Efficient Synthesis of the Disialylated Tetrasaccharide Motif in N-Glycans through an Amide-Protection Strategy
作者:Jiazhou Zhou、Yoshiyuki Manabe、Katsunori Tanaka、Koichi Fukase
DOI:10.1002/asia.201600139
日期:2016.5.6
glycosylation of a sialylated disaccharide with a glucosaminyl donor. This synthetic route enabled the synthesis of the as‐described disialylated structure. A more‐convergent route based on the glycosylation of two sialylated disaccharides was also established to scale up the synthesis. Protection of the amide groups in the sialic acid residues significantly increased the yield of the glycosylation reaction
已合成了在一些N-聚糖末端发现的去唾液酸化的四糖Neu5Ac(α2,3)Gal(β1,3)[Neu5Ac(α2,6)] GlcNAc(1)。化合物1通过唾液酸供体和三糖之间的α-唾液酸化反应获得,三糖是由唾液酸化的二糖与葡萄糖胺基供体的糖基化反应合成的。这种合成途径能够合成上述的二烯丙基化结构。还建立了基于两种唾液酸化二糖糖基化的更趋同途径,以扩大合成规模。唾液酸残基中酰胺基的保护显着提高了两个唾液酸化二糖之间糖基化反应的产率,因此表明唾液酸残基上氢键的存在降低了它们的反应性。