RESUMO
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.
RESUMO
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.
RESUMO
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.
