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

Abstract 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 ( 1 H, 13 C, 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 μ g/mL.