• Journal of Ginseng Research
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• 제19권1호
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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.

• 분석과학
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• 제20권5호
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• pp.400-405
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• 2007

액체크로마토그래피/질량분석법(LC/MS) 및 핵자기공명분광분석법 $^1H(NMR)$을 이용하여 화장품에 들어있는 글리세린을 동시 비교분석하였다. 화장품 시료를 물에 용해시키고 수산화나트륨을 첨가하여 시료용액을 강알칼리 상태로 유지시킨 후, 시료용액 중의 글리세린을 benzoyl chloride로 유도체화 반응 시키고 유도체화된 글리세린을 pentane으로 추출하여 LC/MS로 정량분석 하였다. $^1H$ NMR 분석은 시료를 전처리 없이 $D_2O$ 용매에 직접 용해시키고, 글리세린을 ERETIC(Electronic REference To access In vivo Concentrations) 방법을 이용하여 $^1H$ NMR로 직접 정량분석 하였다. LC/MS 및 NMR 분석결과 LC/MS의 검량선은 $0.1-10{\mu}g/mL$ 농도범위에서 $r^2=0.9991$ 이었고 $^1H$ NMR의 검량선은 $25-500{\mu}g/mL$ 농도범위에서 $r^2=1$의 상관계수를 갖는 좋은 직선성을 얻었다.

• 분석과학
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• 제17권2호
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• pp.98-107
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• 2004

본 연구에서는 $^1H$ NMR 분광분석법 및 HPLC를 이용하여 자동차 부품에 사용된 아크릴 코팅의 성분 및 함량을 분석하였다. $^1H$ NMR 분석 결과 아크릴 코팅은 88.40 wt%의 PMMA, 7.05 wt%의 MMA 및 2.36 wt%의 allyl methacrylate를 포함하고 있다. 또한, 고분자 첨가제로 벤조트리아졸 (Hisorb 328) 및 oxanilide 광안정제, BHT 및 DMP가 $^1H$ NMR 스펙트럼에서 확인되었고 정량적으로 측정되었다. 그러나, Bondapak C18 칼럼, 메탄올 이동상, PDA 검출기를 사용한 역상 HPLC 분석을 통해서는 두개의 광안정제만이 확인되었다. 두 광안정제의 함량은 UV-Vis 흡광광도계를 이용한 정량분석법을 통해 측정되고 NMR 분석 결과와 비교하였다. $^1H$ NMR 스펙트럼으로부터 얻은 분석 정보들이 HPLC에서 얻는 것들 보다 우수하였다.

• 약학회지
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• 제40권3호
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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.

• Applied Biological Chemistry
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• 제38권2호
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• pp.184-189
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• 1995

인삼의 다이올계 조사포닌 분획으로 부터 및 단계의 화학반응을 이용하여 (20S)-ginsenoside $Rh_2$ 및 그 입체이성체인 (20R)-ginsenoside $Rh_2$를 제조하였다. 또한 DEPT, $^1H-^1H$ COSY, HMQC, HMBC 및 NOESY와 같은 NMR 기법을 이용하여 두 화합물의 $^1H-NMR$과 $^{13}C-NMR$의 signal들을 완전히 동정하였다.

• 한국자기공명학회논문지
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• 제19권1호
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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.

• 대한본초학회지
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• 제23권3호
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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.

• Bulletin of the Korean Chemical Society
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• 제28권4호
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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.

• 한국자기공명학회논문지
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• 제19권1호
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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.

• 한국자기공명학회논문지
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• 제21권2호
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• pp.67-71
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• 2017

At high temperature, the roles of $NH_4$ and $H_2O$ in $(NH_4)_2Fe(SO_4)_2{\cdot}6H_2O$ and $(NH_4)_2Zn(SO_4)_2{\cdot}6H_2O$ single crystals were investigated using a pulse NMR spectrometer. Temperature was shown to have a significant influence, causing changes in the deformation of $NH_4$ and $H_2O$. From the $^1H$ NMR and $^{14}N$ NMR spectrum, the forms of environment surrounding $^{14}N$ in $NH_4$ groups is more important than the loss of $H_2O$ groups. NMR studies indicate that $NH_4{^+}$ ions in Tutton salts play an important role in the changes of the crystal structure at high temperatures.