Stilbene impregnation retards brown-rot decay of Scots pine sapwood

Abstract

Stilbenes are abundant in the heartwood of Scots pine (Pinus sylvestris L.) and are known to have strong antifungal efficiency. In this study, Scots pine sapwood blocks were impregnated with crude heartwood extract containing the stilbenes pinosylvin (PS) and the pinosylvin monomethyl ether (PSM). Impregnated blocks were submitted to brown-rot fungi, Coniophora puteana, Gloeophyllum trabeum, and Rhodonia (Poria) placenta, and fungal growth test and decay test were performed. Both tests showed that the impregnation with a high concentration of stilbenes (60 mg g-1 dry wood) significantly suppressed the growth of fungi and slowed down the decay process of wood blocks, especially in case of G. trabeum. However, chemical analysis showed that PS and PSM were degraded by all the three types of fungi, obviously via modification to resveratrol and methylresveratrol. Rhodonia placenta displayed the fastest rate of degradation. Thus, impregnation with biodegradable stilbenes could be a viable alternative for wood preservation only in service situations with low or transient risk of decay.

Antifungal stilbene impregnation: transport and distribution on the micron-level

“…For example, pine extractives can be divided into a hydrophilic (stilbenes and lignans) and a lipophilic part (resin acids, long chain fatty acids and triglycerides) (Figure 1 b). By sequentially extracting pine heartwood chips with non-polar and polar solvents different extracts can be obtained ( Lu et al 2016 ). For example, the extraction with a polar solvent recovers the pinosylvins with high purity ( Fang et al 2013 ).…”

Life cycle assessment of tannin extraction from spruce bark

“…To some extent, recent wood preservation research focused on the exploration of bio-based chemicals, e.g., condensed tannin (Thévenon et al 2009, Tondi et al 2012, Tascioglu et al 2013 or stilbenes (e.g., Lu et al 2016), with presumably lower environmental burden than traditional wood preservatives, e.g., copper or borate preservatives. The use of tannin was developed primarily in the leather and wood adhesives industries (Pizzi 2008), where they are commercialized.…”

Recovery of antifungal compounds from wood and coffee industry side-streams and residues for wood preservative formulations

“…A lot of research has been published during recent decades in bio-based wood preservation studying the possibilities of using many natural-origin chemicals for wood preservation, such as tung oil and linseed oil (Humar and Lesar 2013) and Amorphophallus konjac (devil's tongue plant) extracts (Bi et al 2019). Also research focused on biomimicry of natural durable wood species by treating wood with the extractives, such as the phenolics in Scots pine (Pinus sylvestris) heartwood that confer the durability to wood (Harju et al 2003, Lu et al 2016 has been done. Other means to avoid wood decay have also been studied, e.g.…”

“…pinosylvin, have also shown antifungal activity against wood-decaying fungi and cause moderate decay tolerance in e.g. heartwood of pine (Seppänen et al 2004, Lu et al 2016. Several feedstocks can be considered for the extraction of natural extractives or bio-based chemicals, but as the trend in wood preservation is to use recycled waste and side-streams (Can and Sivrikaya 2017), forest industries are focusing on side-streams and waste generated by themselves, such as tree bark.…”

“…It highlighted the preserving properties of lime-water in Scotch fir wood, as the wood treated with the lime-water mixture lasted in life service 40 years, whereas based on his publication this kind of green wood would decay in 5-7 years with no additional treatment. Several recent studies found other examples of natural chemicals that can prevent the growth of wood-decaying fungi, such as stilbenes (Lu et al 2016), tannins (Anttila et al 2013) and caffeine (Kwaśniewska-Sip et al 2019). Finding sustainable and abundant feedstocks for these chemicals is still under investigation.…”