A SIMPLE STRATEGY FOR CHANGING THE REGIOSELECTIVITY OF GLYCOSIDASE-CATALYSED FORMATION OF DISACCHARIDES

Article abstract of DOI:10.1016/0008-6215(87)80271-9

The regioselectivity of glycosidase-catalysed formation of disaccharides can be changed by using α- or β-glycosyl acceptors with various aglycons.The preponderant formation of other than (1->6) linkages can be effected with glycosidases which normally give (1->6) linkages.Thus, an α-D-galactosidase can be induced to catalyse the formation mainly of α-(1->2)-, α-(1->3)-, or α-(1->6)-linked digalctosides.Both the structure of the aglycon and the configuration of the glycosidic linkage can have a pronounced influence on the regioselectivity of disaccharide formation.Enzymic syntheses, in yields of 20-30percent, are described of α-D-Galp-(1->3)-α-D-Galp-OMe, β-D-Galp-(1->3)-β-D-Galp-OMe, β-D-Galp-(1->6)-α-D-Galp-OMe, α-D-Manp-(1->2)-α-D-Manp-OMe, α-D-Manp-(1->6)-α-D-Manp-OMe, α-D-Galp-(1->2)-α-D-Galp-OPhNO2-o, α-D-Galp-(1->3)-α-D-Galp-OPhNO2-p, α-D-Manp-(1->2)-α-D-Manp-OPhNO2-p, and α-D-Manp-(1->2)-α-D-Manp-(1->2)-α-D-Manp-OMe.Soluble and immobilised enzymes have been used.