An Update on Organohalogen Metabolites Produced by Basidiomycetes

Abstract

Basidiomycetes are an ecologically important group of higher fungi known for their widespread capacity to produce organohalogen metabolites. To date, 100 different organohalogen metabolites (mostly chlorinated) have been identified from strains in 70 genera of Basidiomycetes. This manuscript provides an update of newly discovered chlorinated metabolites described since 1997. Additionally, the biosynthesis, physiological role, environmental fate and significance of Basidiomycete organohalogen metabolites are reviewed. Novel metabolites include chlorinated methoxybenzene azoxyformamide, pterulones (chlorinated1-benzoxepins),chlorinated anisylpropanoids, tri- and tetrachlorinated phenols. Chlorinated p-anisyl metabolites (CAM) are the most ubiquitous and ecologically significant natural organohalogens produced by higher fungi. Evidence is presented indicating their synthesis from phenylalanine via the phenylpropanoid pathway. They are estimated to be produced at a rate of 300 g ha⁻¹ year^-1 in European forests inhabited by the common occurring mushroom, Hypholoma fasciculare. Organohalogen metabolites have several purposeful physiological functions ranging from antibiotic properties, metabolites involved in lignin degradation and synthons for biosynthesis.