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Shen, Wenwen,Wei, Yingjie,Tang, Daoquan,Jia, Xiaobin,Chen, Bin The Korean Society of Ginseng 2017 Journal of Ginseng Research Vol.41 No.1
Background: In the present study, metabolite profiles of ginsenosides Rk1 and Rg5 from red ginseng or red notoginseng in zebrafish were qualitatively analyzed with ultraperformance liquid chromatography/quadrupole-time-of-flight MS, and the possible metabolic were pathways proposed. Methods: After exposing to zebrafish for 24 h, we determined the metabolites of ginsenosides Rk1 and Rg5. The chromatography was accomplished on UPLC BEH C18 column using a binary gradient elution of 0.1% formic acetonitrile-0.1% formic acid water. The quasimolecular ions of compounds were analyzed in the negative mode. With reference to quasimolecular ions and MS2 spectra, by comparing with reference standards and matching the empirical molecular formula with that of known published compounds, and then the potential structures of metabolites of ginsenosides Rk1 and Rg5 were acquired. Results: Four and seven metabolites of ginsenoside Rk1 and ginsenoside Rg5, respectively, were identified in zebrafish. The mechanisms involved were further deduced to be desugarization, glucuronidation, sulfation, and dehydroxymethylation pathways. Dehydroxylation and loss of C-17 residue were also metabolic pathways of ginsenoside Rg5 in zebrafish. Conclusion: Loss of glucose at position C-3 and glucuronidation at position C-12 in zebrafish were regarded as the primary physiological processes of ginsenosides Rk1 and Rg5.
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( Liang Wang ),( Qinghua Liu ),( Yangguang Du ),( Daoquan Tang ),( Michael J. Wise ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 한국미생물·생명공학회지 Vol.46 No.3
Glycogen plays important roles in bacteria. Its structure and storage capability have received more attention recently because of the potential correlations with environmental durability and pathogenicity. However, the low level of intracellular glycogen makes extraction and structure characterization difficult, inhibiting functional studies. Bacteria grown in regular media such as lysogeny broth and tryptic soy broth do no accumulate large amounts of glycogen. Comparative analyses of bacterial media reported in literature for glycogen-related studies revealed that there was no consistency in the recipes reported. Escherichia coli DH5α is a convenient model organism for gene manipulation studies with respect to glycogen. Additionally, M9 minimal salts medium is widely used to improve glycogen accumulation, although its composition varies. In this study, we optimized the M9 medium by adjusting the concentrations of itrogen source, tryptone, carbon source, and glucose, in order to achieve a balance between the growth rate and glycogen accumulation. Our result showed that 1 × M9 minimal salts medium containing 0.4% tryptone and 0.8% glucose was a well-balanced nutrient source for enhancing the growth and glycogen storage in bacteria. This result will help future investigations related to bacterial physiology in terms of glycogen function.
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Wang, Liang,Liu, Qinghua,Du, Yangguang,Tang, Daoquan,Wise, Michael J. The Korean Society for Microbiology and Biotechnol 2018 한국미생물·생명공학회지 Vol.46 No.3
Glycogen plays important roles in bacteria. Its structure and storage capability have received more attention recently because of the potential correlations with environmental durability and pathogenicity. However, the low level of intracellular glycogen makes extraction and structure characterization difficult, inhibiting functional studies. Bacteria grown in regular media such as lysogeny broth and tryptic soy broth do no accumulate large amounts of glycogen. Comparative analyses of bacterial media reported in literature for glycogen-related studies revealed that there was no consistency in the recipes reported. Escherichia coli $DH5{\alpha}$ is a convenient model organism for gene manipulation studies with respect to glycogen. Additionally, M9 minimal salts medium is widely used to improve glycogen accumulation, although its composition varies. In this study, we optimized the M9 medium by adjusting the concentrations of itrogen source, tryptone, carbon source, and glucose, in order to achieve a balance between the growth rate and glycogen accumulation. Our result showed that $1{\times}M9$ minimal salts medium containing 0.4% tryptone and 0.8% glucose was a well-balanced nutrient source for enhancing the growth and glycogen storage in bacteria. This result will help future investigations related to bacterial physiology in terms of glycogen function.
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Experimental modal test of the spiral bevel gear wheel using the PolyMAX method
Tieming Xiang,Diandian Lan,Shaohui Zhang,Wuxiong Li,Daoquan Lin 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.1
To verify the effectiveness and correctness of free modal analysis results from a Spiral bevel gear (SBG) wheel by using Finite element method (FEM), an experimental platform was constructed through the free-hanging support of the SBG wheel. The experiment used the hammer knock percussion for excitation and a three-directional acceleration sensor as signal acquisition equipment and utilized the LMS modal analysis module. The geometric model of the SBG wheel was constructed using an eight-node octagon instead of the SBG wheel outer contour. The experiment then extracted the modal parameters of the wheel using the PolyMAX method and obtained the first- and second-order natural frequencies, damping ratios, and mode shapes of the SBG wheel at 0-7 kHz during the experimental modal test. The results of the experimental test were compared with those of the FEM free modal analysis. The first- and second-order natural frequency error rates by FEM were 0.25 % and 0.45 %, respectively. The experimental modal test result verified the rationality of the model by FEM, thus showing that the result of modal analysis by FEM is reliable and providing a basis for the dynamic characteristic analysis of SBG.
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Shuai Ji,Yujie Wang,Shikai Gao,Xian Shao,Wei Cui,Yan Du,Mengzhe Guo,Daoquan Tang 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.80 No.-
Lots of minor constituents in herbal medicines have shown great potential to devolve into leadcompounds, and their extraction is attracting more and more attention in pharmaceutical industry. Thisstudy provided an example that showed efficient and selective extraction of minor bioactive naturalproducts (prenylatedflavonoids with anti-cancer activities) from an herbal medicine (licorice) using pureionic liquids as green solvents. After investigation of a variety of hydrophobic ionic liquids withultrasonic-assisted extraction, we found that [C8MIM]BF4 (1-octyl-3-methylimidazolium tetrafluor-oborate) was the most effective one for extraction offive representative compounds (isoangustone A,glycycoumarin, licoisoflavanone, licoricidin and glabridin), and solvent to solid ratio, extraction time,extraction temperature and soaking time were then optimized through single-factor experiments andresponse surface methodology. As a result, the established method had significantly higher extractionselectivity than conventional organic solvents, which could be attributed to significant physical change oflicorice microstructures after extraction, as well as strong interactions (especially hydrogen bondinteractions) between [C8MIM]BF4 and prenylatedflavonoids by mechanism study. In addition, 78.92% ofthe extracted prenylatedflavonoids could be readily recovered from [C8MIM]BF4 by using reversed-phasesolid phase extraction, and the recyclability of [C8MIM]BF4 was also confirmed.
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