Biosynthesis of mycophenolic acid. Substrate stereochemistry of farnesyl pyrophosphate: 5,7-dihydroxy-4-methylphthalide farnesyl transferase from Penicillium brevicompactum

Abstract
The enzymic synthesis of 6-farnesyl-5,7-dihydroxy-4-methylphthalide (4a) from 5,7-dihydroxy-4-methylphthalide (2) and (3RS)-mevalonic acid (1a) proceeds with inversion of configuration at C-5 in (1a).