Dynamic birefringence of polymaltotriose solutions

The method of birefringence was used to study polymaltotriose in water and in dimethylsulfoxide. It is shown that the increment of refraction index (Delta n/Delta C) for polymaltotriose in water is high whereas in dimethylsulfoxide it is low. Because of this, the birefringence of molecules in water is due mainly to the effect of macroform, and in dimethylsulfoxide it is determined by intrinsic anisotropy of polarizability of the polysaccharide chain. From the dependence of birefringence [n]/[eta] on molecular mass and on Delta n/Delta C, the intrinsic segment anisotropy of polymaltotriose molecule was estimated to be (alpha(1) - alpha(2))(6) = +33.10(-25) cm(3). Based on the latter value, the optical anisotropy of the glucopyranose cycle was first obtained Delta a(0) = +7.10(-25) cm(3).