Molecular weight and aggregation behaviour in solution of β-d-glucan from Poria cocos sclerotium

The weight-average molecular weights Mw and intrinsic viscosities [ν] of linear β-(1 → 3)-d-glucan (PC3), a major polysaccharide in Poria cocos sclerotium were studied by light scattering and viscometry. The Mw values of glucan PC3 fractions in 20% cadoxen solution and in cadoxen were 20.6 × 104 and 8.93 × 104, respectively. The [ν] values of glucan PC3 in water-cadoxen mixtures underwent an almost discontinuous decrease in the range from 20 to 30% cadoxen. The data (Mw,[ν]) of the unfractionated PC3 and of two fractions in 20% cadoxen and in cadoxen showed that glucan PC3 forms aggregates in 20% cadoxen solution, and dissociates to single chains in cadoxen. The change of aggregation and disaggregation in water-cadoxen mixtures are reversible.