Chemical compounds from Eperua falcata and Eperua grandiflora heartwood and their biological activities against wood destroying fungus (Coriolus versicolor)

The chemical analysis of the compounds present in dichloromethane and ethanolic fractions as well as bioassays enable to understand the differences in the durability of Eperua falcata and Eperua grandiflora. The main distinction between these two species is the acidic subfraction of diterpenoid extract, which is antifungal in Eperua falcata when tested under in-vitro conditions. This study also shows that ethanolic fraction plays an important role in the mechanism of natural durability. Furthermore, it reports the first isolation of cativic acid in Eperua falcata wood

Mechanical potential of eco-OSB produced from durable and nondurable species and natural resins

Oriented strand board (OSB) panels were manufactured with different mixtures of pine and cypress heartwood and resins based on lignin or tannin to develop an eco-friendly wood composite with a natural durability against termite and fungi. Some physical properties and the major elastic moduli of bulk wood as well as of the manufactured panels were determined using different measurement techniques. In addition, a micromechanical model was adapted and validated with the experimental results. The good agreement obtained between the experimental data and model predictions indicates the proper assessment of the most influential parameters, such as raw material and adhesive properties, strand orientation, layer assembly and density profile. A parameter study, enlightening the effect of strand orientation on several elastic constants, enlarges the scope of experiments. We conclude with an optimal combination of resin and wood species mixture resulting in the best performance from a biological and mechanical standpoint

Characterization of the chemical diversity of Sextonia rubra fruits by MALDI-CASI-FT-ICR imaging and molecular networks

International audienc

Characterization of the chemical diversity of Sextonia rubra fruits by MALDI-CASI-FT-ICR imaging and molecular networks

International audienc

Radial distribution of non-structural carbohydrates in Malaysian teak

Non-structural carbohydrates are primary compounds whose distribution in the wood affects its properties. During the two last decades, a high variability of natural durability of plantation teak wood properties has been found with consequences for industry and consumers. In order to further investigate chemical traits for natural durability in Malaysian teak, we studied the radial distribution of main non-structural carbohydrates (NSC) from the sapwood to the inner heartwood. NSC were analysed by thin layer chromatography coupled to an enzymatic method. The main NSC were starch, glucose, fructose and sucrose. Stachyose and raffinose were also detected. Starch was the major NSC while sucrose was the less abundant. NSC were highly accumulated in sapwood and decreased drastically in heartwood. In our sampling, NSC distribution patterns were the same between trees but were different on a quantitative point of view. Our results suggested that NSC were stored as reserve materials in the sapwood and then were used in the sapwoodheartwood boundary for metabolic activities during heartwood formation process. Their involvement in heartwood formation was discussed.Keywords: Tectona grandis, sapwood, heartwood, non-structural carbohydrates, starch

4′,5′-Dihydroxy-epiisocatalponol, a new naphthoquinone from Tectona grandis L. f. heartwood, and fungicidal activity

International audienc

The importance of the Herbarium in Plant Sciences

International audienc