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At least 199 records · Page 11Linked to original sources
PubMed2000

Immunomodulatory constituents from an ascomycete, Emericella aurantio-brunnea.

Fractionation monitored by the immunomodulatory activity of the AcOEt extract of an Ascomycete, Emericella aurantio-brunnea, afforded two known fungal sesterterpenes, variecolin (1) and variecolactone (2), two new variecolin congeners named variecoacetals A (3) and B (4), and a new sesquiterpenetriol diester named emeremophiline (5), as the immunosuppressive constituents of this fungus. The absolute configuration of 1, which was previously not determined, was determined to be (2S,3S,6R,10S,11R,14S,15R,16S) from the NMR spectral data of the (6R,7R)-dimethyl-1,3,5-trioxacycloheptyl derivative of 1 (7). The absolute configurations of the other variecolin congeners, 2-4, and variecolol (6) are also proposed from biosynthetic considerations.

Adjuvants, Immunologic↗
PubMed2003

Six new constituents from an Ascomycete, Chaetomium quadrangulatum, found in a screening study focused on monoamine oxidase inhibitory activity.

A screening study focusing on monoamine oxidase inhibitory activity on the EtOAc extract of an Ascomycete Chaetomium quadrangulatum, which previously gave five unique chromones possessing this activity (chaetoquadrins A-E (1-5)), this time afforded six new constituents termed chaetoquadrins F-K (6-11) in addition to 1-5. The structures of 6-11 have been deduced on the basis of spectral and chemical data, and 7 and 8 have shown appreciable monoamine oxidase inhibitory activity.

Chaetomium↗
PubMed2004

Six immunosuppressive features from an ascomycete, Zopfiella longicaudata, found in a screening study monitored by immunomodulatory activity.

In a screening study on immunomodulatory fungal metabolites, three known anthraquinones, carviolin (roseo-purpurin) (1), 1-O-methylemodin (2), omega-hydroxyemodin (citreorosein) (4), and a new anthraquinone, omega-acetylcarviolin (3), together with a known steroid, ergosta-4,6,8(14),22-tetraen-3-one (5) and a new steroid, 25-hydroxyergosta-4,6,8(14),22-tetraen-3-one (6) were isolated from an Ascomycete, Zopfiella longicaudata, and found to have moderate immunosuppressive activities. The structure-activity relationships of these metabolites are discussed.

Anthraquinones↗
PubMed2004

Inhibition of inducible TNF-alpha expression by oxaspirodion, a novel spiro-compound from the ascomycete Chaetomium subspirale.

In a search for compounds inhibiting the inducible TNF-alpha promoter activity in T cells, a new spiro-compound, designated oxaspirodion, was isolated from fermentations of the ascomycete Chaetomium subspirale. Oxaspirodion inhibited TNF-alpha promoter-driven luciferase reporter gene expression with an IC50 value of 2.5 microg/ml (10 microM) in TPA/ionomycin-stimulated Jurkat T cells. Studies on the mode of action of the compound revealed that the inhibition of the TNF-alpha promoter activity is caused by an inhibition of the phosphorylation of the ERK1/2 kinases. In addition, oxaspirodion inhibited the activation of the transcription factor NF-kappaB, which is involved in the inducible expression of many proinflammatory genes.

Animals↗
PubMedDate not supplied

Inhibition of TNF-alpha promoter activity and synthesis by A11-99-1, a new cyclopentenone from the ascomycete Mollisia melaleuca.

In a search for inhibitors of the inducible tumor necrosis factor-a (TNF-a) promoter activity and synthesis, a new chlorinated cyclopentenone was isolated from fermentations of the ascomycete Mollisia melaleuca. The structure was determined by a combination of spectroscopic techniques The compound blocked the inducible human TNF-alpha promoter activity and synthesis with IC50-values of 2.5-5 microg/ml (8.1-16.1 microM). Studies on the mode of action of the compound revealed that the inhibition of TNF-a promoter activity is caused by an inhibition of the phosphorylation of the IkappaB protein which prevents the activation of the transcription factor NF-xB. No cytotoxic, antibacterial and antifungal activities could be observed up to 100 microg/ml (323 microM) of the compound.

Ascomycota↗
PubMed2005

Pheromones and pheromone receptors are required for proper sexual development in the homothallic ascomycete Sordaria macrospora.

The homothallic, filamentous ascomycete Sordaria macrospora is self-fertile and produces sexual fruiting bodies (perithecia) without a mating partner. Even so, S. macrospora transcriptionally expresses two pheromone-precursor genes (ppg1 and ppg2) and two pheromone-receptor genes (pre1 and pre2). The proteins encoded by these genes are similar to alpha-factor-like and a-factor-like pheromones and to G-protein-coupled pheromone receptors of the yeast Saccharomyces cerevisiae. It has been suggested that in S. macrospora, PPG1/PRE2 and PPG2/PRE1 form two cognate pheromone-receptor pairs. To investigate their function, we deleted (delta) pheromone-precursor genes (delta ppg1, delta ppg2) and receptor genes (delta pre1, delta pre2) and generated single- as well as double-knockout strains. No effect on vegetative growth, fruiting-body, and ascospore development was seen in the single pheromone-mutant and receptor-mutant strains, respectively. However, double-knockout strains lacking any compatible pheromone-receptor pair (delta pre2/delta ppg2, delta pre1/delta ppg1) and the double-pheromone mutant (delta ppg1/delta ppg2) displayed a drastically reduced number of perithecia and sexual spores, whereas deletion of both receptor genes (delta pre1/delta pre2) completely eliminated fruiting-body and ascospore formation. The results suggest that pheromones and pheromone receptors are required for optimal sexual reproduction of the homothallic S. macrospora.

Crosses, Genetic↗
PubMed1997

Ascomycetous yeasts from tropical intertidal dark mud of southeast Brazilian estuaries.

Four different intertidal estuarine sediments had distinct yeast communities. One-hundred-ninety-three yeast isolates were classified in 47 species, with 34 of these in the genus Candida. Candida tropicalis was the only ascomycetous species isolated from all four sites. Other opportunistic pathogens including Candida glabrata, Candida guilliermondii, Candida parapsilosis and Candida krusei were present, especially at the more polluted sites. Pichia species were also frequent isolates with Pichia membranaefaciens, and its anamorph, Candida valida, and other phenotypically similar low assimilation profile species the most frequent. Kluyveromyces aestuarii was prevalent at the only site with well established mangrove vegetation, but not present at the other sites. The sediment yeast communities were distinct from each other, but more similar to each other than to the yeast communities of other ecosystems in the same geographic region.

Journal Article↗
PubMedDate not supplied

Clonality in the postfire root rot ascomycete Rhizina undulata.

The aim of the present work was to investigate the potential for territorial and dispersive clonality in natural populations of the postfire root rot ascomycete Rhizina undulata. Population studies based on vegetative compatibility tests were done with strains isolated from individual sporocarps at five burned sites in three different localities (separated by 20-40 km) in the Curronian Spit of western Lithuania. Among a total of 103 strains, the tests identified 14 distinct vegetative compatibility groups (VCGs) of R. undulata, 13 of which were represented by 2-48 strains and three were encountered at 2-4 different sites. Occurrence on spatially separated sites of the same VCG of the fungus indicated a presence of dispersive clonality in R. undulata populations. On a local scale clusters of vegetative compatible sporocarps usually occupied discrete territories, implying territorial clonality. The two largest VCGs covered areas up to 7 and 3 m across. The results show that both dispersive and territorial clones are characteristics of natural populations of the fungus.

Ascomycota↗
PubMed1993

Lachnumon and lachnumol a, new metabolites with nematicidal and antimicrobial activities from the ascomycete Lachnum papyraceum (Karst.) Karst. I. Producing organism, fermentation, isolation and biological activities.

Several chlorinated metabolites with nematicidal, antimicrobial, and cytotoxic activities were isolated from submerged cultures of the ascomycete Lachnum papyraceum. Three compounds were identified as (+)-mycorrhizin A (3), (+)-chloromycorrhizin A (4) and (+)-dechloromycorrhizin A (5). The occurrence of 5 as a natural product is new. Two compounds, lachnumon (1) and lachnumol A (2), were found to be new fungal metabolites with cytotoxic, nematicidal and antimicrobial activities.

Animals↗
PubMed1993

Lachnumon and lachnumol a, new metabolites with nematicidal and antimicrobial activities from the ascomycete Lachnum papyraceum (Karst.) Karst. II. Structural elucidation.

The structures of two new biologically active chlorinated metabolites isolated from submerged cultures of the ascomycete Lachnum papyraceum have been elucidated by NMR and mass spectroscopy. The compounds, lachnumon (1) and lachnumol A (2), which structurally are related with mycorrhizin A that also is produced by the fungus, contain an unusual chlorinated epoxide group.

Antifungal Agents↗
PubMed1994

Thielocin B3, a novel antiinflammatory human group II phospholipase A2 specific inhibitor from ascomycetes.

Evidence accumulated to date suggests that extracellular group II phospholipase A2 (PLA2-II) is involved in the pathogenesis of inflammatory disease. During screening for PLA2 inhibitors, we found a novel PLA2 inhibitor named thielocin B3 in the culture broth of an ascomycetes. Thielocin B3 strongly inhibited human PLA2-II (IC50 = 0.076 microM) in a reversible and noncompetitive manner (Ki = 0.098 microM), whereas it inhibited human group I PLA2 only weakly (IC50 = 18 microM). It also quenched the tryptophan fluorescence of Naja mocambique venom PLA2; almost 100% quenching being attained at a thielocin B3/enzyme molar ratio of 1.0. Its inhibitory activity toward human PLA2-II and Naja mocambique PLA2 was markedly decreased by methylation of its two carboxyl groups, while the quenching observed for Naja mocambique PLA2 was not altered. These results suggest that the two carboxyl groups do not participate in the binding of thielocin B3 to the enzyme, but play a crucial role in the PLA2 inhibition. Furthermore, in the rat carrageenan-induced pleurisy model, thielocin B3 significantly reduced both exudate volume and PLA2 activity in the exudate when coinjected with carrageenan.

Animals↗
PubMed1995

Metabolites with nematicidal and antimicrobial activities from the ascomycete Lachnum papyraceum (Karst.) Karst. V. Production, isolation and biological activities of bromine-containing mycorrhizin and lachnumon derivatives and four additional new bioactive metabolites.

Eight novel bioactive metabolites were isolated from submerged cultures of the ascomycete Lachnum papyraceum (Karst.) Karst, when CaBr2 was added to the cultures after the onset of secondary metabolism. Four of these metabolites (16 to 19) are bromo analogues of mycorrhizin A and lachnumon, while (l'Z)-dechloromycorrhizin A (12) and the papyracons A (13), B (14), and C (15) are non-halogenated compounds structurally related to the mycorrhizins. All compounds exhibited antimicrobial, cytotoxic, nematicidal and phytotoxic activities. The brominated mycorrhizins and lachnumons were found to be slightly less active than the chlorine-containing compounds. All mycorrhizin derivatives were mutagenic in the Ames test, suggesting DNA-alkylating properties.

Animals↗
PubMed1995

New metabolites with nematicidal and antimicrobial activities from the ascomycete Lachnum papyraceum (Karst.) Karst. VI. Structure determination of non-halogenated metabolites structurally related to mycorrhizin A.

The structure determination of four new biologically active non-halogenated metabolites isolated from submerged cultures of the ascomycete Lachnum papyraceum is described. The compounds are structurally related to the antibiotic mycorrhizin A: (l'Z)-Dechloromycorrhizin A (12), a stereoisomer of dechloromycorrhizin A (5) previously isolated from the same fungus, as well as papyracon A (13), papyracon B (14) and papyracon C (15) containing an exocyclic double bond. The amounts of the latter three increased significantly when CaBr2 was added to the culture medium. The structures were determined by spectroscopic methods.

Anti-Bacterial Agents↗
PubMed1995

New metabolites with nematicidal and antimicrobial activities from the ascomycete Lachnum papyraceum (Karst.) Karst. VII. Structure determination of brominated lachnumon and mycorrhizin A derivatives.

The structure determination of lachnumon B1 (16) and lachnumon B2 (17), brominated derivatives of lachnumon (1), as well as mycorrhizin B1 (18) and mycorrhizin B2 (19), brominated derivatives of mycorrhizin A (3), is described. The compounds, which exhibit similar antimicrobial and nematicidal activity as their chlorinated analogues, were isolated from extracts of cultures of the ascomycete Lachnum papyraceum to which CaBr2 had been added. The structures were elucidated by spectroscopic methods.

Anti-Bacterial Agents↗
PubMed1995

New metabolites with nematicidal and antimicrobial activities from the ascomycete Lachnum papyraceum (Karst.) Karst. IV. Structural elucidation of novel isocoumarin derivatives.

The structures of four new biologically active halogenated dihydroiso coumarins isolated from submerged cultures of the ascomycete Lachnum papyraceum have been elucidated by spectroscopic methods. The compounds are structurally related to lachnumon and mycorrhizin A, which are also produced by the fungus.

Anti-Infective Agents↗
PubMed1996

New metabolites with nematicidal and antimicrobial activities from the ascomycete Lachnum papyraceum (Karst.) Karst. VIII. Isolation, structure determination and biological activities of minor metabolites structurally related to mycorrhizin A.

Five new minor metabolites, papyracon D (6), 6-O-methylpapyracon B (9), 6-O-methylpapyracon C (10), lachnumfuran A (11) and lachnumlactone A (12a), together with the known chloromycorrhizinol A (4), have been isolated from extracts of the culture fluids of the ascomycete Lachnum papyraceum. The compounds, which structures were determined by spectroscopic methods, are structurally related to the nematicidal and antibiotic mycorrhizin A (1), which also is produced by the fungus. The nematicidal, antibiotic and cytotoxic activities of the new compounds are weaker compared to those of mycorrhizin A (1). Papyracon D (6) possesses the highest antibiotic activities while lachnumlactone A (12a) is the most nematicidal and cytotoxic.

Anti-Infective Agents↗
PubMed2002

Biologically active secondary metabolites from the ascomycete A111-95. 1. Production, isolation and biological activities.

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.

Animals↗