Four New 2-Pyrones from Fusarium tricinctum, an Endophytic Fungus of Ligusticum chuanxiong

Aureonitol Analogues and Orsellinic Acid Esters Isolated from Chaetomium elatum and Their Antineuroinflammatory Activity

Overexpression of various pro-inflammatory factors in microglial cells tends to induce neurodegenerative diseases, for which there is no effective therapy available. Aureonitol (1) and seven analogues, including six previously undescribed [elatumenol A-F (2-4, 6-8, respectively)], along with two new orsellinic acid esters [elatumone A and B (9 and 10)], were isolated from Chaetomium elatum. The structures of the compounds were established through comprehensive analysis of spectroscopic data, including high-resolution mass spectra and one- and two-dimensional NMR, and absolute configurations determined by the Mosher method, dimolybdenum tetraacetate-induced circular dichroism, and theoretical calculations including electronic circular dichroism and NMR. Metabolites 3, 4, 7, and 8 exhibited antineuroinflammatory activity by attenuating the production of inflammatory mediators, such as nitric oxide, interleukin-6, interleukin-1β, tumor necrosis factor-α, and reactive oxygen species. Western blot results indicated 8 decreases the level of inducible nitric oxide synthase and cyclooxygenase-2 and suppresses the expression of Toll-like receptor 4 and nuclear factor kappa-B (NF-κB) as well as the phosphorylation of the inhibitor of NF-κB and p38 mitogen-activated protein kinases in lipopolysaccharide-activated BV-2 microglial cells.

Two new N-acetyl-ᴅ-glucosamine derivatives from the medical algae-derived endophytic fungus Penicillium chrysogenum

Two new N-acetyl-ᴅ-glucosamine derivatives, penichryfurans A (1) and B (2), were obtained from the fermentation of an endophytic fungus Penicillium chrysogenum which inhabited the marine medical red alga Grateloupia turuturu. Their structures were established by detailed spectroscopic analysis of 1D and 2D NMR in combination with HRESIMS data. The absolute configurations were determined by the (Mo₂(OAc)₄)-induced CD and comparison of the calculated and experimental electronic curcular dichroism (ECD) spectra. Both compounds were evaluated for their in vitro cytotoxic activities against A549, HeLa, and HepG2 cell lines, among which compound 1 exhibited strong cytotoxicity towards the HepG2 cell line with an IC₅₀ value of 9.0 μM.

2-Pyrones from endophytic fungus Diaporthe foeniculina BZM-15

Foeniculins A-C (1-3) together with a pair of enantiomers (±)-foeniculin D (4) were isolated from endophytic fungus Diaporthe foeniculina BZM-15. Their structures including absolute configurations were unambiguously established by extensive interpretation of the NMR and HR-ESI-MS data, ECD measurements powered by molecular calculations, as well as Mo₂(OAc)₄ mediated CD methodology. The cytotoxic activity assay disclosed that these compounds didn't show any noticeable cytotoxic activity.