• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.751-758
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• 2004

The NCS(Non-Cariogenicity Sugar) from Bacillus sp. S-1013 was purified by cold acetone and methanol precipitation, and DEAE-cellulose ion-exchange and Sephadex G-100 column chromatographies, to yield an amorphous yellow syrup. The melting point and $[\alpha]_D^{20}$ were 155-$157^{\circ}C$ and +53, respectively. Instrumental analyses such as FT-IR, $^1H-NMR, and ^{13}C-NMR$ showed that the NCS contained an O-H group, C-H, C=O, $NH_2$, anomeric carbon, anomeric proton, N-acetylgalactose, fucose, and neuramic acid, thus, the NCS was determined to be a trisaccharide of Fuc($1\longrightarrow4$)GalNAc($2\longrightarrow6$) NeuAc.

• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1666-1671
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• 2008

The mite-control activities of materials obtained from Pelargonium graveolens oil against Dermatophagoides farinae and D. pteronyssinus were examined using an impregnated fabric disk bioassay and were compared with those shown by commercial benzyl benzoate and N,N-diethyl-m-toluamide (DEET). Purification of the biologically active constituents from P. graveolens oil was done by silica gel chromatography and high performance liquid chromatography. The structures of the active components were analyzed by EI/MS, $^{1}H$-NMR, $^{13}C$-NMR, $^{1}H-^{13}C$ COSY-NMR, and DEPT-NMR spectra, and were identified as geraniol ($C_{10}H_{18}O$, MW 154.25, trans-3,7-dimethyl-2,6-octadien-l-ol) and $\beta$-citronellol ($C_{10}H_{20}O$, MW 156.27, 3,7-dimethyl-6-octen-l-o1). Based on the $LD_{50}$ values, the most toxic compound was geraniol (0.26${\mu}g/cm^{2}$), followed by $\beta$-citronellol (0.28${\mu}g/cm^{2}$), benzyl benzoate (10.03${\mu}g/cm^{2}$), and DEET (37.12${\mu}g/cm^{2}$) against D. farillae. In the case of D. pteronyssinus, geraniol (0.28${\mu}g/cm^{2}$) was the most toxic, followed by $\beta$-citronellol (0.29${\mu}g/cm^{2}$), benzyl benzoate (9.58${\mu}g/cm^{2}$), and DEET (18.23${\mu}g/cm^{2}$). These results suggest that D. farinae and D. pteronyssinus may be controlled more effectively by the application of geraniol and $\beta$-citronellol than benzyl benzoate and DEET. Furthermore, geraniol and $\beta$-citronellol isolated from P. graveolens could be useful for managing populations of D. farinae and D. pterollyssinus.

• Applied Biological Chemistry
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• v.41 no.7
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• pp.500-504
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• 1998

The enzymatic transgalactosylation of L-ascorbic acid was investigated to synthesize a chemically stable form of L-ascorbic acid by using commercially available ${\beta}-galactosidases$. Among various enzymes examined, Aspergillus oryzae ${\beta}-galactosidase$ was found to be formed the derivative of ascorbic acid in a high yield from ascorbic acid and lactose. The reaction product was isolated by ion exchange chromatography on a $Dowex\;1\;{\times}\;8$ (Cl - form) resin and Toyopearl HW-40S gel chromatography. The product was identified as $6-O-{\beta}-_D-galactopyranosyl-_L-ascorbic\;acid$ on the basis of various experimental results, viz., UV, IR, $^1H-NMR,\;^{13}C-NMR$ and mass spectral data.

• KSBB Journal
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• v.23 no.2
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• pp.153-157
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• 2008

Maca (Lepidium meyenii) has been used as a food and medicine in Peru for thousands of years. More recently a wide array of commercial maca products have gained popularity as dietary supplements with claims of anabolic and aphrodisiac effects. Even though the biologically active principles of maca are not fully known, the lipidic extract of maca tubers containing macamides showed promising physiological activities. In this study, the lipidic extract were collected from maca tubers by using supercritical carbon dioxide ($SCO_2$). Substance estimated as macamide in the extract was isolated and purified by preparative HPLC with recycling system. Two of the purified substance was identified as N-benzyl-5-oxo-6E,8E-octadecadienamide and N-benzylhexadecan amide by LC/MS, $^1H$-NMR and $^{13}C$-NMR analyses.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.107-110
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• 2000

($^{11}$B NMR measurements have been performed on single crystals of LuNi$_2$B$_2$C superconductor to investigate vortex lattice structures and dynamical behavior. The spectrum in the superconducting state is significantly broadened by local field inhomogeneity due to the vortex lattice and the peak point of the spectrum shifts toward low magnetic field due to the imperfect field penetration. The linewidth of the spectrum reflecting local field variation is much smaller than expected for conventional vortex lattices and shows peculiar increase at low temperature. Furthermore, the transverse relaxation rate, 1/T$_2$, probing the slow motion of vortices, exhibits a single peak as temperature decreases. These prominent results highlight significant fluctuation of vortices even for this low T$_c$, and nearly isotropic 3D superconductor.

• Bulletin of the Korean Chemical Society
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• v.18 no.10
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• pp.1090-1093
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• 1997

The solvent effects on the isotropic NMR shifts in conformationally rigid ligands such as quinuclidine, pyridine, and 4-aminopyridine coordinated to the paramagnetic polyoxometalate, [SiW11CoⅡO39]6- (SiW11Co), are reported. For these complexes the ligand exchange is slow on the NMR time scale and pure 1H NMR signals have been observed at room temperature. The signals for the SiW11Co complexes are shifted upfield whe dimethyl sulfoxide-d6 (DMSO) is added to a D2O solution. 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-. It is shown that both the contact and pseudocontact shifts decrease (the absolute values of the pseudocontact shifts increase), when D2O is replaced by DMSO. It is suggested that D2O, a strong hydrogen bond donor, withdraws electron density from [SiW11CoⅡO39]6-, increasing the acidity of the cobalt ion toward the axial ligand. When D2O is replaced by DMSO, the acidity of the cobalt ion in SiW11Co decreases, weakening the Co-N bond. Then both the contact and pseudocontact shifts are expected to decrease in agreement with the observed solvent effects.

• Natural Product Sciences
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• v.22 no.1
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• pp.41-45
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• 2016

Extraction and fractionation of Pulsatilla koreana flowers followed by, repeated open column chromatography for EtOAc and n-BuOH fractions yielded four flavonoid glycosides, namely, astragalin (1), tiliroside (2), buddlenoide A (3), and apigenin-7-O-(3"-E-p-coumaroyl)-glucopyranoside (4). The chemical structures of these flavonoid glycosides were elucidated on the basis of various spectroscopic methods including electronic ionization mass spectrometry (EI-MS), 1D NMR ($^1H$, $^{13}C$, DEPT), 2D NMR (gCOSY, gHSQC, gHMBC), and infrared (IR) spectrometry. This study represents the first report of the isolation of the flavonoid glycosides from the flowers of P. koreana.

• Analytical Science and Technology
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• v.14 no.2
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• pp.191-195
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• 2001

Cucurbitacin D and F, the protostane type triterpenoid of S. sorbifolia, were isolated with chromatograpic method and used as the standard substances for quantitative analysis. The compounds were identified with $^1H$-NMR, FAB-MS and UV spectrophotometer. They were separated on YMC-Pack ODS-AQ(303)[$250{\times}4.6mm$ I.D., $S-5{\mu}m$, 120A] column by HPLC. Cucurbitacin F was detected at 10.73mg/kg in cortex of S. sorbifolia, but cucurbitacin D was not. The compounds were shown to exihibit significant cytotoxicity($ED_{50}$<$0.1{\mu}g/mL$) against several tumor cell lines and acute toxicity(cucurbitacin D: 4.7mg/kg/day, cucurbitacin F: 2.5mg/kg/day) against BDF-1 mouse.

• YAKHAK HOEJI
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• v.35 no.5
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• pp.427-431
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• 1991

A flavonoidal glycoside was isolated from the whole plant of Hydrocotyle japonica(Um belliferae) and identified as quercetin-3-O-$\beta$-D-galactoside quercetin-3-O-$\beta$-D-(hyperoside) (C$_{21}H_{20}O_{12}$.1/3 $H_2O$, yellow needle crystal, m.p. $249~250^{\circ}$, $[\alpha]^{28}_D^{\circ}$$-65.94^{\circ}$ in pyridine) by physicochemical properties and spectroscopic evidences(UV, IR, NMR and Mass etc., in comparison with authentic sample.

• Journal of the Korean Magnetic Resonance Society
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• v.16 no.2
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• pp.162-171
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• 2012

SAV2228 has an OB (Oligomer-Binding)-motif which is frequently used for nucleic acid recognition. To characterize the activity of translation initiation factor-1 (IF-1) from Staphylococcus aureus, SAV2228 was expressed and purified in Escherichia coli. We acquired 3D NMR spectra showing well dispersed and homogeneous signals which allow us to assign 94.4% of all $^1HN$, $^{15}N$, $^{13}C{\alpha}$, $^{13}C{\beta}$ and $^{13}CO$ resonances. We could predict a secondary structure of SAV2228 using TALOS and CSI from NMR data. SAV2228 was consisted of one ${\alpha}$-helix and five ${\beta}$-sheets. The predicted secondary structure, ${\beta}-{\beta}-{\beta}-{\alpha}-{\beta}-{\beta}$, was similar to other bacterial IF-1, but it was not completely same to the eukaryotic one. Assigned NMR peaks and secondary structre prediction can be used for the study on interaction with nucleic acid in the future.