Natural Function

Abstract

The question that can be asked about all natural products, including naturally occurring halogenated compounds, is “Why do organisms produce organohalogens?” The first review provided evidence that seems to answer this question for several halogenated metabolites (1). For example, in the case of sessile marine organisms, a chemical defense function for these compounds seems paramount, and excellent reviews on this topic are available (39, 2514–2520). Nevertheless, a clear function for most of the identified biogenic organohalogens is presently unknown.

While natural chloromethane may have several functions (42), in Basidiomycetes wood-rot fungi (Phellinus, Inonotus, Fomitosporia, Hymenochaete, Phaeolus, and Fomitopsis) (59) chloromethane is a methyl donor in the biosynthesis of veratryl alcohol, the first step of which is methylation of 4-hydroxybenzoic acid. A second methylation of isovanillic acid affords ultimately veratryl alcohol, the function of which in these fungi is to stabilize lignin peroxidase thus promoting lignin degradation (2521).