A novel xyloglucan from seeds of Afzelia africana Se. Pers.--extraction, characterization, and conformational properties

This paper is the first multi-scale characterization of the xyloglucan extracted from seeds of the African tree Afzelia africana Se. Pers. It describes the extraction and characterization of this polysaccharide in terms of both primary monosaccharide and oligosaccharide composition. It also includes a study of the seed morphology. Morphological characterization includes optical, transmission, and scanning electron microscopy. The polysaccharide exists in thickened cell walls of the cotyledonary cells, and the extracted xyloglucan is structurally quite similar to those from tamarind seed and detarium. Nevertheless there are some subtle differences in the fine structure, particularly in the oligomeric xyloglucan composition. The chain flexibility of the polysaccharide is also discussed in the light of our recent measurements reported elsewhere [Biomacromolecules2004, 5, 2384-2391].