Ecdysteroids, Phenolics, and Alkaloids From a Mangrove-Derived Fungus Aspergillus sp. BCXT-22.1 With Cytotoxic and NO Inhibitory Activities.

An EtOAc extract from the fermentation culture of a mangrove-derived fungus, Aspergillus sp. BCXT-22.1, was investigated, leading to the isolation and structural elucidation of 10 secondary metabolites, including two new compounds, polyporusterone H (1) and stellatinol A (4), along with eight known compounds, panuosterone (2), makisterone A (3), stellatin (5), embeurekol C (6), oxepinamide D (7), oxepinamide F (8), oxepinamide J (9), and protubonine B (10). All of the isolated compounds, except for 8, showed cytotoxicity toward both MCF-7 and SK-Mel-2 cell lines, with IC50 values ranging from 65.38 ± 1.17 to 94.20 ± 3.41 µM. Compound 1 additionally displayed cytotoxicity toward HepG2 cells (IC50 = 87.65 ± 3.49 µM), while exhibiting no cytotoxicity toward the normal human embryonic kidney cell line-293A (HEK-293A) cell line. Besides, compounds 4 and 8 weakly inhibited nitric oxide (NO) overproduction in lipopolysaccharide (LPS)-stimulated BV2 cells, with inhibition rates of 36.6% ± 1.3% and 31.7% ± 2.9% at 40 µM, respectively. Molecular docking simulations suggested that 4 and 8 may exert their NO inhibitory effects by interacting with the active site of the inducible nitric oxide synthase (iNOS) protein, thereby modulating its activity.