A New Xanthone From Mangrove Sediment‐Derived Fungus <i>Aspergillus</i> sp. SCSIO 41430 With Cytotoxic Activity

One new xanthone derivative, sterigmatocystoic acid (1), and 16 known natural products (2-17) were obtained from the fungus Aspergillus sp. SCSIO 41430, which was isolated from mangrove sediment. The structure of the new compound was established based on one- and two-dimensional nuclear magnetic resonance spectral analysis. Compounds 1-17 were evaluated for cytotoxic and phosphodiesterase-4 (PDE4) inhibitory activities. Compound 1 displayed cytotoxic activities against all tested lines A549, SNB-19, MDA-MB-231, PC3, HCT-116, and MDA-MB-435, with 50% inhibitory concentration (IC₅₀) values of 7.52 ± 0.73-39.06 ± 3.59 µM. Compound 6 displayed selective cytotoxic activities against A549, MDA-MB-231, HCT-116, and MDA-MB-435, with IC₅₀ values of 25.57 ± 2.08-37.51 ± 0.73 µM. Compound 5 exhibited obvious inhibition on PDE4 at 10 µM, with an inhibition rate of 40%. The obtained results highlighted the immense potential of the mangrove wetland ecosystem to yield novel natural products as well as bioactive compounds.