Ribitol

Ribitol is a sugar alcohol (pentitol) with the formula C5H12O5. It is the reduced form of the aldose ribose and exists as two enantiomers, D-ribitol and L-ribitol. Its structure is HO-CH2-CHOH-CHOH-CHOH-CH2-OH, a linear five-carbon polyol with a hydroxyl on each carbon.

Ribitol occurs as a biological component through its role in the ribityl side chain of riboflavin (vitamin B2) and its derivatives flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). The flavin cofactors carry a ribityl chain derived from ribitol, which is essential for binding to the isoalloxazine ring. In bacteria and plants, ribitol phosphate is formed during riboflavin biosynthesis.

Commercially, ribitol can be prepared by chemical reduction of ribose-containing materials. It is used as a chemical building block in carbohydrate chemistry and as a reference standard in analytical methods for aldose and alditol identification. It also serves as a precursor for the synthesis of other alditols and their derivatives.

Safety and handling: ribitol is generally considered non-toxic, but, as with other sugar alcohols, excessive consumption may cause gastrointestinal effects in some individuals.

See also: xylitol, arabinitol, ribose, flavin cofactors FMN and FAD, riboflavin.