A member of the class of 2-benzofurans that is 2-benzofuran-1(3H)-one which is substituted at positions 4, 5, 6, and 7 by methyl, methoxy, (2E)-5-carboxy-3-methylpent-2-en-1-yl, and hydroxy groups, respectively. It is an antibiotic produced by Penicillium brevi-compactum, P. stoloniferum, P. echinulatum and related species. An immunosuppressant, it is widely used (partiularly as its sodium salt and as the 2-(morpholin-4-yl)ethyl ester prodrug, mycophenolate mofetil) to prevent tissue rejection following organ transplants and for the treatment of certain autoimmune diseases.