Novel Marine Fungus-Derived Mycophenolic Acids That Inhibit Acute Myeloid Leukemia Cell Proliferation

Nine new mycophenolic acid derivatives, penicacids O-W (1-9), two first-time reported natural products (10, 11), and five known compounds (12-16), were isolated from a marine-derived fungus Penicillium senticosum RCDB005 found in a South China Sea sediment sample. Their structures were determined using NMR, HRESIMS, and optical rotatory dispersion (ORD) spectra, electronic circular dichroism (ECD) calculations, X-ray crystallography, and modified Mosher's methods. Eight of these compounds were evaluated for anti-proliferative effects against nine human cancer cell lines and the IC₅₀ values ranged from nM to μM levels. Compounds 5, 7-9 showed potent inhibition activity against MOLM-13 acute myeloid leukemia cells with IC₅₀ values between 0.13 and 1.13 μM.