Abstract: A novel antibacterial antibiotic, for which the name altersetin is proposed, was isolated from the culture broth of two endophytic Alternaria species. The relative and absolute configuration were assigned by NOESY or CD data, respectively. Altersetin is chemically related to equisetin and showed potent MIC against several pathogenic Gram-positive bacteria, whereas Gram-negative bacteria and pathogenic yeast were not or much less susceptible. Moderate in vivo efficiacy was observed for altersetin in a murine sepsis model.

Abstract: In the course of screening for plant growth regulators from microbial secondary metabolites, we isolated pteridic acids A and B from the fermentation broth of Streptomyces hygroscopicus TP-A0451 as plant growth promoters with auxin-like activity1,2). Pteridic acids induce the formation of adventitious roots in hypocotyl of kidney beans at 1nM as effectively as auxin (indoleacetic acid), a natural plant growth hormone. We herein describe the fermentation, isolation and structure determination of pteridic acids. The producing organism, strain TP-A0451 was isolated from a stem of bracken, Pteridium aquilinum, collected in Toyama, Japan. The seed culture was incubated in a medium consisting of 1% soluble starch, 0.5% glucose, 0.3% NZ-case, 0.2% yeast extract, 0.5% tryptone, 0.1%

Abstract: Streptomyces platensis (strain NRRL 18993), a producer of dorrigocins, was shown to produce migrastatin, a cyclic congener of dorrigocin A previously reported from a different organism. Additionally a new compound isomeric to migrastatin, isomigrastatin, was also isolated and its structure was determined to be a cyclic form of dorrigocin B. Both compounds were fully characterized from MS and NMR data. Product titers of both were improved by the addition of XAD-16 resin to the fermentation medium.

Abstract: Three new natural antibacterial and antifungal dithiolopyrrolone antibiotics were isolated along with the known iso-butyropyrrothine and thiolutine from the fermentation broth of an actinomycete strain which was isolated from a saharian palm grove soil collected at Adrar, south Algeria. The strain was identified as Saccharothrix sp. The three new antibiotics exhibited broad antimicrobial activity against Gram-positive bacteria, yeasts and fungi in vitro.

Abstract: Cell free 1,3-β-D-glucan synthesis by Candida albicans ATCC90028 (purchased from the American Type Culture Collection, VA, USA) and by Aspergillus fumigatus TIMM0063 (kindly gifted from the Teikyo University Institute of Medical Mycology, Tokyo, Japan) were studied by the methods described below. C. albicans was precultured in YPD broth-A [1% w/v of Bacto-peptone, 0.5% w/v yeast extract, 2% w/v glucose] at 35°C overnight. Preculture was inoculated into fresh same medium (inoculum=10% of total volume) and grown for 6 hours at 35°C with shaking. Cells were harvested by centrifugation

Abstract: Eight secondary metabolites were isolated from submerged cultures of the ascomycete A111-95 during a search for new nematicidal metabolites. (-)-Galiellalactone (7) and compound 2 are metabolites previously obtained from cultures of Galiella rufa while the compounds 1, 3, 4, 5, 6 and 8 (3 and 4 were obtained as an unseparable mixture), were isolated as natural products for the first time. Compound 2, pregaliellalactone (5) and the mixture of 3 and 4 showed nematicidal activities towards Caenorhabditis elegans and Meloidogyne incognita. All compounds showed moderate or weak cytotoxic activities.

Abstract: Six GEX1 compounds, GEX1A/herboxidiene and its related 5 novel compounds, were isolated from a culture broth of Streptomyces sp. GEX1 compounds induced both G1 and G2/M arrest in a human normal fibroblast cell line, WI-38. All six compounds up-regulated luciferase reporter gene expression directed by enhancer/promoter of various genes, such as cdc2, IL-2 and SV40 early genes. All GEX1 compounds showed cytotoxic activities in the same order of the up-regulating activities on gene expression, suggesting that these two activities are related. Despite the up-regulating activities on the reporter gene expression, GEX1A/herboxidiene did not enhance the expression of any endogenous genes involved in the cell cycle, proliferation and apoptosis. Although the unique effects of GEX1 compounds on cell cycle and the reporter gene expression were similar to those of trichostatin A (TSA), an inhibitor of histone deacetylase (HDAC), GEX1A/herboxidiene did not affect histone acetylation in cells. In addition, GEX1A/herboxidiene treatment gave rise to the shorter sized transcripts of the cdc25A and cdc2 genes as well as the normal sized ones. These results suggest that GEX1 compounds modulate gene expression by an unknown mechanism.

Abstract: Six structurally related antitumor antibiotics named GEX1 compounds were isolated from a culture broth of Streptomyces sp. GEX1A was identified as a known herbicide, herboxidiene, structurally interested by the tetrahydropyran moiety and the side chain including a conjugated diene. GEX1Q1 to approximately Q5 were determined as novel compounds related to herboxidiene. All GEX1 compounds showed cytotoxicity with IC50 values of 0.0037 to approximately 0.99 microM against human tumor cell lines in vitro, but were not active against both gram-positive and -negative bacteria. Though GEX1A/herboxidiene exhibited antitumor activity in murine tumor-planted mouse models, both GEX1Q3 and GEX1Q5 did not.

Abstract: Kosinostatin, a quinocycline antibiotic was isolated from the culture broth of an actinomycete strain TP-A0468 along with isoquinocycline B. The producing strain was isolated from the seawater sample collected in Toyama Bay and identified as Micromonospora sp. based on the taxonomic study. Kosinostatin was obtained from the culture fluid by solvent extraction and ODS column chromatography. Kosinostatin inhibited the growth of Gram-positive bacteria strongly (MIC=0.039 microg/ml) and Gram-negative bacteria and yeasts moderately (MIC= 1.56 approximately 12.5 microg/ml). It showed cytotoxicity against various cancer cell lines with the IC50 of 0.02 approximately 0.6 microm and inhibited human DNA topoisomerase Ila with the IC50 of 3 approximately 10 microM.

Abstract: Talaromyces flavus FKI-0076, a soil isolate, was found to produce compounds which reinforce the anti-Candida albicans activity of miconazole. Four structurally related compounds, a novel one, designated actofunicone, and the knowns deoxyfunicone, vermistatin and NG-012, were isolated from the culture broth by solvent extraction, ODS column chromatography and HPLC. The structure of actofunicone was elucidated as benzoic acid, 3, 5-dimethoxy-2-[[4-oxo-6-(2-acetyloxy propyl)-4H-pyran-3-yl]carbonyl]-, methyl ester by various spectroscopic analyses including NMR experiments. These compounds potentiated the anti-C. albicans activity of miconazole, decreasing the IC50 value of miconazole from 19μM to 1.6-3.7μM in the presence of the funicones.

Abstract: The structures of argyrins A-H were elucidated by NMR spectroscopy, chemical degradation and X-ray analysis as cyclic octapeptides. Argyrins A and B, in addition to the common amino acids tryptophan, glycine, dehydroalanine and alanine or alpha-aminobutyric acid, sarcosine, contain 2-(1-aminoethyl)thiazol-4-caboxylic acid and the novel amino acid 4'-methoxytryptophan. In argyrins C and D the latter is replaced by 4'-methoxy 2'-methyltryptophan. According to NMR analysis the solution and crystal conformations of argyrins A and B are identical in CDCl3 and slightly different in acetone-d6. Argyrins A and B are identical with the antibiotics A21459 A and B, whose structures are revised with respect to 4'-methoxytryptophan.

Abstract: During our continuing screening for new bioactive metabolites from fungi we discovered recently hexacyclinol (1) as a novel, unusual, oligocyclic metabolite in cultures of the fungal strain Panus rudis HKI 0254. The strain was isolated from basidiospores of this fungus found on dead betula woods collected near Irkutsk (Sibiria, specimen herb. H, DORFELT, Sibiria 299). Panus rudis is of widespread occurrence throughout the world in many different ecotypes and has been reported to produce bioactive secondary metabolites1,2). The basidiomata of Panus rudis from the Sibirian source are growing singly or basal confluent to little tufts, excentric to central, stipitate, infundibuliform, with hazel-brown, strong tomentous pilei until 4.5cm in diameter; pilei and stipes with hairs until 2.5mm,

Abstract: Seven new peptaibols, atroviridins A-C composed of 20 residue amino acids and neoatroviridins A-D with 18 residues, were isolated from the culture broth of fungal strain F80317. The strain F80317 was identified as Trichoderma atroviride from its morphological and cultural characteristics. These compounds showed antimicrobial activity against Grampositive bacteria and phytopathogenic fungi, and exhibited significant cytotoxicity to human cancer cell lines in vitro. Atroviridins showed significant membrane-perturbing activity responsible to their antibiotic action.

Abstract: A new antifungal antibiotic, YM-202204 (1), was found in the culture broth of marine fungus Phoma sp. Q60596. The structure of 1 was determined by several spectroscopic experiments as a new lactone compound. This antibiotic exhibited potent antifungal activities against Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus, and also inhibited glycosyl-phosphatidyl-inositol (GPI)-anchoring in yeast cells.

Abstract: In the search for new naturally occurring anti-angiogenic compounds, we found that a culture broth of an unidentified fungal strain B90911 exerted inhibitory activity on capillary-like tube formation of human umbilical vein endothelial cells (HUVEC) in vitro. Four active compounds were isolated by bioassay-guided separation and their structures were identified to be sulochrin (1), methyl asterric acid (2), and two new asterric acid derivatives, 3-chloroasterric acid (3), and 3,5-dichloroasterric acid (4) by spectroscopic analyses. These compounds significantly inhibited the VEGF-induced tube formation of HUVEC, suggesting that asterric derivatives could be useful for further study as anti-angiogenic agents.

Abstract: We have identified a strain of Streptomyces in which aerial hyphae formation appears to be especially sensitive to inhibition by protein kinase inhibitors. Using this assay, a number of bacterial cultures have been screened and novel inhibitors of eukaryotic protein kinases have been identified. Since M. tuberculosis possesses multiple eukaryotic-like protein kinase genes, we tested the active kinase inhibitors for the inhibition of mycobacterial growth and obtained several potent compounds. This identifies a new biochemical class of antimycobacterial agents.

Abstract: Hormone-sensitive lipase (HSL) is a key enzyme of lipid metabolism and its control is therefore a target in the treatment of diabetes mellitus. Cultures of the Streptomyces species DSM 13381 have been shown to potently inhibit HSL. Ten inhibitors of HSL, termed cyclipostins, have been isolated from the mycelium of this microorganism and a further nine related compounds detected. Their structures were characterized by 2-D NMR experiments and by mass spectrometry and were found to comprise neutral cyclic enol phosphate esters with an additional γ-lactone ring. On account of their ester-bound fatty alcohol side chain, the cyclipostins have physicochemical properties similar to those of triglycerides. The outstanding characteristic of the cyclipostins is their strong anti-HSL activity, with IC50 values in the nanomolar range.

Abstract: The novel cyclic hexadepsipeptide named pipalamycin was isolated from a culture filtrate of Streptomyces sp. ML297-90F8 as an apoptosis-inducing agent. The antibiotic was found to be consisting of each one mole of alanine, N-hydroxyalanine, glycine, N-acylated 3-hydroxyleucine, and two moles of piperazic acid. Pipalamycin induced apoptosis in apoptosis-resistant human pancreatic adenocarcinoma AsPC-1 cells at 0.3 microg/ml in 24 to approximately 48 hours. It also showed antibacterial activity on Gram-positive bacteria such as Staphylococcus aureus and Micrococcus luteus. Fermentation, isolation, structural elucidation and the biological activities of pipalamycin are described.

Abstract: Stachyflin and acetylstachyflin, produced by Stachybotrys sp. RF-7260, were found to have potent anti-influenza A virus activity. Stachyflin is a new class of hemagglutinin fusion inhibitors of influenza A virus. Several derivatives were synthesized from acetylstachyflin and subjected to preliminary examination of their structure-activity relationships. Among them, the 3-oxo and 3,8'-dioxo derivatives showed potent antiviral activity similar to stachyflin. The 3-epi derivative was four times less active than stachyflin. Modification of the 6'-hydroxy group and the C-5' position markedly diminished the antiviral activity.

Abstract: Macrosphelide L has been isolated from a strain of Periconia byssoides originally separated from the sea hare Aplysia kurodai, and the absolute stereostructures of this material and macrosphelide H, previously undetermined, have been elucidated on the basis of spectroscopic analyses using 1D and 2D NMR techniques and some chemical transformation. (R)-Methyl 3-p-bromobenzoyloxy-5-oxohexanoate has been synthesized for configurational assignments of macrosphelide H. These macrosphelides inhibited the adhesion of human-leukemia HL-60 cells to HUVEC.

Abstract: Three new natural dithiopyrrolone antibiotics, 3-methyl-2-butenoylpyrrothine (1), tigloylpyrrothine (2), and n-butyropyrrothine (3) were isolated along with the known iso-butyropyrrothine (4) and thiolutin (5) from the fermentation broth of Saccharothrix sp. SA 233. The structures of the novel compounds were established on the basis on their spectral data.

Abstract: N-Phenylethylamides 1a-1f, were isolated from cultures of three limnic strains GW90a, GW102a and GW73a. Strain GW102a delivered additionally the compound cyclo (isoleucyldehydroalanyl) (2). The structure of these compounds were assigned by a detailed spectral analysis. Due to their potential use as herbicides, various related compounds 1a, 3, 4a and 4b were synthesized. The minimum inhibitory concentration (MIC) against Chlorella vulgaris, Chlorella sorokiniana, Chlorella salina and Scenedesmus subspicatus ranged from 100 to 12.5μg/ml. All these amides were found to be inactive against Mucor miehei, Candida albicans, and some bacteria.

Abstract: In our screening of actinomycetes from the marine environment for bioactive components, a new antibiotic with a novel structure designated as parimycin was obtained from the culture broth of Streptomyces sp. isolate B8652. The structure of the new antibiotic was determined by spectroscopic methods and by comparison of the NMR data with those of the structurally related γ-indomycinone.

Abstract: A detailed screening of the secondary metabolite pattern produced by different athropod associated strains of the species Streptomyces anulatus resulted in the isolation and structure elucidation of the endophenazines A-D (2, 4-6). The structures were assigned by spectroscopic methods and chemical transformations. 4 represents a chromophoric system based on a phenazin-7-one, 5 and 6 are new 5,10-dihydrophenazine derivatives.

Abstract: CJ-15,696 and 7 novel furopyridine antibiotics were isolated from the fungus Cladobotryum varium CL12284. Their structures were determined by X-ray crystallography and spectral analysis. Three biotransformed analogs were also prepared from CJ-15,696. CJ-15,696 showed moderate activity against various Gram-positive bacteria including some drug resistant strains such as methicillin resistant Staphylococcus aureus (MRSA).