Metabolites isolated from the human intestinal fungus Penicillium oxalicum SL2 and their agonistic effects on PXR and FXR

Neuroprotective furanones from a soil-derived fungus Penicillium paxilli ga254

Three furanone derivatives (1-3), including one new compound, penicifuranone A (1), and one new natural product (2), along with one known dihydropyranone (4) were isolated from the solid rice medium fermentation of Penicillium paxilli ga254. The structures of these compounds were elucidated using comprehensive NMR spectroscopic analysis. This study represents the first report of these furanone derivatives from this fungus. Additionally, the neuroprotective effects of these compounds against oxygen-glucose deprivation/reperfusion injury in pheochromocytoma-12 cells were investigated.

Fungal mycobiome dysbiosis in choledocholithiasis concurrent with cholangitis

BACKGROUND

The gut mycobiome might have an important influence on the pathogenesis of choledocholithiasis concurrent with cholangitis (CC). The aim of this study was to characterize the fungal mycobiome profiles, explore the correlation and equilibrium of gut interkingdom network among bacteria-fungi-metabolites triangle in CCs.

METHODS

In a retrospective case-control study, we recruited patients with CC (n = 25) and healthy controls (HCs) (n = 25) respectively to analyze the gut fungal dysbiosis. Metagenomic sequencing was employed to characterize the gut mycobiome profiles, and liquid chromatography/mass spectrometry (LC/MS) analysis was used to quantify the metabolites composition.

RESULTS

The Shannon index displayed a reduction in fungal α-diversity in CCs compared to HCs (p = 0.041), and the overall fungal composition differed significantly between two groups. The dominant 7 fungi species with the remarkable altered abundance were identified (LDA score > 3.0, p < 0.05), including CC-enriched Aspergillus_niger and CC-depleted fungi Saccharomyces_boulardii. In addition, the correlations between CC-related fungi and clinical variables in CCs were analyzed. Moreover, the increased abundance ratio of Basidiomycota-to-Ascomycota and a dense linkage of bacteria-fungi interkingdom network in CCs were demonstrated. Finally, we identified 30 markedly altered metabolites in CCs (VIP > 1.0 and p < 0.05), including low level of acetate and butyrate, and the deeper understanding on the complexity of bacteria-fungi-metabolites triangle involving bile inflammation was verified.

CONCLUSION

Our investigation demonstrated a distinct gut fungal dysbiosis in CCs and proposed that, beyond bacteria, the more attention should be paid to significantly potential influence of fungi and bacteria-fungi-metabolites triangle interkingdom interactions on pathogenesis of CC.

Two pairs of new isobenzofuranone enantiomers from a soil-derived fungus Penicillium canescens DWS225

Two pairs of new isobenzofuranone derivative enantiomers, (±)-penicifurans E (1) and (±)-penicifurans F (2), together with four know compounds (3-6) were isolated from the solid fermentation of Penicillium canescens DWS225. The structures of these enantiomers were elucidated by extensive NMR spectroscopic data, and their absolute configurations were assigned by the experimental and calculated ECD data. The neuroprotective effects of all the isolates against oxygen-glucose deprivation/reperfusion injury in pheochromocytoma-12 cells (PC12) were investigated.

Microbial Metabolites as Ligands to Xenobiotic Receptors: Chemical Mimicry as Potential Drugs of the Future

Xenobiotic receptors, such as the pregnane X receptor, regulate multiple host physiologic pathways including xenobiotic metabolism, certain aspects of cellular metabolism, and innate immunity. These ligand-dependent nuclear factors regulate gene expression via genomic recognition of specific promoters and transcriptional activation of the gene. Natural or endogenous ligands are not commonly associated with this class of receptors; however, since these receptors are expressed in a cell-type specific manner in the liver and intestines, there has been significant recent effort to characterize microbially derived metabolites as ligands for these receptors. In general, these metabolites are thought to be weak micromolar affinity ligands. This journal anniversary minireview focuses on recent efforts to derive potentially nontoxic microbial metabolite chemical mimics that could one day be developed as drugs combating xenobiotic receptor-modifying pathophysiology. The review will include our perspective on the field and recommend certain directions for future research. SIGNIFICANCE STATEMENT: Xenobiotic receptors (XRs) regulate host drug metabolism, cellular metabolism, and immunity. Their presence in host intestines allows them to function not only as xenosensors but also as a response to the complex metabolic environment present in the intestines. Specifically, this review focuses on describing microbial metabolite-XR interactions and the translation of these findings toward discovery of novel chemical mimics as potential drugs of the future for diseases such as inflammatory bowel disease.

Polyketides isolated from an endophyte Penicillium oxalicum 2021CDF-3 inhibit pancreatic tumor growth

Fungal secondary metabolites are inherently considered valuable resources for new drugs discovery. To search for novel fungal secondary metabolites with lead compounds potential, a fungal strain Penicillium oxalicum 2021CDF-3, an endophyte of the marine red algae Rhodomela confervoides, was chemically studied. Cultivation of this fungus on solid rice medium yielded 10 structurally diverse metabolites (1–10), including two new polyketides, namely oxalichroman A (1) and oxalihexane A (2). Their structures were determined by detailed analysis of NMR and HRESIMS spectroscopic data. Oxalihexane A (2) was elucidated as a novel polyketide formed by a cyclohexane and cyclohexanone moiety via an ether bond. The stereochemistry of 2 was successfully assigned by NMR and ECD calculations. In the cytotoxic assay, the new compound 2 showed remarkable inhibitory effect on the human pancreatic cancer PATU8988T cell line. Further pharmacological study demonstrated that the expression level of Cyclin D1 was down-regulated by the treatment with 2, which suggested that cell cyclin abnormity was involved in pancreatic tumor cell apoptosis. Moreover, the activation of Wnt5a/Cyclin D1 signaling pathway might be involved in the mechanism of panreatic tumor cell apoptosis induced by 2.