• Title/Summary/Keyword: metabolite

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Correlation between Metabolite Peak Area Ratios on the Influence of Poor Shimming by $^1H$ MR Spectroscopy

  • Baik, Hyun-Man;Choe, Bo-Young;Suh, Tae-Suk;Lee, Hyuong-Koo
    • Journal of the Korean Magnetic Resonance Society
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    • v.3 no.2
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    • pp.140-148
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    • 1999
  • Using 1H magnetic resonance spectroscopy (MRS), we quantitatively evaluated correlation representing linear relationship between the metabolite peak area ratios associated with poor shimming conditions. The inadequate shimming due to linear shim offsets directly affected overall MR spectral quality as well as peak area for each metabolite. Three major peaks such as N-acetylaspartate (NAA), creatine (Cr,) choline (Cho) were used as a reference for data analysis. Despite considerable variations of metabolite peak area, a significant correlation between the metabolite peak area ratios relative to Cr was established while the correlation between the peak area ratios relative to Cho and NAA was not. The present study suggested that metabolite peak area ratios based on the metabolite of Cr could be an acceptable quantification method even under the poor shimming in clinical MRS examination.

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Determination of urinary metabolite of IBP after oral administration and dermal application to rats (흰쥐를 이용한 IBP의 경구투여 및 피부도포 후 요중 대사물질 측정)

  • Min Kyung Jin;Cho Young Joo;Cha Chun Geun
    • Journal of Environmental Health Sciences
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    • v.28 no.1
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    • pp.67-77
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    • 2002
  • This study was aimed to determine the urinary metabolite of IBP, one of the organophosphorus pesticides, as the biomarkers of exposure. Urine samples were collected for 24 hours in metabolic cages after oral administration and dermal application of IBP to rats. Identification of the derivatized urinary metabolite was determined by GC/MS and excretion time courses of the urinary metabolite was analyzed by GC/FPD. Urinary metabolite o IBP, diisopropyl phosphorothioate, was detected in rats urine both after oral administration and dermal application of IBP. Parent compound was not detected in the experiment. In GC/MS, the mass spectral confirmation for diisopropyl phosphorothioate ion was identified at m/z 254. Diisopropyl phosphorothioate was excreted within 48 hours and 72 hours after oral administration and dermal application of IBP, respectively. In this study, the same urinary metabolite of IBP was detected both in oral and dermal exposure. Generally, excretion of the urinary metabolite after oral administration was faster than after dermal application. It is suggested that urinary diisopropyl phosphorothioate could be used as the biomarkers of exposure to IBP.

Analysis of Amineptine and its Metabolites in Human Urine by Gas Chromatography/Mass Spectrometry (Gas Chromatography/Mass Spectrometry를 이용한 뇨중 Amineptine과 그 대사체 분석방법에 관한 연구)

  • Lee, Jeong Ae;Kim, Younglim;Lho, Dong-Seok
    • Analytical Science and Technology
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    • v.13 no.3
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    • pp.385-393
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    • 2000
  • A gas chromatography-mass spectrometric (GC/MS) procedure for the determination of amineptine (dihydro-10, 11-dibenzo[a, d] cycloheptenyl-5-amino-7-heptanoic acid) and its main metabolites in human urine was described. Amineptine has been known to be extensively metabolized by the ${\beta}$-oxidation of the heptanoic side chain with formation of pentanoic side chain metabolite ($C_5$-metabolite), and lactamizarion by internal dehydration of (${\beta}$-oxidized metabolite (${\delta}$-lactam). The detection of these compounds was based on acid hydrolysis, liquid-liquid extraction and trimethylsilylated derivatization of the carboxylic acid group. For the determination of amineptine and its metabolites in biological fluids, selected ions at the m/ 192, molecular ion and one of the characteristic ions were monitored by GC/MS. On the excretion study of amineptine in human urine, 70-90% of amineptine, ${\delta}$-lactam, and $C_5$-metabolite were found to be excreted within 4 hours and their excretion completed within 20 hours.

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Preliminary Study on Magnetic Resonance Temperature Measurement using Brain-Metabolite Phantom (뇌 대사물질 팬텀을 이용한 뇌의 자기공명 온도측정법에 관한 기초 연구)

  • Han, Yong-Hee;Jang, Moo-Young;Mun, Chi-Woong
    • Journal of Biomedical Engineering Research
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    • v.31 no.5
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    • pp.412-416
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    • 2010
  • In this study, we measured the chemical shift change of metabolite peaks in the brain-metabolite phantom according to the temperature variation using nuclear magnetic resonance(NMR). The temperature range in NMR system was controled from 25 to 80 (5 step) by internal temperature controller. Temperature coefficients of each metabolite peaks were also calculated from the measured chemical shift depending on the temperature. The chemical shift changes depending on temperature were validated by linear regression method for each metabolite peaks. The temperature coefficients of $_{tot}Cr$, Cho, Cr, NAA, and Lac were 0.0086, 0.0088, 0.0091, 0.0089, and 0.0088ppm/$^{\circ}C$, respectively. This study shows that chemical shift change of brain metabolite and temperature variation have linear relationship each other. This also makes authors believe that brain temperature measurement is possible using MR spectroscopic imaging technique.

Effects of Age, Environments and Sex on Plasma Metabolite Levels in Young Holstein Calves

  • Sasaki, O.;Yamamoto, N.;Togashi, K.;Minezawa, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.5
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    • pp.637-642
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    • 2002
  • Thirty Holstein calves were used to determine effects of age, environment and sex on blood metabolite concentrations during 1 to 90 d of age. Calves were weaned at 75 d of age. Environmental effects are grouped by the difference in month at birth and site of feeding. Blood samples were obtained every 2 or 3 d. The mean metabolite concentration every 3 d was used for the statistical analysis. Dairy bodyweight gain was not affected by environmental group and sex effect. Concentrations of plasma glucose, nonesterified fatty acids (NEFA), triglyceride, total cholesterol and total ketone changed with growth. These developmental changes in metabolite levels would be caused by ruminal maturation with increment of grain intake. Levels of plasma urea nitrogen, glucose, NEFA, triglyceride and total cholesterol drastically changed during a few weeks after birth, indicating that the physiological state in calves greatly changed during that time. Effects of the environmental group and sex were significant in almost all metabolites. Temperature influenced plasma metabolite concentrations. The plasma metabolite concentrations were affected more intensely by heat stress in the infant period than in the neonatal period.

Practical Guide to NMR-based Metabolomics - II : Metabolite Identification & Quantification

  • Jung, Young-Sang
    • Journal of the Korean Magnetic Resonance Society
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    • v.22 no.1
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    • pp.10-17
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    • 2018
  • Metabolite identification and quantification are one of the foremost important issues in metabolomics. In NMR based metabolomics, mainly one-dimensional proton NMR spectra of biofluids, such as urine and serum are measured. However, it is not always easy to identify and quantify metabolites in one-dimensional proton NMR spectra. This article introduces useful public metabolite databases, metabolic profiling software, and articles.

Aspochalasin I, a Melanogenesis Inhibitor from Aspergillus sp.

  • Choo, Soo-Jin;Yun, Bong-Sik;Ryoo, In-Ja;Kim, Young-Hee;Bae, Ki-Hwan;Yoo, Ick-Dong
    • Journal of Microbiology and Biotechnology
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    • v.19 no.4
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    • pp.368-371
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    • 2009
  • In the course of screening for the melanogenesis inhibitors, aspochalasin I was isolated from solid-state culture of Aspergillus sp. Fb020460. Its structure was determined by spectroscopic analysis including mass spectroscopy and NMR analysis. Aspochalasin I potently inhibited melanogenesis in Mel-Ab cells with an $IC_{50}$ value of $22.4{\mu}M$ without cytotoxicity.

Cyclo(Dehydrohistidyl-L-Tryptophyl), an Inhibitor of Nitric Oxide Production from a Fungal Strain, Fb956

  • Noh, Hyun-Jeong;Sohn, Mi-Jin;Yu, Hyung-Eun;Yoo, Ick-Dong;Kim, Won-Gon
    • Journal of Microbiology and Biotechnology
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    • v.17 no.10
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    • pp.1717-1720
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    • 2007
  • In the course of screening for nitric oxide inhibitors in activated microglial BV-2 cells, cyclo(dehydrohistidyl-L-tryptophyl) was isolated from solid-state fermentation cultures of an unidentified fungal strain, Fb956. Its structure was determined by spectroscopic methods including 2D NMR and chiral TLC analyses. Cyclo(dehydrohistidyl-L-tryptophyl) was found to have an inhibitory activity on nitric oxide production with an $IC_{50}$ of $6.5\;{\mu}M$ in activated BV-2 cells. The structure determination and biological activity of cyclo(dehydrohistidyl-L-tryptophyl) was reported for the first time in this study.

Flavone Biotransformation by Aspergillus niger and the Characterization of Two Newly Formed Metabolites

  • Mahmoud, Yehia A.-G.;Assawah, Suzan W.;El-Sharkawy, Saleh H.;Abdel-Salam, Amal
    • Mycobiology
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    • v.36 no.2
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    • pp.121-133
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    • 2008
  • Aspergillus niger isolated from Allium sativum was used at large scale fermentation (150 mg flavone/200ml medium) to obtain suitable amounts of the products, efficient for identification. Then spectral analysis (UV, IR, $^1H$-NMR, $^{13}C$-NMR) and mass spectrometry were performed for the two products, which contributed to the identification process. The metabolite (1) was identified as 2'-hydroxydihydrochalcone, and the metabolite (2) was identified as 2'-hydroxyphenylmethylketone, which were more active than flavone itself. Antioxidant activities of the two isolated metabolites were tested compared with ascorbic acid. Antioxidant activity of metabolite (1) was recorded 64.58% which represented 79% of the antioxidant activity of ascorbic acid, and metabolite (2) was recorded 54.16% (67% of ascorbic acid activity). However, the antioxidant activity of flavone was recorded 37.50% which represented 46% of ascorbic acid activity. The transformed products of flavone have anti-microbial activity against Pseudomonas aeruginosa, Aspergillus flavus and Candida albicans, with MIC was recorded $250{\mu}g/ml$ for metabolite (2) against all three organism and 500, 300, and $300{\mu}g/ml$ for metabolite (1) against tested microorganisms (P. aeruginosa, Escherichia coli, Bacillus subtilis, and Klebsiella pneumonia, Fusarium moniliforme, A. flavus, Saccharomyces cerviceae, Kluveromyces lactis and C. albicans) at this order.