The Journal of Antibiotics
Online ISSN : 1881-1469
Print ISSN : 0021-8820
ISSN-L : 0021-8820
Volume 57 , Issue 10
Showing 1-10 articles out of 10 articles from the selected issue
  • YUFEI FENG, NOBUYASU MATSUURA, MAKOTO UBUKATA
    2004 Volume 57 Issue 10 Pages 627-633
    Published: October 25, 2004
    Released: January 27, 2009
    JOURNALS FREE ACCESS
    Indocarbazostatins C (3) and D (4), new inhibitors of NGF-induced neurite outgrowth were isolated from culture broth of a mutant strain, Streptomyces sp. MUV-6-83. The structural elucidation of 3 and 4 revealed that these inhibitors were methyl ester analogs of the corresponding ethyl ester compounds, indocarbazostatin (1) and indocarbazostatin B (2), respectively.
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  • YOICHI HAYAKAWA, TOMOKI YAMASHITA, TOSHIYA MORI, KOJI NAGAI, KAZUO SHI ...
    2004 Volume 57 Issue 10 Pages 634-638
    Published: October 25, 2004
    Released: January 27, 2009
    JOURNALS FREE ACCESS
    An antitumor antibiotic, tyroscherin, was isolated from the culture of a fungus identified as Pseudallescheria sp. The structure of tyroscherin including the absolute stereochemistry was determined as shown in Fig. 1 by NMR and degradation studies. Tyroscherin selectively inhibited IGF-1-dependent growth of MCF-7 human breast cancer cells with an IC50 of 9.7ng/ml.
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  • YASUNORI MURAMATSU, TAKASHI OHNUKI, MICHIKO MIYAZAWA ISHII, MASAAKI KI ...
    2004 Volume 57 Issue 10 Pages 639-646
    Published: October 25, 2004
    Released: January 27, 2009
    JOURNALS FREE ACCESS
    Novel nucleoside antibiotics were isolated from the cultured broth of the strain classified as Streptomyces sp. SANK 62799. The strain produced four novel capuramycin derivatives designated as A-503083 A, B, E and F. Their structures were elucidated as 2'-O-carbamoyl derivatives of A-500359 A, B (capuramycin), E and F, respectively. A-503083 A, B, E and F inhibited bacterial phospho-N-acetylmuramyl-pentapeptide-translocase (translocase I: EC 2.7.8.13) with IC50 values of 0.024, 0.038, 0.135 and 17.9μM, respectively.
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  • RENATA L. A. FURLAN, STEPHEN J. WATT, LEANDRO M. GARRIDO, GUSTAVO P. A ...
    2004 Volume 57 Issue 10 Pages 647-654
    Published: October 25, 2004
    Released: January 27, 2009
    JOURNALS FREE ACCESS
    Cosmomycin D (CosD) is the major constituent fraction isolated from a culture of Streptomyces olindensis ICB20. The ability of this compound to intercalate with double-stranded DNA was studied by gel mobility shift assays and electrospray ionization mass spectrometry (ESI-MS). ESI-MS experiments showed that the complex of CosD with 16-mer double-stranded DNA was at least as stable as a complex of daunorubicin with the same DNA sequence. This is the first study showing DNA binding properties of an anthracycline containing a β-rhodomycinone aglycone chromophore O-linked to two trisaccharide chains.
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  • TIM SCHUHMANN, STEPHANIE GROND
    2004 Volume 57 Issue 10 Pages 655-661
    Published: October 25, 2004
    Released: January 27, 2009
    JOURNALS FREE ACCESS
    The plecomacrolides bafilomycin A1 and B1 (1, 2) and concanamycin A (3), produced by different Streptomyces species, show a unique macrolactone structure with characteristic side chains and exhibit striking biological activities including distinct V-type ATPase inhibition. The biosynthesis of 1 and 2 has been established by feeding experiments with 13C-labelled precursors. Both, bafilomycin (1, 2) and concanamycin (3) feature an "unusual C2 chain extension unit" of as yet unknown origin which was addressed by feeding labelled 2-hydroxyand 2-methoxymalonyl-derivatives.
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  • MASAYOSHI ARAI, YUKIO KOIZUMI, HITOSHI SATO, TAKUMI KAWABE, MASASHI SU ...
    2004 Volume 57 Issue 10 Pages 662-668
    Published: October 25, 2004
    Released: January 27, 2009
    JOURNALS FREE ACCESS
    The DNA-damaging agent bleomycin arrests the cell cycle at the G2 phase of Jurkat cells defective in the G1 checkpoint, and microtubule-acting colchicine arrests it at the M phase. Boromycin itself, an actinomycete metabolite, showed no effect on the cell cycle status of Jurkat cells at least up to 340nM. However, the compound (3.4-340nM) was found to abrogate bleomycin-induced G2 arrest even at 3.4nM, resulting in a drastic decrease in cells at the G2 phase and increase in cells at the subG1 phase. On the other hand, boromycin did not show any effect on the colchicine-induced M phase arrest in Jurkat cells, nor on the cell cycle status of the bleomycin-treated or -untreated HUVEC, normal cells conserving both G1 and G2 checkpoints. Furthermore, boromycin potentiated anti-tumor activity of bleomycin in scid mice inoculated with Jurkat cells. These data suggest that boromycin disrupts the cell cycle at the G2 checkpoint of cancer cells selectively, leading to sensitization of cancer cells to anti-cancer reagents.
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  • MAGDALENA SLISZ, BARBARA CYBULSKA, JAN MAZERSKI, JOLANTA GRZYBOWSKA, E ...
    2004 Volume 57 Issue 10 Pages 669-678
    Published: October 25, 2004
    Released: January 27, 2009
    JOURNALS FREE ACCESS
    The novel group of amphotericin B (AmB) cationic derivatives has been examined in terms of relationship between self-association and selective toxicity. In all determinations AmB has been used as reference compound. In vitro toxic effects of the compounds on human erythrocytes were determined by measuring leakage of intracellular potassium ions and hemolytis. Antifungal effects were determined as MIC and intracellular potassium loss. The compounds self-association was followed by UV-Vis spectroscopy. The results suggested that: i) unlike AmB the monomer/self-associated species ratio is not an essential in governing the selective toxicity of the derivatives studied; ii) the presence of a bulky substituent in the AmB molecule, preferably located at the amino group of mycosamine moiety is the structural factor essential for the selective toxicity improvement.
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  • KEIKO ISHINO, JUN ISHIKAWA, YOKO IKEDA, KUNIMOTO HOTTA
    2004 Volume 57 Issue 10 Pages 679-686
    Published: October 25, 2004
    Released: January 27, 2009
    JOURNALS FREE ACCESS
    A clinical isolate (designated PRC104) of methicillin-resistant Staphylococcus aureus was discovered with a novel aminoglycoside resistance profile, including unusually high resistance (MIC 128μg/ml) to arbekacin (an effective anti-MRSA drug in Japan). We characterized the activity and gene of its bifunctional aminoglycoside-modifying enzyme, AAC(6')/APH(2"), in comparison with those of a regular one that has been known as the critical resistance basis to both gentamicin and arbekacin in methicillin-resistant Staphylococcus aureus. The aac(6')/aph(2") gene of strain PRC104 contained a single base alteration at a novel site (G 1126A) resulting in one amino acid substitution (S376N) in the phosphorylation catalytic motif. The phosphorylation activity of the PRC104 enzyme was enhanced for arbekacin and reduced for gentamicin. Both strain PRC104 and S. aureus RN4220 containing the cloned gene were identical in terms of the substrate specificity of the enzyme as well as the aminoglycoside resistance profile, although both mRNA and aminoglycoside resistance levels were markedly high in strain PRC104. Therefore, the cloned aac(6')/aph(2") gene may represent the molecular basis for the novel aminoglycoside modification capability as well as novel aminoglycoside resistance profile of S. aureus PRC104.
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  • VI (3). Role of Substituents on Dilactone Ring of UK-2A and Antimycin A3 against Generation of Reactive Oxygen Species in Porcine Renal Proximal Tubule LLC-PK1 Cells
    KEN-ICHI FUJITA, TETSUO KISO, YOSHINOSUKE USUKI, TOSHIO TANAKA, MAKOTO ...
    2004 Volume 57 Issue 10 Pages 687-690
    Published: October 25, 2004
    Released: January 27, 2009
    JOURNALS FREE ACCESS
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  • LI SUN, ALINE C. LINDBECK, ANGELA M. NILIUS, TIMOTHY B. TOWNE, CASEY C ...
    2004 Volume 57 Issue 10 Pages 691-694
    Published: October 25, 2004
    Released: January 27, 2009
    JOURNALS FREE ACCESS
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