Diisoprenyl Cyclohexene-Type Meroterpenoids with Cytotoxic Activity from a Mangrove Endophytic Fungus Aspergillus sp. GXNU-Y85.

Five new diisoprenyl cyclohexene-type meroterpenoids, aspergienynes J-N (1-5), along with three known analogues (6-8), were obtained from the mangrove endophytic fungal strain Aspergillus sp. GXNU-Y85. The chemical structures, including their absolute configurations, were established via spectroscopic data and comparison of experimental and calculated ECD spectra. Cytotoxicity assay results indicated that compound 8 had strong cytotoxicity against HeLa cancer cells, and its IC50 value was 11.8 µM. In addition, flow cytometry analysis revealed that the cytotoxicity of 8 was due to the induction of G1 cell cycle arrest and apoptosis in HeLa cells.

Cytotoxic metabolites from the mangrove endophytic fungus Aspergillus sp. GXNU QG1a.

A new benzoquinone, guxiumasperone A (1), and a new diisoprenyl-cyclohexene-type meroterpenoids, biscognienyne M (2), along with four known diisoprenyl-cyclohexene analogues was isolated from the mangrove endophytic fungus Aspergillus QG1a. Their structures were determined by extensive spectral analysis of 1D and 2D NMR, HR-ESI- MS, and X-ray crystallography. Compound 1 was deduced by a single-crystal X-ray diffraction analysis, and the absolute configuration of 2 was further unequivocally elucidated by comparing the experimental electronic circular dichroism (ECD) data with calculated ECD spectra. Compounds 1 and 2 showed significant cytotoxic activity against selected tumour cells. Particularly, compound 2 exhibited strong activity against A2780 cancer cells with an IC50 value of 6.8 µM.

Diisoprenyl-cyclohexene-type meroterpenoids from a mangrove endophytic fungus Aspergillus sp. GXNU-Y65 and their anti-nonalcoholic steatohepatitis activity in AML12 cells.

Nine previously undescribed diisoprenyl-cyclohexene-type meroterpenoids, aspergienynes A-I, together with five known analogues, were obtained from the mangrove endophytic fungal strain Aspergillus sp. GXNU-Y65. The diisoprenyl-cyclohexene-type meroterpenoids were elucidated based on multispectroscopic analysis, and the previously undescribed compounds' absolute configurations were established via electronic circular dichroism calculations. Biological activity results indicated that aspergienyne C (compound 3) had strong anti-nonalcoholic steatohepatitis activity against AML12 cells treated with PA (Palmitic acid) + OA (Oleic acid). At the same concentration of 20 µM, 3 significantly reduced triglyceride (TG) content compared with fenofibrate (positive control) in PA + OA treated AML12 cells, and obviously increased phosphorylation of acetyl-CoA carboxylase.

A new sulphur-containing metabolite from a mangrove endophytic fungus Aspergillus sp. GXNU-MA.

A new sulphur-containing metabolite, asperiguxidione A (1), was isolated from a mangrove endophytic fungus Aspergillus sp. GXNU-MA, and four known alkaloids 2-5, were isolated together from this strain. Their structures were determined by the com-bination of 1D and 2D NMR spectroscopy, HR-ESI-MS, and ECD analysis. Compounds 1 and 2 exhibited mediate activity against Staphylococcus aureus and Enterobacter aerogenes with equal MIC values of 12.5 µg/mL. Compound 3 reduced NO production in LPS-stimulated cells with an IC50 value of 13.329 ± 0.53 µg/mL in the anti-inflammatory assay.

Isolation and insecticidal activities of new cyclic peptides from mangrove endophytic fungus Aspergillus sp. GXNU-4QQY1a.

An investigation on bioactive metabolites from the mangrove endophytic fungus Aspergillus sp. GXNU-4QQY1a led to the isolation of two undescribed cyclic peptides, guaspertide A (1) and guaspertide B (2), together with six known compounds, 3-8. These structures and the new compounds' absolute configuration were determined by mass spectrometry analysis, nuclear magnetic resonance spectrum, electronic circular dichroism, and single-crystal X-ray diffraction. Insecticidal assays were carried out with compounds 1-8, and the results showed that compounds 1-3 and 8 exhibited good insecticidal activity against citrus psyllids.

Asperphenyltones A and B: New Phenylfuropyridinone Skeleton from an Endophytic Aspergillus sp. GXNU-A1.

Chemical investigation of the fermentation extract of the mangrove endophytic fungus Aspergillus sp. GXNU-A1, isolated from Acanthus ilicifolius L., discovered an undescribed pair of enantiomers (asperphenyltones A and B (±1)), together with four previously described metabolites: nodulisporol (2), isosclerone (3), 2,3,4-trihydroxy-6-(hydroxymethyl)-5-methylbenzyl alcohol (4), and 4,6-dihydroxy-5-methoxy-7-methyl-1,3-dihydroisobenzofuran (5). Analyses of the 1D and 2D NMR spectroscopic data of the compounds supported their structural assignments. The presence of the asperphenyltones A and B, which are a pair of enantiomers, was established by HR-ESI-MS, 1D and 2D NMR data and confirmed by single-crystal X-ray diffraction analysis. Metabolites 1-5 were evaluated for their anti-inflammatory effects on the production of nitric oxide (NO), and 1, 3, and 4 showed significant potential inhibitory activities against NO production in activated macrophages with IC50 values of 26-40 µM, respectively.