Uncertainties in the use of periodate oxidation for determination of dextran structure

A glucan of high molecular weight isolated from stale sugar-cane, and previously shown to have a marked effect on sucrose crystallisation processes-1, is a relatively linear dextran. Approximately 96-97% of its D-glucose residues are involved in (1 yields 6)-alpha-D linkages and constitute the linear backbone of the polymer. The remaining 3-4% of D-glucose residues form branch-points by (1 yields 3)-alpha-D linkages. The periodate-oxidation technique, which has been extensively used by other workers to determine dextran structure, gave erroneous results when applied to the dextran from stale sugar-cane.