Periodate Technique for the Identification of Sugar Phosphates

Abstract

THE mechanism of action of periodate on sugar phosphates has not been fully established and there is some controversy regarding the origin of the products of periodate action^1,2,3. The convenient identification by chemical techniques of sugars esterified to phosphates at their terminal carbon atom depends on their oxidation by periodate to yield glycolaldehyde phosphate which may be identified by colorimetric procedures⁴. The extended periods required for theoretical periodate consumption coupled with the marked interference of both periodate and iodate in the conventional colorimetric method for glycolaldehyde determination (Fig. 1) have rendered this technique either equivocal or impractical. Treatment of aldose or ketose phosphates with sodium borohydride yields the corresponding polyol phosphates which are readily cleaved by periodate with theoretical consumption of oxidant generally occurring within 30 minutes.