Novel biotransformation of a 2-pyrone to a substituted benzoic acid

It was found that Macrophoma commelinae (IFO 9570) had an ability to transform 5-acetyl-4-methoxy-6-methyl-2-pyrone (1) to 4-acetyl-3-methoxy-5-methylbenzoic acid (2). This biotransformation was investigated using 13C- and 14C-labeled compounds. It is likely that 2 is formed by condensation of the added 2-pyrone and a catabolic pyruvate.