Co‐Oxidative Transformation of Piperine to Piperonal and 3,4‐Methylenedioxycinnamaldehyde by a Lipoxygenase from Pleurotus sapidus

The valuable aroma compound piperonal with its vanilla‐like olfactory properties is of high interest for the fragrance and flavor industry. A lipoxygenase (LOX(Psa)1) of the basidiomycete Pleurotus sapidus was identified to convert piperine, the abundant pungent principle of black pepper (Piper nigrum), to piperonal and a second volatile product, 3,4‐methylenedioxycinnamaldehyde, with a vanilla‐like odor through an alkene cleavage. The reaction principle was co‐oxidation, as proven by its dependence on the presence of linoleic or α‐linolenic acid, common substrates of lipoxygenases. Optimization of the reaction conditions (substrate concentrations, reaction temperature and time) led to a 24‐fold and 15‐fold increase of the piperonal and 3,4‐methylenedioxycinnamaldehyde concentration using the recombinant enzyme. Monokaryotic strains showed different concentrations of and ratios between the two reaction products.