Chromanone-type compounds from marine sponge-derived Daldinia eschscholtzii KJMT FP 4.1

In our investigation on chemical diversity of secondary metabolites from marine microorganisms, a sponge-derivedfungus was found to produce a glycosylated aromatic compound, karimanone (1). The fungal strain was isolatedfrom an Indonesian sponge Xestospongia sp. collected in Karimunjawa National Park, Central Java, Indonesia, andwas identified as Daldinia eschscholtzii based on the internal transcribed spacer rRNA gene sequence. Herein, wedescribe the isolation and characterization of karimanone (1), a new chromanone-type compound, along with threebiosynthetically related metabolites 2–4. All compounds were active against a multidrug-resistant strain of Salmonellaenterica ser. Typhi with an MIC of 62.5 μg/ml for compound 2 and 125 μg/ml for compounds 1, 3, and 4.

Cytotoxic and antibacterial polyketide-indole hybrids synthesized from indole-3-carbinol by

Two skeletally undescribed polyketide-indole hybrids (PIHs), named indolchromins A and B, were generated from indole-3-carbinol (I3C) in the fungal culture (). The indolchromin structures were elucidated mainly by their 1D and 2D NMR spectra with the former confirmed by the single-crystal X-ray crystallographic analysis. Each indolchromin alkaloid was chirally separated into four isomers, whose absolute configurations were assigned by comparing the recorded circular dichroism (CD) spectra with the electronic CD (ECD) curves computed for all optional stereoisomers. Furthermore, the indolchromin construction pathways in fungal culture were clarified through enzyme inhibition, precursor feeding experiment, and energy calculation. The cascade reactions, including decarboxylative Claisen condensation catalyzed by 8-amino-7-oxononanoate synthase (AONS), C()-H activation, double bond migration, and Michael addition, all undergone compatibly during the fungal cultivation. In an MIC range of 1.3-8.6 μmol/L, (2,4)- and (2,4)-indolchromin A and (2,4)-indolchromin B are inhibitory against , , sp., , and . (2,4)-Indolchromin A and (2,4)-indolchromin B were cytotoxic against the human breast cancer cell line MDA-MB-231 with IC values of 27.9 and 131.2 nmol/L, respectively, with the former additionally active against another human breast cancer cell line MCF-7 (IC 94.4 nmol/L).

Dalestones A and B, two anti-inflammatory cyclopentenones from Daldinia eschscholzii with an edited strong promoter for the global regulator LaeA-like gene / 中国天然药物

Replacement of the native promoter of theglobal regulator LaeA-like gene of Daldinia eschscholzii by a strong gpdA promoter led to the generation of two novel cyclopentenone metabolites, named dalestones A and B, whose structures were assigned by a combination of spectroscopic analysis, modified Mosher's reaction, and electronic circular dichroism (ECD). Dalestones A and B inhibit the gene expression of TNF-α and IL-6 in LPS-induced RAW264.7 macrophages.

Daldinia eschscholtzii (Ascomycota, Xylariaceae) isolated from the Brazilian Amazon: taxonomic features and mycelial growth conditions / Daldinia eschscholzii (Ascomycota, Xylariaceae) isolado na Amazônia brasileira: características taxonômicas e condições de crescimento micelial

The Amazon has a high diversity of fungi, including species of the genus Daldinia (Ascomycota, Xylariaceae), which produce secondary metabolites with recognized nematicidal and antimicrobial activity. The ecological role of Daldinia is important, as stromata serve as refuges to many insects and arthropodes, and the fungi contribute to the degradation of vegetable organic matter. The aim of this study was to analyze the taxonomic features and mycelial growth conditions in vitro of a Daldinia specimen collected in the Brazilian Amazon. Morphological and molecular studies of the fungus identified it as D. eschscholtzii. To evaluate mycelial growth, we cultivated the fungus at 20, 25, 30, 35, and 40 °C in malt extract-peptone agar (MEPA), malt extract-peptone (MEP), potato dextrose (PD), and minimum medium (MM). The best mycelial growth occurred at 35 °C, although the greatest amount of biomass was obtained at 25 °C and 30 °C. PD proved to be the best medium for biomass production.

A Amazônia apresenta alta diversidade de fungos, incluindo Daldinia (Ascomycota, Xylariaceae), cujas espécies produzem metabólitos secundários com reconhecida atividade antimicrobiana e nematicida. O papel ecológico é importante, visto que estromas servem de abrigo para muitos insetos e artrópodes, além de contribuir na degradação da matéria orgânica vegetal. O objetivo desse estudo foi analizar as características taxonômicas e as condições do crescimento micelial in vitro de um espécime de Daldinia coletado na Amazônia brasileira. Estudos morfológicos e moleculares do fungo o indetificaram como D. eschscholtzii. Para avaliação do crescimento micelial o fungo foi cultivado nas temperaturas de 20, 25, 30, 35 e 40 °C e nos meios de cultura extrato de malte-peptona ágar (EMPA), extrato de malte-peptona (EMP), batata dextrose (BD) e meio mínimo (MM). O melhor crescimento micelial ocorreu a 35 °C, entretanto, a maior quantidade de biomassa foi obtida a 25 e 30 °C. O meio BD provou ser o melhor meio para produção de biomassa.

Diaporthin and Orthosporin from the Fruiting Body of Daldinia concentrica

In our continuing study on the chemical constituents in the fruiting bodies of Daldinia concentrica, diaporthin and orthosporin were isolated. Their chemical structures were assigned based on various spectral studies. Diaporthin and orthosporin, phytotoxins previously found in Aspergillus ochraceus, were isolated from wood-rotting mushroom D. concentrica for the first time.