Dactylfungins and Tetralones: Bioactive Metabolites from a Nematode-Associated .

A chemical investigation of , isolated from cysts of the plant parasitic nematode , affored three dactylfungin derivatives (-) and three tetralone congeners (-). Dactylfungin C (), laburnicolin (), and laburnicolenone () are previously undescribed natural products. Chemical structures of the isolated compounds were determined based on 1D and 2D NMR spectroscopic analyses together with HR-ESI-MS spectrometry and comparison with data reported in the literature.

Laburnicolamine: A Rare Penillic Acid Congener from the Nematode Cyst-Associated Fungus Laburnicola nematophila.

A chemical investigation of a methanol extract derived from a solid-state rice culture of the nematode-cyst associated fungus Laburnicola nematophila K01 led to the isolation and characterization of a previously undescribed penillic acid analogue named laburnicolamine (1). The chemical structure was elucidated through comprehensive 1D and 2D NMR spectroscopic analyses in methanol-d and DMSO-d, alongside with HR-ESI-MS spectrometry. The absolute configuration of 1 was concluded through the electronic circular dichroism (ECD) and time-dependent density functional theory-ECD (TDDFT-ECD) computations compared to its acquired spectrum.

Laburnicotides A-F: Acyclic -Acetyl Oligopeptides from the Nematode-Cyst-Associated Fungus .

Nematode-associated fungi revealed the potential to produce a broad spectrum of chemical scaffolds. In this study, a mycelial extract of , a fungal strain derived from the cereal cyst nematode , was chemically explored and afforded six unprecedentedly reported acylic -acetyl oligopeptides, laburnicotides A-F (-). Structure elucidation of the isolated compounds was established based on comprehensive 1D and 2D NMR spectroscopic analyses together with the acquired HR-ESI-MS spectrometric data.

Omnipolyphilins A and B: Chlorinated Cyclotetrapeptides and Naphtho-α-pyranones from the Plant Nematode-Derived Fungus .

Chemical exploration for two isolates of the recently described ascomycete species , derived from the eggs of the plant parasitic nematode , afforded the identification of many compounds that belong to various metabolite families: two previously undescribed chlorinated cyclotetrapeptides, omnipolyphilins A () and B (), one new pyranonaphthoquinone, ventiloquinone P (), a 6,6'-binaphto-α-pyranone dimer, talaroderxine D () in addition to nine known metabolites (-) were isolated from this biocontrol candidate. All isolated compounds were characterized by comprehensive 1D, 2D NMR, and HR-ESI-MS analyses. The absolute configurations of the cyclotetrapeptides were determined by a combination of advanced Marfey's method, ROE correlation aided by conformational analysis, and TDDFT-ECD calculations, while ECD calculations, Mosher's method, and experimental ECD spectra were used for ventiloquinone P () and talaroderxine D ().

Lachnuoic Acids A-F: Ambuic Acid Congeners from a Saprotrophic Lachnum Species.

Chemical prospection of an extract derived from a saprotrophic fungus Lachnum sp. IW157 resulted in the isolation and characterization of six unprecedentedly reported ambuic acid analogues named lachnuoic acids A-F (1-6). Chemical structures of 1-6 were determined based on comprehensive 1D and 2D NMR spectroscopic analyses together with HR-ESI-MS spectrometry.

Bioactive Naphtho-α-Pyranones from Two Endophytic Fungi of the Genus .

In the course of our survey to study the metabolic potential of two species of a new helotialean genus , namely and , their crude extracts were obtained using different cultivation techniques, which led to the isolation and characterization of two new naphtho--pyranone derivatives recognized as a monomer () and its 6,6'-homodimer () together with two known diketopiperazine congeners, outovirin B () and (3,6)-3,6-dibenzylpiperazine-2,5-dione (). The structures of isolated compounds were determined based on extensive 1D and 2D NMR and HRESIMS. The absolute configuration of new naphtho--pyranones was determined using a comparison of their experimental ECD spectra with those of related structural analogues.

Polydomus karssenii gen. nov. sp. nov. is a dark septate endophyte with a bifunctional lifestyle parasitising eggs of plant parasitic cyst nematodes (Heterodera spp.).

In this study fungal strains were investigated, which had been isolated from eggs of the cereal cyst nematode Heterodera filipjevi, and roots of Microthlaspi perfoliatum (Brassicaceae). The morphology, the interaction with nematodes and plants and the phylogenetic relationships of these strains originating from a broad geographic range covering Western Europe to Asia Minor were studied. Phylogenetic analyses using five genomic loci including ITSrDNA, LSUrDNA, SSUrDNA, rpb2 and tef1-α were carried out.

Biosynthesis of Antibacterial Iron-Chelating Tropolones in as Response to Glycopeptide-Producing Streptomycetes.

The soil microbiome comprises numerous filamentous fungi and bacteria that mutually react and challenge each other by the production of bioactive secondary metabolites. Herein, we show in liquid co-cultures that the presence of filamentous Streptomycetes producing antifungal glycopeptide antibiotics induces the production of the antibacterial and iron-chelating tropolones anhydrosepedonin () and antibiotic C () in the mold . Additionally, the biosynthesis of the related polyketide tripyrnidone () was induced, whose novel tricyclic scaffold we elucidated by NMR and HRESIMS data.

Biosynthesis of oxygenated brasilane terpene glycosides involves a promiscuous N-acetylglucosamine transferase.

Investigation of the metabolome of the ascomycete Annulohypoxylon truncatum led to the identification of novel oxygenated brasilane glycosides and the revision of the stereochemistry of the brasilane A octahydro-1H-indene core scaffold to trans. The bra biosynthetic gene cluster containing five genes (braA-braE) was identified and verified by heterologous expression experiments in Aspergillus oryzae demonstrating that BraC is a multifunctional P450 monooxygenase. In vitro studies of BraB revealed it to be a very rare fungal UDP-GlcNAc dependent N-acetylglucosamine transferase.

Stieleriacines, -Acyl Dehydrotyrosines From the Marine Planctomycete sp. nov.

Bacteria of the phylum occur ubiquitously in marine environments and play important roles in the marine nitrogen- and carbon cycle, for example as scavengers after phototrophic blooms. Here, we describe the isolation and characterization of the planctomycetal strain Enr13 isolated from a sp. biofilm obtained from seawater sediment close to Panarea Island, Italy.