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Your search keyword '"Zhao, Yan-cong"' showing total 5 results
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5 results on '"Zhao, Yan-cong"'

4. Molecular Cloning, Expression and Characterization of the Porcine Defensin 2 in E. coli

Author

Li, Chun-li, Zhao, Yan-cong, Song, Xiao-yan, Huang, Xian-xian, and Zhao, Wei-dong

Abstract

Porcine defensin 2(pBD2)is a cationic 37-amino acid antimicrobial peptide with disulfide bonds. Synthetic pBD2 had broad antimicrobial activity against pathogenic bacteria, and thus pBD2 could be a good candidate as a bactericidal agent for pigs. This study reported the successful recombinant expression of pBD2 in Escherichia coli and analysis of its antimicrobial activity, its hemolytic activity, salt-tolerance and thermal stability as well. The pBD2 gene, obtained by RT-PCR using the tongue total RNA as a template and cloned into pET30a expression vector, was transformed into E. coli BL21 (DE3) plysS. The recombinant pBD2 was expressed after induction by IPTG and purified by His tag affinity column with 95 purity. The recombinant pBD2 exhibited antimicrobial activity against both Gram-positive S. aureus and Gram-negative E. coli including the multi-resistant E. coli. The minimum inhibitory concentration (MIC) of recombinant pBD2 against tested bacteria was 10 μg-mL, and the recombinant pBD2 could kill 50 E. coli at 14.39 μg-mL and S. aureus at 21.1 μg-mL. In addition, pBD2 showed low hemolytic activity, salt-tolerance and thermal stability, the properties would be important for its application in practice.

Published
2013

5. [Identification of main chemical constituents of diterpene lactone effective fraction of Andrographis panniculata by HPLC-DAD/ESI-MS and their preliminary pharmacodynamics research].

Author

Li JH, Xu XX, Zhao YC, and Han G

Subjects
Animals, Cell Line, Tumor, Cell Proliferation drug effects, Chromatography, High Pressure Liquid, Female, Humans, Lung Neoplasms physiopathology, Mice, Mice, Inbred C57BL, Spectrometry, Mass, Electrospray Ionization, Andrographis chemistry, Antineoplastic Agents, Phytogenic administration & dosage, Antineoplastic Agents, Phytogenic chemistry, Drugs, Chinese Herbal administration & dosage, Drugs, Chinese Herbal chemistry, Lung Neoplasms drug therapy
Abstract

Objective: To establish an HPLC-DAD/ESI-MS method for quickly identifying chemical constituents in diterpene lactone effective fraction of Andrographis panniculata and to study its pharmacodynamics., Method: The separation was performed on an Agilent SB-C18 column (2.1 mm x 150 mm, 5 μm) with a mobile phase of acetonitrile (A) and water (B). The flow rate was maintained at 0.4 mL x min(-1) and detection wavelength was set at 205 nm. The samples were analyzed in positive ion mode, and mass scan range was m/z 50-1 000. Using two kinds of tumor cell lines made living animal models, and studied preliminary pharmacodynamics on anti-tumor aspect., Result: Five diterpene lactones in the diterpene lactone effective fraction of A. panniculata could be separated in one run. Pharmacodynamic experiments showed that the effectve fraction had an inhibitory effect on the growth of tumor., Conclusion: A rapid and efficient HPLC-ESI-MS method to determine the chemical constituents in diterpene lactone effective fraction of A. panniculata has been established, and the preliminary pharmacodynamics research has been done, which could be used for the quality control and further studies of diterpene lactone effective fraction of A. panniculata in vivo.

Published
2014

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