• Title/Summary/Keyword: Mass Spectrometry (MS)

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Identification of Glutathione Conjugates of 2, 3-Dibromopropene in Male ICR Mice

  • Lee Sang Kyu;Baik Seo Yeon;Jeon Tae Won;Jun In Hye;Kim Ghee Hwan;Jin Chun Hua;Lee Dong Ju;Kim Jun Kyou;Yum Young Na;Jeong Tae Cheon
    • Archives of Pharmacal Research
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    • v.29 no.2
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    • pp.172-177
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    • 2006
  • Hepatotoxic potential of 2, 3-dibromopropene (2, 3-DBPE) and its conjugation with glutathione (GSH) were investigated in male ICR mice. Treatment of mice with 20, 50, and 100 mg/kg of 2, 3-DBPE for 24 h caused elevation of serum alanine aminotransferase and aspartate aminotransferase activities. The hepatic content of GSH was not changed by 2, 3-DBPE. Meanwhile, the GSH content was slightly reduced when mice were treated with 2, 3-DBPE for 6 h and significantly increased 12 h after the treatment. Subsequently, a possible formation of GSH conjugate of 2, 3-DBPE was investigated in vivo. After the animals were treated orally with 20, 50, and 100 mg/kg of 2, 3-DBPE, the animals were subjected to necropsy 6, 12, and 24 h later. A conjugate of S-2-bromopropenyl GSH was identified in liver and serum treated with 100 mg/kg of 2, 3-DBPE by using liquid chromatography-electrospray ionization tandem mass spectrometry. The protonated molecular ions $[M+H]^+$ of S-2-bromopropenyl GSH were observed at m/z 425.9 and 428.1 in the positive ESI spectrum with a retention time of 6.35 and 6.39 min, respectively. In a time-course study in livers following an oral treatment of mice with 100 mg/kg of 2, 3-DBPE for 6, 12, and 24 h, the 2, 3-DBPE GSH conjugate was detected maximally 6 h after the treatment. The present results suggested that 2, 3-DBPE-induced hepatotoxicity might be related with the production of its GSH conjugate.

Survey of the heavy metal contents in avian eggs from Korean markets (국내 유통 중인 식용란의 중금속 함량 조사)

  • Kang, Kyoung-Sook;Park, Hyoung-Sook;Choi, Tae-Seok;Shin, Bang-Woo;Lee, Jeong-Hark
    • Korean Journal of Veterinary Service
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    • v.34 no.3
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    • pp.279-284
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    • 2011
  • This study was carried out to estimate the heavy metal contents (Pb, Cd, Cr, Cu, Mn) in avian eggs sold in Seoul area, Korea from August to December, 2010. The contents of lead, cadmium, chrome, copper, manganese were estimated by inductively coupled plasma mass spectrometry. The concentrations of heavy metals (mean${\pm}$standard deviation, mg/kg) in the avian eggs were as follows: Pb $0.010{\pm}0.018$, Cd $0.000{\pm}0.001$, Cr $0.018{\pm}0.022$, Cu $0.637{\pm}0.163$, Mn $0.397{\pm}0.132$. The contents of lead and cadmium in the eggs were lower than that in meat and other foods of previously reported results. Whereas the contents of copper, manganese were similar to the previously previous results. The average daily intakes of lead and cadmium in the avian eggs were 0.1 and 0.8% respectively, as compared with PTWI (Provisional Tolerable Weekly Intakes) established by FAO/WHO Expert Committee for Food Safety Evaluation.

Analysis of tert-Butanol, Methyl tert-Butyl Ether, Benzene, Toluene, Ethylbenzene and Xylene in Ground Water by Headspace Gas Chromatography-Mass Spectrometry

  • Shin, Ho-Sang;Kim, Tae-Seung
    • Bulletin of the Korean Chemical Society
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    • v.30 no.12
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    • pp.3049-3052
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    • 2009
  • Methyl tert-butyl ether (MTBE) is added to gasoline to enhance the octane number of gasoline, tert-butyl alcohol (TBA) is major degradation intermediate of MTBE in environment, and benzene, toluene, ethyl benzene and xylene (BTEX) are also major constituents of gasoline. In this study, a simplified headspace analysis method was adapted for simultaneous determination of MTBE, TBA and BTEX in ground water samples. The sample 5.0 mL and 2 g NaCl were placed in a 10 mL vial and the solution was spiked with fluorobenzene as an internal standard and sealed with a cap. The vial was placed in a heating block at 85 $^{\circ}C$ for 30 min. The detection limits of the assay were 0.01 ${\mu}$g/L for MTBE and BTEX, and 0.02 ${\mu}$g/L for TBA. The method was used to analyze 110 ground water samples from various regions in Korea, and to survey the their background concentration in ground water in Korea. The samples revealed MTBE concentrations in the range of 0.01 - 0.45 ${\mu}$g/L (detection frequency of 57.3%), TBA concentrations in the range of 0.02 - 0.08 ${\mu}$g/L (detection frequency of 5.5%), and total BTEX concentrations in the range of 0.01 - 2.09 ${\mu}$g/L (detection frequency of 87.3%). The developed method may be used when simultaneously determining the amount of MTBE, TBA and BTEX in water.

Thermal and Photochemistry of Methyl Iodide on Ice Film Grown on Cu(111)

  • Sohn, Young-Ku;White, John M.
    • Bulletin of the Korean Chemical Society
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    • v.30 no.7
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    • pp.1470-1474
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    • 2009
  • Thermal and photochemistry of methyl iodide ($CH_3I)\;adsorbed\;on\;D_2O$ ice film on Cu(111) at 100 K were studied using temperature-programmed desorption (TPD) time-of-flight mass spectrometry (TOF-MS), X-ray and ultraviolet photoelectron spectroscopies. On the basis of TPD, multilayer and monolayer $CH_3I$ molecules desorb from $D_2O$ ice layer at 120 and 130 K, respectively. Photo-irradiation at 100 K exhibits dramatic changes in the TPD and I $3d_{5/2}\;XPS\;of\;CH_3I$ on ice film, due to a dramatic dissociation of $CH_3I$. The dissociation is likely activated by solvated electrons transferred from the metal substrate during photo-irradiation. No other photo-initiated reaction products were found within our instrumental detection limit. During photo-irradiation, the $CH_3I$, $CH_3$ and I could be trapped (or solvated) in ice film by rearrangement (and self-diffusion) of water molecules. A newly appeared parent molecular desorption peak at 145 K is attributed to trapped $CH_3I$. In addition, the $CH_3$ and I may diffuse through ice and chemisorb on Cu(111), indicated by TPD and I $d_{5/2}$ XPS taken with photo-irradiation time, respectively. No molecular ejection was found during photo-irradiation at 100 K. The work functions for $CH_3I/Cu(111),\;D_2O/Cu(111)\;and\;CH_3I/D_2$O/Cu(111) were all measured to be about 3.9 eV, 1.0 eV downward shift from that of clean Cu(111).

Change of the Protection Efficiency in Each Part of Developed Pesticide-Proof Clothes by Repeated Washings (개발 과수용 농약방제복의 반복세탁에 따른 부위별 농약 방호성능의 변화)

  • Shin, Jeoung-Hwa;Hwang, Kyoung-Sook;Lee, Hyo-Hyeon
    • The Korean Journal of Community Living Science
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    • v.22 no.4
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    • pp.615-621
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    • 2011
  • This study was conducted to evaluate of the protection efficiency in each part of developed pesticide-proof clothes by repeated washings. We investigated the effect of repeated laundering on mechanical properties of pesticide-proof clothes (not washed vs 5 times washed). We also examined pesticide infiltration rate into the pesticide-proof clothes by repeated laundering. The patches(TCL paper, surface area 50cm2)were attached to the inside of pesticide-proof clothes(head, chest, right upper-arm, right forearm, left thigh, left calf, back) which subjects had dressed in during pesticide spraying. The patches were detached from working clothes after work. For the extraction of pesticide in pesticide-proof clothes, sonication was applied for 30 min with methanol. The gas chromatography/mass spectrometry (GC/MS) was applied to identify the pesticide component. The results of this study are as follows: The force strength, water-vapour resistance and surface wetting resistance of pesticide-proof clothes decreased 5 times more in washed clothes. The concentration of pesticide was the highest in the head area of pesticide-proof clothes. In seven parts of TLC paper attached to the pesticide proof clothes, the concentration of pesticide was higher in the left thigh. The penetration part and concentration of pesticide increased as washing was repeated. Therefore the conclusion which can be drawn from this study is this: protection efficiency of pesticide-proof clothes decrease by repeated washings.

Anthocyanins in 'Cabernet Gernischet' (Vitis vinifera L. cv.) Aged Red Wine and Their Color in Aqueous Solution Analyzed by Partial Least Square Regression

  • Han, Fu-Liang;Jiang, Shou-Mei;He, Jian-Jun;Pan, Qiu-Hong;Duan, Chang-Qing;Zhang, Ming-Xia
    • Food Science and Biotechnology
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    • v.18 no.3
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    • pp.724-731
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    • 2009
  • Anthocyanins are considered one of the main color determinants in aged red wine. The anthocyanins in aged red wine made from 'Cabernet Gernischet' (Vitis vinifera L. cv.) grape were investigated by high performance liquid chromatography- electronic spray ionization- mass spectrometry (HPLC-ESI-MS) and their color presented in aqueous solution were evaluated using partial least square regression (PLS). The results showed that there were 37 anthocyanins identified in this wine, including 22 pyranoanthocyanins. The analysis of PLS indicated that different anthocyanins showed distinct color values: malvidin 3-O-(6-O-acetyl)-glucoside-4-vinylguaiacol (Mv3-acet-glu-vg) presented the highest color values, while malvidin 3-O-glucoside (Mv3-glu) showed least. Among the free non-acylated anthocyanins, peonidin 3-O-oglucoside (Pn3-glu) showed the highest color values; the coumarylated anthocyanins presented higher color values than their corresponding acetylated anthocyanins and parent anthocyanins; pyranoanthocyanins presented also higher color values than their original anthocyanins; the color of anthocyanins depended on their structure. This work will be helpful to reveal evolution in aged red wine.

Isolation and Identification of Two Flavonoids from Pear (Pyrus pyrifolia Nakai cv. Chuhwangbae) Fruit Peel (추황배(Pyrus pyrifolia Nakai cv. Chuhwangbae) 과피로부터 2종의 Flavonoids의 단리·동정)

  • Lee, Sang Won;Lee, Yu Geon;Cho, Jeong-Yong;Kim, Young Chool;Lee, Sang-Hyun;Kim, Wol-Soo;Moon, Jae-Hak
    • Korean Journal of Food Science and Technology
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    • v.47 no.2
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    • pp.170-175
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    • 2015
  • The methanol extract of Asian pear (Pyrus pyrifolia N. cv. Chuhwangbae) fruit peel was purified using solvent fractionation, Sephadex LH-20 column chromatography, and octadecylsilane high performance liquid chromatography. Based on the electrospray ionization mass spectrometry and nuclear magnetic resonance data, the two isolated compounds were identified as quercetin 3-O-${\beta}$-D-glucopyranoside (1) and 3,5,6,7,8,3',4'-heptahydroxyflavan [(-)-dulcisflavan, 2]. Compounds 1 and 2 were isolated and identified for the first time from Asian pears and pears, respectively.

Isolation and Identification of Antioxidants from Peanut Shells and the Relationship between Structure and Antioxidant Activity

  • Wee, Ji-Hyang;Moon, Jae-Hak;Eun, Jong-Bang;Chung, Jin-Ho;Kim, Young-Gook;Park, Keun-Hyung
    • Food Science and Biotechnology
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    • v.16 no.1
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    • pp.116-122
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    • 2007
  • Four compounds with antioxidant activity were isolated from the MeOH extract of peanut shells (pod) and identified as 5,7-dihydroxychromone (1), eriodictyol (2), 3',4',7-trihydroxyflavanone (3), and luteolin (4) by electron impact-mass spectrometry (EI-MS) and nuclear magnetic resonance (NMR) analyses. The relationship between antioxidant activity and chemical structure of the isolated compounds with their analogues [(-)-epicatechin, quercetin, taxifolin] was examined by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and using the 2-deoxy-D-ribose degradation system. The order of antioxidant activity on the basis of DPPH radical-scavenging was quercetin = (-)-epicatechin (6.0 molecules) > taxifolin (4,5 molecules) > 4 (luteolin; 4.0 molecules) > 2 (eriodictyol; 2.5 molecules) > 3 (3',4',7-trihydroxy-flavanone; 2.0 molecules) > 1 (5,7-dihydroxychromone; 0.5 molecules). On the other hand, using the 2-deoxy-D-ribose degradation system, the order of antioxidant activity was quercetin > 4 >> (-)-epicatechin ${\geq}\;2\;{\geq}$ taxifolin > 3 > 1. These compounds from peanut shells may provide defensive measures against oxidative stress and insects in the soil.

Enzymatic Synthesis and Characterization of Galactosyl Trehalose Trisaccharides

  • Kim, Bong-Gwan;Lee, Kyung-Ju;Han, Nam-Soo;Park, Kwan-Hwa;Lee, Soo-Bok
    • Food Science and Biotechnology
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    • v.16 no.1
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    • pp.127-132
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    • 2007
  • [ ${\alpha},\;{\alpha}$ ]-Trehalose was efficiently modified by a transgalactosylation reaction of Escherichia coli ${\beta}-galactosidase$ using lactose as a donor to yield two galactosyl trehalose trisaccharides. The reaction products of trehalose by the enzyme were observed by thin layer chromatography (TLC) and high performance anion exchange chromatography (HPAEC) and were purified by BioGel P2 gel permeation chromatography and recycling preparative HPLC. Liquid chromatography-mass spectrometry (LC-MS) and ^{13}C$ nuclear magnetic resonance (NMR) analyses revealed that the structures of the main products were $6^2-{\beta}-D-galactosyl$ trehalose (1) and $4^2-{\beta}-D-galactosyl$ trehalose (2). A reaction of 30%(w/v) trehalose and 15%(w/v) lactose at pH 7.5 and $45^{\circ}C$ resulted in a total yield of approximately 27-30% based on the amount of trehalose used. The galactosyl trehalose products were not hydrolyzed by trehalose. In addition the mixture of transfer products (9:1 ratio of 1 to 2) showed higher thermal stability than glucose, lactose, and maltose, but less than trehalose, against heat treatment over $100^{\circ}C$ at pH 4 and 7. It also exhibited better thermal stability than sucrose at pH 4 alone.

Volatile Compounds Isolated from Edible Korean Fatsia Shoots (Aralia elata Seem.) (두릅의 휘발성 향기성분에 관한 연구)

  • Kim, So-Mi;Chung, Tae-Young
    • Applied Biological Chemistry
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    • v.39 no.5
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    • pp.389-397
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    • 1996
  • The volatile concentrate obtained from the edible Korean dureup plant (Aralia elata Seem.) by a distillation-extraction system was separated into hydrocarbon and oxygen-containing fractions, and the latter was further separated into nine subfractions by silica gel column chromatography. Gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) were utilized to identify 167 volatile compounds in the fractions. The volatile compounds included 72 hydrocarbons, 31 alcohols, 23 aldehydes, 16 esters, 10 acids, 6 ketons, 3 furans, 2 phenols, 1 indole, 1 oxide, 1 sulfide, and 1 lactone. ${\beta}-Caryopyllene$, a sesquiterpene hydrocarbon, was the most abundant volatile compound identified in Korean dureup (19.53%). Dureup oil was found to possess a woody or herbaceous aroma following sensory evaluation of each fraction and individual volatile component using a GC-sniff apparatus.

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