• Parasites, Hosts and Diseases
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• v.33 no.1
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• pp.65-68
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• 1995

We examined stool specimens of the residents in the emigi·ation camp in Tijuana, Mexico for helminth eggs or protozoan cysts with formalin-ethyl acetate concentration method in February and July 1992. Out of 92 examined samples, number of positive was 49 (53.3%). While number of cumulative positive was 66 (71.7%). Cysts of Entnmoeba coli (29.3%) Giardio lomblia (9.8%), Entamoebo histolytica (7.6%), and eggs of Tqenic app. (6.5) were most frequently observed. Filtered water supply and chemotherapy were required in this camp.

• Journal of the Korean Chemical Society
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• v.32 no.2
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• pp.144-148
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• 1988

A novel synthetic route to 1,4-dihydropyridine mono carboxylic acid derivatives is described. Allyl methyl 2,6-dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3, 5-dicarboxylate (IV) was treated with $Pd(OAc)_2$ in dioxane for 30 min at 110$^{\circ}C$ with reflux to give the mono acid compound(V) in 94% yield. The mono acid intermediate was converted to 2-(N-benzyl-N-methylamino)ethyl methyl 2,6-dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3, 5-dicarboxylate (VII) (Nicardipine) and their derivatives in 70~85% yield.

• Journal of Ginseng Research
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• v.13 no.1
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• pp.66-70
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• 1989

The specific growth rate was investigated to find the of(emits of major ginseng components in fractions extracted by several solvents on the growth of Candida parapsilosis. The cell proliferation of C. purapsilosis was inhibited by fraction A(hexane soluble components), while enhanced by fraction B(Et2O soluble components), C(AcOEt soluble components), E and F(dialysis outer and inner extract). The additive stimulant effect of cell proliferation was exerted by fraction D(crude saponinE) and B, C or E.

• Journal of the Korean Wood Science and Technology
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• v.29 no.4
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• pp.48-52
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• 2001

The needles of Pinus densiflora, grown in the campus of Kangwon National University were collected, extracted with acetone-$H_2O$ (7:3, v/v) and freeze dried to give 10.4 g of ethylacetate soluble powder. A portion of the freeze dried powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol, and ethanol-hexane mixture as eluents. The extractives contained a large amount of flavan compounds in addition to a small amount of flavonoid derivatives such as kaempferol-3-O-glucopyranoside, and quercetin-(6"-O-acetyl)-glucopyranoside which has not been isolated from this species yet. Some spectrometric analyses such as NMR and FAB-MS were performed to identify the structures of the isolated flavonoid derivatives.

• Korean Journal of Microbiology
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• v.36 no.4
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• pp.312-315
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• 2000

Paecilomyces tenuipes DGUM 32001, an entomopathogenic fungus, was examined to evaluate in vitro cytotoxicity against several human cancer cells. The fruiting bodies of P. tenuipes were extracted with methanol and fractioned with some organic solvents i.e. chloroform, ethyl acetate, and butanol. The methanol extracts of P. tenuipes showed significant cytotoxicity against human cancer cell lines; HeLa, HeLa S3, and A-431. Among the fractions tested, the ethyl acetate fraction had the highest cytotoxicity against three cancer cell lines. The $IC_{50}$ values of ethyl acetate fraction against HeLa, HeLa S3, and A-431 were 13, 35, and 30 $\mu$g/ml, respectively. However, cytotoxicity might not be due to apoptosis. The methanol extract of cultured mycelia showed high cytotoxicity against HeLa cell lines.

• Korean Journal of Agricultural Science
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• v.23 no.2
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• pp.177-181
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• 1996

Biological activities of MeoH extract of Phytolaccn americana L. was investigated. The extract was reextracted with ethyl acetate and fractionated by silica gel colum chromatography. The active compound was analysed by IR. $^1H$-NMR, $^{13}C$-NMR and MS and identified as $\alpha$-spinasterol. $\alpha$-spinasterol induced necrosis of primary root and resulted the death of the examed plant. The compound also inhibited growth of Mucor racemous but it showed weak cytotoxicity to 2 animal cancer cell lines (L1210, K562).

• Korean journal of food and cookery science
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• v.13 no.1
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• pp.56-63
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• 1997

Antimicrobial activity of Sancho (Zanthoxylum schinifolium) was investigated. Methanol extract of dried Sancho was fractionated to hexane, chloroform, ethylacetate, butanol, and aqueous fractions. Chloroform fraction among these fractions showed the highest inhibitory effect on the microorganisms such as Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Lactobacillus plantarum at 1000 $\mu\textrm{g}$/$m\ell$. Chloroform fraction was further fractionated into 4 fractions by silica gel column and thin layer chromatography (TLC). The fraction 3 on TLC exhibited the highest antimicrobial activity. In the 2nd fractionation, subfration 2 was identified as hexadecanoic acid by MS, $^1$H-NMR and IR.

• Elastomers and Composites
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• v.38 no.4
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• pp.316-325
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• 2003

The blends of waste-polyethylene (W-PE)/waste-ethylene vinyl acetate copolymer (W-EVA) with inorganic and phosphorous flame retardants (i.e., aluminium hydroxide, magnesium hydroxide, and so on) were prepared by melt mixing techniques at different compositions and foamed. The flame retardancy and foaming properties of the blends, limiting oxygen index (LOI), heat release rate (HRR), carbon monoxide yield (COY), total heat release (THR), effective heat of combustion (EHC), expandability and cell structure were investigated using cone calorimeter, SEM, LOI tester and polarizing microscope. When the composition ratios of the W-PE/W-EVA blends were 50/50 (w/w), and the ranges of the flame retardants contents were $175{\sim}220 phr$, we could obtain foams with the uniform and closed cell, high expandability (1900 % or more), high LOI, and low HRR values. These results depend on crosslinking and loaming conditions, a char formation and smoke suppressing effect. Aluminium hydroxide had more effect in the increase of LOI than magnesium hydroxide, while magnesium hydroxide considerably affected the decrease of HRR and COY.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.590-595
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• 1995

To examine the characteristics of antioxidative compounds from Capsella bursa-pastoris, ethanol extracts were separated into five organic solvent fractions; hexane(Fr.H), diethyl ether (Fr.E), ethyl acetate(Fr.EA), butanol (Fr.B), and water(Fr.D) fractions. Fr.B showed the greatest electron donating ability and inhibitory effect on lipid peroxidation. Whereas Fr.E had the most excellent activity in the superoxide radical scavenging activity by xanthine/xanthine oxidase-cytochrome c reduction system. The inhibitory effect of each fraction on xanthine oxidase was also measured. Fr.E had the strongest inhibitory effect on xanthine oxidase and $IC_{50}$ was $5.65\;{\mu}g$. The results indicate that the superoxide radical scavenging activity of Fr.E is caused by the inhibitory effect on radical generating system of xanthine oxidase. Also the order of inhibitory effect on xanthine oxidase was Fr.B

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.458-463
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• 2003

This study was conducted to investigate the effects of dandelion leaf (Taraxacum officinale) extracts on hepatic antioxidative system in high cholesterol-fed rats. Four groups of rats were given high cholesterol diets containing 10 g cholesterol/kg and 2.5 g sodium cholate/kg for 6 weeks. The control group received a diet without dandelion leaf extract and the other three groups received dandelion leaf extracts, ie, water, ethyl acetate and ether extracts, respectively. There were no significant difference in cytochrome P-450 contents among four groups. Hepatic xanthine oxidase activity was significantly lower in water extract group than the other three groups. Superoxide dismutase activity was significantly lower in three dandelion leaf extract groups, but catalase activity was significantly higher in three dandelion leaf extract groups than control group. Glutathione peroxidase and glutathione S-transferase activities were significantly increased in water extract group than control group. Lipid peroxide content was decreased in water extract group than control group.