Evidence of a new biotransformation pathway of p-coumaric acid into p-hydroxybenzaldehyde in Pycnoporus cinnabarinus

• DOI: 10.1007/s002530100761
• Publication Date: 2002-10-06T14:44:27Z
• Authors: A. Lomascolo; D. Navarro; M. Delattre; M. Asther; L. Lesage-Meessen; I. Estrada Alvarado
• Keywords: p-Coumaric acid; Biotransformation; Coumaric acid

Pycnoporus cinnabarinus MUCL39533 was shown to be able to convert p-coumaric acid into p-hydroxybenzaldehyde, a component of high organoleptic note present in natural vanilla aroma. Use of phospholipid-enriched medium led to high-density cultures of P. cinnabarinus, since dry mycelial biomass was increased three-fold as compared to glucose medium. In the presence of phospholipids, 155 mg l(-1) p-hydroxybenzaldehyde was produced as the major compound on culture day 13 with a molar yield of 26%. The degradation pathways of p-coumaric acid were investigated. Based on the different metabolites identified, an oxidative side-chain degradation pathway of p-coumaric acid conversion to p-hydroxybenzoic acid was suggested. This acid was further reduced to p-hydroxybenzaldehyde and p-hydroxybenzyl alcohol, or hydroxylated and reduced to protocatechyl derivatives. Additionally, a reductive pathway of p-coumaric acid with 3-(4-hydroxyphenyl)-propanol as the terminal product occurred.