• Archives of Pharmacal Research
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• v.17 no.1
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• pp.42-44
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• 1994

The activity-guided fractionation of some medicinal plants led to yield five kinds of natural stilbene compounds namely 3, 5-dihydroxy-4'-methoxystillbene(I), rhapontigenin(II), reveratrol(III), rhaponticin(IV) and piceid(V) and two common flavonoids, apigenin(VI) and luteolin(VII) as active principles of the antitumor property, in vitro, against five kinds of human tumor cell lines, A-549, SK-OV-3, SK-MEL-2, XF-498 and HCT15.

• Korean Journal of Pharmacognosy
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• v.36 no.4 s.143
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• pp.282-290
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• 2005

The MeOH extract of the the leaves of Salix hallaisanensis (Salicaceae) was partitioned successively with $CHCl_3$, 20% MeOH, 40% MeOH and 60% MeOH solution. From the fractions obtained, 9 compounds were isolated, $diosmetin-7-O-{\beta}-d-glucoside$ (I), $diosmetin-7-O-{\beta}-D-glucosyl-(1{\rightarrow)6)-{\beta}-d-glucoside$ (II), $diosmetin-7-O-{\beta}-d-xylosyl-(1{\rightarrow}6)-{\beta}-D-glucoside$ (III), $quercetin-3-O-{\beta}-d-galactoside$ (hyperoside) (IV), $quercetin-3-O-{\alpha}-l-rhamnosyl-(1{\rightarrow}6)-{\beta}-D-glucoside(rutin)$ (V), luteolin (VI), $luteolin-7-O-{\beta}-d-glucoside$ (VII), $kaempferol-3-O-{\alpha}-l-rhamnosyl-(1{\rightarrow}6)-{\beta}-D-glucoside$ (VIII), and (+)-catechin (IX).

• Journal of the Korean Chemical Society
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• v.32 no.4
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• pp.358-370
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• 1988

Several new ion exchange resins have been synthesized from chloromethyl styrene-1,4-divinylbenzene(DVB) with 1%, 2%, 4%, and 10%-crosslinking and macrocyclic ligands of cryptand type by interpolymerization method. The adsorption characteristics and the pH, time, solvents and concentration dependence of the adsorption of metal ions by this resin were studied. The correlation between the separation characteristics of uranium, rare earths and transition metal on the resins and the stability constants of complexes with macrocyclic ligands have been examined. The resins were very stable in both acidic and basic media and have good resistance to heat at $280^{\circ}C$. The $UO_2^{+2}$ aqueous solution are not adsorbed on the resins below pH 3.0, but the power of adsorption of $UO_2^{2+}$ increased rapidly above pH 4.0. The optimum equilibrium time for adsorption of metallic ions was twenty minutes and adsorptive power decreased in proportion to crosslinking size of the resins and order of dielectric constants of solvents used and the selective sequence for metal cations is in the order of $UO_2^{2+},\;Cu^{2+}\;and\;Nd^{3+}$.

• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1141-1149
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• 2003

The structures and gas-phase ionization energies (ΔG°) of Meldrum's acid (I) and related cyclic (II-VI) and acyclic compounds (VII-IX) are investigated theoretically at the MP2/6-31+$G^*$, B3LYP/6-31+$G^*$, B3LYP/6- 311+$G^{**}$, B3LYP/6-311++G(3df,2p) and G3(+)(MP2) levels. Conformations of three neutral cyclic series vary gradually from boat (Meldrum's acid, I), to twisted chair (II) and to chair (III) as the methylene group is substituted for the ether oxygen successively. The preferred boat form of I can be ascribed to the two strong $n_O$ → σ* c-c antiperiplanar vicinal charge transfer interactions and electrostatic attraction between negatively charged C¹ and positively charged C⁴at the opposite end of the boat. All the deprotonated anionic forms have half-chair forms due to the two strong $n_C$ → π* c=0 vicinal charge transfer interactions. The dipole-dipole interaction theory cannot account for the higher acidity of Meldrum's acid (I) than dimedone (III). The origin of the anomalously high acidity of I is the strong increase in the vicinal charge transfer ($n_C$ → π* c=0) and 1,4-attrative electrostatic interactions (C¹↔C⁴) in the ionization (I → $I^-$ + $H^+$). In the acyclic series (VII-IX) the positively charged end atom, C⁴, is absent and the attractive electrostatic stabilization (C¹↔C⁴) is missing in the anionic form so that the acidities are much less than the corresponding cyclic series.

• Journal of the Korean Wood Science and Technology
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• v.34 no.3
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• pp.73-83
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• 2006

The dried needles (1.5 kg) of Abies koreana and Abies holophylla were ground, extracted with acetone-$H_2O$ (7:3, v/v), concentrated, and fractionated with a series of hexane, methylene chloride, ethyl acetate and water on a separatory funnel. Each fraction was freeze dried, then a portion of ethyl acetate soluble powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. The isolated compounds were identified by cellulose TLC, $^1H$, $^{13}C-NMR$, COSY, HETCOR, FAB and EI-MS. The needles of Abies koreana and Abies holophylla contained a large amount of aromadendrin-7-O-${\beta}$-D-glucopyranoside (compound III), polydatin (compound VI), (-)-rhododendrol-2-O-${\beta}$-D-glucopyranoside (compound VII), in addition to a small amount of (+)-catechin (compound I), kaempferol-3-O-${\beta}$-D-glucopyranoside (compound IV), myricetin-3-O-${\beta}$-D-glucopyranoside (compound V), naringenin-7-O-${\beta}$-D-glucopyranoside (compound II). DPPH analysis was also tested to investigate the antioxidative effects on the isolated compounds and (+)-catechin and polydatin were effective.

• YAKHAK HOEJI
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• v.52 no.4
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• pp.241-251
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• 2008

In this study, isolation of antioxidative compounds was performed for development of anti-oxidizing agent. $CHCl_{3}$, $H_{2}O$, 30%, 60% MeOH, MeOH fractions were examined antioxidative activity by DPPH method, TBARS assay, and SOD like activity. It was revealed that 30%, 60% MeOH fractions had significant antioxidative activity. From 30%, 60% MeOH fraction, nine compounds were isolated and elucidated kaempferol $3-O-{\alpha}-L-rhamnopyranosyl$ $(1{\rightarrow}6)-{\beta}-D-glucopyranoside$ (1), quercetin $7-O-{\beta}-D-glucopyranoside$ (II), quercetin $3-O-{\alpha}-L-rhamnopyranosyl$ $(1{\rightarrow}6)$ ${\beta}-D-glucopyranoside(rutin)$ (III), 6-hydroxykaempferol $3-O-{\beta}-D-glucopyranoside$ (lV), kaempferol $3-O-{\beta}-D-glucopyranosyl$ $(1{\rightarrow}2)$ ${\beta}-D-glucopyranoside$ (V), kaempferol $3-O-{\beta}-D-glucopyranoside$ (VI), luteolin (VII), quercetin $3-O-{\beta}-D-glucopyranoside$ (VIII), apigenin $7-O-{\beta}-D-glucuronopyranoside$ (IX) through physicochemical data and spectroscopic methods (Negative FAB-MS, $^1H-NMR$, $^{13}C-NMR$). Entirely, all compounds had similar antioxidative activity, but more OH group had more antioxidative activity.

• Journal of the Korean Wood Science and Technology
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• v.34 no.1
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• pp.79-85
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• 2006

Paulownia coreana Uyeki fruits were collected, extracted with acetone-$H_2O$ (7:3, v /v), fractionated with n-hexane, methylene chloride, and ethyl acetate, then freeze dried to give some dark brown powder. The ethyl acetate soluble mixture was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. Spectrometric analysis such as NMR and MS including TLC were performed to establish the structures of the isolated compounds. From the ethyl acetate fraction, one phenolic acid (I) and five flavonoids (II~VI) and were isolated and elucidated. The antioxidative activities were tested on the isolated compounds, crude and fractionated extractives by DPPH radical scavenging method. The result showed that caffeic acid, kaempferol, luteolin, quercetin and the EtOAc soluble fraction exhibited higher activities than those of ${\alpha}$-tocopherol and BHT.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.267.2-267.2
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• 2016

Semiconductor photo-catalysis offers the potential for complete removal of toxic chemicals through its effective and broad potential applications. Various new compounds and materials for chemical catalysts were synthesized in the past few decades. As one of the most important II-VI group semiconductors, zinc sulfide (ZnS) with a wide direct band gap of 3.8 eV has been extensively investigated and used as a catalyst in photochemistry, environmental protection and in optoelectronic devices. In this work, the ZnS films and nanostructures have been successfully prepared by wet chemical method. We show that the agglomerates with four successive scales are always observed in the case of the homogeneous precipitation of zinc sulfide. Hydrodynamics plays a crucial role to determine the size of the largest agglomerates; however, other factors should be invoked to interpret the complete structure. In addition, studies of the photocatalytic properties by exposure to UV light irradiation demonstrated that ZnS nanocrystals (NCs) are good photo-catalysts as a result of the rapid generation of electron-hole pairs by photo-excitation and the highly negative reduction potentials of excited electrons. A combination of their unique features of high surface-to volume ratios, carrier dynamics and rich photo-catalytic suggests that these ZnS NCs will find many interesting applications in semiconductor photo-catalysis, solar cells, environmental remediation, and nano-devices.

• YAKHAK HOEJI
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• v.13 no.2_3
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• pp.62-66
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• 1969

Ten new N$^{4}$-furoylsulfonamides were synthesized such as N$^{4}$-furoyl-N$^{1}$-(4,6-dimethyl-2-pyrimidinyl) sulfanilamide (I), N$^{4}$-furoylsulfanilamide (II), N$^{4}$-furoyl-N$^{1}$-(2,6-dimethoxy-4-pyrimidinyl) sulfanilamide (III), N$^{4}$-furoyl-N$^{1}$-(4-methyl-2-pyrimidinyl) sulfanilamide (IV), N$^{4}$-furoyl-N$^{1}$-(6-methoxy-3-pyridazinyl) sulfanilamide (V), N$^{4}$-furoyl-N$^{1}$-2-pyrimidinylsulfanilamide (VI), N$^{4}$-furoyl-N$^{1}$-(3,4-dimethyl-5-isoxazolyl) sulfanilamide (VII), N$^{4}$-furoyl-N$^{1}$-2-thiazoilysulfanilamide (VIII), N$^{4}$-furoyl-N$^{1}$-(5-methoxy-2-pyrimidinyl) sulfanilamide (IX) and N$^{4}$-furoyl-N$^{1}$-(2,6-dimethyl-4-pyrimidinyl) sulfanilamide (X). They were obtained by the action of N$^{1}$-(4,6-dimethyl-2-pyrimidinyl) sulfanilamide, N$^{1}$-(2,6-dimethoxy-4-pyrimidinyl) sulfanilamide, N$^{1}$-(4-methyl-2-pyrimidinyl) sulfanilamide, N$^{1}$-(6-methoxy-3-pyridazinyl) sulfanilamide, N-2-pyrimidinyl sulfanilamide, N$^{1}$-(3,4-dimethyl-5-isoxazolyl) sulfanilamide, N$^{1}$-2-(thiazolysulfanilamide), N$^{1}$-(5-methoxy-2-pyrimidinyl) sulfanilamide and N$^{1}$-(2,6-dimethyl-4-pyrimidinyl) sulfanilamide with furoyl chloride in 4% NaOH solution. Of the above ten compounds, N$^{4}$-furoylsulfathiazole exhibited a good antibacterial action against Staphylococeus aureus and Escherichia coli.

• Journal of the Korean Wood Science and Technology
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• v.9 no.2
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• pp.1-30
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• 1981

To investigate the formation of the chromophoric structures taking place during the alkaline pulping vanillyl alcohol [${\alpha}-^{13}C$] guaiacylglycerol-${\beta}$-aryl ether [${\alpha}-^{13}C$ or ${\gamma}-^{13}C$] and phenylcoumarn [${\alpha}-^{13}C$] units as model lignins were treated with 1N sodium hydroxide at 165$^{\circ}C$ for 1.5-3 hours. From the chemical structures of the isolated products and $^{13}C$-NMR Spectra of the reaction mixtures, the main conclusion is as follows; 1) Condensation products of II-1-5 were identified from the reaction mixture of vanillyl alcohol treated with alkali and theses compounds afforded the quinonmethide structure(Fig. 3-7) by air oxidation. 2) Treatment of guaiacylglycerol-${\beta}$-aryl ether unit gave ${\varphi}$-aryl-${\beta}$-aroxy quinone structures (IV-15, IV-16), diguaiacyl-1, 4-penta-diene ${\beta}$, ${\beta}$'-diaroxyl distyrene methane unit, ${\beta}$-aroxy distyrene methane. These distyrene methanes of the compounds are transformed by air oxidation into the corresponding o-quinonemethide units (V-8, V-9). 3) On the treatment of phenylcoumaran, the stilbene derivative was formed in quantitative yield and dimerized(VI-11) in preference to oxidation to the corresponding extended quinone structures. The chromophoric structures taken place during the alkaline treatment of the model lignins are thought to be some important types in alkaline pulping on the basis of the reaction mechanism in this experiment.