The Journal of Antibiotics
Online ISSN : 1881-1469
Print ISSN : 0021-8820
ISSN-L : 0021-8820
Volume 54 , Issue 11
Showing 1-17 articles out of 17 articles from the selected issue
  • KOSAKU TAKAHASHI, EISUKE TSUDA, KAZUHIKO KUROSAWA
    2001 Volume 54 Issue 11 Pages 867-873
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    SW-163A and B, novel immunosuppressants, were isolated from the culture broth of Streptomyces sp. SNA15896. The molecular formulas of SW-163A and B were determined as C34H42N2O12 and C33H40N2O12 based on the HRFAB-MS analysis, respectively. Both compounds were elucidated to be a large ring ester structure through spectroscopic analyses including various NMR measurements. SW-163A and B showed immunosuppressive and antimicrobial activities in vitro.
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  • RYUICHI SEKIZAWA, ISAO MOMOSE, NAOKO KINOSHITA, HIROSHI NAGANAWA, MASA ...
    2001 Volume 54 Issue 11 Pages 874-881
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    We have isolated four related compounds named phepropeptins A, B, C, and D, as inhibitors of proteasome proposed to regulate many cellular functions. From an NMR analysis, the phepropeptins appeared as cyclic hexapeptides, differing in the two residues of the constituent amino acids from one another, with four conserved amino acid moieties. Based on an amino acid analysis, we synthesized two possible cyclic peptides to phepropeptin B that differ in the configurations. A comparison of the properties between the natural and synthesized compounds revealed that the structure of phepropeptin B was cyclo(-L-Leu-D-Phe-L-Pro-L-Phe-D-Leu-L-Val-). The phepropeptins showed inhibition to the proteasomal chymotrypsin-like activity but not to α-chymotrypsin.
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  • RYUJI UCHIDA, HIROSHI TOMODA, MASAYOSHI ARAI, SATOSHI OMURA
    2001 Volume 54 Issue 11 Pages 882-889
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    Chlorogentisylquinone, a new inhibitor of neutral Sphingomyelinase activity, was purified from the culture broth of a fungal strain FOM-8108 isolated from a marine environment by solvent extraction, silica gel chromatography and Sephadex LH-20 chromatography. Its chemical structure was elucidated by spectroscopic studies including 1H, 13C, DEPT, HMQC and HMBC NMR experiments. Chlorogentisylquinone inhibited neutral Sphingomyelinase activity of rat brain membranes with an IC50 value of 1.2μM.
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  • KAZUYUKI MINAGAWA, SHUICHI KOUZUKI, KAZUHIDE NOMURA, TAKAHIRO YAMAGUCH ...
    2001 Volume 54 Issue 11 Pages 890-895
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    In the course of screening for yeast squalene synthase inhibitors, bisabosqual A was isolated from the culture broth of Stachybotrys sp. RF-7260. The related compounds bisabosquals B, C and D were also isolated from Stachybotrys ruwenzoriensis RF-6853. Bisabosquals inhibited squalene synthases. IC50 values of bisabosqual A against the microsomal squalene synthases from Saccharomyces cerevisiae, Candida albicans, HepG2 cell and rat liver were 0.43, 0.25, 0.95 and 2.5μg/ml, respectively. Bisabosqual C exhibited inhibitory activities similar to bisabosqual A. Bisabosqual A showed broad spectrum antifungal activity in vitro.
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  • KAZUYUKI MINAGAWA, SHUICHI KOUZUKI, KAZUHIDE NOMURA, YOSHIMI KAWAMURA, ...
    2001 Volume 54 Issue 11 Pages 896-903
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    The squalene synthase inhibitor bisabosqual A was isolated from the culture broth of Stachybotrys sp. RF-7260, and its structure was determined on the basis of spectroscopic methods including detailed 2D NMR analyses. The structures of bisabosquals B, C and D isolated from Stachybotrys ruwenzoriensis RF-6853 were determined by spectroscopic methods and chemical reactions. The absolute stereochemistry of bisabosquals A, B and D was determined by X-ray crystallographic analysis. They have novel cis-fused tetracyclic structures with a bisabolane-type sesquiterpene and phenol moieties.
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  • SHUZO WATANABE, HIDEO HIRAI, MASARU ISHIGURO, TAKAHITO KAMBARA, YASUHI ...
    2001 Volume 54 Issue 11 Pages 904-910
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    A new squalene synthase (SSase) inhibitor, CJ-15, 183 (I) was isolated from the fermentation broth of a fungus, Aspergillus aculeatus CL38916. The compound potently inhibited rat liver and Candida albicans microsomal SSases and also inhibited the human enzyme. It also showed antifungal activities against filamentous fungi and a yeast. The structurewas determined to be an aliphatic tetracarboxylic acid compound consisting of an alkyl γ-lactone, malic acid and isocitric acid moieties by spectroscopic studies.
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  • YUTAKA SUGIE, HIDEO HIRAI, TAISUKE INAGAKI, MASARU ISHIGURO, YOON-JEON ...
    2001 Volume 54 Issue 11 Pages 911-916
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    A new antibiotic, CJ-17, 665 (I) was isolated from the fermentation broth of Aspergillus ochraceus, CL41582. It inhibits growth of multi-drug resistant Staphylococcus aureus, Streptococcus pyogenes, and Enterococcus faecalis, with MICs of 12.5, 12.5 and 25μg/ml, respectively. The structure contains a diketopiperazine and an indole N-oxide moiety that is unusual in natural products.
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  • YUTAKA SUGIE, HIDEO HIRAI, HIROKO KACHI-TONAI, YOON-JEONG KIM, YASUHIR ...
    2001 Volume 54 Issue 11 Pages 917-925
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    Two new antibiotics, CJ-16, 264 (I) and CJ-16, 367 (II), were isolated from the fermentation broth of an unidentified fungus CL39457. These antibiotics have a pyrrolizidinone skeleton, first discovered in fungi. Compounds I and II inhibit the growth of Gram-positive multi-drug resistant bacteria and some Gram-negative strains such as Moraxella catarrhalis and Escherichia coli with altered permeability (imp). Comparison of an antibacterial profile between the two compounds suggested that the gamma-lactone portion of I is important for the activity.
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  • MASAFUMI NAKAO, KEN-ICHIRO MIYAGAWA, YOSHITAKA NAKANO, TAKESHI SAKANE, ...
    2001 Volume 54 Issue 11 Pages 926-933
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    Novel anti-Helicobacter pylori antibiotics, pyloricidins A, A1, A2, B, C and D, were discovered in the culture broth of two bacilli strains. Pyloricidins selectively inhibited the growth of H. pylori. Pyloricidin B was efficacious in the treatment of gastric infection caused by H. pylori in Mongolian gerbils and may be promising for cure of H, pylori infection as a single agent.
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  • YOICHI NAGANO, KOJI IKEDO, AKIRA FUJISHIMA, MOTOWO IZAWA, SHIGETOSHI T ...
    2001 Volume 54 Issue 11 Pages 934-947
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    Novel anti-Helicobacter pylori antibiotics, pyloricidins A, A1 A2, B, C and D were isolated from Bacillus sp. HC-70 and Bacillus sp. HC-72 by column chromatographies using adsorption and ion exchange resins. Their structures have been elucidated based on spectroscopic and degradation studies and shown to be peptide-like compounds. These compounds contained two unusual amino acids, viz., 5-amino-2, 3, 4, 6-tetrahydroxyhexanoic acid and 3-amino-3-phenylpropionic acid (β-phenylalanine). The structure-activity relationship studies suggested that 3-(5-amino-2, 3, 4, 6-tetrahydroxyhexanoyl)amino-3-phenylpropiomc acid moiety was essential for anti-H. pylori activity,
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  • RICHARD M. HALL, MICHAEL J. DAWSON, CAROL A. JONES, ANDREW D. ROBERTS, ...
    2001 Volume 54 Issue 11 Pages 948-957
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    The biotransformation of the fungal protein synthesis inhibitor sordarin is reported. Nine taxonomically diverse organisms supported the isolation and identification of twelve modified products. The structural diversity of the biotransformation products observed and their value in supporting further chemistry is discussed.
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  • QIANG GAO, ARNOLD L. DEMAIN
    2001 Volume 54 Issue 11 Pages 958-961
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    The bioconversion of penicillin G, an inexpensive substrate, to the valuable intermediate for semi synthetic cephalosporin production, deacetoxycephalosporin G (DAOG), had been recently shown to be increased by eliminating agitation and adding decane. The present work examining other solvents shows that all alkanes tested are equivalent to decane in activity but that other solvents are either inhibitory or less active than alkanes. Optimum conditions of pH and temperature for the alkane system are not very different from the previously used aqueous system.
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  • WEIMIN HU, RITSUKO NARASAKI, SHIGEKI OHYAMA, KEIJI HASUMI
    2001 Volume 54 Issue 11 Pages 962-966
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    Staplabin and SMTPs, a family of triprenyl phenol metabolites of Stachybotrys microspora, enhance fibrinolysis by modulating plasminogen conformation to increase its susceptibility to activation by plasminogen activators. We found that the production of these metabolites were markedly elevated by feeding the microbial culture with an amino acid or an amino alcohol that is a partial molecular constituent of the compound. Thus, the addition of 5-aminovaleric acid, 2-aminoethanol, Ser, Phe, Leu, Trp, Orn and Lys at lOOmg/ml resulted in 7- to 45-fold increases in the production of Staplabin, SMTP-1, -3, -4, -5, -6, -7 and -8, respectively. Although the feeding at day 0 to 3 of culture supported the selective production, the supplementation after 5 days had little or no effect. When non-constituent amino acids were supplemented to cultures, production of hitherto uncharacterized congeners was observed.
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  • YUAN R. CHENG, JIE HUANG, HUA QIANG, WEN L. LIN, ARNOLD L. DEMAIN
    2001 Volume 54 Issue 11 Pages 967-972
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
    Rapamycin (RPM) is produced by Streptomyces hygroscopicus FC904 isolated from soil in Fuzhou, China. It is a triene macrolide antibiotic with potential application as an immunosuppressant and drug for human gene therapy. In an attempt to improve rapamycin production, mutation and screening of the parent culture have been carried out. Thousands of survivors were obtained after mutagenesis by NTG (3mg/ml) and UV (SOW, 15cm, 30 seconds) of spore suspensions. None showed improved production of RPM. We determined the susceptibility to antibiotics of S. hygroscopicus FC904 by two fold dilutions of antibiotics in oatmeal agar plates. It was found that the strain was resistant to penicillin, erythromycin, RPM, tetracycline and chloramphenicol, but susceptible to mitomycin C (MIC, 10μg/ml) and aminoglycosides such as gentamicin (MIC, 0.1μg/ml), kanamycin (MIC, 0.1μg/ml) and streptomycin (MIC, 0.3 μg/ml). Protoplasts of strain FC904 were prepared after finding the best conditions for their formation. They were treated with gentamicin, erythromycin, mitomycin C and NTG. Surprisingly, gentamicin was especially effective for obtaining higher RPM-producing mutants. Mutant C14 was selected by exposing the protoplasts of the parent strain FC904 to 1 μg/ml of gentamicin at 28°C for 2 hours. A higher RPM-producing mutant (C14-1) was obtained from the protoplasts of mutant C14 treated with gentamicin, and its titer was 60% higher than that of the parent strain FC904 by HPLC analysis. Another improved mutant (C14-2) was obtained from the spores of mutant C14 treated with 1 μg/ml of gentamicin plus 2 mg/ml of NTG at 28°C for 2 hours. Mutant O14-2 had a titer 124% higher than FC904. The possible mechanism for the effect of gentamicin by using protoplasts or spore suspensions will be discussed, i.e. the possibility of gentamicin being a mutagen or a selective agent.
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  • E. K. S. VIJAYAKUMAR, KIRITY ROY, C. P. HIREMATH, S. K. DESHMUKH, TRIP ...
    2001 Volume 54 Issue 11 Pages 973-976
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
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  • KATSUOMI ICHIKAWA, TAISUKE INAGAKI, YASUHIRO KOJIMA, TAKA-AKI NAKAMURA ...
    2001 Volume 54 Issue 11 Pages 977-979
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
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  • YASUNOBU MURAKAMI, TORU OKUDA, KAZUTOSHI SHINDO
    2001 Volume 54 Issue 11 Pages 980-983
    Published: November 25, 2001
    Released: September 19, 2008
    JOURNALS FREE ACCESS
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