• Title/Summary/Keyword: $^1H-NMR$

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Complete Assignment of $^{1}H$ and $^{13}C$-NMR Signals for (20S) and (20R)-Protopanaxadiol by 2D-NMR Techniques (2D-NMR 기법을 이용한 (20S)와 (20R)-Protopanaxadiol의 $^{1}H$- 및 $^{13}C$-NMR 완전 동정)

  • 백남인;김동선
    • Journal of Ginseng Research
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    • v.19 no.1
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    • pp.45-50
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    • 1995
  • (20S)- and (20R)-protopanaxadiol were prepared from crude ginseng saponin by chemical treatment. The $^{1}H$- and $^{13}C$-NMR signals of these compounds were fully assigned by various NMR techniques such as DEPT, 1H-1H COSY, HMQC, HMBC and NOESY.

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Comparative analysis of glycerin in cosmetics by LC/MS and 1H NMR (LC/MS와 1H NMR을 이용한 화장품속의 글리세린 비교분석)

  • Park, Gyo-Beom;Park, Chan Jo;Lee, Sueg-Geun
    • Analytical Science and Technology
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    • v.20 no.5
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    • pp.400-405
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    • 2007
  • The comparative analysis of glycerin in cosmetic samples was carried out by LC/MS and $^1H$ NMR spectrometry. For the LC/MS analysis, aqueous solution was controlled in strong basic condition with sodium hydroxide, and benzoyl chloride was added to the solution for the derivatization of glycerin. The derivative was extracted using pentane and analyzed by the LC/MS. For the $^1H$ NMR analysis, sample was directly dissolved in $D_2O$ solvent without pretreatment. The quantitative analysis of glycerin was done by $^1H$ NMR ERETIC method. The analysis results of LC/MS and $^1H$ NMR showed that the calibration curves were a good linearity with $r^2=0.9991$ in the range of 0.1 to $10{\mu}g/mL$ and $r^2=1$ in the range of 25 to $500{\mu}g/mL$, respectively.

Complete Assignment of $^1H$- and $^{13}C-NMR$ in (20R)-panaxadiol and (20R)-panaxatriol ((20R)-파낙사디올과 (20R)-파낙사트리올에 대한 $^1H$- 및 $^{13}C-NMR$의 완전동정)

  • Kim, Dong-Seon;Baek, Nam-In;Park, Jong-Dae;Lee, You-Hui;Kim, Shin-Il
    • YAKHAK HOEJI
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    • v.40 no.3
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    • pp.293-299
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    • 1996
  • The $^1H$- and $^{13}C$-NMR signals of (20R)-panaxadiol and (20R)-panaxatriol were completely assigned by the extensive application of modern 2D-NMR techniques, $^1H-^1H$ COSY, HMQC and HMBC.

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Analytical Study for an Acrylic Coating (아크릴 코팅의 성분 분석 연구)

  • Kim, Seog-Jun
    • Analytical Science and Technology
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    • v.17 no.2
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    • pp.98-107
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    • 2004
  • In this study, $^1H$ NMR spectroscopy and HPLC were used to identify the type and quantity of each component in an acrylic coating materials applied for an automotive part. By the $^1H$ NMR analysis, it was found that this acrylic coating contained about 88.40 wt% of poly methyl methacrylate (PMMA), 7.05 wt% of methyl methacrylate (MMA), and 2.36 wt% of allyl methacrylate. Polymer additives such as a benzotriazole light stabilizer (Hisorb 328), an oxanilide light stabilizer, butylated hydroxy toluene (BHT), and dimethyl phthalate (DMP) were also identified and measured quantitatively from the $^1H$ NMR spectra. However, only two light stabilizers were identified by reverse phase (RP) HPLC analysis using Bondapak C18 column, methanol mobile phase, and a PDA (Photodiode array) detector. The contents of two light stabilizers in the acrylic coating were measured by a quantitative analysis through UV-Vis spectroscopy and compared with the NMR data. The analytical informations from $^1H$ NMR spetra were better than those from HPLC-PDA plot.

Complete Assignment of $^1H-$ and $^{13}C-NMR$ Signals for (20S)- and (20R)-ginsenoside $Rh_2$ by 2D-NMR Techniques (2D-NMR 기법을 이용한 (20S)-와 (20R)-ginsenoside $Rh_2$$^1H-$$^{13}C-NMR$ Signals의 완전 동정)

  • Kim, Dong-Seon;Lee, You-Hui;Park, Jong-Dae;Jeong, So-Young;Lee, Chun-Bae;Kim, Shin-Il;Baek, Nam-In
    • Applied Biological Chemistry
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    • v.38 no.2
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    • pp.184-189
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    • 1995
  • (20S)- and (20R)-Ginsenoside $Rh_2$ were prepared from crude ginseng saponin by chemical treatments. The $^1H-$ and $^{13}C-NMR$ signals of these compounds were fully assigned by various NMR techniques such as DEPT, $^1H-^1H$ COSY, HMQC, HMBC and NOESY.

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Ferroelectric-Paraelectric Phase Transition of CsH2PO4 studied by Static NMR and MAS NMR

  • Lim, Ae Ran;Lee, Kwang-Sei
    • Journal of the Korean Magnetic Resonance Society
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    • v.19 no.1
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    • pp.29-35
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    • 2015
  • The microscopic dynamics of $CsH_2PO_4$, with two distinct hydrogen bond lengths, are studied by static nuclear magnetic resonance (NMR) and magic angle spinning (MAS) NMR. The proton dynamics of the two crystallographically inequivalent hydrogen sites were discussed in terms of the $^1H$ NMR and $^1H$ MAS NMR spectra. Although the hydrogen bonds have two inequivalent sites, H(1) and H(2), distinct proton dynamics for the two sites were not found. Further, the $^{133}Cs$ spectrum is more or less continuous near $T_{C1}$ (=153 K). Finally, the phase transition mechanism of $T_{C1}$ in $CsH_2PO_4$ is related to the ordering of protons.

Quantitative Analysis of Quality Control of Natural Medicine by $^1H-NMR$ Spectrometry-Quantitative Analysis of Hesperidin from Citrus unshiu ($^1H-NMR$을 이용한 한약재의 품질 평가 방법 확립;진피의 Hesperidin 정량분석)

  • Ahn, Eun-Mi;Baek, Mi-Young
    • The Korea Journal of Herbology
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    • v.23 no.3
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    • pp.27-32
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    • 2008
  • Objectives : In this paper, we describe that $^1H-NMR$ spectroscopy may be superior to the conventional HPLC for the quantitative analysis of hesperidin from Citrus unshiu. Methods : $^1H-NMR$ spectra (400 MHz) were recorded in $DMSO-d_6$ using a Varian UNITY Inova AS 400 FT NMR spectrometer. One hundred milligram of powdered Citrus unshiu was weighed out and mixed with 1 ml of $DMSO-d_6$ with sonication for 30 min (room temperature). The extracts were filtrated through a 0.45 ${\mu}m$ PVDF filter and 0.5 ml of filtrated extract used for quantitative $^1H-NMR$ measurement (added 1 mg of dimethyl terephthalate as internal standard). The quantity of hesperidin was calculated by the ratio of the intensity of the compound to the known amount of internal standard. For HPLC analysis, the half gram of plant material was extracted with 60 ml of MeOH for 2 hours. The extracts were made 100 ml volume and analyzed by a Waters HPLC system using a YMC ODS column. The total flow rate was 1.0 ml/min with a sample volume 10 ${\mu}l$ and UV detection at 280nm. Results : The contents of hesperidin in Citrus unshiu was determined $5.33{\pm}0.06$% in the quantitative $^1H-NMR$ method and $5.15{\pm}0.12%$ in HPLC method. Using the quantitative $^1H-NMR$ the contents of hesperidin can be determined in much shorter time than the conventional HPLC measurements. Conclusions : From those results, the advantages of quantitative $^1H-NMR$ analysis are that can be analyzed to identify and quantify, and no reference compounds required for calibration curve. Besides, it allows rapid and simple quantification for hesperidin with an analysis time for only 10 min without any pre-purification steps.

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Metabolic Discrimination of Safflower Petals of Various Origins Using 1H NMR Spectroscopy and Multivariate Statistical Analysis

  • Whang, Wan-Kyun;Lee, Min-Won;Choi, Hyung-Kyoon
    • Bulletin of the Korean Chemical Society
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    • v.28 no.4
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    • pp.557-560
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    • 2007
  • The metabolic discrimination of safflowers from various geographical origins was performed using 1H nuclear magnetic resonance (NMR) spectroscopy followed by principal components analysis. With a combination of these techniques, safflower samples from different origins could be discriminated using the first two principal components (PC) of the 1H NMR spectra of the 50% methanol fractions. PC1 and PC2 accounted cumulatively for 91.3% of the variation in all variables. The major peaks in the 1H NMR spectra that contributed to the discrimination were assigned to fatty acid (terminal CH3), lactic acid, acetic acid, choline derivatives, glycine, and safflower yellow derivatives. In this study, we suggest that various types of safflower can be discriminated using PCA and 1H NMR spectra.

Structural characteristics of [N(CH3)4]2CdCl4 determined by 1H MAS NMR, 13C CP/ MAS NMR, and 14N NMR

  • Lee, Seung Jin;Lim, Ae Ran
    • Journal of the Korean Magnetic Resonance Society
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    • v.19 no.1
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    • pp.18-22
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    • 2015
  • The structural geometry of $[N(CH_3)_4]_2CdCl_4$ in a hexagonal phase is studied by $^1H$ MAS NMR, $^{13}C$ CP/MAS NMR, and $^{14}N$ NMR. The changes in the chemical shifts for $^{13}C$ and $^{14}N$ in the hexagonal phase are explained by the structural geometry. In addition, the temperature dependencies of the spin-lattice relaxation time in the rotating frame $T_{1{\rho}}$ for $^1H$ MAS NMR and $^{13}C$ CP/MAS NMR are measured.

Multivariate Analysis on 1H-NMR Spectroscopy of Olive Flounder Paralichthys olivaceus Serum (1H-NMR 스펙트럼의 다변량통계분석을 통한 넙치(Paralichthys olivaceus)의 백신 반응의 지표물질 분석)

  • Cho, Ji-Young
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.45 no.4
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    • pp.367-371
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    • 2012
  • To investigate the relationship between metabolic changes in $^1H$-nuclear magnetic resonance (NMR) spectra and fish vaccination, serum was collected from olive flounders treated with a formalin-killed Edwardsiella tarda vaccine and used for $^1H$-NMR metabolite profiling. Principal component analysis and partial least squares were applied to the $^1H$-NMR profile to reduce its complexity and establish class-related clusters. Relative lipid regions were distinguished in vaccinated and non-vaccinated serum. Then, the lipids were extracted from the serum and analyzed. Triolein was identified.