arabinofuranose

Arabinofuranose is the five-membered ring form (furanose) of the monosaccharide arabinose. It is an aldopentose that cyclizes to a tetrahydrofuran ring with an anomeric carbon at C1. In solution, arabinofuranose can exist as two enantiomeric series, D- and L-arabinofuranose, and within each series as alpha- or beta-anomers. The ring can interconvert with the open-chain form and between anomers through mutarotation.

Natural occurrence of arabinofuranose is widespread in biology, particularly in plant cell walls. It appears as L-arabinofuranose units in arabinans and in arabinogalactan–proteins, and as side chains in pectins and various hemicelluloses. It is also found in microbial and fungal glycoconjugates, contributing to the structure and properties of cell walls and to antigenic determinants. In plants and microbes, arabinofuranose-containing polysaccharides influence porosity, rigidity, and interactions with other biomolecules.

In chemistry and biochemistry, arabinofuranose serves as a common sugar moiety in nucleosides and glycoconjugates. A prominent example is the anticancer and antiviral drug cytarabine (ara-C), which contains a beta-D-arabinofuranosyl cytosine nucleoside. Arabinofuranosides are used in glycoside chemistry and biosynthesis studies to understand enzyme specificities and to design glycomimetics. The distinct stereochemistry and ring form of arabinofuranose underpin its biological interactions and applications.