title: Biosynthetic Pathway for Veratryl Alcohol in the Ligninolytic Fungus Phanerochaete chrysosporium.
abstract: Veratryl alcohol (VA) is a secondary metabolite of white-rot fungi that produce the ligninolytic enzyme lignin peroxidase. VA stabilizes lignin peroxidase, promotes the ability of this enzyme to oxidize a variety of physiological substrates, and is accordingly thought to play a significant role in fungal ligninolysis. Pulse-labeling and isotope-trapping experiments have now clarified the pathway for VA biosynthesis in the white-rot basidiomycete Phanerochaete chrysosporium. The pulse-labeling data, obtained with C-labeled phenylalanine, cinnamic acid, benzoic acid, and benzaldehyde, showed that radiocarbon labeling followed a reproducible sequence: it peaked first in cinnamate, then in benzoate and benzaldehyde, and finally in VA. Phenylalanine, cinnamate, benzoate, and benzaldehyde were all efficient precursors of VA in vivo. The isotope-trapping experiments showed that exogenous, unlabeled benzoate and benzaldehyde were effective traps of phenylalanine-derived C. These results support a pathway in which VA biosynthesis proceeds as follows: phenylalanine --> cinnamate --> benzoate and/or benzaldehyde --> VA.
authors.affiliation: Forest Products Laboratory, U.S. Department of Agriculture, Madison, Wisconsin 53705.
authors.forename: K A
authors.initials: KA
authors.lastname: Jensen
authors.forename: K M
authors.initials: KM
authors.lastname: Evans
authors.forename: T K
authors.initials: TK
authors.lastname: Kirk
authors.forename: K E
authors.initials: KE
authors.lastname: Hammel