Viscometry of curdlan, a linear (1 -> 3)-beta-D-glucan, in DMSO or alkaline solutions

A simple method to obtain the molecular weight of curdlan was found by visc ometry in its alkaline or DMSO solution. DMSO was found to be the most appr opriate solvent for measuring M-upsilon of curdlan. Based on two Sakurada-H ouvink equations, [eta] = KMa, which have been obtained so far in alkaline solutions, two sets of parameters of the equation in the DMSO solution, tha t is, K = 3.5 x 10(-4) a = 0.65 and K = 1.6 x 10(-4), a = 0.74 were introdu ced, respectively. Both parameter sets seemed to serve practically to measu re the molecular weight of curdlan. In addition, using the equation obtaine d with several NaOH concentrations, the previous speculation that curdlan c onformation changes from a rigid rod to random coil with alkaline concentra tion was confirmed.