• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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• pp.399-405
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• 1998

This study was carried out to investigate the effects of herb extracts on lipid oxidation and free radical reaction in iron sources reacted with active oxygen species. The catalytic effects of active oxygen on lipid oxidation in oil emulsion tended to show more active in the order of OH, H2O2 and KO2. Herb extracts tended to show a little catalytic effect and active oxygen scavenging ability of herb extracts didn't show. But herb extracts played role as a strong chelating agents to bind iron if Fe2+ ion exist in oil emulsion. The contents of Fe2+ ion and total iron in Salvia miltiorrhiza Bge. and Angelica gigas Nakai were higher than those of Prunus persica Stockes and pinus strobus. The content of asocrbic acid in Pinus strobus showed the highest (26.97ppm) among several herb extracts. Electron donating abilities of Pinus strobus and Salvia miltiorrhiza Bge. were 79.54% and 77.11%, respectively, which were higher contents than those of Prunus persical Stokes and Angelica gigas Nakai. The SOD-like activity of Prunus persca Stokes showed 0.16 optical density (O.D), which means the most strong antioxidant activity among other herb extracts. The nitrite scavening effects tended to be different depending on pH. Pinus strobus and Angelica gigas Nakai showed 99.8% and 98.6% nitrite scavening effects at pH 1.2. And the effects were decreased as pH was increased. Especially, they didn't show the nitrite scavenging effect in pH 6.0. In conculsin, the Prinus strobus extract among herb extracts were the most effective antioxidant by evaluating several functional tests.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.626-632
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• 2001

The plant extracted from Nameko, Gallic, Green tea, Allspice, Polygonum multiflorum, Schizandra chinensis, Armeniacae and Pine needle were utilized to investigate the effects of extracts on free radical reaction, lipid oxidation and nitrite scavenging ability. The pH of ethanol extracts showed a higher than that of hot water extracts, among of which were showed the lowest pH 3.0 in Schizandra chinensis. The important factor of lipid oxidation were $Fe^{2+}$ ion and active oxygen, in which were bound by plant extracts in case of $Fe^{2+}$ ion existed. However, the hydroxyl radical scavenging ability of extracts were lowed, compared to extracts reacted with $Fe^{2+}$ ion. Among of them, the hydroxyl radical scavenging ability of Nameko and Pine needle extracts had a lower TBARS value than those of control. The iron content of extracts were less than 2.0 mg/100 g, but the total iron content of Schizandra chinensis extracts were 6.8 mg/100 g. The ethanol extracts of pine needle were higher than those of hot water extracts on the basis of $Fe^{2+}$ ion content. The ascorbic acid content of green tea showed 14.3 mg/100 g in hot water extracts and 16.7 mg/100 g in ethanol extracts. Electron donating ability of extracts showed more than 50%, except Nameko and allspices, which were higher in ethanol extracts than those of hot water extracts. The superoxide dismutase(SOD)-like activity of green tea showed 85.3% and 63.5% in hot water and ethanol extracts, respectively. The nitrite scavenging ability of green tea was the most effective in both extracts.

• Nuclear Engineering and Technology
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• v.17 no.1
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• pp.8-15
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• 1985

A model for thermal interactions of debris/water with gas flow from within and below debris bed was presented for severe accident analysis in LWR. The consumption of steam, production of hydrogen in the debris bed, generation of gases from below debris bed and generation of chemical heat are included in the conservation equations. The model has been incorporated in the MARCH code to estimate the gas production due to both metal/oxidation and hot debris/concrete interaction. The results indicate that the hydrogen source can potentially give a significant impact on the containment pressure transient and the conductive heat loss to concrete and the convective gas cooling in the debris bed have a small effect on the debris bed coolability. However, the reheating and melting of the debris particles could be delayed by the interaction of debris with concrete.

• Journal of Life Science
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• v.25 no.4
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• pp.425-432
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• 2015

This study was performed to develop high-value-added biomaterials for health and beauty products. Extracts of ethanol and hot water and their subsequent organic solvent fractions were prepared from Lees of Wookukseng (LW), a commercialized Korean traditional rice wine. We investigated their activities on blood coagulation, platelet aggregation, hemolysis against human red blood cells (hRBCs), and anti-oxidation. The water content, pH and brix of the LW were 80.3%, 3.94 and 13.0°, respectively. The yield of ethanol extraction (6.62%) was 3.15 times higher than that of hot-water extraction (2.1%), and the ethyacetate fraction (EAF) of ethanol extract showed the highest content of total polyphenol (128 mg/g) among the various fractions. In anticoagulation activity assay, the EAF of ethanol extract showed a 15-fold extension in TT, PT, and aPTT, indicating that the EAFs contain various inhibitory substances against thrombin, prothrombin and coagulation factors. In anti-platelet aggregation activity assay, the butanol fraction and water residue of ethanol extract showed significant inhibition activity. The activities were comparable to aspirin, a commercial anti-thrombosis agent. The above extracts and fractions did not show hemolysis activity against hRBC up to 5 mg/ml, and had radical scavenging activity against DPPH anion, ABTS cation and nitrite. Our results suggest that the active fractions prepared from LW, which has no specific usage until now, have a high potential as novel resources for anti-thrombosis agents.

• Biomolecules & Therapeutics
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• v.23 no.3
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• pp.283-289
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• 2015

The half-dried leaves of Stewartia. pseudocamellia were extracted with hot water (SPE) and partitioned with n-hexane (SPEH), dichloromethane (SPED), and ethyl acetate (SPEE) successively. SPE and SPEE showed significant inhibitory effects against melanogenesis and tyrosinase activities. By bioassay-guided isolation, ten phenolic compounds were isolated by column chromatography from SPEE. The whitening effect of the isolated compounds from SPEE were tested for the inhibitory activities against melanogenesis using B16 melanoma cells, in vitro inhibition of tyrosinase, and L-3,4-dihydorxy-indole-2-carboxylic acid (L-DOPA) auto-oxidation assay. A cytotoxic activity assay was done to examine the cellular toxicity in Raw 264.7 macrophage cells. Of the compounds isolated, gallic acid and quercetin revealed significant inhibitory activities against melanogenesis compared to arbutin. In particular, quercetin exhibited similar inhibitory activities against tyrosinase and L-DOPA oxidation without cytotoxicity. These results suggested that SPE could be used as a potential source of natural skin-whitening material in cosmetics as well as in food products.

• The Korean Journal of Mycology
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• v.26 no.4 s.87
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• pp.502-510
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• 1998

The hot-water extract of fruiting bodies in Fomitella fraxinea had potent anti-complementary activities. After fractionation of water-soluble polysaccharides by DEAE-Sephadex A-25 column chromatography, major anti-complementary activity was concentrated into the FF-AP1 among three polysaccharides (FF-NP, FF-AP1, FF-AP2). FF-AP1 was fractionated into $FF-AP1{\alpha}$ and $FF-AP1{\beta}$ obtained from the adsorbed fraction and unadsorbed fraction by affinity chromatography using a ConA-sepharose 4B column, respectively. $FF-AP1{\beta}$, which exihibited the highest anti-complementary activities had an IR absorption peak of $890cm^{-1}$, and a M.W. of about 15,000 (gel filtration). Anti-complementary activity of FF-AP1 decreased greatly by pronase treatment and periodate oxidation. $FF-AP1{\beta}$ responsible for potent anti-complemenary activities of Fomitella fraxinea was an acidic protein-containing heteroglycan consisted of 48% glucose, 13% mannose, and 12% galactose as major component sugars, 9.6% protein, 6% uronic acids.

• Journal of Life Science
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• v.18 no.8
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• pp.1106-1114
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• 2008

The antioxidants activities in water and 95% ethanol extracts of wa-song (Orostachys japonicus A. Berger) dried by sun, hot air and lyophilization were measured in vitro reaction system. In reaction system containing linoleic acid, the antioxidant activities against lipid oxidation enhanced in proportion to storage time. The antioxidant activity of ethanol extracts was higher than that of water extracts. In the drying methods, wa-song extracts showed higher antioxidant activity in the other of hot air-dried, lyophilized and sun-dried. The lipid oxidation system containing the promoting factors, such as $Fe^{+2}$ and $Cu^{+2}$ions, also showed that the ethanol extract of hot air-dried wa-song possessed the highest antioxidant activity. Soybean oil and lard being added with various levels (0.1, 0.5 and 1.0 g/100 g) of the ethanol extract of hot air-dried wa-song were stored at $60^{\circ}C$ (for 28 days) or $180^{\circ}C$ (for 48 hr). Its extract appeared to lower the acid value of soybean oil, wheras it failed to lower the acid value for lard at early storage time, but it was lower than control and BHT after 28 days. Anicidine value and peroxide value were lower soybean and lard added wa-song extract than control and BHT for storage for 28 days at $60^{\circ}C$. In 28 days, its value was significantly decreased in proportion to sample concentration. TBA value was increased during storage time at $60^{\circ}C$, but it was significantly decreased by sample concentration after storage 36 hours at $180^{\circ}C$ storage. Therefore results suggest ethanol extract of hot air-dried wa-song could be potential candidates for natural antioxidants for materials containing lipid.

• Journal of Powder Materials
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• v.10 no.5
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• pp.337-343
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• 2003

Nanostructured Cu-$Al_2O_3$ composite powders were synthesized by thermochemical process. The synthesis procedures are 1) preparation of precursor powder by spray drying of solution made from water-soluble copper and aluminum nitrates, 2) air heat treatments to evaporate volatile components in the precursor powder and synthesis of nano-structured CuO + $Al_2O_3$, and 3) CuO reduction by hydrogen into pure Cu. The suggested procedures stimulated the formation of the gamma-$Al_2O_3$, and different alumina formation behaviors appeared with various heat treating temperatures. The mean particle size of the final Cu/$Al_2O_3$ composite powders produced was 20 nm, and the electrical conductivity and hardness in the hot-extruded bulk were competitive with Cu/$Al_2O_3$ composite by the conventional internal oxidation process.

• Korean Journal of Pharmacognosy
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• v.33 no.4 s.131
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• pp.359-363
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• 2002

Antioxidant properties of the extracts of Acanthopanax senticosus were investigated. The dried roots, stems or leaves were extracted with hot water or ethanol each. The ethanol extracts exhibited higher potency than aqueous extracts in scavenging free radicals and in inhibiting microsomal lipid peroxidation: the aqueous extracts of stems showed higher anti-oxidant effects than the root extracts. Copper-mediated LDL oxidation was also protected by the ethanol exlracts: antioxidant effects of the extracts tested were stronger than ascorbic acid, but not butylated hydroxytoluene. The activity of angiotensin converting enzyme was effectively suppressed by the aqueous extracts of the stems. However, in vivo antioxidant properties of the ethanol extracts of the stems did not seem to be significant, judged from the lipid peroxide values of serum and liver in normal mice. Thus, the ethanol extracts of the stems were shown to be more potent for protecting biological systems against various oxidant stresses in vitro, but not in vivo.

• Korean Chemical Engineering Research
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• v.62 no.2
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• pp.142-146
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• 2024

There is growing interest in natural cosmetic ingredients as natural cosmetics become popular. As a part of effort to look for natureal cosmetic agent, seaweed Sargassums were tested for functional cosmetic agents. Effective materials were extracted from Sargassum coreanum. Sargassum hemiphyllum, and Sargassum patens by simple hot water extraction. Antioxidation, whitening, anti-wrinkle, UV absorption and anti-inflammation effects were studied for functional cosmetic agents. Sargassum extracts indicated excellent cell viability, strong anti-oxidation effect by DPPH radical scavenging activity and showed significant whitening effect from tyrosinase inhibition. However, effects of antiwrinkle, UV absorption and anti-inflammation were negligible. In conclusion, Sargassum coreanum extracts showed good possibility for anti-oxidation and whitening cosmetic agent.