH methane hydrates are structurally transformed to the crystalline me framework of sI, leading to favorable change of the lattice dimension of the host-guest networks. The High Power Decoupling $^{13}C$ NMR and Raman spectroscopies were used to identify structure transitions of the mixed $CH_4+C_2H_6$ hydrates (sIIl) and hydrocarbons (methylcyclohexane, isopentane) + $CH_4$ hydrates (sH). The resulting spectra indicate that most of the synthesized sII and sH hydrates were transformed to methane hydrate of sl under 110 bar and particularly the coexistence of sl with sII or sH appear according to the surrounding methane-rich gas conditions. The present findings might be expected to Provide rational evidences regarding the preponderant occurrence of naturally-occurring sI methane hydrates in marine sediments.

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Proteasome Inhibition Activity of Hericium erinaceum (노루궁뎅이 버섯의 Proteasome 저해 작용)

  • Lee, Han-Na;Kim, Yu-Jin;Shim, Sang-Hee
    • Korean Journal of Pharmacognosy
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    • v.39 no.4
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    • pp.365-368
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    • 2008
  • Recently proteasome inhibitors have been emerged as potential anticancer agents. In a continuous study on exploring proteasome inhibitors from natural products, fruiting body of Hericium erinaceum was investigated. The MeOH extracts of the fruiting body of Hericium erinaceum was fractionated with several solvents and the fractions were evaluated on the activity to screen the proteasome inhibitors. The n-Hexane and CHCl3 frs. showed potent activity, of which chemical investigations led to ergosterol peroxide (1), hericenones C (2) and D (3). Their structures were determined by spectroscopic methods such as $^1H$-NMR, $^{13}C$-NMR, and FABMS spectra.

Isolation and Characterization of Soil Humic Substances (토양 부식질의 추출 및 특성)

  • 신현상;이창훈;유지호;정근호;이창우
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2002.09a
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    • pp.191-194
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    • 2002
  • Humic acid, fulvic acid and humin present in volcanic ash soil were isolated by IHSS standard procedure and their characteristics were analyzed as a basic study to evaluate the effect of humic substances on the behaviour of pollutants in contaminated surface soil. The volcanic ash soil contained 42.1 % of total organic matter based on the oven-dried soil, and humin, humic and fulvic acids corresponded to 67.5 %, 15.2 %, 7.6 % of TOM respectively. Structural informations of the humic fractions were obtained from their elemental analysis and IR, CPMAS C-13 NMR spectral analysis and the differences among them are discussed with their C/H, O/C ratios and distributions of carbon types in the molecules.

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Enzymatic Synthesis of Vanillin-a -Glucoside and Ethyl Vanillin-a -Glucoside (효소적 방법에 의한 Vanillin-$\alpha$ -Glucoside 및 Ethyl Vanillin-$\alpha$ -Glucoside의 합성)

  • 김삼곤;김근수;나도영;김영회
    • Journal of the Korean Society of Tobacco Science
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    • v.25 no.2
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    • pp.120-127
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    • 2003
  • Cyclodextrin glucanotransferase (CGTase) from Bacillus stearothermophilus synthesized vanillin and ethyl vanillin monoglucoside, with a series of its maltooligoglucosides by transglycosylation with dextrin as a donor, and vanillin or ethyl vanillin as an acceptor. The monoglucoside formed from reaction mixture of vanillin or ethyl vanillin by the successive actions of CGTase and Rhizopus glucoamylase was isolated by extraction with n-butanol saturated with water and silica gel column chromatography. The structure of the isolated monoglucoside was identified as vanillin- $\alpha$ -D-glucoside and ethyl vanillin- $\alpha$ -D-glucoside, respectively, by FAB-MS, UV, IR, 1H-NMR, 13C-NMR spectra and products by hydrolysis with acid, $\alpha$ - and $\beta$ -glucosidases.

Novel Antioxidants, Stc-l and Stc-2, from Stereum ostrea

  • Kim, Young-Hee;Yun, Bong-Sik;Kim, Jong-Pyong;Moon, Suk-Sik;Yoo, Ick-Dong
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1998.11a
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    • pp.131-131
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    • 1998
  • In the course of screening for new natural compounds having antioxidant activity from microbials, mushrooms as well as plants. We have isolated novel sesquiterpenoid and officinalic acid from methanolic extracts of Stereum ostrea. The dried fruit body( 450 g) of Stereum ostrea was extracted with methanol, then methanolic extract was partitioned between water and hexane, chloroform, and ethyl acetate, subsequently. The chloroform extract was subjected on silica gel, Sephadex LH-20 and RP-18 column chromatography, successively. And two compounds were isolated and identified as new triterpenoids and officinalic acid using $^1$H - NMR, $\^$13/C - NMR as well as Mass spectra.

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Enzymatic Synthesis of Maltol-$\alpha$-Glucoside and Ethyl Maltol-$\alpha$-Glucoside (Maltol-$\alpha$-Glucoside 및 Ethyl Maltol-$\alpha$-Glucoside의 효소적 합성)

  • 김삼곤;김근수;김영회
    • Journal of the Korean Society of Tobacco Science
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    • v.24 no.2
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    • pp.94-100
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    • 2002
  • Cyclodextrin glucanotransferase from Bacillus stearothemophilus and Bacillus macerans synthesized maltol and ethyl maltol monoglucoside, with a series of its maltooligo-glucosides by transglycosylation with dextrin as a donor, and maltol or ethyl maltol as an acceptor. The monoglucoside formed from reaction mixture of maltol or ethyl maltol by the successive actions of Bacillus stearothemophilus cyclodextrin glucanotransferase and Rhizopus glucoamylase was isolated by Diaion HP-20 column and silica gel column chromatography. The structure of the isolated monoglucoside was identified as maltol-$\alpha$-D-glucoside and ethyl maltol-$\alpha$-D-glucoside, respectively, by FAB-MS, UV, $^1$H-NMR, $^{13}$ C-NMR spectra and products by hydrolysis with acid, $\alpha$ - and $\beta$ -glucosidases.

Effects of Axial Ligand Basicity on the Isotropic NMR Shifts in Pyridine-Type Ligands Coordinated to the Paramagnetic Polyoxometalate, $[SiW_{11}Co^{11}O_{39}]^{6-}$

  • 김지영;박석민;소현수
    • Bulletin of the Korean Chemical Society
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    • v.18 no.4
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    • pp.369-373
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    • 1997
  • When 1H NMR spectra of pyridine, 4-amino-, 4-methyl-, and 4-cyanopyridine coordinated to the paramagnetic polyoxometalate, [SiW11CoⅡO39]6- in D2O are compared, both α- and β-proton peaks are shifted upfield as the basicity of the ligand decreases. The isotropic shifts are separated into contact and pseudocontact contributions by assuming that the contact shifts are proportional to the isotropic shifts of the same ligands coordinated to [SiW11NiⅡO39]6-. This separation reveals that the shift variations with the axial ligand basicity are dominated by changes in the magnetic anisotropy (pseudocontact shift) of [SiW11CoⅡ(ptl)O39]6- (ptl=pyridine-type ligand). The magnitude of the magnetic anisotropy in a series of pyridine-type ligands increases linearly as the pKa of their conjugate acids decreases.

Physicochemical Characterization and NMR Assignments of Ginsenosides Rb1, Rb2, Rc, and Rd Isolated from Panax ginseng

  • Cho, Jin-Gyeong;Lee, Min-Kyung;Lee, Jae-Woong;Park, Hee-Jung;Lee, Dae-Young;Lee, Youn-Hyung;Yang, Deok-Chun;Baek, Nam-In
    • Journal of Ginseng Research
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    • v.34 no.2
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    • pp.113-121
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    • 2010
  • The fresh ginseng roots were extracted with aqueous methanol, and the obtained extracts were partitioned using ethyl acetate, n-butanol, and water, successively. The repeated silica gel and octadecyl silica gel column chromatogaraphy for n-butanol fraction afforded four diol ginseng saponins, ginsenosides $Rb_1$, $Rb_2$, $R_c$, and Rd. The physicochemical, spectroscopic, and chromatographic characteristics of these ginsenosides were measured and compared with those reported in the literature. Some of the peak assignments in previously published $^1H$- and $^{13}C$-nuclear magnetic resonance (NMR) spectra were inaccurate. This study employed two-dimensional NMR experiments, including $^1H-^1H$ correlation spectroscopy, heteronuclear single quantum correlation, and heteronuclear multiple bond connectivity, to determine exact peak assignments.