D-Xylose (Xyl)

D-Xylose is a five-carbon monosaccharide, commonly known as wood sugar, that is primarily utilized in clinical medicine as a diagnostic tool rather than a therapeutic target [1]. It is the central component of the D-xylose absorption test, which assesses the functional integrity of the small intestinal mucosa to distinguish between malabsorption syndromes and pancreatic insufficiency [2][3]. Upon oral administration, D-xylose is absorbed by the duodenum and jejunum and excreted primarily by the kidneys, providing a measurable index of intestinal surface area and transport efficiency [4]. While it serves as a natural substrate for the initiation of glycosaminoglycan chain synthesis in human proteoglycans, there are no established pharmaceutical drugs that target the xylose molecule for therapeutic modulation [1][4]. Consequently, its significance in biotechnology and medicine is confined to its role as a diagnostic agent and a structural component in carbohydrate chemistry [2].

Other names

Wood sugar(+)-XyloseD-xylopyranoseXylopyranose

Used as a diagnostic substrate administered orally; it is absorbed in the proximal small intestine via passive diffusion and facilitated transport, and then excreted unchanged in the urine to measure mucosal absorptive capacity [2][4].