Preparation of Calcium Melibionate1

It has been found possible to prepare the comparatively rare salt, calcium melibionate, in any desired quantity by electrolytic oxidation of a crude solution of melibiose. The melibiose solution , prepared from commercial raffinose, is subjected to electrolytic oxidation in the presence of calcium carbonate and calcium bromide, and the calcium melibionate is crystallized directly from t he electrolyte. The optical rotation of a 2-percent aqueous solution of calcium melibionate, expressed on the anhydrous basis, was found to be [a)1°+ 106.2°, which disagrees with the value, [a)}; +88.6°, reported in the li terature. Calcium melibionate forms a basic calcium salt, Ca( C12H21 0 12)2.4CaO. This is analogous to the basic calcium salts of lactobionic and maltobionic acids.