Wood species resistant to biodegradation by fungi contain phenolic compounds with proven fungicidal activity. Saprophytic fungi are able to colonize wood and later begin to break down its polymeric components through metal-dependent reactions. These generate free radicals at the onset of the degradation process. Later on, extracellular enzymes are active that use metallic cofactors. Five lignans were isolated from the methanolic extracts of the Chilean heartwoods (Austrocedrus chilensis, Fitzroya cupressoides, and Pilgerodendron uviferum) belonging to the Cupressaceae: isotaxiresinol, secoisolariciresinol, isolariciresinol, didemethylmatairesinol, and matairesinol. Their structures were determined spectroscopically. The antioxidant activity of the methanolic extracts and the isolated compounds was determined in vitro against the radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and their iron-chelating capacity was evaluated by the Chrome Azurol S assay. All isolated methanolic extracts and lignans exhibited antioxidant activity against DPPH and Fe-chelating capacity with values greater than 87%. This may be interpreted that the antioxidant properties and metal-chelating capacity of these compounds have a protective effect on the wood of these species when exposed to attacks by saprophytic fungi.
Holzforschung is an international scholarly journal that publishes cutting-edge research on the biology, chemistry, physics and technology of wood and wood components. High quality papers about biotechnology and tree genetics are also welcome. Rated year after year as one of the top scientific journals in the category of Pulp and Paper (ISI Journal Citation Index), Holzforschung represents innovative, high quality basic and applied research.