• Journal of Korean Society for Atmospheric Environment
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• v.21 no.2
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• pp.191-204
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• 2005

Building and furnishing materials and consumer product are important sources of volatile organic compounds(VOCs) and other aldehydes in the indoor environment. Some available evidence indicates that VOCs can cause adverse health effects to the building occupants and contribute to some of the symptoms of what we call, 'Sick House Syndrome' in Korea. The aims of this study were to evaluate the efficiency of emission system and to investigate comparison of the emission characteristics of different building materials such as wall-papers, paints, and adhesives. The emission of VOCs from building materials were determined in the small chambers defining the temperature, relative humidity, and ventilation rate in this study. VOCs were sampled for 20 minutes using Tenax-TA tubes and analysed by GC-MS with thermal desorption. The stability of conditions for temperature and relative humidity in this small chamber system showed that the fluctuation of temperature was between 25.4$\pm$0.3$^{\circ}C$ and that of relative humidity was 50.2$\pm$0.6$\%$ under the airflow rate of 167 mL/min. The emission tests from building materials resulted in TVOC emission rates of 0.011 $\~$ 3.108 mg/m$^{2}$h after 7 days. The general wall-papers emitted toluene abundantly and the natural wall-papers mainly emitted n-butanol and a minor amount of alkanes compound such as n -tetradecane. The remainder consisted of toluene, m,p -xylene, and styrene. The paints mainly emitted toluene and the adhesives mainly emitted chloroform as well as toluene. As a result, this study is expected to suggest meaningful data for future studies in exposure control through selecting healthy building materials and for the establishment of guidelines for various building materials in Korea.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.93-97
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• 2005

Three antioxidants, Sa-1, Sa-2 and Sa-3, were isolated from the MeOH extract of the mushroom Sarcodon aspratus through EtOAc extraction, silica gel and Sephadex LH-20 column chromatography, and $C_{18}$ HPLC. The structures of the compounds were determined mainly by NMR and mass spectroscopic data analyses. Sa-1, Sa-2 and Sa-3 were identified as diketopiperazines, and their structures were determined to be cyclo(prolyl-valyl), cyclo(prolyl-leucyl) and cyclo(prolyl-isoleucyl), respectively. This is the first time that these compounds were isolated from this mushroom. They showed antioxidant activity by scavenging DPPH radical $(EC_{50}\;0.15{\sim}0.18\;mM)$ and superoxide radical $(EC_{50}\;0.21{\sim}0.24\;mM)$.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.1
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• pp.57-64
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• 2013

Cells can resist and even recover from stress induced by acute hypoxia, whereas chronic hypoxia often leads to irreversible damage and eventually death. Although little is known about the response(s) to acute hypoxia in neuronal cells, alterations in ion channel activity could be preferential. This study aimed to elucidate which channel type is involved in the response to acute hypoxia in rat pheochromocytomal (PC12) cells as a neuronal cell model. Using perfusing solution saturated with 95% $N_2$ and 5% $CO_2$, induction of cell hypoxia was confirmed based on increased intracellular $Ca^{2+}$ with diminished oxygen content in the perfusate. During acute hypoxia, one channel type with a conductance of about 30 pS (2.5 pA at -80 mV) was activated within the first 2~3 min following onset of hypoxia and was long-lived for more than 300 ms with high open probability ($P_o$, up to 0.8). This channel was permeable to $Na^+$ ions, but not to $K^+$, $Ca^+$, and $Cl^-$ ions, and was sensitively blocked by amiloride (200 nM). These characteristics and behaviors were quite similar to those of epithelial sodium channel (ENaC). RT-PCR and Western blot analyses confirmed that ENaC channel was endogenously expressed in PC12 cells. Taken together, a 30-pS ENaC-like channel was activated in response to acute hypoxia in PC12 cells. This is the first evidence of an acute hypoxia-activated $Na^+$ channel that can contribute to depolarization of the cell.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.984-993
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• 1999

The ethanol extracts and its n-hexane fraction of Dystaenia takesimana Kitagawa exhibited growth inhibition on Listeria monocytogenes ATCC 19111, ATCC 19112, ATCC 19113, ATCC 19114 and ATCC 15313. The minimum inhibitory concentration of the ethanol extract and its n-hexane fraction were 50 ppm and below 30 ppm on Listeria monocytogenes respectively. By silica gel column chromatography, the active fraction A8 was obtained from the ethanol extract of Dystaenia takesimana Kitagawa. After three times of column chromatography, the SBD-1 and SBD-2 were separated from the A8 fraction of the ethanol extract of Dystaenia takesimana Kitagawa. Antimicrobial activity of the SBD-l and SBD-2 was lower than that of the A8. And the A8 exhibited growth inhibition on five strains of Listeria monocytogenes at the level of $10{\sim}30$ ppm and the bactericidal effect was confirmed at same the level. The purified antimicrobial active compound was identified as (9z)-heptadeca-l,9-dien-4,6-diyn-3,8-diol, falcarindiol, by EI/MS, $^{1}H-NMR$ and $^{13}C-NMR$.

• Korean Journal of Medicinal Crop Science
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• v.11 no.2
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• pp.161-166
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• 2003

Korean ginseng(Panax gmseng C.A. Meyer) is very difficult to obtain stable production of qualified ginseng roots because of variable stresses in soil environments. In environment stresses, soil condition is the most important factor, among which nutrients, especially inorganic materials such as N, P, K, Ca, Mg, Fe, etc., influence greatly on the ginseng growth. However, present ginseng field soils in Korea contain so much amount of such inorganic materials that a variety of remarkable disorders were noted in many ginseng plantations, resulting in decrease of qualitative ginseng production. Therefore, it is required to search for genetic resources and genes tolerant to salt stress for the development of ginseng cultivars. Selection of stress-tolerant ginseng lines in fields is very difficult because it is almost impossible to control properly the environmental conditions of soil. On the contrary, it can be studied with ease to search for stress-tolerant ginseng lines through in vitro culture because of easy manipulation of stress conditions. Murashige & Skoog(MS) media with 2.5 folds of $KNO_3,\;NH_4NO_3,\;MgSO_4\;7H_2O,\;KH_2PO_4,\;and\;CaCl_2\;2H_2O$ was established for the selection of ginseng lines tolerant to salt stress under the embryo culture.

• Analytical Science and Technology
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• v.28 no.1
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• pp.58-64
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• 2015

This study aimed to investigate the concentration distributions and formation characteristics of trihalomethanes (THMs) in drinking water supplies to rural communities. Water samples were collected twice from 40 rural households located on the outskirts of Chuncheon city of Gangwon Province in the summers of 2010 and 2011, and urban drinking water samples were collected from 20 faucets during the same period in 2011 for comparison purpose. Water temperature, pH, and residual chlorine (total and free) concentrations were measured in the field, and samples were analyzed for dissolved organic carbon (DOC) and THM concentrations in the laboratory. The average DOC concentrations in rural water samples were not greatly different between groundwater (n = 20) and surface water (n = 20) which were used as sources for drinking water (1.81 vs. 1.91 mg/L). However, the average concentrations of total THMs (TTHMs) in groundwater ($9.77{\mu}g/L$) were much higher than those in surface water ($2.85{\mu}g/L$) and similar to those in urban drinking water samples ($10.8{\mu}g/L$). Unlike urban water supply, rural water (particularly groundwater) contained more brominated THM species such as dibromochloromethane (DBCM), suggesting its relatively high content of bromide ion (Br-). This study showed that rural water supplies have different THM formation characteristics from urban water supplies, probably due to their differences in source water quality properties.

• The Korean Journal of Food And Nutrition
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• v.27 no.3
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• pp.532-537
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• 2014

Cortex Phellodendri (CP) is derived from the dried bark of Phellodendron amurense. It has been widely used as a drug in traditional Korea medicine for treating diarrhea, jaundice, swelling pains in the knees and feet, urinary tract infections, and infections of the body surface. Many analytical methods have been used to study oriental herbal medicines, such as thin-layer chromatography, column liquid chromatography, and high performance liquid chromatography (HPLC). In this study, preparative centrifugal partition chromatography (CPC) was successfully carried out in order to separate pure compounds from a CP methanol extract. The optimum two-phase CPC solvent system was composed of n-butanol: acetic acid: water (4:1:5 v/v/v). The flow rate of the mobile phase was 3 mL/min in ascending mode with rotation at 1,000 rpm. The CPC-separated fraction and purification procedures were carried out by preparatory HPLC. The $^1H$ NMR spectrum revealed that the resonances at ${\delta}$ 4.10 and 4.20 ppm corresponded to three protons ($-OCH_3$), whereas those at ${\delta}$ 6.10 ppm corresponded to two protons ($-OCH_2O-$). Further, two aromatic protons (H-11 and H-12) conveys a doublet-doublet pattern. The H-11 doublet and H-12 doublet appear at ${\delta}$ 7.98 and 8.11, respectively. The $^{13}C$ NMR. spectrum showed a tetrasubstituted with a methylenedioxy group at C2 and C3, and two methoxy groups at C9 and C10. The chemical structure of the berberine was identified by $^1H$, $^{13}C$-nuclear magnetic resonance and electrospray ionization-mass spectroscopy spectral data analysis.

• The Korean Journal of Pharmacology
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• v.32 no.2
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• pp.127-138
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• 1996

The effects of adenosine analogues on the electrically-evoked acetylcholine(ACh) release and the influence of ischemia on the effects were studied in the rat hippocampus. Slices from the rat hippocampus were equilibrated with $0.1{\mu}M$ $[^3H]-choline$ and the release of the labelled product, $[^3H]-ACh$, was evoked by electrical stimulation(3 Hz, 2 ms, 5 $VCm^{-1}$ and rectangular pulses for 2 min), and the influence of various agents on the evoked tritiumoutflow was investigated. Ischemia(10 min with 95% $N_2$ + 5% $CO_2$) increased both the basal and evoked ACh release. These increases were abolished by glucose addition into the superfused medium, and they significantly inhibited either by 0.1 & $0.3{\mu}M$ TTX pretreatment or by removing $Ca^{++}$ in the medium. MK-801($1{\sim}10{\mu}M$), a specific NMDA receptor antagonist, and glibenclamide $(1{\mu}M)$, a $K^+-channel$ inhibitor, did not alter the evoked ACh release and nor did they affect the ischemia-induced increases In ACh release. However, polymyxin B(0.03 mg), a specific protein kinase C inhibitor, significantly inhibited the effects of ischemia on the evoked ACh release. Adenosine and $N^6-cyclopentyladenosine$ decreased the ACh release in a dose dependent manner in ischemic condition, though the magnitude of inhibition was far less than those in normal(normoxic) condition. However, the treatment with $5{\mu}M$ DPCPX, a potent $A_1-adenosine$ receptor antagonist, potentiated the ischemia-effect. These results indicate that the evoked-ACh release is potentiated by ischemia, and this process being most probably mediated by protein kinase C, and that the decreased effect of ACh release mediated by $A_1-adenosine$ receptor is significantly inhibited in ischemic state.

• Applied Biological Chemistry
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• v.20 no.1
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• pp.109-116
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• 1977

Much attention has been paid to the fact that quite a few herbicides such as phenylcarbamates, phenylureas, and acylanilides form azo compounds known as carcinogens by virtue of the microoranisms in soil. In consequence, many investigators synthesized. TCAB, an azo compound, starting from 3,4-dichloronitrobenzene for the related studies. However, the authors were under the necessity of synthesizing $^{14}C-ring-labeled$ TCAB from $^{14}C-ring-labeled$ 3,4-DCA available, in addition to making up for the disadvantage of dechlorination in the reduction of 3,4-dichloronitrobenzene. The new method is as follows:TCAB, $^{14}C-ring-labeled$ and non-labeled, was produced by aerial oxidation of 3,4-DCA catalyzed by CuCl with pyridine as solvent at $60^{\circ}C$ for 5-12 hrs, giving 80.2% yield. The procedure forpurification was described in detail. The identities of TCAB isomers were confirmed by means of autoradiography, TLC, GLC, IR, and MS.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.539-547
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• 2013

This study investigates the change of chemical components, antioxidant and antimutagenic activity in Glycyrrhiza uralensis Fischer stems and leaves (GU) by the various processing methods, as follows: fresh (GU-1), dried under the shade (GU-2), blanched (GU-3), roasted 3 times (GU-4), roasted 4 times (GU-5). The components have been identified and quantified through the use of gas chromatograph-mass spectrometry (GC-MS). At results, cis-1,3-dimethyl-2-methylenecyclohexaneat at 19.7 min and n-hexadecanoic acid at 21.5 min were detected in five kinds of extract. 3-O-Methyl-D-fructose at 17.8 min was observed in four extracts except in GU-1 and aminopyrazine at 19.8min was observed in four extracts except in GU-4. The total phenolics contents was high in GU-4(3.38 g/100 g). ABTS radical scavenging was high in GU-5($EC_{50}$, 0.57 ug) and DPPH radical scavenging was high in GU-4($EC_{50}$, 2.66 ug). The extracts of GU-3, GU-4, and GU-2 were most potent in anti-mutagenicity activity against 1-NP, Trip-P-1, and Trip-P-2, respectively. GU-3 and GU-4 also showed most potent effect of anti-mutagenicity on 2-AA and AFB1, respectively.