Novel Derivatives of Nucleoside, Diaryl Ether and Benzoquinone Isolated from the Marine-Derived Fungus Aspergillus sp. RCDB-W7.

Three novel derivatives of nucleoside (1), diaryl ether (6) and benzoquinone (11), along with 13 known compounds (2-5, 7-10, 12-16), were obtained from the ethyl acetate extract of the fungus Aspergillus sp. RCDB-W7. Structural elucidation was made through nuclear magnetic resonance (NMR), optical rotatory dispersion (ORD) spectra, high-resolution electrospray ionization mass spectrometry (HRESIMS), and electronic circular dichroism (ECD) calculations. The antibacterial and antileukemic activities of 16 isolated compounds were evaluated. Compounds 9 (64 μg/mL) and 10 (32 μg/mL) showed weak antibacterial activity against Staphylococcus aureus Newman, while none exhibited activity against Escherichia coli AB1157 or Klebsiella pneumoniae 210715XJ024 [MIC (minimum inhibitory concentration) above 64 μg/mL]. In the MOLM-13 acute myeloid leukemia cell line, compounds 1, 6, 8, and 9 showed weak cytotoxicity (cell viability 69.86%, 67.83%, 59.21%, and 56.18% at 50 μM, respectively), whereas compounds 10 and 14 displayed moderate activity (cell viability 33.45% and 29.31% at 50 μM, respectively).