Lewis acids have been studied as catalysts in the organosolv treatment of wheat straw. Fractionation of the lignocellulosic biomass and fragmentation of lignin have been performed in aqueous ethanol in the presence of FeCl 2 , CuCl 2 , FeCl 3 , Ga(OTf) 3 , ZrOCl 2 or Sc(OTf) 3. The lignins were characterised in terms of molecular weight, ␤ O 4 linkage content and chemical functions through size exclusion chromatography; thioacidolysis; 31 P and 13 C NMR spectroscopies. The degree of delignification and the yield of Klason lignin increased with the hardness of the Lewis acid. About half of the delignification products were water-soluble monomers and oligomers. The nature of the Lewis acid influenced also the characteristics of the precipitated lignins. The molecular mass, the amount of OH groups and of aliphatic C O bonds decreased as cation hardness increased.

Research on antifungal compounds from the durable wood from French Guiana Amazonian forest trees highlights the correlation between the activity of their extracts against wood-rotting fungi and human pathogens. The fractionation of an ethyl acetate extract of Sextonia rubra wood led to the isolation of rubrenolide (1) and rubrynolide (2). The potential of compounds 1 and 2 is described through the evaluation of their activity against 16 pathogenic fungi and their cytotoxicity toward NIH-3T3 mammalian fibroblast cells.