Qualitative and quantitative determination of extractives in heartwood of Scots pine (Pinus sylvestris L.) by gas chromatography

Chemical Composition and Antifungal Activity of Extracts from the Xylem of Cinnamomum camphora

“…Most scholars think that some compounds possessing antibacterial properties include chemically diverse structure types such as terpenoids, alkaloids, flavones, glycosides, saponins, quinines, coumarins, stilbenes, esters, phenols, aldehydes, alcohols, sterids, organic acids, etc. Studies have shown that phenolic compounds influence the durability of natural wood, and that resin acids have a restraining effect on fungi (Ekeberg et al 2006). The mechanism of antifungal activity of extracts from the xylem of C. camphora could be explained as some phenolic compounds attacking the cell wall and cell membrane, altering their function and structure, causing swelling and permeability augmentation (Mishra et al 1991).…”

Identification of black pine (Pinus nigraArn.) heartwood as a rich source of bioactive stilbenes by qNMR

“…The need for screening of hundreds of samples prompted us to develop a method that should have the advantage of very fast and costless analysis. The target analytes (pinosylvin and its methyl ethers) had been previously analyzed using gas or liquid chromatographic methods . In both cases the time for analysis of the extract of each sample ranged from 30 to 60 min.…”

Influence of wood durability on the suppressive effect of increased temperature on wood decay by the brown-rot fungus Postia placenta

“…It is noteworthy that the samples incubated for 10 weeks at 23.5°C showed an exceptionally low extractive content (2.3%), the mean extractive content (13.5%) of all the other inoculated hW samples being similar to that of control. As the concentrations of hW extractives can vary between Scots pine trees (Venäläinen et al 2004) and between outer and inner hW (Ekeberg et al 2006), the relatively high loss of hemicellulose in hW samples incubated for 10 weeks at 23.5°C could be related to an initially low extractive content in these particular samples. Regarding fungal utilization of cellulose, after 6 and 10 weeks of incubation temperatures at 21, 23.5 and 30°C, the lignin-cellulose ratios were 0.59, 0.66 and 0.57 and 0.81, 0.62 and 0.59, respectively (Figure 1b).…”

“…It is known that natural wood durability towards both brown and white rot fungi tends to increase at higher wood extractive contents (Carneiro et al 2009). This is the case for Scots pine hW with elevated concentrations of phenols, resin acids and free fatty acids (Ekeberg et al 2006). Being excellent antioxidants, stilbenes in Scots pine hW presumably interfere with the free-radical driven lignocellulose degradation mechanism during incipient decay (Ritschkoff 1996).…”