Arabinofuranosyl residues on substituted xylan (AX)

Arabinofuranosyl residues on substituted xylan are key structural components of arabinoxylan, a major hemicellulose found in the cell walls of cereal grains such as wheat, rye, and barley (Scheller & Ulvskov, 2010). These residues consist of alpha-L-arabinofuranose units linked to the C(O)-2 and/or C(O)-3 positions of the beta-1,4-linked D-xylopyranosyl backbone. The pattern and degree of this substitution significantly influence the physicochemical properties of the polymer, including its water solubility, viscosity, and susceptibility to enzymatic degradation (Izydorczyk & Biliaderis, 1995). While not a traditional human therapeutic protein target, these residues serve as critical substrates for various carbohydrate-active enzymes (CAZymes), such as alpha-L-arabinofuranosidases, which are utilized in industrial biotechnology and as digestive aids to improve the nutritional value of animal feed and human diets. In the human gut, these residues are fermented by specific microbiota, such as Bifidobacterium species, leading to the production of beneficial short-chain fatty acids (SCFAs) like butyrate and propionate, which play roles in maintaining intestinal health and metabolic homeostasis (Riviere et al., 2016).

Other names

ArabinoxylanL-Arabinofuranosyl side chainsAlpha-L-arabinofuranosyl residuesXylan arabinosyl groups

Enzymatic hydrolysis of the alpha-1,2 or alpha-1,3 glycosidic linkages by specific glycoside hydrolases (such as GH43 and GH51 families) to release arabinose and expose the xylan backbone for further degradation by xylanases.