• 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.

• 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.

• Natural Product Sciences
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• v.14 no.3
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• pp.177-181
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• 2008

Five polyacetylenes, ginsenoyne K (1), (Z)-1-methoxyheptadeca-9-en-4,6-diyne-3-one (2), panaxydol (3), panaxydiol (4), and (E)-heptadeca-8-en-4,6-diyne-3,10-diol (5) were isolated from the adventitious roots of Panax ginseng and their chemical structurFive polyacetylenes, ginsenoyne K (1), (Z)-1-methoxyheptadeca-9-en-4,6-diyne-3-one (2), panaxydol (3), panaxydiol (4), and (E)-heptadeca-8-en-4,6-diyne-3,10-diol (5) were isolated from the adventitious roots of Panax ginseng and their chemical structures were elucidated by interpretation of spectroscopic data. Among the isolated compounds, compounds 2 and 5 were reported for the first time as a natural product. Ginsenoyne K (1) showed dose-dependent inhibitory effect on dopa oxidase activity of tyrosinase.es were elucidated by interpretation of spectroscopic data. Among the isolated compounds, compounds 2 and 5 were reported for the first time as a natural product. Ginsenoyne K (1) showed dose-dependent inhibitory effect on dopa oxidase activity of tyrosinase.

• Journal of the Korean Magnetic Resonance Society
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• v.25 no.2
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• pp.12-16
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• 2021

Daphnia magna is used as target organism for environmental metabolomics. The metabolome of D. magna was studied with NMR spectroscopy. Most studies used the extract of D. magna, but the reproducibility cannot be obtained using extracted sample. In this study, lyophilized D. magna samples were analyzed with two different ¹H NMR techniques, HR-MAS on intact tissues and solution NMR on extracted tissues. Samples were measured three times using 600 MHz NMR spectrometer. Metabolite extraction required more than twice as many D. magna, but the metabolite intensity was lower in solution NMR. In the spectra of HR-MAS NMR, the lipid signal was observed, but they did not interfere with metabolite profiling. We also confirmed the effect of swelling time on signal intensities of metabolites in HR-MAS NMR, and the results suggest that appropriate swelling should be used in lyophilized D. magna to improve the accuracy of metabolite profiles.

• Journal of Ginseng Research
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• v.44 no.6
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• pp.770-774
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• 2020

Background: Fermentation has been shown to improve the biological properties of plants and herbs. Specifically, fermentation causes decomposition and/or biotransformation of active metabolites into high-value products. Polyacetylenes are a class of polyketides with a pleiotropic profile of bioactivity. Methods: Column chromatography was used to isolate compounds, and extensive NMR experiments were used to determine their structures. The transformation of polyacetylene in red ginseng (RG) and the production of cazaldehyde B induced by the extract of RG were identified by TLC and HPLC analyses. Results: A new metabolite was isolated from RG fermented by Chaetomium globosum, and this new metabolite can be obtained by the biotransformation of polyacetylene in RG. Panaxytriol was found to exhibit the highest antifungal activity against C. globosum compared with other major ingredients in RG. The fungus C. globosum cultured in RG extract can metabolize panaxytriol to Metabolite A to survive, with no antifungal activity against itself. Metabolites A and B showed obvious inhibition against NO production, with ratios of 42.75 ± 1.60 and 63.95 ± 1.45% at 50 µM, respectively. A higher inhibitory rate on NO production was observed for Metabolite B than for a positive drug. Conclusion: Metabolite A is a rare example of natural polyacetylene biotransformation by microbial fermentation. This biotransformation only occurred in fermented RG. The extract of RG also stimulated the production of a new natural product, cazaldehyde B, from C. globosum. The lactone in Metabolite A can decrease the cytotoxicity, which was deemed to be the intrinsic activity of polyacetylene in ginseng.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2004.10a
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• pp.209-209
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• 2004

• Journal of Microbiology and Biotechnology
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• v.19 no.1
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• pp.51-54
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• 2009

Myxobacteria, Gram-negative soil bacteria, are a well-known producer of bioactive secondary metabolites. Therefore, this study presents a methodological approach for the high-throughput screening of secondary metabolites from 4 wild-type Myxococcus xanthus strains. First, electrospray ionization mass spectrometry (ESI-MS) was performed using extracellular crude extracts. As a result, 22 metabolite peaks were detected, and the metabolite profiling was then conducted using the m/z value, retention time, and MS/MS fragmentation pattern analyses. Among the peaks, one unknown compound peak was identified as analogous to the myxalamid A, B, and C series. An analysis of the tandem mass spectrometric fragmentation patterns and HR-MS identified myxalamid K as a new compound derived from M. xanthus. In conclusion, LC-MS/MS-based chemical screening of diverse secondary metabolites would appear to be an effective approach for discovering unknown microbial secondary metabolites.

• Journal of Korean Biological Nursing Science
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• v.23 no.3
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• pp.159-169
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• 2021

Purpose: The purpose of this study was to analyze research trends and find whether Post-Traumatic Stress Disorder (PTSD) of refugees could affect structural or functional changes of brains of those under MRI, focusing on volumes, functional connectivities, and metabolites. Methods: A literature search was done using PubMed, Embase, RISS, and KMBase to identify studies that matched our research purpose. A total of eight studies were identified using Prisma flow diagram by two reviewers independently. Results: Eight studies were identified. Three studies were on North Korean defectors as subjects. The number of studies that observed structural changes, functional changes, and metabolite changes in brains was 2, 5, and 2, respectively. Although each study observed various parts of the brain, anterior cingulate cortex (ACC) was observed commonly in three studies. The PTSD group showed reduction of ACC volume and N-acetyl-aspartate (NAA) metabolite in ACC compared to the non- PTSD group. When exposed to negative stimuli, the PTSD group showed higher neural activity than the non-PTSD group, but not vice versa. Conclusion: ACC showed significant difference in volume, neural activity, and NAA metabolite between the PTSD and the non-PTSD group, resulting in significant differences in structural changes, functional changes, metabolite changes, respectively. This study showed the need for conducting more research using various biomarkers to clarify the relationship between PTSD of refugees and their brain changes.

• Journal of the Korean Magnetic Resonance Society
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• v.22 no.4
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• pp.91-100
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• 2018

Benzisothiazolinone (BIT) is the preservative that is widely used in industrial and household products. In this study, zebrafish (Danio rerio) was exposed to BIT at different concentrations (control, 0.5 g/L, 1.0 g/L and 2.0 g/L) for 72 hours. The techniques of nuclear magnetic resonance (NMR) spectroscopy were applied to analyze the effects of BIT on zebrafish. The advantages of NMR are the minimal sample preparation and high reproducibility of experimental results. With the multivariate statistical analysis, dimethylamine, N-acetylaspartate, glycine and histidine were identified as an important metabolite in differentiating between the control and BIT-exposed group. This study will improve the understanding the metabolite changes in the zebrafish in response to BIT exposure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.4
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• pp.357-360
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• 2003

Methanol extracts from Paeonia lactiflora showed a strong inhibition against platelet aggregation on platelet activation test. Therefore, the bioactive constituents from Paeonia lactiflora were prepared using chromatography methods and were analyzed by NMR and reference data. Compound 1b was confirmed a same structure with henzoyloxypaeoniflorin, compound 2e was a same structure with paeoniflorin; main product of Paeonia lactiflora. Analytical data of compound 3a were not consistent with any known paeoniflorin soucture, but showed the souctural similarity with it. And also the aggregation inhibition activity of compound 3a showed a strong inhibition($\geq$ 90%) induced by collagen. Therefore it suggested that the structure of compound 3a may be the similar structure of benzoyloxypaeoflorin with a functional group in place of benzoyl group and/or a different functional group in stead of Rl. We suggested that benzoyl group of benzoyloxypaeoniflorin substitued instead of 5-carbon OH group on glycoside moiety paeoniflorin played role of the metabolite in case of a platelet aggregation inhibition activity. Paeoniflorin showed more strong inhibition by thrombin than collagen. Therefore, it may be destructed a calcium metabolite as a forming $Ca^2＋$ chelate. Compound 3a may be that other functional group instead of OH group of 5-carbon on glycoside moiety of paeoniflorin and/or OH group of benzoyl moiety of paeoniflorin played role of the metabolite in a platelet aggregation inhibition.