Abstract

Araucaria araucana is a native species in Chile that inhabits a wide climatic variation with a cool and humid temperate climate, with snow in winter and dry atmosphere during summer. Its success in surviving extreme conditions and resisting the depredation of pathogens is due in part to the extractables and resin it has in the bark and its wood. Lignans are usually the major compounds and have a great interest for their medicinal properties and be a rich source of antioxidants. The lignans are part of the phenolic extractables reported in conifers (together with stilbenes and flavonoids), mainly accumulated in the heartwood, and which have a great interest for their medicinal and antioxidant properties. In addition, these compounds would be related to the high resistance to attack by pathogens such as xylophagous fungi. In Araucaria araucana the knots are characterized by their extreme hardness and high resistance to biodegradation. In other coniferous species of the northern hemisphere there are studies on the knots where there is a large accumulation of extractables, even more than in the heartwood. With techniques such as gas chromatography, HPLC and HPTLC it was possible to identify several lignans such as eudesmin found in high abundance in the most apolar fractions of the extract. The role of eudesmin in the protection of wood is not clear, but it is known to have moderate biological activity against phytopathogenic fungi, human pathogenic bacteria and anticancer activity.