|IUPAC name||(2S,3R,4R,5S)-2,3,4,5- tetrahydroxy-6-oxohexanoic acid|
|Other names||L-Iduronic acid, D-ido-Hexuronic acid, IdoA|
|SMILES|| C(=O)C(C(C(C(C(=O)O)O)O)O)O or
|Molar mass||194.139 g/mol|
| Except where noted otherwise, data are given for|
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references
L-Iduronic acid (IdoA) is the major uronic acid component of the glycosaminoglycans (GAGs) dermatan sulfate and heparin. It is also present in heparan sulfate although here in a minor amount relative to its carbon-5 epimer glucuronic acid.
IdoA is a hexapyranose sugar. Most hexapyranoses are stable in one of two chair conformations 1C4 or 4C1. L-iduronate is different and adopts more than one solution conformation, with an equilibrium existing between three low energy conformers. These are the 1C4 and 4C1 chair forms and an additional 2</sub>S0 skew-boat conformation.
IdoA may be modified by the addition of a O-sulfate group at carbon position 2 to form 2-O-sulfo-L-iduronic acid (IdoA2S).
When internally positioned within an oligosaccharide the 1C4 and 2S0 conformations (shown below for IdoA2S) predominate.
- IDU 1C4.jpeg
- IDU 2S0.jpeg
- Ferro, D. R. Provasoli, A. (1990). "Conformer populations of L-iduronic acid residues in glycosaminoglycan sequences". Carbohydr. Res. 195: 157-167.