Deoxysugars

Deoxysugars are a class of monosaccharides in which one or more hydroxyl groups present in the corresponding aldose or ketose are replaced by hydrogen, yielding a sugar that is missing one or more oxygen atoms relative to its parent sugar. The most prominent example is 2-deoxyribose, the sugar component of DNA, which lacks the 2′-hydroxyl on ribose. In contrast to RNA, which uses ribose, DNA uses this deoxygenated sugar, contributing to its chemical stability.

Several deoxysugars occur naturally as components of carbohydrates, glycoproteins, and secondary metabolites. Deoxyhexoses such as fucose and rhamnose are common examples; these sugars are found in various plant, bacterial, and animal glycoconjugates. In addition, many natural products feature deoxysugar moieties that modulate biological activity. Notably, certain antibiotics contain deoxysugars such as desosamine and mycarose attached to aglycone structures, influencing pharmacological properties.

Biosynthesis and occurrence emphasize the diversity of deoxysugars. They arise through enzymatic deoxygenation or specialized pathways that remove oxygen atoms from standard hexoses or pentoses. In biochemistry and molecular biology, deoxysugars are primarily highlighted for their role in DNA and for their presence in glycosides and natural products, where they contribute to structural variation and biochemical function.

Analytical and practical aspects include identification and characterization by carbohydrate chemistry techniques, as well as chemical and enzymatic methods for synthesizing or attaching deoxysugars. Deoxysugars remain an area of study for understanding carbohydrate diversity, nucleic acid chemistry, and the design of glycosylated drugs.