• Title/Summary/Keyword: topoisomerase

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Mutations in the GyrA Subunit of DNA Gyrase and the ParC Subunit of Topoisomerase IV in Clinical Strains of Fluoroquinolone-Resistant Shigella in Anhui, China

  • Hu, Li-Fen;Li, Jia-Bin;Ye, Ying;Li, Xu
    • Journal of Microbiology
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    • v.45 no.2
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    • pp.168-170
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    • 2007
  • In this research 26 Shigella isolates were examined by PCR and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (QRDRs). We tested for the presence of qnr genes by PCR in 91 strains, but no qnr genes were found. The results did show, however, some novel mutations at codon 83 of gyrA ($Ser{\rightarrow}Ile$) and codon 64 of parC ($Ala64{\rightarrow}Cys,\;Ala64{\rightarrow}Asp$), which were related to fluroquinolone resistance.

DNA Topoisomerase I Inhibitory Activity of Stilbenes and Oligostilbenes from Leaf and Stem of Vitis amurensis

  • Kang, Na-Na;Ha, Do Thi;Park, Chang-Sik;Myung, Pyung-Keun;Bae, Ki-Hwan
    • Natural Product Sciences
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    • v.16 no.4
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    • pp.223-227
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    • 2010
  • The DNA Topoisomerase I (DNA Topo I) inhibitory effect of ten isolated compounds (1.10) from the leaf and stem of Vitis amurensis were examined. Among them, amurensin G (5) and r-2-viniferin (7) showed high potent inhibitory activity against DNA Topo I. DNA Topo I, an important target for anticancer drugs, can cause DNA breaks and play a key role during cell proliferation, transcription and repair. Thus, the results suggest that the selected compounds (5 and 7) from Vitis amurensis have a possibility as DNA Topo I-targeting anticancer agents.

Synthesis of Indeno[1.2-c]indenoisoquinoline Derivatives as Potential Topoisomerase I Inhibitors

  • Quynh, Le-Manh;Thanh, Le-Nguyen;Gang, Seong-Gyoung;Chung, Byung-Ho;Cho, Won-Jea
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.340.3-341
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    • 2002
  • During the research for the development of antitumor agents. we found the 3-arylisoquinoline derivatives exhibited potent cytotoxicity against human tumor cell lines. For extending our study on these compounds. indeno[1.2-c]isoquinolines were chosen as the next research target due to previous studied data of the compounds that showed potent topoisomerase I inhibition activity as well as cytotoxicity against many kinds of tumor cell lines. Retrosynthetic consideration of indeno[1.2-d]isoquinolines indicates that the coupling of o-methyltoluamide with o-hydroxymethylbenxonitrile might afford 3-arylisoquinoline which could be translerred to the aldehtde. Indeno [1.2-c]isoquinolines can be formed by and inframolecular ring cyclization method. Various derlvatives of this compound including 11-alkoxy-6-methyl-6H. 11H-indeno[1.2-c]isoquinolin-5-one and biological activity will be presented with the docking model with topisomerase 1 enzyme.

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Antitumor constituents from the sclerotium of Poria cocos

  • Li, Gao;Xu, Ming-Lu;Seo, Chang-Seob;Kim, Hyo-Jin;Lee, You-Jeong;Lee, Yeun-Koung;Lee, Chong-Soon;Woo, Mi-Hee;Son, Jong-Keun
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.256.3-257
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    • 2003
  • The bioactivity-guided fractionation of an active methylene chloride extract of the sclerotium of Poria cocos led to the isolation of compounds 1-5. These compounds were tested in the human colon carcinoma and human breast carcinoma cell lines, compounds 3, 4, and 5 exhibited IC50 values of 10.8, 15.4, and 5.1 $\mu\textrm{g}$/$m\ell$ against human colon carcinoma cell line. In addition, compounds 3, 4 and 5 showed moderate activities as inhibitors of Topoisomerase I and all compounds were inactive in the Topoisomerase II inhibition.

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NMR Studies on Antitumor Drug Candidates, Berberine and Berberrubine

  • Jeon, Young-Wook;Jung, Jin-Won;Kang, Mi-ran;Chung, In-Kwon;Lee, Weon-tae
    • Bulletin of the Korean Chemical Society
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    • v.23 no.3
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    • pp.391-394
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    • 2002
  • Berberine and berberrubine, which display antitumor activity, have also demonstrated distinct enzyme-poisoning activities by stabilizing topoisomerase Ⅱ-DNA cleavable complexes. The protoberberine berberrubine differs in chemical structure with berberine at only one position, however, it shows a prominent activity difference from berberine. Solution structures of berberine and berberrubine determined by NMR spectroscopy are similar, however, the minor structural rearrangement has been observed near 19 methoxy or hydroxyl group. We suggest that the DNA cleavage activities of topoisomerase Ⅱ poisons could be correlated with both chemical environments and minor structural change together with hydrophobicity of interacting side chains of drugs with DNA molecule.

Pharmacokinetic Scaling of SJ-8029. a Novel Anticancer Agent Possessing Microtubule and Topoisomerase Inhibiting Activities. by Species-Invariant Time Methods

  • Kim, Dong-Hwan;Shin, Beom-Soo;Cho, Chang-Youn;Park, Si-Koung;Chung, Sung-Gan;Cho, Eui-Hwan;Lee, Sun-Hwan;Joo, Jeong-Ho;Kwon, Ho-Suk
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.422.1-422.1
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    • 2002
  • This study examined the pharmacokinetic disposition of SJ-8029. a novel anticancer agent possessing microtubule and topoisomerase inhibiting activities. in mice. rats. rabbits and dogs after i.v. administration. The serum concentration-time curves of SJ-8029 were best described by tri-exponential equations in all these animal species. The mean CI. $V_{ss}$ and $t_{1/2}$ were 0.3 L/h. 0.1 Land 63.2 min in mice. 1.5 L/h. 1.6 Land 247.7 min in rats. 13.8 L/h. 39.6 Land 245.9 min in rabbits. and 29.2 L/h. 44.6 Land 117.4 min in dogs. respectively. (omitted)

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The activity - binding affinity relationship of topoisomerase I inhibitors by flexible docking with FlexiDock

  • Kim, Ji-Hyun;Park, In-Hee;Kim, Choon-Mi
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.159.1-159.1
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    • 2003
  • Human Topoisomerase I (topo I) helps the control of DNA supercoiling in cells by assisting breaking and religation of DNA strand. It is essential for cellular metabolism and survival, hence, a good target for a novel class of anticancer drugs. As topo I inhibitor binds to the DNA-topo I complex, the religation of DNA strand is suppressed which results in the death of the target cell. Seven compounds of H-Imidazo[4, 5-g]phthalazing-4, 9-dione derivatives with $IC_50$ in the range of 0.001 and 6.27 $\mu$M in 5 different cancer cells and four compounds of 7-chloro-6-quinazoline-5, 8-dione derivatives with positive and negative topo I inhibition activities were studied. (omitted)

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