Thickening and water-absorbing agent made from euglenoid polysaccharide

Paramylon, a storage polysaccharide of Euglena gracilis, is a linear β-1,3-glucan with a weight-average molecular weight of ∼2.0 × 105. Sequential long-chain acylation and succinylation of paramylon yielded amphiphilic paramylon acylate succinates. Owing to their amphiphilicity, these paramylon derivatives showed higher viscosity than paramylon succinate when dispersed in an aqueous solution. Examination of the viscosity of aqueous solutions containing paramylon acylate succinates differing in chain length and degree of substitution of long-chain acyl groups (DSlca) revealed that the longer the acyl chain and the higher the DSlca, the higher the viscosity of the aqueous solution. Solution casting yielded transparent and mechanically tough films from paramylon acylate succinates. These films had high water absorbability, up to ∼1000 times their weight.