• Journal of Korea Foresty Energy
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• v.21 no.1
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• pp.41-48
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• 2002

The barks of oak trees (Quercus acutissima and Quercus variabilis) were collected, extracted with acetone-$H_2O$ (7:3, v/v), fractionated with hexane, $CH^2C1^2$ EtOAc and -$H_2O$, then freeze dried to give dark brown powder. The EtOAc soluble mixtures of the trees were chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. The structures of isolated compounds were characterized by $^1H$, $^13C$ and 2D-NMR spectroscopy and molecular weights were determined by FAB-MS spectra. The isolated compounds from Quercus acutissima were (+)-catechin, (+)-gallocatechin, gallic acid and taxifolin-3-O-$\beta$-D-glucopyranoside and the compounds from Quercus variahilis (+)-catechin, caffeic acid and taxifolin-3-O-$\beta$-D-glucopyranoside.

• Journal of the Korean Magnetic Resonance Society
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• v.16 no.1
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• pp.1-10
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• 2012

A new scalaran class sesterterpenoid with five known ones was isolated from a marine sponge Smenospongia species collected from the Gageo island, Korea. Chemical structure of all of compounds was determined on the basis of a combination of extensive 1D and 2D NMR experiments and MS data. The new compound exhibited a new functional group on a common scalaran sesterterpene skeleton, identified as 12-deacetoxy-23-deacetoxyscalarin. The compound 1 moderately showed the effect of the activation of AMP-activated protein kinase (AMPK) in L6 myoblast cell.

• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.169-174
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• 1994

Antitumor antibiotic HS-1 was purified from the culture broth of a streptomyces floridae SHS-1372 which had been isolated from soil, by solvent extraction, silica gel column chromatography and gel filtration. It was confirmed that HS-1 was active against gram positive bacteria and cancer cells(K562, P388, MCF-7, HT-29). Through the analysis of UV spectrum, melting point, IR spectrum, FAB-MS, $_{1}$H-NMR, $_{13}$C-NMR, 2D-NMR spectra, HS-1 could be identified sa the actinomycin X$_{2}$ antibiotics containing actinocine chromophore and peptides consisted of threonine, proline, methylvaline, sarcosine, D-valine and 4-ketoproline.

• Journal of the Korean Magnetic Resonance Society
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• v.5 no.2
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• pp.91-98
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• 2001

The $^1$H and $^{13}$ C NMR spectra of chivosazole F from Sorangium cellulosum were completely assigned by a combination of ID and 2D NMR techniques. The configurations of double bonds were confirmed from the ROESY spectra. The stereochemistry at asymmetric carboncenters was partially assigned on the basis of the results of NOE analysis.

• Journal of the Korean Chemical Society
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• v.58 no.5
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• pp.450-455
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• 2014

In the present study, a series of novel N-(1H-benzo[d]imidazol-2-yl)methyl-5-[(hetero)aryl-1,3,4-oxadiazol-2-yl]methanamine (4a-4j) were efficiently synthesized. Condensation of hydrazide derivative 3 with various carboxylic acid derivatives yielded N-[(1H-benzo[d]imidazol-2-yl)methy](5-substituted-1,3,4-oxadiazol-2-yl)methanamine (4a-4j) and compound 5-{[(1H-benzo[d]imidazol-2-yl)methylamino]methyl}-1,3,4-oxadiazole-2-thiol (4k) was obtained on treating hydrazide 3 with carbon disulfide. All the newly synthesized analogues were characterized by IR, $^1H$ NMR, $^{13}C$ NMR and mass spectral data.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.263-263
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• 1994

Annexin I is a member of the in family of calcium dependent phospholipid banding proteins and is an in vitro phospholipase $A_2$ (PLA$_2$) inhibitor. The mechanism of PLA$_2$ inhibition by annexin I is still ambiguous. The structure of annexin I was studied at the atomic level by using nuclear magnetic resonance (NMR), circular dichrotsm (CD) and fluorescence spectroscopy. Recombinant human annexin I and N-terminally truncated annexin I (1-31 deleted: d-annexin I) were purified and their NMR spectra were compared. The NMR spectra of the two were similar. When $Ca^{2+}$ ion added to annexin I ad d-annexin I, peak broadening occurred, but no significant spectroscopic change was observed. When porcine pancreatic PLA$_2$ was added to deuterium labeled annexin I, an interaction of annexin I with PLA$_2$ was observed as indicated by the disappearance and shift of several peaks in the NMR spectrum. This result supports a protein-protein interaction mechanism for PLA$_2$ inhibition by annexin I.I.

• Journal of the Korean Chemical Society
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• v.36 no.5
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• pp.685-691
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• 1992

The $d^8$-transition metal complexes containing diphosphine, $MCl_2PP$ were prepared by using $K_nMCl_m$ as starting materials, wherein M were Ni(II), Pd(II), Pt(II) and Au(III) and PP were bis(diphenylphosphino)methane(dppm), bis(diphenylphosphino)ethane(dppe), bis(diphenylphosphino)propane (dppp) and bis(diphenylphosphino)ethylene(dppety). The complexes were characterized by the spectral property $(^H-NMR$, $^{31}P-NMR$ and UV-Visible spectra) together with elemental analysis. The complexes were tested for the catalytic activity on the formation reactions of 3(2H)-furanone and cyclic carbonate. The only Ni(II)- and Pd(II)-diphosphine complexes displayed a good catalytic effects in the production of 3(2H)-furanone from 2-methyl-3-butyn-2-ol [reaction (1)]. But all the diphosphine complexes as catalyst were almost inactive towards cyclic carbonate production preaction [reaction (2)].

• Bulletin of the Korean Chemical Society
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• v.19 no.5
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• pp.519-524
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• 1998

In this work, we applied the 1D 11B nutation NMR method for the analysis of the local structural environments in powdered borosilicates (SiO2-B2O3). Spin dynamics during a rf irradiation for spin I=3/2 was analytically calculated with a density matrix formalism. Spectral simulation programs were written in MATLAB on a PC. Two borosilicates prepared by the sol-gel process at different stabilization temperature were used for the 1D 11B nutation NMR experiment. The 11B NMR parameters, quadrupole coupling constants (e2qQ/h) and asymmetry parameters (η), for each borosilicate were extracted from the nonlinear least-squares fitting. The effects of heat treatments on the local structures of boron sites in borosilicates were discussed.

• Journal of Applied Biological Chemistry
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• v.58 no.3
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• pp.233-236
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• 2015

The flowers of Magnolia obovata were extracted with aqueous MeOH and fractionated into EtOAc, n-BuOH, and $H_2O$ fractination. Three alkyl glycosides were isolated from the EtOAc fraction through repeated silica gel and ODS column chromatography. The structures were identified to be 2-methylbutan-1-ol-${\beta}$-$\small{D}$-galacto-pyranoside (1), 2-methylbutan-1-ol-${\beta}$-$\small{D}$-glucopyranoside (2), and 2-methylpropan-1-ol-${\beta}$-$\small{D}$-glucopyranoside (3) on the basis of spectroscopic analyses such as fast atom bombardment mass spectrometry, infrared spectroscopy, 1D nuclear magnetic resonance (NMR) ($^1H$ and $^{13}C-NMR$), and 2D NMR (gCOSY, gHSQC, and gHMBC). These compounds were isolated for the first time from the flower of M. obovata in this study.

• Bulletin of the Korean Chemical Society
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• v.14 no.5
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• pp.588-592
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• 1993

The $^1H-NMR$ signals of the heme methyl, propionate and related chemical groups of cytochrome $c_3$ from Desulfovibrio vulgaris Miyazaki F (D.v. MF) were site-specifically assigned by means of 1D-NOE, 2D-DQFCOSY and 2D-TOCSY spectra. They were consistent with the site-specific assignments of the hemes with the highest and second-lowest redox potentials reported by Fan et al. (Biochemistry, 29, 2257-2263 1990). The site-specific heme assignments were also supported by NOE between the methyl groups of these hemes and the side chain of Val-18.