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N Naruse

Publications and source records attributed to N Naruse.

At least 19 recordsLinked to original sources
PubMed2002

Direct imaging of the InSb001-c8 x 2 surface: evidence for large anisotropy of the reconstruction.

We have observed the InSb(001)-c(8 x 2) surface by using high-resolution transmission electron microscopy in the profile-imaging geometry. All images observed at temperatures up to 420 degrees C agree well with the c(8 x 2) model reported by Kumpf et al. [Phys. Rev. Lett. 86, 3586 (2001)]]. 1/30 sec real-time observations at 420 degrees C evidence that a part of the subsurface and surface layers (called a gull-type segment) undergo switching to and from a bulk configuration. The finding is suggestive of large anisotropy in the mean square displacement of the c(8 x 2) surface.

Journal Article↗
PubMed2000

Luminacins: a family of capillary tube formation inhibitors from Streptomyces sp. I. Taxomony, fermentation, isolation, physico-chemical properties and structure elucidation.

A new family of capillary tube formation inhibitors, designated luminacins, has been discovered in the fermentation broth of a soil bacterium. The strain was identified as Streptomyces sp. Mer-VD1207 from taxonomic studies. By means of a series of chromatographic procedures, fourteen structurally related components, luminacins A1, A2, B1, B2, C1, C2, D, E1, E2, E3, F, G1, G2, and H, were isolated, and their structures were elucidated on the basis of spectroscopic analyses.

Angiogenesis Inhibitors↗
PubMed2000

Luminacins: a family of capillary tube formation inhibitors from Streptomyces sp. II. Biological activities.

Twelve of the fourteen isolated components of the luminacin family were assayed for activity to inhibit capillary tube formation in vitro. Seven of them showed potent activity with IC50 values of less than 0.1 microg/ml in a rat aorta matrix culture model. Luminacin D, the strongest inhibitor, inhibited both endothelial cell proliferation and capillary tube formation. Morphological observation suggested that luminacin D inhibited the rearrangement of endothelial cells in the initial stage of tube formation. Luminacins and their derivatives are good candidates for application as angiogenesis inhibitors with a novel mechanism of action.

Angiogenesis Inhibitors↗
PubMed1999

EM2487, a novel anti-HIV-1 antibiotic, produced by Streptomyces sp. Mer-2487: taxonomy, fermentation, biological properties, isolation and structure elucidation.

For the purpose of discovering novel agents that inhibit HIV-1 replication at the transcriptional level, we have established cell lines reflecting the HIV-1 long terminal repeat-driven gene expression. Using these cell lines, we have screened approximately 10,000 microorganism products and found that the culture supernatant of Streptomyces sp. Mer-2487 suppresses the HIV-1 Tat-induced gene expression without affecting the basal or tumor necrosis factor-alpha-induced transcription. The purified active component has a unique structure, as shown in Fig. 1. This compound has an inhibitory effect on HIV-1 replication in chronically infected cells as well as acutely infected cells, suggesting that the inhibition occurs at a postintegration step of HIV-1 proviral DNA in the HIV-1 replication cycle.

Anti-Bacterial Agents↗
PubMed1998

K1115 A, a new anthraquinone derivative that inhibits the binding of activator protein-1 (AP-1) to its recognition sites. I. Biological activities.

K1115 A, a new anthraquinone derivative, was isolated from the culture broth of Streptomyces griseorubiginosus (Mer-K1115). K1115A inhibited the direct binding of activator protein-1 (AP-1) to AP-1 oligonucleotide (IC50 = 100 microM), and the production of collagenase in IL-1 alpha-stimulated rat synovial cells (IC50 = 60 microM). In vivo, the application of K1115 A decreased phorbol myristate acetate (PMA)-induced mouse ornithine decarboxylase (ODC) activity. These results indicated that K1115 A is able to attenuate the inflammatory response mediated by AP-1.

Animals↗
PubMed1998

K1115 A, a new anthraquinone that inhibits the binding of activator protein-1 (AP-1) to its recognition sites. II. Taxonomy, fermentation, isolation, physico-chemical properties and structure determination.

A new inhibitor of the action of activator protein-1 (AP-1), designated K1115 A, was isolated from the fermentation broth of an actinomycete strain Mer-K1115. K1115 A was determined to be a new anthraquinone, 3,8-dihydroxy-1-propylanthraquinone-2-carboxylic acid, based on spectroscopic analysis, derivatization experiments and biosynthetic studies with 13C-enriched acetic acid. Two co-produced compounds, K1115 B1 and B2, were also isolated and characterized as new members of the naphthopyranomycin and exfoliamycin group.

Anthraquinones↗
PubMed1997

Borrelidin is an angiogenesis inhibitor; disruption of angiogenic capillary vessels in a rat aorta matrix culture model.

Borrelidin, an antibiotic from Streptomyces rochei, was found to be an angiogenesis inhibitor in a rat aorta matrix culture model which forms capillary vessels in vitro. Borrelidin strongly inhibited capillary tube formation with a 50%-inhibitory concentration value of 0.8 nM, and decreased the number of capillary tubes within 24 hours when added after maturation of tube formation. Borrelidin remarkably disrupted capillary tubes in a dose-dependent manner, by inducing apoptosis of the tube-forming cells.

Animals↗
PubMed1995

Growth inhibition of human glioma cells by superinduced human interferon-beta.

Superinduction of human interferon-beta (HuIFN-beta) from human glioma cells has greater cytotoxicity than purified HuIFN-beta derived from fibroblasts. However, superinduction requires several reagents like polyI:polyC, cycloheximide, and actinomycin D, which may contaminate the conditioned medium and obscure the effect of superinduced HuIFN-beta. The present study used minimum doses of polyI:polyC and cycloheximide without actinomycin D to superinduce HuIFN-beta. The superinduced HuIFN-beta was purified by passing the medium through molecular sieve column chromatography. Fractionation of the eluate provided semipurified superinduced HuIFN-beta which demonstrated a growth inhibitory effect against both the U251-MG autologous human glioma cell line and the SK-MG-1 homologous glioma cell line. This effect was neutralized by addition of anti-HuIFN-beta monoclonal antibody (YSB-1). In a separate experiment, combinations of superinduction reagents were found not to have growth inhibitory effects because all inhibition in superinduced medium was completely neutralized by YSB-1. Superinduced HuIFN-beta has a pure growth inhibitory effect on both autologous and homologous glioma cells, so may affect autocrine secretion of cytokines.

Antibodies, Monoclonal↗
PubMed1995

Structure of new cyclic depsipeptides, Bu-2841-08 and -10.

The structures of new antibiotics, Bu-2841-08 and -10, have been determined. They are cyclic depsipeptides and the sequence of amino acid residues was established by mass spectral analysis of the hydrolyzed linear peptide and NMR spectral analysis of the parent cyclic peptides.

Amino Acid Sequence↗
PubMed1993

New antiviral antibiotics, kistamicins A and B. II. Structure determination.

The structures of antiviral antibiotics kistamicins A and B have been determined by a combination of chemical degradation and spectral analysis. They are commonly composed of D-tyrosine, 3,5-dihydrophenylglycine, a biphenyl ether bis-amino acid, and a diphenyl substituted indole tris-amino acid, forming a tricyclic ring structure. Kistamicin B possessed a phenethylamide at the amino terminal of kistamicin A. They are structurally related to the nuclei of the vancomycin group antibiotics particularly to antibiotic complestatin.

Amino Acid Sequence↗
PubMed1992

Sultriecin, a new antifungal and antitumor antibiotic from Streptomyces roseiscleroticus. Production, isolation, structure and biological activity.

Streptomyces roseiscleroticus L827-7 (ATCC 53903) produced a novel antifungal and antitumor antibiotic, sultriecin. It exhibited in vitro antifungal activity and potent in vivo antitumor activity against P388 and L1210 leukemias, and B16 melanoma. Sultriecin is composed of several unique structural units; a conjugated triene, an alpha,beta-unsaturated delta-lactone, and a sulfate functionality.

Animals↗
PubMed1992

Quartromicin, a complex of novel antiviral antibiotics. I. Production, isolation, physico-chemical properties and antiviral activity.

A strain of Amycolatopsis orientalis No. Q427-8 (ATCC 53884) was found to produce a complex of new antiviral antibiotics, quartromicin which consisted of at least six components A1, A2, A3, D1, D2 and D3. Structural studies suggested that they are a novel type of molecules unrelated to any known antibiotics. Each component of quartromicin exhibited antiviral activity against herpes simplex virus type 1, influenza virus type A and human immunodeficiency virus.

Actinomycetales↗
PubMed1991

Fluvirucins A1, A2, B1, B2, B3, B4 and B5, new antibiotics active against influenza A virus. I. Production, isolation, chemical properties and biological activities.

Five unidentified actinomycete strains produced a series of novel antiviral antibiotics which have a unique 2,6-dialkyl-10-ethyl-3(or 9)-hydroxy-13-tridecanelactam nucleus substituted with 3-amino-3,6-dideoxy-L-talose or 3-amino-3,6-dideoxy-L-mannose(L-mycosamine). The antibiotic components exhibited potent inhibitory activity against influenza virus type A Victoria strain infection in Madin Darby canine kidney cells by the cytopathic effect reduction assay.

Actinomycetales↗