• Journal of Nutrition and Health
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• v.23 no.2
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• pp.135-147
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• 1990

This study was devised to observe the cytotoxic activities of garlic extracts against various cancer cells, that is, murine leukemic lymphocyte(L1210 and P388) and human rectal(HRT-18) and colon cancer cells(HCT-48 and HT-29) in vitro, and murine ascitic tumor cell(S-180) in vivo. Each cell-line except S-180 was cultured in medium containing serial concentration of the garlic extract in vitro. Inhibitory effect n the growth rate of the cancer cells was stronger in extracts of petroleum ether than that of ethanol. A lipid soluble compound in the extracts of garlic was cytocidal to murine leukemic cells, human rectal and colon cancer cells in vitro. The growth rates of the cancer cells in medium containing garlic extracts were inhibited gradually to a significant degree in proportion to the increase of the extract concentration. The cytotoxic activity of garlic active fraction from TLC was about 2.3 times more potent than that of crude garlic extract, one unit of cytotoxic activity against L1210 cells being equivalent to 4.2$\mu\textrm{g}$ and 1.8$\mu\textrm{g}$ from the crude garlic and active fraction, respectively. The Rf value of the active fraction on silica-gel TLC was 0.18 in condition that petroleum ether/ethyl ether/acetic acid mixture(90:10:1, v/v/v) was used as a developing solvent. The survival times of mice inoculated with S-180 cells were extended about 1.5 to 2 times in the groups treated with garlic extract(through i.p. and oral administration) compared with their control group(no garlic extract treatment). Observations were carried out on S-180. Ethanol extracts of garlic injured markedly tumor cells within 3 hours after injection.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.15-21
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• 2007

The aim of this paper is controlling ignition timing and load in homogeneous charge compression ignition (HCCI) combustion with low cetane number fuel, hydrogen. Homogeneous charge compression ignition (HCCI) combustion is an advanced combustion technology that achieves higher thermal efficiency and lower $NO_x$ emissions than that of conventional combustion system. Dimethyl ether (DME), which has been researched widely as the most attractive alternative fuel of diesel, is attractive for HCCI combustion because of the easy evaporation. In this study, the single cylinder DME engine operated with a direct injection system has been used to investigate combustion processes and emissions of DME HCCI with a premixed hydrogen supply. The experiment was carried out under various engine speed and fraction rates of hydrogen. As a result, the increase of fraction rates of hydrogen retard the DME ignition timing and eliminated the knocking during high engine speed condition. IMEP was increased with increase of fraction rates of hydrogen by 30%. 40% of the fraction rates of hydrogen resulted in misfiring. The $NO_x$ emission was reduced by increasing the fraction rates of hydrogen, but HC emission was increased.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.595-600
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• 1997

The antioxidant activity of the solvent fractions extracted from onion skin was examined. The antioxidant activity of methanol extract at the cencentration of 0.02% and 0.03% was stronger than that of mixed tocopherol. The antioxidant activity of the fractions of methanol extract increased in the order of butanol> ethyl acetate> ethyl ether> water fraction. The antioxidant activity of each fractions was strongly related with total phenol content and HDA. Further separation of butanol fraction by TLC yielded 6 fluorescent bands with Rf values of 0.20, 0.33, 0.49, 0.60 and 0.94. The total phenol content and HDA of fluorescent band, Rf 0.96, were remarkable higher than those of the other band and exhibited a strong UV absorption at 255 nm and 317 nm, which would be specifically produced by flavonol. Spectral analyses indicated that the major antioxidant component was quercetin aglycone (3,3',4',5,7-pentahydroxyflavone).

• YAKHAK HOEJI
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• v.37 no.5
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• pp.476-482
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• 1993

For the investigation of medicinal resources in Crataegus species, the present study was carried out to evaluate the pharmaco-constituents in the leaves of Crataegus Pinnatifida var. psilosa (Rosaceae). Fruits has folk medicine in Korea. From the $Et_{2}$O fraction of MeOH extract, a new compound, apigenin-8-C-(6"-acetyl)-$\beta$-D-glucopyranoside, named psilosin and three known compounds, ursolic acid, phytosterol complex and (-)-epicatechin were isolated and identified on the basis of their physico-chemical properties and spectroscopic evidences (UN, IR, NMR and mass etc.) in comparison with authentics, respectively.

• Journal of Food Hygiene and Safety
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• v.12 no.4
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• pp.315-320
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• 1997

Panax ginseng C.A. Meyer has been extensively used in the traditional oriental medicine as a restorative, tonic and prophylatic agent. This study was devised to develop a chemopreventive agent from panax ginseng to be able to suppress the genotoxicity and oxidative damage by ractive oxygen species, which are involved with cancer or aging. Ginseng petroleum ether extract (GPE) and one of its fraction, P2, showed an antioxidative effect on the lipid peroxidiphenyl-2-picryl hydrazil (DppH) radical generation. They also showed the suppressive effect of H2O2 or KO2 induced DNA damage by single cell gel electrophoresis (SCGE). Results from our study indicate that GPE and P2 are capable of protecting lipid peroxidation, and oxidative DNA damage. Therefore, GPE and P2 may be useful chempreventive agents which are involved with cancer and aging.

• Korean Journal of Pharmacognosy
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• v.11 no.2
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• pp.69-74
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• 1980

The rhizome of Polygonatum robustum Nakai (Liliaceae) has been used as a crude drug for the purpose of tonic and thirst cure in Korea. The dried rhizomes were extracted with hot ether, then the residue was extracted with hot alcohol. 1) The three kinds of chemical constituents, substance, I, II and III were isolated by silicagel column chromatography from ether and alcohol extracts of the rhizomes. Substance I was confirmed as ${\beta}-sitosterol$, $C_{29}H_{50}O$ by mass and IR spectroscopy. Substance II was identified as stigmasterol by GLC. 2) Substance III was obtained by crystallization from the column chromatography of alcohol fraction. It was suggested as diosgenin based on chemical and spectral discussions. 3) The concentration of blood sugar was significantly decreased in the group administered the ether extract with 20% dextrose and adrenaline in comparison to that of 20% dextrose and adrenaline along.

• Journal of the Korean Wood Science and Technology
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• v.31 no.3
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• pp.30-34
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• 2003

This study was carried out to investigate the constituents of Platycarya strobilacea (Juglandaceae) wood. To isolate compounds, wood was extracted with ethanol (EtOH) and then partitioned with petroleum ether, diethyl ether (Et₂O) and ethyl acetate (EtOAc) successively. After partitioned, diethyl ether fraction was subjected to column chromatography with various solvent system in silica gel and/or Sephadex LH-20. Structures were elucidated by spectroscopic methods including MS, ¹H, ¹³C and 2D-NMR experiments. Three compounds were isolated from the wood and identified as kaempferol 3-O-𝛼-L-rhamnopyranoside (afzelin, I), quercetin 3-O-𝛼-L-rhamnopyranoside (quercitrin, II), myricetin 3-O-𝛼-L-rhamnopyranoside (myricitrin, III).

• Journal of Life Science
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• v.21 no.9
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• pp.1214-1218
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• 2011

We investigated the fruits of Rubus crataegifolius Bge, a plant which has been traditionally used in Korea in phytotherapy, to describe antioxidant materials from plant sources. R. crataegifolius fruits were extracted with methanol and further fractionated into n-hexane, diethyl ether, and ethyl acetate. The antioxidant activity of each fraction and the residue was assessed using a 1,1-diphenyl-2-picrylhydrazyl (DPPH), $H_2O_2$ radical scavenging method, and their cytotoxicity on human primary kerationcyte (HK) was determined by an MTS assay. The R. crataegifolius fruit methanol extract showed strong antioxidant activity (75.04%, 50%) compared with vitamin C (79.9%, 54.1%) by the DPPH, and $H_2O_2$ method, respectively. The measured activity from the subsequent extracts of the methanol extract were 20.3% for n-hexane fraction (HF), 68.8% for diethyl ether fraction (DF), 67.1% for ethyl acetate fraction (EF), and 67.1% for the residue fraction (RE) by DPPH and 2.2% for HF, 1.6% for DF, 10% for EF, and 50% for the RE by $H_2O_2$ assay. An oxidative stress model of HK was established under a suitable concentration (1 mM). The cell viability of the RE treated group increased and the percentage of apoptotic cells decreased at concentrations of 0.005-0.02% RE compared with the $H_2O_2$ treated group. Fruit extracts of the medicinal plant R. crataegifolius showed potent antioxidant activity and the ability to relieve cell damage from $H_2O_2$ induced injury to HK.

• The Journal of Korean Medicine
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• v.31 no.3
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• pp.98-106
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• 2010

Objective: To examine the in vitro antioxidant and hepatoprotective properties of Amomum xanthoides extract and its fractions. Methods: Methanol extract of Amomum xanthoides was fractionated into three fractions; petroleum ether fraction (PFAX), water fraction (WFAX) and ethyl acetate fraction (AFAX). The antioxidant and hepatoprotective effects of these fractions were compared by in vitro experiments. Results: The total phenols content and DPPH (1 1-Diphenyl-2-picrylhydrazyl) radical scavenging activity was found significant in AFAX when compared with other fractions (PFAX, WFAX). AFAX significantly inhibited NO production by RAW 264.7 cells in LPS-activated condition. In Hep $G_2$ cells, AFAX markedly prevented the leakage of LDH and release of AST against CCl4 challenge. Conclusion: Amomum xanthoides and especially ethyl acetate fraction have potent antioxidative and hepatoprotective properties.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.13-21
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• 1998

To investigate the cytotoxic effect of Platycodon grandiflorum DC, petroleum ether extract of Platycodon grandiflorum DC was partially purified by a silica gel column chromatography. Among several fractions, fraction D which was obtained under the elution with a 7:3 mixture of petroleum ether and ethyl ether, showed patent cytotoxicity against mouse leukemia cell line (L1210), human rectum cancer cell line (HRT-18) and human colon cancer cell lint (HCT-48).