• Korean Journal of Pharmacognosy
• /
• v.34 no.2 s.133
• /
• pp.190-192
• /
• 2003

Anitioxidative activities againt 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical were evaluated for ten diarylheptanoids, $1,7-bis-(3,4-dihydroxyphenyl)-heptane-3-O-{\beta}-D-glucopyranosyl(1{\rightarrow}3)-{\beta}-D-xylopyranoside(1)$, $1,7-bis-(3,4-dihydroxyphenyl)-heptane-3-O-{\beta}-D-apiofuranosyl(1{\rightarrow}6)-{\beta}-D-glucopyranoside(2)$, $1,7-bis-(3,4-dihydroxyphenyl)-heptane-5-O-{\beta}-D-glucopyranoside(3)$, 1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptane(4), $1,7-bis-(3,4-dihydroxyphenyl)-heptane-3-one-5-O-{\beta}-D-glucopyranoside(5)$, oregonin(6), hirsutanonol(7), hirsutenone(8), $1,7-bis-(3,4-dihydroxyphenyl)-5-hydroxyheptane-3-O-{\beta}-D-xylopyranoside(9)$ and platyphylloside(10), which were isolated from Alnus japonica. Aglycones (4,7 and 8) and mono glycosides (3,6 and 9) showed more strong antioxidative activities than diglycosides (1 and 2) against the DPPH radical. Especially, hirsutenone(8) showed superior activity among ten diarylheptanoid.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.25 no.8
• /
• pp.664-669
• /
• 2012

Nano-structured one-dimensional $Na_2Ti_6O_{13}$ particles were synthesized by a molten salt process. Effects of processing parameters on the microstructure and band gap energy of the $Na_2Ti_6O_{13}$ powder were studied in this paper. For the synthesis of the $Na_2Ti_6O_{13}$ particles, two different raw materials of tubular shaped Na-titanate (Na-TiNT) and spherical shaped $TiO_2$ were utilized. Synthesizing with the raw material of Na-TiNT, around 70nm thick 1D-$Na_2Ti_6O_{13}$ with the bandgap energy of 3.5 eV was obtained at $810^{\circ}C$. Below $810^{\circ}C$ or without the presence of NaCl, 1D-$Na_2Ti_6O_{13}$ was in a relatively short in length and agglomerated state. With the processing temperature increased, the thickness of the 1D-$Na_2Ti_6O_{13}$ was also observed to be increased. On the other hand, when $TiO_2$ was employed as a raw material, the mixed amount of $Na_2CO_3$ played an important role in transforming the morphology and phase of the raw material, affecting the bandgap energy of the synthesized product. Specific surface area of the synthesized 1D-$Na_2Ti_6O_{13}$ was significantly affected by the raw and mixed materials as well as processing temperature. When Na-TiNT was processed at $810^{\circ}C$ with NaCl, the specific surface area of the 1D-$Na_2Ti_6O_{13}$ showed the best value of 30.63 $m^2/g$.

• Journal of the Korean Magnetics Society
• /
• v.18 no.2
• /
• pp.67-70
• /
• 2008

$Tb_2Bi_1Ga_xFe_{5-x}O_{12}$(x=0, 1) fabricated by sol-gel and vacuum sealed annealing process. $Tb_2Bi_1Ga_xFe_{5-x}O_{12}$(x=0, 1) have been studied by x-ray diffraction(XRD), vibrating sample magnetometer, and $M\ddot{o}ssbauer$ spectroscopy. The crystal structures were found to be a cubic garnet structure with space group Ia3d. The determined lattice constants $a_0$ of x = 0, and 1 are $12.497\AA$, and $12.465\AA$, respectively. The distribution of gallium and iron in $Tb_2Bi_1Ga_xFe_{5-x}O_{12}$ is studied by Rietveld refinement. Based on Rietveld refinement results, the terbium and bismuth ions occupy the 24c site, iron ions occupy the 24d, l6a site, and nonmagmetic gallium ions occupy the 16a site. In order to verify the magnetic site occupancy of iron and gallium, we have taken $M\ddot{o}ssbauer$ spectra for $Tb_2Bi_1Ga_xFe_{5-x}O_{12}$(x=0, 1) at room temperature. From the results of $M\ddot{o}ssbauer$ spectra analysis, the absorption area ratios of Fe ions for $Tb_2Bi_1Fe_5O_{12}$ on 24d and 16a sites are 60.8 % and 39.2 %, respectively, and the absorption area ratios of Fe ions for $Tb_2Bi_1Fe_5O_{12}$ on 24d and 16a sites are 74.7 % and 25.3 %, respectively. It is noticeable that all of the nonmagnetic Ga atoms occupy the 16a site by vacuum annealing process.

• Journal of the Korean Chemical Society
• /
• v.55 no.4
• /
• pp.638-643
• /
• 2011

The synthesis of biologically active 1H-1,4-diazepines 4a-d and 3H-1,5-benzodiazepines 5a-d in good yields, from the heterocyclization reaction of 2-(4-methylthio benzenesulfonyl)-1,3-dimethyl/1-methyl-3-phenyl/1,3-diphenyl/1-methyl-3-ethoxy propane-1,3-dione 3a-d with ethylenediamine (EDA) and o-phenylenediamine (o-PDA), respectively, in the presence of silica sulfuric acid (SSA) is described. The novel ${\beta}$-diketones/${\beta}$-ketoesters 3a-d were synthesized by the condensation reaction of 4-methylthiobenzenesulfonyl chloride 1 with various ${\beta}$-diketones/${\beta}$-ketoesters 2a-d. All structures of the newly synthesized compounds were elucidated by elemental analysis and spectral studies. The compounds 4a-d and 5a-d have been screened for antimicrobial, antifungal and anthelmintic activity.

• Korean Journal of Medicinal Crop Science
• /
• v.4 no.2
• /
• pp.101-108
• /
• 1996

This study was conducted to investigate the effect of growth regulators and $GeO_2$ on the induction and proliferation of callus and the effect of $GeO_2$ and citric acid on the Ge content of callus from explants and plant, Angelica koreana Max. The results obtained were summarized as follows. The callus induction was most effective on MS (Murashige and Skoog) medium containing 1. 0ppm 2, 4 - D with petiolule. The proliferation of callus was most effective at 2. 0ppm 2, 4 - D on the medium, at 2. 5ppm $GeO_2$ on the medium containing 2. 0ppm 2, 4 - D, and at $0.\;1{\sim}1mM$citric acid on the medium at pH6 containing 2. 0ppm 2, 4 - D and 2. 5ppm $GeO_2.$ The more $GeO_2$ in MS medium up to 20ppm, the more Ge content in callus. Ge content in callus was highest when the medium was supplemented with 0. 1mM citric acid and the pH of medium was low. The Ge content in plant was high in order of leaf > root > stem. Application $GeO_2$ to the soil increased Ge content in plant and application of 1mM citric acid with $GeO_2$ resulted in increasing Ge content highest in plant, but application more than l0mM citric acid resulted in Ge content decreased. Application of $GeO_2$ increased Ge content in callus and plant but had a tendency to decrease some mineral content, on the other hand application of $0.\;1{\sim}1mM$ citric acid with $GeO_2$ had a tendency to increase mineral content.

• Korean Journal of Pharmacognosy
• /
• v.47 no.3
• /
• pp.204-210
• /
• 2016

Phytochemical investigation of the 80% MeOH extract from the stems of Lagerstroemia indica resulted in the isolation of eighteen compounds; four norsesquiterpenes, fourteen phenolic derivatives. Their chemical structures were characterized by spectroscopic methods to be tachioside (1), isotachioside (2), 2,4,6-trimethoxyphenyl ${\beta}$-D-glucopyranoside (3), gallic acid 4-methyl ether (4), protocatechuic acid (5), gallic acid (6), vanillic acid (7), vanillin (8), 2-methoxy-5-hydroxymethyl-phenyl-1-O-(6"-galloyl)-${\beta}$-D-glucopyranoside (9), 2,4,6-trimethoxyphenol-1-O-${\beta}$-D-(6'-O-galloyl)-glucopyranoside (10), 4-hydroxy-3-methoxyphenyl-1-O-(6'-O-galloyl)-${\beta}$-D-glucopyranoside (11), vomifoliol (12), vomifoliol 9-O-${\beta}$-D-glucopyranoside (13), 6R,9R-3-oxo-${\alpha}$-ionol-9-O-${\beta}$-D-glucopyranoside (14), dihydrophaseic acid 4'-O-${\beta}$-D-glucopyranoside (15), ${\beta}$-hydroxypropiovanillone 3-O-${\beta}$-D-glucopyranoside (16), myrciaphenone A (17), and coumaric acid (18). Compounds 1-5 and 7-18 were isolated for the first time from this plant. Compounds 1-18 were investigated for their antioxidant properties using DPPH and ABTS radical scavenging capacity assay, $Fe^{2+}$ chelating, and FRAP assay. It was found that 4, 6, and 11 possessed the highest antioxidant capacities.

• Journal of the Mineralogical Society of Korea
• /
• v.17 no.4
• /
• pp.309-325
• /
• 2004

The Cannington Ag-Pb-Zn deposit, northwest Queensland, Australia developed around the host rocks composing banded and migmatitic gneisses, sillimanite-garnet schist and amphibolite. Three crystal habits of sillimanite, gahnite (Zn-spinel) and garnet porphyroblasts occurred on the host rocks of the Cannington deposit could be used to delineate metamorphism that closely associated with Zn-mineralization in the deposit. Linkages the metamorphism to Zinc-mineralization is determined in four chemical systems, KFMASH (K$_2$O-FeO-MgO-Al$_2$O$_3$-SiO$_2$-$H_2O$), KFMASHTO (K$_2$O-FeO-MgO-Al$_2$O$_3$-SiO$_2$-$H_2O$-TiO$_2$-Fe$_2$O$_3$), NCKFMASH (Na$_2$O-CaO-K$_2$O-FeO-MgO-AlO$_3$-SiO$_2$-$H_2O$) and MnNCK-FMASH (MnO-Na$_2$O-CaO-K$_2$O-FeO-MgO-AlO$_3$-SiO$_2$-$H_2O$), using THERMOCALC program (version 3.1; Powell and Holland 1988). Partial melting in MnNCKFMASH and NCKFMASH systems occurs at lower temperature than in the KFMASH and KFMASHTO systems. The partial melting temperature decreases with increasing of Na/(Na+Ca+K) of the bulk rock compositions in the MnNCKFMASH system. The host rocks have melted ca 15 vol.% in the MnNCKFMASH system at peak metamorphic conditions (634$\pm$62$^{\circ}C$ and 4.8$\pm$1.3 kbar), but partial melting have not occurred in KFMASHTO system. Based on calculations of sillimanite isograd in different systems and sillimanite modal pro-portion, prismatic and rhombic sillimanite and gahnite porphyroblasts including prismatic sillimanite inclusion probably have resulted from pressure and temperature increasing through partial melting (from 550～$600^{\circ}C$, 2.0～3.0 kbar to 700～75$0^{\circ}C$, 5.0～7.0 kbar), furthermore have experienced N-S then W-E crustal shortening during D$_1$ and D$_2$ deformation. Consequently, Zinc mineralization related to gahnite growth occurred during D$_2$ and was redistributed and upgraded by partial melting and retrograde metamorphism into structural and rheological sites during shearing in D$_3$.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.4
• /
• pp.1177-1181
• /
• 2014

A 2D grid-like (4, 4)-connected topology coordination polymer, $[Co(BTA)_2(H_2O)_2]_n$ (1), where HBTA = 2-(1H-benzotriazol-1-yl)acetic acid, has been synthesized by hydrothermal method and characterized by single crystal X-ray diffraction, IR spectroscopy, elemental analysis and surface photovoltage spectroscopy (SPS). X-ray diffraction analyses indicated that 1 displays octahedral metal centers with secondary building units (SBUs) [$Co(BTA)_2(H_2O)_2$] bridged by the $BTA^-$ ligands. In the crystal, the 2D supramolecular architecture is further supported by $O-H{\cdots}O$, $O-H{\cdots}N$, $C-H{\cdots}O$ hydrogen bonds and ${\pi}{\cdots}{\pi}$ stacking interactions. The SPS of polymer 1 indicates that there are positive response bands in the range of 300-600 nm showing photo-electric conversion properties. There are good relationships between SPS and UV-Vis spectra.

• Journal of the Korean Magnetics Society
• /
• v.13 no.1
• /
• pp.36-40
• /
• 2003

We have grown D $y_{x}$B $i_{3-x}$F $e_{5}$ $O_{12}$ (x = 0.5,1.0, 1.5,2.0) magnetic garnet thin films upon $Al_2$O3i and GGG substrate using Pechini process. The annealing temperature to get single phase D $y_{x}$B $i_{3-x}$F $e_{5}$ $O_{12}$ garnet is dependent on substrate, i.e. the annealing temperature for GGG substrate il 5$0^{\circ}C$ lower than that for $Al_2$ $O_3$ substrate. The grains of garnet thin film grown on GGG (111) plane align along [111] direction, and in this case the hysteresis curve does not saturate up to H : 5000 Oe. We attribute this phenomenon to rotation magnetization process. The maximum amount of Bi substitution in polycrystalline D $y_{x}$B $i_{3-x}$F $e_{5}$ $O_{12}$ thin film prepared by Pechini process is restricted to 2.0 Bi atom/unit cell, and this value is less than that in single garnet crystall grown by LPE method.own by LPE method.ethod.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1997.10a
• /
• pp.59-65
• /
• 1997

The calibration of O.M.D is carried out experimentally and is analysed theoretically. O.M.D experimentally measures the change in optical density of artificially contaminated oil which contains Fe powder of 5, 10, 20, 30, 40, 50, 70, 100, 200 ppm. The change in optical density, D$_1$ means the logarithmic transmittance of I$_0$ over $I_1 D_2$ denotes the logarithmic transmittance I$_2$ over I$_1$ on electromagnetic force which arranges the ferrous particles along the line of magnetic force. The theoretical D$_1$ which increases linearly as increasing Fe concentrations, is analysed by light attenuation theory. The difference between theoretical D$_1$ and experimental D$_1$ is due to the attenuation of micro bubbles and the agglomeration of fine particles in the sample oil. The calibrated O.M.D is applied to the sample oil from the high-powered diesel engine. Also the results are compared with those out of the off-line techniques such as JOAP and ICP.