A novel two-step enzymatic synthesis of blastose, a beta-D-fructofuranosyl-(2 %26lt;-%26gt; 6)-D-glucopyranose sucrose analogue

作者：Miranda Molina Alfonso; Castillo Edmundo; Lopez Munguia Agustin

来源：Food Chemistry, 2017, 227: 202-210.

DOI：10.1016/j.foodchem.2017.01.094

• Blastose
• Trehalose
• Levansucrase
• Trehalase
• Regioselectivity
• Prebiotics

Blastose, a natural disaccharide found in honey, is usually found as a byproduct of fructo-oligosaccharide synthesis from sucrose with fructosyltransferases. In this study, we describe a novel two-step biosynthetic route to obtain blastose, designed from a detailed observation of B. subtilis levansucrase (SacB) acceptor structural requirements for fructosylation. The strategy consisted first in the synthesis of the trisaccharide O-beta-D-Fruf-(2 <-> 6)-O-alpha-D-Glcp-(1 <-> 1)-alpha-D-Glcp, through a regioselective beta-D-transfructosylation of trehalose (Tre) which acts as acceptor in a reaction catalyzed by SacB using sucrose or levan as fructosyl donor. In this reaction, levansucrase (LS) transfers regioselectively a fructosyl residue to either C-6-OH group of the glucose residues in Tre. The resulting trisaccharide obtained in 23% molar yield based on trehalose, was purified and fully characterized by extensive NMR studies. In the second step, the trisaccharide is specifically hydrolyzed by trehalase, to obtain blastose in 43.2% molar yield based on the trisaccharide. This is the first report describing the formation of blastose through a sequential transfuctosylation-hydrolysis reaction.

• 出版日期2017-7-15