A new trisaccharide, 3G-.ALPHA.-D-glucosyl-sucrose, synthesized by the transglucosidase action of immobilized buckwheat .ALPHA.-glucosidase.

Enzymatic synthesis of a-glucosyl-sucrose through the transglucosidase action of immobilized buckwheat a-glucosidase was attempted in a reaction system containing maltose and sucrose.Three kinds of nonreducing trisaccharides were produced, and a large portion of the trisaccharide was 4Ga-D-glucosyl-sucrose (erlose).Another was a new trisaccharide, 0-a-D-glucopyranosyl-(l ->-3)-0a-D-glucopyranosyl-(l -^-2)-O-^-D-fructofuranoside (3G-a-D-glucosyl-sucrose; [a]D+ 120°, in water), and the other was 6G-a-D-glucosyl-sucrose (theanderose; [a]D+ 107°, in water).The new trisaccharide was named "esculose."