Polyoxygenated cyclohexenoids from the endophytic fungus, Aspergillus aculeatus BCC69431 and biological properties

Four undescribed polyoxygenated compounds, including aspergilosidic acid, aspergilosidols A, B, and aspergilosidone, along with seven known compounds were isolated from the endophytic fungus, Aspergillus aculeatus BCC69431. The chemical structures with their absolute stereochemistry were determined by NMR spectroscopic information, CD spectral data, and chemical reaction. The isolated compounds were evaluated for biological activities such as antimalarial, antimycobacterial, antibacterial, anti-plant pathogenic fungal activities, as well as cytotoxicity against cancerous (MCF-7 and NCI–H187) and non-cancerous (Vero) cells. Only violaceoid A (8) exhibited antimalarial against Plasmodium falciparum, K1 strain (IC50 9.62 μM), antibacterial against Staphylococcus aureus (MIC 12.50 μg/mL), and antifungal against Colletotrichum acutatum (MIC 50.0 μg/mL) activities without significant cytotoxicity. In addition, himeic acid G (11) showed anti-Mycobacterium tuberculosis activity with MIC value of 25.0 μg/mL with no cytotoxicity at the maximum tested concentration (50 μg/mL), while microsphaerone C (9) possessed cytotoxicity against NCI–H187 with IC50 value of 1.88 μM.