THE FORMATION OF A DIMERIC PRODUCT OF RAFFINOSE BY THE ACTION OF GALACTOSE-OXIDASE

1. Galactose oxidase is known to catalyze the oxidation of the C-6 hyd roxymethyl group of galactose to an aldehyde group. 2. When the produc ts of a galactose oxidase-catalase treatment of raffinose were examine d by gel filtration and ion exchange chromatography, we found that in addition to the expected 6''-aldehydoraffinose, two other components w ere present. 3. One component was neutral and had an elution volume cl ose to that of maltopentaose and on treatment with sodium borohydride or hypoiodite, this component was converted to raffinose or 6''-carbox yraffinose, respectively. 4. Fast atom bombardment mass spectroscopy i n the negative mode indicated that the major molecular ion had an M/Z of 1003. 5. These data are consistent with this component being a dime r of 6''-aldehydoraffinose.