A New Trisaccharide, 6F-α-D-Glucosyl-sucrose, Synthesized by Trans-glucosylation Reaction of Brewer's Yeast α-Glucosidase

Enzymatic synthesis of oligosaccharide through the transglucosylation reaction of brewer’s yeast α-glucosidase was attempted in the reaction system containing only sucrose as substrate. As the transglucosylation product, a new nonreducing trisaccharide was chromato-graphically isolated in crystalline form (monohydrate). giving mp 139~142°C and + 102 (in water). The trisaccharide was confirmed to be 6F-α-d-glucosyl-sucrose, that is, O-α-d-glucopyranosyl-(1 → 6)-O-β-d-fructofuranosyl-(2 → 1)-O-α-d-glucopyranoside, of which undecaacetate gave mp 148°C and (in chloroform), and this sugar was named “isomelezitose.”