Ojinnaka C, Jay A J, Colquhoun I J, Brownsey G J, Morris E R, Morris V J
Department of Food Science and Technology, Cranfield University, Silsoe College, Bedford, UK.
Int J Biol Macromol. 1996 Oct;19(3):149-56. doi: 10.1016/0141-8130(96)01120-8.
Acetan is an anionic bacterial polysaccharide. The chemical repeat unit consists of a cellobiose unit solubilised by attachment of a charged pentasaccharide sidechain to one of the glucose residues. The repeat unit contains two sites of acetylation. 1H and 13C NMR studies, coupled with both basic-methylation and mild-methylation studies, have shown that acetylation occurs at C6 on the (1,2)D-Man and the (1,34)D-Glc residues. A variety of techniques including NMR, optical rotation, circular dichroism and DSC show evidence for a thermoreversible conformational order (helix)-disorder (coil) transition for acetan in aqueous solution. The studies suggest that acetylation of the backbone does not prevent helix formation.
