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.