• The Korean Journal of Ecology
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• v.24 no.1
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• pp.35-43
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• 2001

Accumulation, elimination and subcellular distribution of heavy metals in Littorina brevicula exposed to cadmium and zinc separately and concurrently were investigated. When the winkles had been exposed to 400 ㎍/L CdCl₂ and 3000 ㎍/l ZnSO₄ separately for 90 days, each of the metal body burden in the whole sofl parts increased in proportion to time of exposure until 70 days. But it didn't increase after 70 days. But when the winkles had been exposed to cadmium and zinc simultaneously, cadmium body burden decreased but zinc body burden increased as compared to the winkles exposed to each of the metal. We also found that cadmium accumulated in the winkles was not depurated for 42 days, but zinc accumulated in them was depurated. Especially, zinc was depurated faster when they had been exposed to mixture of cadmium and zinc. After the winkles had been exposed to cadmium and zinc separately for 70 days, about 60% cadmium of the total body burden was associated with the soluble fraction, while about 75% zinc of the total body burden was associated with insoluble fraction. And these trends of metal partitioning did not alter when the winkles had been exposed to metal mixture. After the soluble fraction applied to gel-filtration chromatography column, the distribution patterns of cadmium and zinc associated with proteins or ligands were different each other. Most of cadmium (＞90%) in the soluble fraction was bound to MBP-1 (Metal-binding protein-1), about 6.5 kDa), while zinc was distributed evenly to HMW (High molecular weight fraction, >60 kDa), MBP-1, MBP-2 (about 5 kDa), LMW (Low molecular weight fraction, <1 kDa).

• Macromolecular Research
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• v.14 no.5
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• pp.510-516
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• 2006

Lactide was produced from oligomeric PLA by back-biting reaction of the OH end groups. For optimization of the reaction conditions, the effects of temperature, pressure, PLA molecular weight, and catalyst type on the lactide synthesis were examined. The fraction of D,L-lactide decreased with increasing temperature. Among the various Sn-based catalysts, the D,L-lactide fraction was maximized when SnO was used. A higher yield with lower racemization was observed at lower pressure. The conversion of PLA was maximized at an oligomeric PLA molecular weight of ca. 1380. The yield of lactide increased but the fraction of D,L-lactide decreased with increasing molecular weight. The highest conversion with the lowest racemization degree was obtained at a catalyst concentration of 0.1 wt%. The lactide was more sensitive to racemization because of the entropic effect.

• Korean journal of food and cookery science
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• v.3 no.1
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• pp.78-85
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• 1987

2M D-glucose and 2M D-glucose with 0.4M citric acid were heated at $100^{\circ}C$ for 12, 24, 48hours. The color intensity of these browning reaction products and the fractionated materials by Sephadex G-15 were measured as absorbance at 490nm with a spectrophotometer. The control (soybean oil) and the soybean oil substrates containing equal amounts of ethanol extracts taken from each fraction group were stored at $40.0\pm$1.0^{\circ}C$$ in an incubator for 30 days Antioxidant activities of browning reaction products determined by peroxide value and TBA value the soybean oil. The results were as follows. 1. According to increase heating time and to add citric acid, color intensity was increased. Color intensity of Fraction II(fraction 10~18 high molecular weight) was higher than other fraction group, especially Fraction II of sample F (glucose with citric acid, heated at $100^{\circ}C$ for 48hours) was the highest. 2. All of the fractionated material was showed antioxidant effect but Fraction I (high molecular weight) was more oxidized than the control Fraction IV, V (fraction 28~45; low molecular weight) was showed the highest antioxidant effect.

• Preventive Nutrition and Food Science
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• v.11 no.4
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• pp.261-267
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• 2006

This study investigated the physiological activities of different molecular weight (MW) fractions of crude polysaccharide from $D\check{o}d\check{o}k$ (Codonopsis lanceolata). The crude polysaccharide cut off for each fraction was: <1,000 MW (Fr I), 1,000 MW

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.651-657
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• 1995

The antioxidative activity of each fraction in human milk was examined using H2O2 and FeSO4-induced lipid peroxidation of mouse liver homogenate in order to elucidate the antioxidative substances of human milk. High molecular weight(~>20KD) fraction had more antioxidative effect on lipid peroxidation than low molecular weight(~ <20KD) fraction. Furthermore, the changes of antioxidative enzyme activities were estimated during lactation to study the roles of human milk. The human milk showed high activities of catalase, glutathione(GSH) peroxidase and GSH S-transferase. These results suggest that the antioxidative activities may mostly be attributed to high molecular weight fraction containing catalase, GSH peroxidase and GSH S-transferase.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.630-634
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• 2011

Enzymatic hydrolysate of porphyran from Porphyra yezoensis was prepared by treatment with ${\beta}$-agarase. The hydrolysate was fractioned into molecular sizes of <3, 3-30, and 30-300 kDa using an ultrafiltration membrane. The membrane fractions were further separated into neutral and anionic fractions using Dowex $1{\times}8$ ion exchange chromatography. After hydrolysis of porphyran with ${\beta}$-agarase, 23.2% of the starting porphyran was recovered as a neutral fraction of low-molecular weight (<3 kDa), and 28.9% remained as an enzyme-resistant anionic fraction of high molecular weight (>300 kDa). Desulfation of porphyran and $^{13}C$-NMR analysis of the anionic fraction of low molecular weight (<3 kDa) showed that the anionic fraction has a backbone consisting of 3-linked ${\beta}$-D-galactose units alternating with either 4-linked a-L-galactose 6-sulfate or 3, 6-anhydro-a-L-galactose units. These results indicate that porphryan is a copolymer of two moieties, about 25% of which are composed of neoagarose moieties and 75% as anionic moieties.

• The Journal of the Society of Stroke on Korean Medicine
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• v.15 no.1
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• pp.1-12
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• 2014

■ Objectives This study was designed to investigate the effects of Ephedra Herba hexane fraction on lipid levels in serum and lipid accumulation in liver tissue in Hyperlipidemic mice. ■ Methods Hyperlipidemia was induced by providing high fat diet for 4 weeks. Normal group was provided with normal diet. CTL groupwas provided with high fat diet. Ephedra Herba hexane fraction group was provieded with high fat diet and administered orally in the concentration of 1.5mg/kg body weight/day for 2 weeks. In this experiment, effects on total cholesterol, HDL-cholesterol, triglyceride, AST, ALT, fasting blood glucose in serum were measured. In addition histopathological changes in liver tissue were also observed. ■ Results Ephedra Herba hexane fraction did not affects weight gain, serum AST and ALT in hyperlipidemic mice. Oral administration of Ephedra Herba hexane fraction lowered levels of total cholesterol and triglyceride, which were elevated by induction of hyperlipidemia. In addition, Ephedra Herba hexane fraction group showed downward tendency of lipid accumulation compared with CTL group. Finally, administration of Ephedra Herba hexane fraction lowered fasting blood glucose significantly. And Ephedra Herba hexane fraction also ameliorates anti-oxidative stress systems in internal organs which play key role in disease prevention. ■ Conclusion These results suggest that Ephedra Herba hexane fraction can prevent lipid accumulation in liver tissue through regulation of dyslipidemia and hyperglycaemia.

• Journal of Environmental Science International
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• v.7 no.1
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• pp.104-111
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• 1998

The Dongbok lake water before and after alum coagulation and activated carbon adsorption were analyzed in terms of organic contents, molecular weight distributuin (MWD), and UV-absorbance. Dissolved organic compounds in the Dongbok lake were fractionated into three molecular size classes by gel permeation chromatography. The fractionation was reasonably successful in isolating compounds with The bulk of the dissolved carbon was present in compounds of molecular weight in the range of 3,000~10,000. Alum coagulation preferentially treated molecules of high molecular weight, which has molecules larger than 10,000. The dissolved organic carbon (DOC) removal after activated carbon adsorption was high in the Fraction B , IR . The $A_{260}$/DOC ratio after alum and activated carbon treatment the Fraction II, III. This results suggest that the organics remaining after each treatment has a trihalomethane formation potential

• Korean Journal of Pharmacognosy
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• v.29 no.2
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• pp.120-124
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• 1998

For the purpose of evaluating protective components against alcohol-induced toxicity, the active components enhancing alcohol metabolism was pursued from water soluble fraction by ethanol precipitation and DEAE-cellulose chromatographic technique. As a result, various high molecular weight fractions from Aloe vera and Aloe arborescens, on a single oral administration in rats were found to cause a significant decrease in the blood ethanol concentration as well as enhancement of liver cytosolic ADH and ALDH activities and among which, a strong acidic high molecular weight fraction was demonstrated to exhibit the most potent enhancing activity on ethanol metabolism.

• Food Science of Animal Resources
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• v.32 no.3
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• pp.308-315
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• 2012

This study was conducted to examine the effects of egg shell membrane hydrolysates (ESMH) on skin whitening, wound healing, and UV-protection. ESMH was divided into three groups by molecular weight (Fraction I: above 10 kDa of ESMH, Fraction II: 3 kDa-10 kDa of ESMH, Fraction III: below 3 kDa of ESMH). As a result, all of ESMHs showed over 90% of protein contents. The wound healing experiment using HaCaT cells showed that the fraction I was slightly superior to other fractions depending on the concentration though it was not significantly different. In the experiments of inhibition of tyrosinase and L-3,4-dihydroxyphenylalanine (L-DOPA) oxidation to verify the L-DOPA whitening effect, the whole ESMH (before fractioning) showed a similar amount of inhibition effect with arbutin (control). In the inhibition of melanin formation in B16-F1 melanoma cells, the fraction I showed a high inhibitory effect. In the experiment for protecting the skin from ultraviolet rays using HaCaT cells, all the fractions showed a higher rate of cell viability than the control. In conclusion, this study confirmed that the cosmetic effects of ESMHs such as skin whitening, wound healing, and UV-protection, which were divided depending on the molecule weight. We could confirm that the possibility of ESMHs as a material for functional cosmetics.