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1.
Nat Prod Res ; 35(1): 34-40, 2021 Jan.
Article in English | MEDLINE | ID: mdl-31135188

ABSTRACT

Six julichrome derivatives including a new monomeric julichrome named as julichrome Q10 (1), and previous reported julichrome Q6 (2), julichrome Q6.6 (4), julichrome Q3.5 (5), julichrome Q5.6 (6), julichrome Q2.3 (7), along with a diketopiperazine gliotoxin (3) were isolated from a soil derived strain Streptomyces sp. The structures of these compounds were identified by HR-ESI-MS, UV, IR and NMR methods. The isolated compounds were tested for their in vitro cytotoxicity against human hepatocarcinoma HepG-2 and SMMC-7721 cell lines, human breast cancer MCF-7 and MDA-MB-231 cell lines, and human normal heptical LO2 cell line. Gliotoxin (3) showed the most cytotoxic activity against the tested tumor cell lines, with IC50 values ranging from 0.11 to 1.45 µM. Julichrome Q6.6 (4) displayed selective cytotoxic activity against SMMC-7721, MCF-7 and MDA-MB-231 cell lines.


Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Gliotoxin/pharmacology , Streptomyces/chemistry , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , China , Drug Screening Assays, Antitumor , Gliotoxin/chemistry , Gliotoxin/isolation & purification , Hep G2 Cells , Humans , Magnetic Resonance Spectroscopy , Molecular Structure , Soil Microbiology , Spectrometry, Mass, Electrospray Ionization , Streptomyces/isolation & purification
2.
Biochem Biophys Res Commun ; 528(3): 594-600, 2020 07 30.
Article in English | MEDLINE | ID: mdl-32507600

ABSTRACT

Pyruvate kinase M2 (PKM2) functions as an important rate-limiting enzyme of aerobic glycolysis that is involved in tumor initiation and progression. However, there are few studies on effective PKM2 inhibitors. Gliotoxin is a marine-derived fungal secondary metabolite with multiple biological activities, including immunosuppression, cytotoxicity, and et al. In this study, we found that Gliotoxin directly bound to PKM2 and inhibited its glycolytic activity in a dose-dependent manner accompanied by the decreases in glucose consumption and lactate production in the human glioma cell line U87. Moreover, Gliotoxin suppressed tyrosine kinase activity of PKM2, leading to a dramatic reduction in Stat3 phosphorylation in U87 cells. Furthermore, Gliotoxin suppressed cell viability in U87 cells, and cytotoxicity of Gliotoxin on U87 cells was obviously augmented under hypoxia condition compared to normal condition. Finally, Gliotoxin was demonstrated to induce cell apoptosis of U87 cells and synergize with temozolomide. Our findings identify Gliotoxin as a new PKM2 inhibitor with anti-tumor activity, which lays the foundation for the development of Gliotoxin as a promising anti-tumor drug in the future.


Subject(s)
Antineoplastic Agents/isolation & purification , Antineoplastic Agents/pharmacology , Enzyme Inhibitors/isolation & purification , Enzyme Inhibitors/pharmacology , Gliotoxin/isolation & purification , Gliotoxin/pharmacology , Pyruvate Kinase/antagonists & inhibitors , Antineoplastic Agents/administration & dosage , Apoptosis/drug effects , Aquatic Organisms/chemistry , Cell Line, Tumor , Cell Survival/drug effects , Cell-Free System , Drug Synergism , Enzyme Inhibitors/administration & dosage , Fungi/chemistry , Gliotoxin/administration & dosage , Glycolysis/drug effects , Humans , Phosphorylation , Temozolomide/administration & dosage
3.
Mar Drugs ; 13(10): 6259-73, 2015 Oct 02.
Article in English | MEDLINE | ID: mdl-26445050

ABSTRACT

The discovery of new bioactive compounds from marine natural sources is very important in pharmacological research. Here we developed a Wnt responsive luciferase reporter assay to screen small molecule inhibitors of cancer associated constitutive Wnt signaling pathway. We identified that gliotoxin (GTX) and some of its analogues, the secondary metabolites from marine fungus Neosartorya pseufofischeri, acted as inhibitors of the Wnt signaling pathway. In addition, we found that GTX downregulated the ß-catenin levels in colorectal cancer cells with inactivating mutations of adenomatous polyposis coli (APC) or activating mutations of ß-catenin. Furthermore, we demonstrated that GTX induced growth inhibition and apoptosis in multiple colorectal cancer cell lines with mutations of the Wnt signaling pathway. Together, we illustrated a practical approach to identify small-molecule inhibitors of the Wnt signaling pathway and our study indicated that GTX has therapeutic potential for the prevention or treatment of Wnt dependent cancers and other Wnt related diseases.


Subject(s)
Apoptosis/drug effects , Colorectal Neoplasms/drug therapy , Gliotoxin/pharmacology , Neosartorya/metabolism , Adenomatous Polyposis Coli/genetics , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Down-Regulation/drug effects , Genes, Reporter/genetics , Gliotoxin/isolation & purification , HCT116 Cells , Humans , Luciferases/genetics , Secondary Metabolism , Wnt Signaling Pathway/drug effects , beta Catenin/genetics
4.
Chem Biodivers ; 12(3): 432-42, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25766916

ABSTRACT

The cytotoxic activities of extracts (50 µg/ml) from 48 fungal strains, recovered from sediments of Pecém's offshore port terminal (Northeast coast of Brazil), against HCT-116 colon cancer cell lines were investigated. The most promising extract was obtained from strain BRF082, identified as Dichotomomyces cejpii by phylogenetic analyses of partial RPB2 gene sequence. Thus, it was selected for bioassay-guided isolation of the cytotoxic compounds. Large-scale fermentation of BRF082 in potato dextrose broth, followed by chromatographic purification of the bioactive fractions from the liquid medium, yielded gliotoxin (4) and its derivatives acetylgliotoxin G (3), bis(dethio)bis(methylsulfanyl)gliotoxin (1), acetylgliotoxin (5), 6-acetylbis(dethio)bis(methylsulfanyl)gliotoxin (2), besides the quinazolinone alkaloid fiscalin B. All isolated compounds were tested for their cytotoxicities against the tumor cell lines HCT-116, revealing 4 and 3 as the most cytotoxic ones (IC50 0.41 and 1.06 µg/ml, resp.).


Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Biological Products/chemistry , Biological Products/pharmacology , Fungi/chemistry , Geologic Sediments/microbiology , Antineoplastic Agents/isolation & purification , Biological Products/isolation & purification , Brazil , Colonic Neoplasms/drug therapy , Fungi/genetics , Gliotoxin/analogs & derivatives , Gliotoxin/chemistry , Gliotoxin/isolation & purification , Gliotoxin/pharmacology , HCT116 Cells , Humans , Indoles/chemistry , Indoles/isolation & purification , Indoles/pharmacology , Phylogeny , Quinazolines/chemistry , Quinazolines/isolation & purification , Quinazolines/pharmacology
5.
Mar Drugs ; 12(11): 5657-76, 2014 Nov 24.
Article in English | MEDLINE | ID: mdl-25421322

ABSTRACT

The production of fungal metabolites can be remarkably influenced by various cultivation parameters. To explore the biosynthetic potentials of the marine fungus, Neosartorya pseudofischeri, which was isolated from the inner tissue of starfish Acanthaster planci, glycerol-peptone-yeast extract (GlyPY) and glucose-peptone-yeast extract (GluPY) media were used to culture this fungus. When cultured in GlyPY medium, this fungus produced two novel diketopiperazines, neosartins A and B (1 and 2), together with six biogenetically-related known diketopiperazines,1,2,3,4-tetrahydro-2, 3-dimethyl-1,4-dioxopyrazino[1,2-a]indole (3), 1,2,3,4-tetrahydro-2-methyl-3-methylen e-1,4-dioxopyrazino[1,2-a]indole (4), 1,2,3,4-tetrahydro-2-methyl-1,3,4-trioxopyrazino[1,2-a] indole (5), 6-acetylbis(methylthio)gliotoxin (10), bisdethiobis(methylthio)gliotoxin (11), didehydrobisdethiobis(methylthio)gliotoxin (12) and N-methyl-1H-indole-2-carboxamide (6). However, a novel tetracyclic-fused alkaloid, neosartin C (14), a meroterpenoid, pyripyropene A (15), gliotoxin (7) and five known gliotoxin analogues, acetylgliotoxin (8), reduced gliotoxin (9), 6-acetylbis(methylthio)gliotoxin (10), bisdethiobis(methylthio) gliotoxin (11) and bis-N-norgliovictin (13), were obtained when grown in glucose-containing medium (GluPY medium). This is the first report of compounds 3, 4, 6, 9, 10 and 12 as naturally occurring. Their structures were determined mainly by MS, 1D and 2D NMR data. The possible biosynthetic pathways of gliotoxin-related analogues and neosartin C were proposed. The antibacterial activity of compounds 2-14 and the cytotoxic activity of compounds 4, 5 and 7-13 were evaluated. Their structure-activity relationships are also preliminarily discussed.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antineoplastic Agents/pharmacology , Neosartorya/metabolism , Starfish/microbiology , Alkaloids/chemistry , Alkaloids/isolation & purification , Alkaloids/pharmacology , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification , Cell Line, Tumor , Diketopiperazines/chemistry , Diketopiperazines/isolation & purification , Diketopiperazines/pharmacology , Gliotoxin/chemistry , Gliotoxin/isolation & purification , Gliotoxin/pharmacology , Humans , Magnetic Resonance Spectroscopy/methods , Mass Spectrometry/methods , Neosartorya/isolation & purification , Secondary Metabolism , Structure-Activity Relationship
6.
Mar Drugs ; 12(1): 69-87, 2013 Dec 24.
Article in English | MEDLINE | ID: mdl-24368570

ABSTRACT

Gliotoxin, a secondary metabolite produced by marine fungus Aspergillus sp., possesses various biological activities including anticancer activity. However, the mechanism underlying gliotoxin-induced cytotoxicity on human cervical cancer (Hela) and human chondrosarcoma (SW1353) cells remains unclear. In this study, we focused on the effect of gliotoxin induction on apoptosis, the activating expressions of caspase family enzymes in the cells. Apoptotic cell levels were measured through DAPI and Annexin V/Propidium Iodide (PI) double staining analysis. The apoptotic protein expression of Bcl-2 and caspase family was detected by Western blot in Hela and SW1353 cells. Our results showed that gliotoxin treatment inhibited cell proliferation and induced significant morphological changes. Gliotoxin induced apoptosis was further confirmed by DNA fragmentation, chromatin condensation and disrupted mitochondrial membrane potential. Gliotoxin-induced activation of caspase-3, caspase-8 and caspase-9, down-regulation of Bcl-2, up-regulation of Bax and cytochromec (cyt c) release showed evidence for the gliotoxin activity on apoptosis. These findings suggest that gliotoxin isolated from marine fungus Aspergillus sp. induced apoptosis in Hela and SW1353 cells via the mitochondrial pathway followed by downstream events leading to apoptotic mode of cell death.


Subject(s)
Antineoplastic Agents , Apoptosis/drug effects , Aspergillus/chemistry , Biological Products/pharmacology , Gliotoxin/isolation & purification , Gliotoxin/pharmacology , Annexin A5 , Apoptosis Regulatory Proteins/antagonists & inhibitors , Apoptosis Regulatory Proteins/biosynthesis , Caspases/biosynthesis , Cell Line, Tumor , Chondrosarcoma/drug therapy , Coloring Agents , DNA Fragmentation , Female , Gene Expression Regulation, Neoplastic/drug effects , HeLa Cells , Humans , Indoles , Membrane Potential, Mitochondrial/drug effects , Phosphatidylserines/metabolism , Propidium , Proto-Oncogene Proteins c-bcl-2/biosynthesis , Uterine Cervical Neoplasms/drug therapy
7.
Med Mycol ; 51(2): 121-7, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23323804

ABSTRACT

Caspofungin is a member of the echinocandin class of antifungal agents that inhibit the synthesis of ß 1,3 glucan thus disrupting fungal cell wall structure and function. Exposure of the Aspergillus fumigatus cultures to caspofungin (0.01, 0.1 or 1.0 µg/ml) resulted in a reduction in cell growth, but the production of the epipolythiodioxopiperazine toxin, gliotoxin, was comparable, or greater, in cultures exposed to caspofungin than untreated controls. Exposure of A. fumigatus hyphae to 1.0 µg/ml caspofungin for 4 h resulted in the release of amino acids (P = 0.01), protein (P = 0.002) and gliotoxin (P = 0.02). Cultures of A. fumigatus incubated in the presence of caspofungin for 4 or 24 h demonstrated enhanced gliotoxin release (P = 0.04 and 0.03, respectively) and biosynthesis (P = 0.04 and 0.03, respectively) compared to that by control cultures. The results presented here indicate that exposure of A. fumigatus to caspofungin results in increased cell permeability and an increase in the synthesis and release of gliotoxin. Since gliotoxin has well established immunosuppressive properties it is possible that exposure of A. fumigatus to caspofungin may potentiate the production of this toxin at the site of infection. Elevated gliotoxin biosynthesis may be an attempt by the fungus to restore the redox balance of the cell following exposure to the antifungal agent but the overall effect appears to be enhanced synthesis and release.


Subject(s)
Antifungal Agents/pharmacology , Aspergillus fumigatus/drug effects , Echinocandins/pharmacology , Gliotoxin/metabolism , Immunosuppressive Agents/metabolism , Amino Acids/metabolism , Aspergillosis/microbiology , Aspergillus fumigatus/growth & development , Aspergillus fumigatus/metabolism , Caspofungin , Fungal Proteins/metabolism , Gliotoxin/isolation & purification , Hyphae , Immunosuppressive Agents/isolation & purification , Lipopeptides , Oxidation-Reduction , Time Factors
8.
Fungal Genet Biol ; 49(4): 302-12, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22405895

ABSTRACT

Although initially investigated for its antifungal properties, little is actually known about the effect of gliotoxin on Aspergillus fumigatus and other fungi. We have observed that exposure of A. fumigatus to exogenous gliotoxin (14 µg/ml), under gliotoxin-limited growth conditions, results in significant alteration of the expression of 27 proteins (up- and down-regulated >1.9-fold; p<0.05) including de novo expression of Cu, Zn superoxide dismutase, up-regulated allergen Asp f3 expression and down-regulated catalase and a peroxiredoxin levels. Significantly elevated glutathione GSH levels (p<0.05), along with concomitant resistance to diamide, were evident in A. fumigatus ΔgliT, lacking gliotoxin oxidoreductase, a gliotoxin self-protection gene. Saccharomyces cerevisiae deletents (Δsod1 and Δyap1) were hypersensitive to exogenous gliotoxin, while Δgsh1 was resistant. Significant gliotoxin-mediated (5 µg/ml) growth inhibition (p<0.001) of Aspergillus nidulans, Aspergillus terreus, Aspergillus niger, Cochliobolus heterostrophus and Neurospora crassa was also observed. Growth of Aspergillus flavus, Fusarium graminearum and Aspergillus oryzae was significantly inhibited (p<0.001) at gliotoxin (10 µg/ml), indicating differential gliotoxin sensitivity amongst fungi. Re-introduction of gliT into A. fumigatus ΔgliT, at a different locus (ctsD; AFUA_4G07040, an aspartic protease), with selection on gliotoxin, facilitated deletion of ctsD without use of additional antibiotic selection markers. Absence of ctsD expression was accompanied by restoration of gliT expression, and resistance to gliotoxin. Thus, we propose gliT/gliotoxin as a useful selection marker system for fungal transformation. Finally, we suggest incorporation of gliotoxin sensitivity assays into all future fungal functional genomic studies.


Subject(s)
Antifungal Agents/pharmacology , Aspergillus fumigatus/drug effects , Aspergillus fumigatus/growth & development , Gene Expression Regulation, Fungal/physiology , Gliotoxin/pharmacology , Oxidoreductases/genetics , Antifungal Agents/isolation & purification , Antifungal Agents/metabolism , Ascomycota/drug effects , Aspergillosis/microbiology , Aspergillus/drug effects , Aspergillus fumigatus/genetics , Aspergillus fumigatus/physiology , Biomarkers , Diamide/pharmacology , Down-Regulation , Fungal Proteins/metabolism , Fusarium/drug effects , Gene Expression Regulation, Fungal/drug effects , Gliotoxin/isolation & purification , Gliotoxin/metabolism , Glutathione/metabolism , Neurospora crassa/drug effects , Oxidation-Reduction , Oxidoreductases/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Sequence Deletion , Superoxide Dismutase/metabolism , Up-Regulation
9.
J Appl Microbiol ; 112(5): 865-73, 2012 May.
Article in English | MEDLINE | ID: mdl-22372472

ABSTRACT

AIMS: The aim of this study was to determine total fungal counts and the relative density of Aspergillus fumigatus and related species in silage samples intended for bovines before and after fermentation as well as to monitor the natural occurrence of gliotoxin in silage samples (pre- and postfermentation). METHODS AND METHODS: The survey was performed in farms located in São Paulo and Rio de Janeiro States in Brazil. In addition, the ability of A. fumigatus strains and related species strains to produce gliotoxin was also evaluated. A total of 300 samples were taken, immediately after opening of the silo (3-5 months) and during the ensiling period. Fungal counts were done by the surface-spread method. Gliotoxin production ability of isolates and natural contamination were determined by HPLC. RESULTS: All postfermented samples had a total number of moulds exceeding 1 × 10(4) CFU g(-1), with Aspergillus sp. as the most prevalent genus. Frequency of strains, among A. fumigatus and related species, was able to produce gliotoxin was similar in pre- and postfermented samples, except for sorghum, which showed differences between both kinds of samples. The highest toxin levels were produced by strains isolated from postfermented samples. More than 50% of the samples showed gliotoxin contamination levels that exceeded concentrations known to induce immunosuppressive and apoptotic effects in cells. CONCLUSIONS: The present data suggest that care should be taken because gliotoxin contamination in feedstuffs could affect productivity and also present a health risk for herds. SIGNIFICANCE AND IMPACT OF THE STUDY: Gliotoxin was found at quite important concentrations levels in pre- and postfermented substrates and its presence could therefore probably affect the productivity and health of herds. Current conservation and management practices do not avoid contamination with A. fumigatus on silage. Therefore, farm workers should be adequately protected during its handling.


Subject(s)
Animal Feed/microbiology , Aspergillus fumigatus/isolation & purification , Gliotoxin/isolation & purification , Silage/microbiology , Sorghum/microbiology , Zea mays/microbiology , Animals , Aspergillus fumigatus/pathogenicity , Brazil , Cattle , Colony Count, Microbial , Edible Grain/drug effects , Fermentation , Food Contamination/analysis
10.
Anal Bioanal Chem ; 401(8): 2519-29, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21879298

ABSTRACT

Gliotoxin is produced by non-ribosomal peptide synthesis and secreted from certain fungi, including Aspergillus fumigatus. It is an epipolythiodioxopiperazine that contains an intact disulphide bridge and is the focus of intense research as a consequence of its negative immunomodulatory properties. Gliotoxin detection is generally enabled by reversed-phase-high-performance liquid chromatography (RP-HPLC), with absorbance detection (220-280 nm), or liquid chromatography-mass spectrometry, yet detection is not readily achievable by matrix-assisted laser desorption ionisation-time-of-flight mass spectrometry (MALDI-ToF MS). We have developed a single-pot derivatisation strategy which uses sodium borohydride-mediated reduction of gliotoxin followed by immediate alkylation of exposed thiols by 5'-iodoacetamidofluorescein to yield a stable product, diacetamidofluorescein-gliotoxin (GT-(AF)(2)), of molecular mass 1103.931 Da ((M+H)+). This product is readily detectable by RP-HPLC and exhibits a 6.8-fold increase in molar absorptivity compared with gliotoxin, which results in a higher sensitivity of detection (40 ng; 125 pmoL). GT-(AF)(2) also fluoresces (excitation/emission, 492:518 nm). Unlike free gliotoxin, the product (>800 fmol) is detectable by MALDI-ToF MS. Sporidesmin A can also be detected by RP-HPLC and MALDI-ToF MS (>530 fmol) using this strategy. We also demonstrate that the strategy facilitates detection of gliotoxin (mean ± SD = 3.55 ± 0.07 µg 100 µL(-1); n = 2) produced by A. fumigatus, without the requirement for organic extraction of culture supernatants and associated solvent removal. GT-(AF)(2) is also detectable (150 ng; 460 pmol) by thin-layer chromatography.


Subject(s)
Aspergillus fumigatus/chemistry , Chromatography, High Pressure Liquid/methods , Gliotoxin/analysis , Immunosuppressive Agents/analysis , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Gliotoxin/isolation & purification , Immunosuppressive Agents/isolation & purification , Sensitivity and Specificity
11.
Biomed Chromatogr ; 24(8): 887-92, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20033890

ABSTRACT

A rapid, sensitive and specific high-performance thin-layer chromatographic (HPTLC) method was developed and validated for determination of gliotoxin in Aspergillus infected immunocompromised patients with invasive aspergillosis (IA). Densitometric analysis of gliotoxin was carried out in the absorbance mode at 254 nm after single-step extraction with chloroform. The method uses TLC aluminum plates pre-coated with silica gel 60F-254 as a stationary phase and toluene-isoamyl alcohol-methanol (10:0.5:0.5, v/v/v) as mobile phase, which gives compact spot of gliotoxin (R(f) = 0.51). The calibration curve was linear (r(2) > or = 0.994) between peak area and concentration in the tested range of 100-1000 ng spot(-1) with minimum detectable range 0.025 ng mu(-1) of serum sample. The mean +/- SD value of slope and intercept of the standard chromatogram of gliotoxin were found to be 523.2 +/- 1.555635 and 915.8 +/- 30.68843, respectively. The developed method is simple, rapid, precise and less costly than earlier diagnostic methods, and different serum samples can be run on a single TLC plate for comparative analysis. The proposed method can be used to analyze gliotoxin in patient serum for easy, rapid and cost-effective diagnosis of IA.


Subject(s)
Aspergillosis/diagnosis , Chromatography, Thin Layer/methods , Diagnostic Techniques and Procedures , Gliotoxin/blood , Aspergillosis/microbiology , Aspergillus/chemistry , Aspergillus/isolation & purification , Gliotoxin/isolation & purification , Humans , Sensitivity and Specificity
12.
Nat Prod Res ; 23(3): 203-7, 2009.
Article in English | MEDLINE | ID: mdl-19235019

ABSTRACT

A new gliotoxin analogue (1), as well as four known compounds gliotoxin (2), bisdethiobis (methylthio) gliotoxin (3), bis-N-norgliovictin (4) and didehydrobisdethiobis (methylthio) gliotoxin (5), were isolated from a culture of marine-derived fungus Aspergillus fumigatus Fres. The structure of 1 was determined on the basis of spectroscopic methods. All five compounds were evaluated for the cytotoxic effects on tsFT210 cell line by the SRB method.


Subject(s)
Aspergillus fumigatus/chemistry , Gliotoxin , Animals , Cell Line, Tumor , Cell Survival/drug effects , Gliotoxin/analogs & derivatives , Gliotoxin/chemistry , Gliotoxin/isolation & purification , Gliotoxin/pharmacology , Magnetic Resonance Spectroscopy , Mice , Molecular Structure
13.
Microbes Infect ; 9(1): 47-54, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17196420

ABSTRACT

Gliotoxin is a mycotoxin having a considerable number of immuno-suppressive actions and is produced by several moulds such as Aspergillus fumigatus. In this study, we investigated its toxic effects on human neutrophils at concentrations corresponding to those found in the blood of patients with invasive aspergillosis. Incubation of the cells for 10min with 30-100ng/ml of gliotoxin inhibited phagocytosis of either zymosan or serum-opsonized zymosan without affecting superoxide production or the exocytosis of specific and azurophil granules. Gliotoxin also induced a significant re-organization of the actin cytoskeleton which collapsed around the nucleus leading to cell shrinkage and the disappearance of filopodia. This gliotoxin-induced actin phenotype was reversed by the cAMP antagonist Rp-cAMP and mimicked by pCPT-cAMP indicating that it probably resulted from the deregulation of intracellular cAMP homeostasis as previously described for gliotoxin-induced apoptosis. By contrast, gliotoxin-induced inhibition of phagocytosis was not reversed by Rp-cAMP but by arachidonic acid, another member of a known signalling pathway affected by the toxin. This suggests that gliotoxin can affect circulating neutrophils and favour the dissemination of A. fumigatus by inhibiting phagocytosis and the consequent killing of conidia.


Subject(s)
Actins/metabolism , Aspergillus fumigatus/metabolism , Cytoskeleton/drug effects , Gliotoxin/toxicity , Neutrophils/drug effects , Phagocytosis/drug effects , Actins/physiology , Arachidonic Acid/metabolism , Aspergillosis/immunology , Aspergillosis/metabolism , Aspergillosis/microbiology , Aspergillus fumigatus/chemistry , Aspergillus fumigatus/immunology , Cyclic AMP/metabolism , Cytoskeleton/metabolism , Gliotoxin/immunology , Gliotoxin/isolation & purification , Gliotoxin/metabolism , Humans , NADPH Oxidases/metabolism , Neutrophils/enzymology , Neutrophils/immunology , Neutrophils/metabolism , Phagocytosis/immunology , Signal Transduction/drug effects
14.
J Antibiot (Tokyo) ; 59(4): 248-50, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16830893

ABSTRACT

A new antibacterial dioxopiperazine, dehydroxybisdethiobis(methylthio)gliotoxin (1), and the previously described bisdethiobis(methylthio)gliotoxin (2) and gliotoxin (3), have been isolated from the broth of a marine-derived fungus of the genus Pseudallescheria. The structure and absolute stereochemistry of the new compound was assigned on the basis of NMR and CD experiments. Compounds 1 to approximately 3 exhibit potent antibacterial activity against the methicillin-resistant and multidrug-resistant Staphylococcus aureus with MIC values of 31.2, 31.2, and 1.0 microg/ml, respectively. Compound 3 also exhibited a significant radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC50 value of 5.2 microM.


Subject(s)
Anti-Bacterial Agents/pharmacology , Gliotoxin/analogs & derivatives , Gliotoxin/pharmacology , Pseudallescheria/metabolism , Staphylococcus aureus/drug effects , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Circular Dichroism , Free Radical Scavengers/isolation & purification , Free Radical Scavengers/pharmacology , Gliotoxin/chemistry , Gliotoxin/isolation & purification , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Molecular Structure , Phaeophyceae/microbiology , Pseudallescheria/isolation & purification , Seawater/microbiology
15.
J Infect Chemother ; 9(2): 114-21, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12825108

ABSTRACT

Invasive aspergillosis has become a serious problem in clinical practice, but the actual factor that confers virulence on the fungus has not been thoroughly elucidated. To identify and isolate the immunosuppressive substances produced by the fungus, the bioactivity of culture filtrates was assessed, and analyses of the culture filtrates were carried out. Culture filtrates from different strains of Aspergillus fumigatus were assessed for their effect on human polymorphonuclear leukocytes and murine macrophages. To assess their activities in vivo, their effect on the survival of mice infected by the fungus was also studied. Subsequently, the composition of the culture filtrates was analyzed by gas chromatography-mass spectrometry. The analyses revealed that the culture filtrates contained gliotoxin at concentrations of 3 to 4 microgram/ml, and some other unidentified compounds. The bioactivities of the culture filtrates were similar to those of gliotoxin. The fungal culture filtrate reduced the survival of infected mice, but the filtrate itself did not cause the death of mice. However, all the bioactivities could not be accounted for by gliotoxin itself. These results indicate that gliotoxin in the culture filtrates may be responsible for part of the immunosuppressive activity, but some other components produced by A. fumigatus contribute, in an additive or synergistic manner, to the virulence of the fungus.


Subject(s)
Aspergillus fumigatus/pathogenicity , Gliotoxin/toxicity , Immunosuppressive Agents/toxicity , Animals , Chemotaxis, Leukocyte/drug effects , Gas Chromatography-Mass Spectrometry , Gliotoxin/isolation & purification , Humans , Male , Mice , Molecular Weight , Neutrophils/drug effects , Neutrophils/immunology , Respiratory Burst/drug effects
16.
Mycopathologia ; 127(1): 19-27, 1994 Jul.
Article in English | MEDLINE | ID: mdl-7523950

ABSTRACT

A phosphate-solubilizing strain of Penicillium bilaii was tested for the production of gliotoxin and other toxic compounds. The strain was fermented under five different conditions to allow the expression of various metabolites, including gliotoxin. These included Czapek-yeast extract medium under both shaken and still conditions as well as Czapek-yeast extract/malt extract/peptone medium and sucrose/glycerol medium in shake flasks. In addition, culture filtrate from an industrial fermentation of the fungus was examined. No gliotoxin was produced in any of the media. No other expected P. bilaii metabolites were found. Three compounds were identified in all samples: dibutyl phthalate, 1-(4-hydroxy-phenyl)ethanone and 4-hydroxy-3,6-dimethyl-2H-pyran-2-one. The production of other metabolites was dependent on the culture conditions. Two hyalodendrin derivatives were found in some fermentations and two related compounds were tentatively identified. None of the compounds found have been reported as toxic. The identity of the culture was confirmed by comparison with the ex-type culture of P. bilaii.


Subject(s)
Acetophenones/metabolism , Dibutyl Phthalate/metabolism , Gliotoxin/biosynthesis , Penicillium/metabolism , Pyrones/metabolism , Acetophenones/chemistry , Acetophenones/isolation & purification , Culture Media , Dibutyl Phthalate/chemistry , Dibutyl Phthalate/isolation & purification , Fermentation , Gas Chromatography-Mass Spectrometry , Gliotoxin/chemistry , Gliotoxin/isolation & purification , Molecular Structure , Penicillium/growth & development , Pyrones/chemistry , Pyrones/isolation & purification
19.
J Med Vet Mycol ; 27(1): 45-50, 1989.
Article in English | MEDLINE | ID: mdl-2474066

ABSTRACT

A bovine udder infected with Aspergillus fumigatus was analysed by physico-chemical methods (thin layer chromatography, high performance liquid chromatography and direct exposure probe-mass spectrometry) for the presence of mycotoxins. Gliotoxin, a fungal metabolite with cytotoxic and immunosuppressive properties was isolated for the first time from naturally infected tissue. The gliotoxin concentration analysed (9.2 mg kg-1 udder) was approximately 100 times higher than the concentration known to produce morphological changes of cells. Gliotoxin may play an important role in the establishment and development of an infection with A fumigatus.


Subject(s)
Aspergillosis/veterinary , Aspergillus fumigatus/metabolism , Gliotoxin/isolation & purification , Mammary Glands, Animal/analysis , Mastitis, Bovine/microbiology , Mycotoxins/isolation & purification , Animals , Aspergillosis/microbiology , Cattle , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Female , Gliotoxin/biosynthesis , Mammary Glands, Animal/microbiology , Mass Spectrometry , Molecular Structure
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