• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.480-486
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• 1998

It was investigated that the reduction of the intense brown color and increase of solubility, and depolymerization of polymerized melanoidins by ozonolysis affect their antioxidative and antimutagenic activities. Melanoidins was depolymerized and decolorized by ozonolysis. Ozone-treated melanoidins revealed a lower antioxidative activity and a higher antimutagenic activity than those of the untreated control. Fractions of ozone-treated melanoidins showed three peaks resemble to that of the melanoidins on Sephadex column chromatogram. Melanoidins of above MW 1,200 showed intense brown color. However, the strongest electron-donating ability was detected in the melanoidins of between MW 750 to 900. Ozone-treated and ozone-untreated melanoidins of between MW 900 to 1,000 revealed the higher antioxidative and antimutagenic activities.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.70.3-70.3
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• 2016

Active galactic nuclei (AGNs) typically show a non-thermal continuum locally represented by a power-law and many prominent emission lines in the UV and optical regions. AGNs are classified by two types, where Type I AGNs exhibit both broad and narrow lines and only narrow lines are observed in Type 2 AGNs. The unification models of AGNs invoke the existence of a molecular torus just outside of the broad line region. In the presence of a high column HI region associated with the molecular torus, we propose that significant fraction of broad line photons near Lyman series can be scattered by atomic hydrogen in the torus. In particular, $Ly{\alpha}$ being the strongest emission line, strong linear polarization may develop around $Ly{\alpha}$ through Rayleigh scattering. We adopt a Monte Carlo technique to investigate the polarized transfer of $Ly{\alpha}$ in a thick HI region with the shape of a torus. We consider the range of HI column density N_HI = 1020-23 with fixed geometric parameters of the torus such as the inner and outer radii and the height. We present the polarized spectra and angular distribution of Rayleigh scattered radiation around $Ly{\alpha}$. We find that the $Ly{\alpha}$ core part is polarized in the direction perpendicular to the symmetry axis whereas in the far wing part it is polarized in the parallel direction. It is concluded that the unification of AGNs implies that $Ly{\alpha}$ can be uniquely polarized through Rayleigh scattering.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.163-171
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• 2016

We investigated the intensity and pattern of the scent produced by diploid and tetraploid Cymbidium flowers, using an electronic nose with 6 metal oxide sensors (MOS). The MOS responses were evaluated by principal component analysis, discriminant function analysis, and sensor data. These analyses revealed that tetraploid flowers had a stronger scent than diploid flowers in Cymbidium Golden Elf 'Sundust'. Furthermore, among the different flower parts-column, lip, and petals-the column produced the strongest scent. There was no significant difference between the flowering periods of diploid and tetraploid potted Cymbidium Golden Elf 'Sundust' and Cymbidium Elma 'Orient Toyo' grown in a greenhouse. Moreover, there were no significant differences between the number of flowers per flower stem and the length of flower stems on the diploid and tetraploid plants of these two Cymbidium cultivars. This study provides potentially useful information for the breeding of polyploidy Cymbidium in the floriculture industry.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.692-697
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• 1998

GTP cyclohydrolase I catalyzing the first reaction in the biosynthesis of pterin moiety of folic acid in bacteria, was purified from Streptomyces tubercidicus by at least 203-fold with a yield of 32% to apparent homogeneity, using ammonium sulfate fractionation, DEAE-cellulose, Sepharose CL-6B, and hydroxylapatite column chromatography. The molecular weight of the native enzyme was estimated to be 230,000 daltons by gel permeation chromatography. The purified enzyme gave a single band on sodium dodesyl sulfate-polyacrylamide gel electrophoresis and its molecular weight was apparently 58,000 daltons. These results indicate that the enzyme consists of four subunits with the same molecular weight. The $K_m$ and $V_{max}$ values for GTP of the purified enzyme were determined to be 80${\mu}$M and 90nmol/min (mg protein), respectively. The optimum pH and temperature for the enzyme reaction were pH 7.5-8.5 and $40-42^{\circ}C$, respectively. Coenzyme or metal ion was not required for the enzyme activity. The enzyme activity was inhibited by most divalent cations, while it was slightly activated by potassium ion. In case of nucleotides, CTP, GMP, GDP, and UTP inhibited enzyme activity, among which GDP exhibited the strongest inhibitory effect.

• 한국해양학회지
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• v.27 no.4
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• pp.259-267
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• 1992

A survey of CTD casting was taken in April 1991 in the eastern Yellow Sea. The vertical structure of water column consists of the upper mixed warm, the mid cold and the lower warm layers devised clearly by a seasonal thermocline and the temperature inversion. A strongest temperature inversion is found in the southern part of the survey area. Where the low-layer water is $3^{\circ}C$ higher than the mid-layer water. The area of the temperature inversion covers about $100{\;}km{\;}{\times}{\;}100{\;}km$ and it is observed 1.5 month later. The temperature and salinity of the low-layer water shows a core structure in vertical sections and the tongue-like distribution extending from the south to the north, implying that the warm and saline water found in the oceanic front south of the survey area in early spring is advocated to the north over 150 km underneath the Yellow Sea cold water.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.466-471
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• 1994

The antioxidant activity of methanol extracts of thirty plants was tested using the methol of 1, 1-diphenyl-2-pi-cryl hydrazyl (DPPH) reactivity. Four methanol extracts from Zingiber officinale, Piper nigrum , Zanthoxylum schinifolium and Capsocum annuum were found to be the most effective on DPPH radical scavenging activity. The next effective ones were Perilla frutescens , Sedium sarmentosum , Raphnus sativas, aArctium lappa, Beta vulgaris. Brassica oleracea var. Acephala, bBrassica juncea inorder, and the others did not show a considerable activity. The methanol extract obtained from the seed coats of Zanthoxylum schinifolium was fractinated with several sovlents. The interphase materials exhibited the strongest antioxidant activity and was further purified by silica gel and Sephadex LH-20 column chormatography. Two active principles were isolated and identified as quercetin -3-O-$\alpha$-L-rhamonopyranoiside(quercitrin) and quercetin 3-O-$\alpha$-D-galactopyranoside (hyperoside) by ultraviolet(UV), proton nuclear magetic resonance (1H-NMR) and carbon nuclear magnetic resonance (13C-NMR). Its antioxidative activity was a little higher that that of L-ascorbic acid.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.706-709
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• 2003

The antioxidant activities of methanol and dichloromethane/acetone extracts of twenty three seaweeds were tested by using 1,1-Diphenyl-2-picryl-hydrazyl(DPPH) at a $100{\mu}g/ml$ concentrations. The dichloromethane/acetone extracts of three seaweeds(Symphyocladia latiuscula, Gloiopoltis furcata, Sagassum thunbergii), were found to be most effective in DPPH radical scavenging activity. The DPPH radical scavenging effect of these seaweeds was Symphyocladia latiuscula(85.82%), Gloiopoltis furcata(82.83%), Sagassum thunbergii(74.05%) in order. These seaweeds were evaluated using the pyrogallol UV-VIS spectrophotometeric method to generate superoxide anion. Among them, the methanol extracts of six seaweeds were showed weak superoxide dismutase-like activities. The dichloromethane/acetone extracts obtained from Symphyocladia latiuscula was fractionated with $CH_2Cl_2$, n-hexane, 15% aq.MeOH, n-BuOH, $H_2O$. The 15% aq.MeOH soluble fraction exhibiting the strongest antioxidative activities was further purified by C18 column flash chromatography and reversed HPLC. The two active principles of Symphyocladia latiuscula were isolated and characterized as 2,3,6-tribromo-4,5-dihydroxybenzyl alcohol(1), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether(2).

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.111.2-112
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• 2003

A total of 20 extracts derived from different plant family commonly used in Indonesian traditional inflammation medicine were screened for their inhibitory effect on soybean lipoxygenase (SBL) and hyaluronidase (HAse) activity. Three methanol extracts, the bark of Cinnamomum burmanni (CB), the leaves of Piper betel (PB), and fruit of Barringtonia acutangula (BA) were found to have high inhibitory effects, whereas the methanol extract of the leaves of Mimusops elengi (ME) have medium inhibitory effect. The IC50 of CB, PB, BA and ME were found to be 21.7, 16.9, 39.1 and 62.8 g/$m\ell$, respectively. Among the tested extracts, only CB inhibited HAse (IC50 = 27g/$m\ell$). CB was successively fractionated with n-hexane, ethyl acetate, butanol and water. The EtOAc fraction having the strongest activity was fractionated and some compounds were isolated and purified by a preparative HPLC(Develosil ODS-HG-5 column). Coumarin and 2-hydroxy cinnamaldehyde. were identified through the analyses of UV-Vis absorption 1H-NMR, 13C-NMR and FAB+-MS spectra.

• Journal of the Korean Wood Science and Technology
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• v.33 no.5 s.133
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• pp.86-91
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• 2005

Six compounds were isolated from the EtOAc and $Et_2O$ fractions of the bark of Rhus chinensis by repeated column chromatography with $SiO_2$ and Sephadex LH-20. The structures were determined by instrumental analysis using MS and NMR spectrophotometer as: gallic acid (1), methyl gallate (2), 6, 7-dimethoxycoumarin (3), orcinol-${\beta}$-D-glucoside (4), scopoletin (5), semialactone (6). Among these compounds, 6,7-dimethoxycoumarin (3) was isolated from this plant for the first time. To measure the antioxidant activity, the DPPH radical scavenging activity test was performed. Gallic acid (1) showed the strongest activity, while orcinol-${\beta}$-D-glucoside (4), semialactone (5) and scopoletin (6) had the low activities.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.526-529
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• 1993

The present study was conducted to investigate nitrite-scavenging ability of the components of Cassiae torae semen, Cassia tora L. The nitrite-scavenging effects of fractions obtained from methanol extract of Cassiae torae semen, Cassia tora L. were strong in ethyl acetate fraction, chloroform fraction, water soluble fraction and ethyl ether fraction in order. Compound D showed the strongest nitrite-scavenging effects among compound A, B, C, D separated from Cassiae torae semen. Compound D separated from Cassiae torae semen possessed ten-fold stronger the nitrite-scavenging effect than ascorbic acid.