Nilsson K G
Swedish Sugar Co. Ltd., Arlöv.
Carbohydr Res. 1987 Sep 15;167:95-103. doi: 10.1016/0008-6215(87)80271-9.
The regioselectivity of glycosidase-catalysed formation of disaccharides can be changed by using alpha- or beta-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 alpha-D-galactosidase can be induced to catalyse the formation mainly of alpha-(1----2)-, alpha-(1----3), or alpha-(1----6)-linked digalactosides. 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 20-30%, are described of alpha-D-Galp-(1----3)-alpha-D-Galp-OMe, beta-D-Galp-(1----3)-beta-D-Galp-OMe, beta-D-Galp-(1----6)-alpha-D-Galp-OMe, alpha-D-Manp-(1----2)-alpha-D-Manp-OMe, alpha-D-Manp-(1----6)-alpha-D-Manp-OMe, alpha-D-Galp-(1----2)-alpha-D-Galp-OPhNO2-o, alpha-D-Galp-(1----3)-alpha-D-Galp-OPhNO2-p, alpha-D-Manp-(1----2)-alpha-D-Manp-OPhNO2-p, and alpha-D-Manp-(1----2)-alpha-D-Manp-(1----2)-alpha-D-Manp+ ++-OMe. Soluble and immobilised enzymes have been used.
通过使用带有各种糖苷配基的α-或β-糖基受体，可以改变糖苷酶催化形成二糖的区域选择性。通常生成（1→6）键的糖苷酶可以实现除（1→6）键以外的其他键的优势形成。因此，可以诱导α-D-半乳糖苷酶主要催化形成α-（1→2）-、α-（1→3）-或α-（1→6）-连接的二半乳糖苷。糖苷配基的结构和糖苷键的构型都可以对二糖形成的区域选择性产生显著影响。文中描述了α-D-吡喃半乳糖基-（1→3）-α-D-吡喃半乳糖基-OMe、β-D-吡喃半乳糖基-（1→3）-β-D-吡喃半乳糖基-OMe、β-D-吡喃半乳糖基-（1→6）-α-D-吡喃半乳糖基-OMe、α-D-吡喃甘露糖基-（1→2）-α-D-吡喃甘露糖基-OMe、α-D-吡喃甘露糖基-（1→6）-α-D-吡喃甘露糖基-OMe、α-D-吡喃半乳糖基-（1→2）-α-D-吡喃半乳糖基-OPhNO₂-o、α-D-吡喃半乳糖基-（1→3）-α-D-吡喃半乳糖基-OPhNO₂-p、α-D-吡喃甘露糖基-（1→2）-α-D-吡喃甘露糖基-OPhNO₂-p和α-D-吡喃甘露糖基-（1→2）-α-D-吡喃甘露糖基-（1→2）-α-D-吡喃甘露糖基-OMe的酶促合成，产率为20-30%。已使用了可溶性酶和固定化酶。
