Three New Antibacterial Mycophenolic Acid Derivatives from the Marine‐Derived Fungus Penicillium sp. HN‐66

Three new mycophenolic acid derivatives, penicacids L−N (1–3), together with four known analogues, were isolated from a fungus Penicillium sp. HN‐66 derived from a South China Sea marine sediment. The structures of compounds 1–3 were determined on the basis of HR‐ESI‐MS, NMR (1H, 13C, HSQC and HMBC) data analyses, and comparison of optical rotations. Antimicrobial activities of 1–7 were tested. The results showed that compounds 1–3 and 5–7 had weak inhibitory effects against E. coli ATCC 25922 with the MIC values of 50 μg/mL.