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ABSTRACT: Natural products produced by microorganisms are important starting compounds for drug discovery. Secondary metabolites, including antibiotics, have been isolated from different Streptomyces species. The production of these metabolites depends on the culture conditions. Therefore, the development of a new culture method can facilitate the discovery of new natural products. Here, we show that mycolic acid-containing bacteria can influence the biosynthesis of cryptic natural products in Streptomyces species. The production of red pigment by Streptomyces lividans TK23 was induced by coculture with Tsukamurella pulmonis TP-B0596, which is a mycolic acid-containing bacterium. Only living cells induced this pigment production, which was not mediated by any substances. T. pulmonis could induce natural-product synthesis in other Streptomyces strains too: it altered natural-product biosynthesis in 88.4% of the Streptomyces strains isolated from soil. The other mycolic acid-containing bacteria, Rhodococcus erythropolis and Corynebacterium glutamicum, altered biosynthesis in 87.5 and 90.2% of the Streptomyces strains, respectively. The coculture broth of T. pulmonis and Streptomyces endus S-522 contained a novel antibiotic, which we named alchivemycin A. We concluded that the mycolic acid localized in the outer cell layer of the inducer bacterium influences secondary metabolism in Streptomyces, and this activity is a result of the direct interaction between the mycolic acid-containing bacteria and Streptomyces. We used these results to develop a new coculture method, called the combined-culture method, which facilitates the screening of natural products.
Applied and environmental microbiology 01/2011; 77(2):400-6. · 3.69 Impact Factor
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ABSTRACT: Alchivemycin A, a novel polycyclic polyketide, was isolated from the culture extract of a plant-derived actinomycete Streptomyces sp. The structure and relative configuration were elucidated by spectroscopic analysis and X-ray crystallography, and the absolute configuration was determined by a (1)H NMR anisotropy method using MPA ester derivatization. The new compound contains an unprecedented heterocyclic ring system, 2H-tetrahydro-4,6-dioxo-1,2-oxazine. Alchivemycin A showed potent antimicrobial activity against Micrococcus luteus and inhibitory effects on tumor cell invasion.
Organic Letters 08/2010; 12(15):3402-5. · 5.86 Impact Factor
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ABSTRACT: Two novel anthraquinones, lupinacidins A (1) and B (2), have been isolated from the culture broth of a new endophytic actinomycete belonging to the genus Micromonospora. Lupinacidins were found to show significant inhibitory effects on the invasion of murine colon 26-L5 carcinoma cells without inhibiting cell growth.
Bioorganic & Medicinal Chemistry Letters 08/2007; 17(13):3702-5. · 2.55 Impact Factor
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ABSTRACT: In the screening of antitumor compounds from microbial secondary metabolites, myxochelin A was isolated from a culture broth of Nonomuraea pusilla TP-A0861. The absolute configuration was determined to be S by synthesizing both enantiomers from an L- or D-lysine derivative and comparing their specific rotations. Both enantiomers of myxochelin A showed remarkable inhibitory effects on the invasion of murine colon 26-L5 carcinoma cells at non-cytotoxic concentrations.
The Journal of Antibiotics 12/2006; 59(11):698-703. · 1.65 Impact Factor
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ABSTRACT: A new cytotoxic compound, pterocidin, was isolated from the endophytic Streptomyces hygroscopicus TP-A0451, and the structure was determined on the basis of spectroscopic data. Pterocidin showed cytotoxicity against some human cancer cell lines with IC50 values of 2.9-7.1 microM.
The Journal of Antibiotics 04/2006; 59(3):193-5. · 1.65 Impact Factor
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ABSTRACT: The biosynthetic gene cluster of goadsporin, a polypeptide antibiotic containing thiazole and oxazole rings, was cloned from Streptomyces sp. TP-A0584. The cluster contains a structural gene, godA, and nine god (goadsporin) genes involved in post-translational modification, immunity and transcriptional regulation. Although the gene organization is similar to typical bacteriocin biosynthetic gene clusters, each goadsporin biosynthetic gene shows low homology to these genes. Goadsporin biosynthesis is initiated by the translation of godA, and the subsequent cyclization, dehydration and acetylation are probably catalysed by godD, godE, godF, godG and godH gene products. godI shows high similarity to the 54 kDa subunit of the signal recognition particle and plays an important role in goadsporin immunity. Furthermore, four goadsporin analogues were produced by site-directed mutagenesis of godA, suggesting that this biosynthesis machinery is used for the heterocyclization of peptides.
Microbiology 01/2006; 151(Pt 12):3923-33. · 3.06 Impact Factor
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ABSTRACT: The staurosporine biosynthetic gene cluster in Streptomyces sp. TP-A0274 consists of 15 sta genes. In the cluster, it was predicted that staN, which shows high similarity to cytochrome P450 is involved in C-N bond formation between the nitrogen at N-12 of aglycone and the carbon at C-5' of deoxysugar. The staN disruptant produced holyrine A instead of staurosporine. The structure of holyrine A is aglycone linking to 2,3,6-trideoxy-3-aminoaldohexose between N-13 and C-1' of deoxysugar. Holyrine A was converted to staurosporine by the staD disruptant. These results indicate that StaN, cytochrome P450 is responsible for C-N bond formation. This is the first example of C-N bond formation catalyzed by cytochrome P450. In addition, holyrine A was confirmed to be an intermediate of staurosporine biosynthesis, which suggests that the N- and O-methylation at C-3' and C-4' takes place after the formation of the C-N bond between C-5' and N-12 in the biosynthetic pathway.
Bioscience Biotechnology and Biochemistry 10/2005; 69(9):1753-9. · 1.28 Impact Factor
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ABSTRACT: In the screening for muscarinic M3 receptor binding inhibitors from microbial secondary metabolites, the extract of Nocardia nova JCM 6044 was found to be highly active. Bioassay-guided isolation led to the identification of three siderophores, nocardimicins G (1), H (2) and I (3). Their chemical structures were determined by spectroscopic analysis using NMR and MS. 1 and 2 inhibited the binding of tritium-labeled N-methylscopolamine to the muscarinic M3 receptor with Ki values of 0.44 microM and 0.37 microM, respectively, whereas 3 showed no inhibition at 10 microM. 1 and 2 also showed weak binding inhibitory activity to the M5 receptor but not to the M1, M2 and M4 receptors at 10 microM.
The Journal of Antibiotics 10/2005; 58(9):566-72. · 1.65 Impact Factor
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ABSTRACT: An antifungal pentaene macrolide TPU-0043 was isolated from Streptomyces sp. TP-A0625. The absolute configuration of TPU-0043 was determined to be 2R-(n-butyl)-16-methyl-3S,5S,7S,9R,11R,13R,15S,26S, 27R-nonahydroxyoctacosa-16,18,20,22,24-pentaenoic acid, 27-lactone, by X-ray crystallography of its 13-p-bromobenzenesulfonyl derivative.
The Journal of Antibiotics 09/2005; 58(8):523-5. · 1.65 Impact Factor
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ABSTRACT: In the screening for muscarinic M3 receptor binding inhibitors from microbial secondary metabolites, the extract of Nocardia sp. TP-A0674 was found to be highly active. Bioassay-guided fractionation of it led to the isolation of six new siderophores, nocardimicins A (1), B (2), C (3), D (4), E (5), and F (6), as active principles. Their chemical structures were determined by spectroscopic and degradation analysis. Of these congeners, nocardimicin B (2) inhibited the binding of tritium-labeled N-methylscopolamine to the muscarinic M3 receptor most potently with a Ki value of 0.13 microM. Compound 2 showed more selective activity to M3 and M4 receptors than other subtypes.
Journal of Natural Products 08/2005; 68(7):1061-5. · 3.13 Impact Factor
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ABSTRACT: The anchorage-independence of cells is closely related to their tumorigenicity. In the screening of inhibitors of anchorage-independent growth of tumor cells, anicemycin was isolated from the fermentation broth of an actinomycete strain TP-A0648. The producing strain was isolated from a leaf of Aucuba japonica collected in Toyama, Japan and identified as Streptomyces sp. based on the taxonomic data. The structure of anicemycin was elucidated as a new analog of spicamycin by NMR and MS analysis. Anicemycin inhibited the anchorage-independent growth of the human ovary cancer SKOV-3 cells with an IC50 of 0.015 microM about three times more potently than their anchorage-dependent growth.
The Journal of Antibiotics 06/2005; 58(5):322-6. · 1.65 Impact Factor
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ABSTRACT: The structure assigned to the antitumor antibiotic BU-4664L from Micromonospora sp. was revised to 5,10-dihydro-4,6,8-trihydroxy-10-(3,7,11-trimethyl-trans-2,trans-6,10-dodecatrienyl)-11H-dibenzo[b,e] [1,4]-diazepin-11-one based on the NMR analysis.
The Journal of Antibiotics 06/2005; 58(5):350-2. · 1.65 Impact Factor
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ABSTRACT: A new pyrrolizidine alkaloid, cremastrine (1), was isolated from the bulbs of Cremastra appendiculata. Its configuration was determined by spectroscopic and chemical analyses. Compound 1 inhibited the binding of tritium-labeled N-methylscopolamine to the muscarinic M3 receptor with a K(i) value of 126 nM.
Journal of Natural Products 05/2005; 68(4):572-3. · 3.13 Impact Factor
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ChemInform 04/2005; 36(21).
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ABSTRACT: Pradimicin, a mannose-binding antifungal antibiotic, induces apoptosis-like cell death in Saccharomyces cerevisiae. Previously we found that the substitution of the 74th amino acid from glycine to cysteine in Ypd1 yields a mutant resistant to pradimicin. In this study, the involvement of a membrane-spanning osomosensor, Sln1, which is located upstream of Ypd1, was investigated. A mutant, sln1 DeltaNG, that lacks the putative N-glycosylation sites in the extracellular domain became resistant to pradimicin. On the other hand, the null mutants of Ssk1, Pbs2, and Hog1, which are located downstream of the Sln1 cascade, were sensitive to pradimicin as well as the wild-type strain. In conclusion, pradimicin exerts its fungicidal action with the involvement of Sln1, but the downstream branch, Ssk1 and the HOG pathway, is not involved.
Bioscience Biotechnology and Biochemistry 02/2005; 69(1):238-41. · 1.28 Impact Factor
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ABSTRACT: Aspergillus fumigatus TP-F0196 produces pseurotin A, synerazol and gliotoxin. Phenylalanine is a common biosynthetic precursor of these antibiotics. Feeding fluorophenylalanine to the culture induced the production of novel fluorinated analogs. These fluorinated antibiotics were obtained from the culture broth by solvent extraction and purified by chromatographies, and their antimicrobial and antitumor activities were investigated. Among the novel fluorinated analogs, 19- and 20-fluorosynerazols exhibited potent anti-angiogenic activity in the chorioallantoic membrane assay. In addition, 19-fluorosynerazol showed more potent cytocidal activity against several cancer cell lines than synerazol.
The Journal of Antibiotics 12/2004; 57(11):748-54. · 1.65 Impact Factor
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The Journal of Antibiotics 09/2004; 57(8):537-40. · 1.65 Impact Factor
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ABSTRACT: In a previous study, endophytic Streptomyces sp. R-5 isolated from a field-grown rhododendron was able to confer disease resistance on tissue-cultured seedlings of rhododendron when applied to medium surfaces in flasks. Here, the isolate was identified as Streptomyces galbus Frommer based on various physiological characteristics and analysis of the 16S rDNA sequence. Its major antimicro-bial metabolites were identified as actinomycin X2 and fungichromin by analyses using liquid chromatography/mass spectometry and nuclear magnetic resonance.
Journal of General Plant Pathology 01/2004; 70(1):66-68. · 0.69 Impact Factor
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ABSTRACT: Pradimicin is an antifungal antibiotic which induces apoptosis like cell death in the yeast Saccharomyces cerevisiae. Pradimicin-resistant mutants were isolated from the S. cerevisiae and the mutation points were analyzed. A point mutation of YPD1 that led to a substitution of the 74th glycine (Gly74) to cysteine (Cys) was identified in a mutant strain NH1. In S. cerevisiae, Ypd1 transfers a phosphoryl group from the sensor kinase Slnl to the response regulator Sskl which regulates a downstream MAP kinase in response to hyperosmotic stress. Gly74 is located in a three-residue reverse turn domain that connects two alpha-helices, one of which contains a histidine residue which is phosphorylated. In the reverse turn, glycine (relative position +10 to the active-site histidine) is highly conserved in Ypd1 and other histidine-containing phosphotransfer proteins. It was therefore suggested that the substitution of Gly74 to Cys altered the Ypd1 structure, which resulted in the resistance to pradimicin.
The Journal of Antibiotics 01/2004; 56(12):1053-7. · 1.65 Impact Factor
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ABSTRACT: A novel shuttle integration cosmid vector (pTOYAMAcos), based on pKU402, and shuttle integration vectors (pTYM18 and pTYM19) were constructed for the cloning of actinomycete DNA and its heterologous expression. These vectors contain oriT of an IncP transmissible plasmid in order to transfer genes by conjugation from Escherichia coli to actinomycetes, and they also contain int derived from actinophage phiC31 in order to integrate site-specifically into the chromosomal DNA. pTOYAMAcos contains the lambdacos site to promote packaging of vectors containing 35 to approximately 45-kb DNA fragments into lambda particles. pTYM18 and pTYM19 contain kanamaycin and thiostrepton resistance genes, respectively, and have multiple cloning sites including EcoRI and HindIII sites, which are available for blue/white screening in E. coli. To demonstrate the utility of these vectors, we expressed the entire gene cluster for rebeccamycin biosynthesis from Lechevalieria aerocolonigenes using pTOYAMAcos and detected rebeccamycin production in transformed S. lividans. In addition, we demonstrated the utility of pTYM 19 in a gene-disruption complementation test. L. aerocolonigenes deltarebC strain, which is defective in rebeccamycin production because of a rebC deletion, was restored to rebeccamycin production by complemention by rebC cloned in pTYM 19.
The Journal of Antibiotics 12/2003; 56(11):950-6. · 1.65 Impact Factor
