• Natural Product Sciences
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• v.6 no.4
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• pp.193-198
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• 2000

Phytochemical study of the constitutive polyphenolics of the flower aqueous alcohol extract of Tamarix tetragyna was carried out. The new sulphated flavonol, quercetin 3',4'-dimethyl ether $3-O-KSO_3$ as well as the new natural galloyl glucose, $2-O-galloyl-({\alpha}/{\beta})-^4C_1-glucopyranose$ were isolated and characterized. The known sulphated flavonols, kaempferol 7,4-dimethyl ether $3,5-di-O-KSO_3$, quercetin 7-methyl ether $3,3',4'-tri-O-KSO_3$, quercetin 7,4'-dimethyl ether $3-O-KSO_3$ and quercetin $3-O-KSO_3$ and the known sulphated phenolics, isoferulic acid $3-O-KSO_3$ and ellagic acid 4,4'-dimethyl ether $3-O-KSO_3$ were also separated and identified. The structures were established by conventional methods of analysis and confirmed by $^1H-,\;^{13}C-NMR$ and negative ESI-mass spectrometry. 2D-homonuclear chemical shift correlation NMR experiment was applied for the new natural galloylglucose.

• Polymer(Korea)
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• v.39 no.2
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• pp.287-292
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• 2015

Characterization of a series of bio-based terpolymers containing various amounts of ethylene glycol, 1,4-cyclohexylene dimethanol, and isosorbide units were studied by $^1H$ NMR and $^{13}C$ NMR. The NMR results revealed that they had all random microstructures and that their sequence distribution was affected by the content of isosorbide. From DSC data for the terpolymer series investigated, it was observed that the glass transition temperature increased mainly as the content of isosorbide increased. The glass transition temperatures of terpolymers were estimated from the composition by extended Fox equation.

• Korean Journal of Pharmacognosy
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• v.25 no.3
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• pp.209-213
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• 1994

For the investigation of medicinal resources from Taraxacum species, the studies were carried out to evaluate the pharmaco-constituents in the aerial part of Taroxacum hallaisanensis, an endemic plant of Korea. From BuOH fraction of the MeOH extract, compound 1 (protocatechuic acid, $C_7H_6O_4,\;3,4-dihydroxy\;benzoic\;acid)$, compound 2 $[C_{22}H_{31}O_6,\;luteolin-7-O-{\alpha}-_L-rhamnopyranosyl(1{\rightarrow}6)-{\beta}-_D-glucopyranoside]$, and compound 3 $[C_{15}H_{20}O_6,\;luteolin-7-O-{\beta}-_D-glucopyranoside]$ were isolated by column chromatographic separation using polyamide and ODS-gel. The structures were elucidated by means of physico-chemical evidences($^1H-NMR,\;{12}^C-NMR$, IR, EI-Mass, FAB-Mass and GC).

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1537-1541
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• 2006

The $^1H$ and $^{13}C$ chemical shifts of eleven flavone derivatives were completely determined by basic 1D and 2D NMR experiments. Nineteen flavone derivatives including the above eleven derivatives were examined for anti-oxidative effects using the 1,1-diphenyl-2-picryl-hydrazyl assay and Caenorhabditis elegans. In order to understand the relationships between the structures of flavone derivatives and their anti-oxidative activities, a Comparative Molecular Field Analysis was performed.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.2
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• pp.441-445
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• 2005

Tripterygium regelii has been used as an oriental medicine, especially antiparasitic, anti-inflammatory and detoxifying agents in East asia. During our research to develop new antitumor agents from natural products, MeOH ext. and CH2Cl2 ext. of Tripterygium regelii showed the potent antitumor activity. In order to purify active compounds from Tripterygium regelii, activity-guided fractionation was carried out. Silica gel and RP-18 column chromatography for the active fraction led to the isolation of two compounds and their antitumor activities were studied. Those two compounds didn't show potent antitumor activity against human tumor cell lines. The structure of two compounds were determined by $^1H-NMR$, $^{13}C-NMR$, DEPT, $^1H-^{13}C$ COSY and IR spectrum. Compound I and Compound II were turned out to be Celastrol, and ${\beta}-sitosteryl-3-o-{\beta}-D-glucopyranoside$ respectively.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.1027-1029
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• 2011

Two new phenolic glycosides were isolated from the rhizomes of Curculigo orchioides Gaertn.. Based on comprehensive spectroscopic analyses including IR, MS, 1D- and 2D NMR (COSY, HSQC, and HMBC), their structures were elucidated as 3-hydroxyl-5-methyphenol-1-O-[${\beta}$-D-glucopyranosyl-($1{\rightarrow}3$)-${\beta}$-D-glucopyranoside (1) and 1',3'-dimethoxyl-4-hydroxyalangifolioside (2).

• Archives of Pharmacal Research
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• v.21 no.5
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• pp.618-620
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• 1998

Four thymol derivatives, 2,5-dimethoxythymol (1), 2-methoxythymol isobutyrate (2), 10-isobutyloxy-8,9-epoxythymolisobutyrate (3) and 10-(2-methylbutyloxy)-8,9-eposythymolisobutyrate (4) were isolated from the aerial parts of Carpesium divaricatum. the structures were elucidated by high field 1D and 2D NMR techniques.

• Natural Product Sciences
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• v.19 no.3
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• pp.215-220
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• 2013

Three C-glucosyl flavones (1 - 3), one xanthone (4), and four flavanonols (5 - 8) were isolated by various chromatographic methods from the leaves and stems of Desmodium caudatum (Thunb.) DC. Chemical structures of these compounds were elucidated by 1D and 2D NMR and mass spectroscopy. The compounds were identified as swertisin (1), spinosin (2), 7-methyl-apigenin-6-C-${\beta}$-glucopyranosyl-2"-O-${\beta}$-D-xylopyranoside (3), 1,3,5,6-tetrahydroxyxanthone (4), yokovanol (5), aromadendrin (6), 2'-hydroxy yokovanol (7), and 2'-hydroxy neophellamuretin (8). Compounds 2 - 4 were first isolated from D. caudatum, as well as the spectroscopic data for compound 3.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3425-3428
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• 2011

Apolipoprotein A-I (Apo A-I) is a major component for high density lipoproteins (HDL). A number of mimetic peptides of Apo A-I were screened from the phase-displayed random peptide library by utilizing monoclonal antibodies (A12). Mimetic peptide for A12 epitope against Apo A-I was selected as CPFARLPVEHHDVVGL (pA1). From the BLAST search, the mimetic peptide pA1 had 40% homology with Apo A-I. As a result of the structural determination of this mimotope using homo/hetero nuclear 2D-NMR techniques and NMR-based distance geometry (DG)/molecular dynamic (MD) computations, DG structure had low penalty value of 0.3-0.7 ${\AA}^2$ and the total RMSD was 0.6-1.6 ${\AA}$. The mimotope pA1 exhibited characteristic conformation including a ${\beta}$-turn from Pro[7] to His[11].

• Journal of Magnetics
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• v.2 no.2
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• pp.35-37
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• 1997

A sample of YBa2Cu3O7-x fluorinated by a high temperature (400$^{\circ}C$) gas exchange technique has been investigated by means of 19F NMR (nuclear magneti resonance) measurements in both superconducting and normal state. As a result, behaviors characteristic of the superconductor, including a peculiarity in the spin-lattice relaxation rate (1/T1) around 250 K, were observed.