Streptococcus pneumoniae (SP) bacteria cause serious invasive diseases. SP bacteria are covered by a capsular polysaccharide (CPS) that is a virulence factor and the basis for SP polysaccharide and glycoconjugate vaccines. The serotype 9V is part of the currently marketed conjugate vaccine and contains an acetate modification. To better understand the importance of glycan modifications in general and acetylation in particular, defined oligosaccharide antigens are needed for serological and immunological studies. Here, we demonstrate a convergent [2 + 3] synthetic strategy to prepare the pentasaccharide repeating unit of 9V with and without an acetate group at the C-6 position of mannosamine.

中文翻译：

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肺炎链球菌血清型9V寡糖抗原的合成。

肺炎链球菌（SP）细菌会引起严重的侵袭性疾病。SP细菌被荚膜多糖（CPS）覆盖，荚膜多糖是一种致病因子，是SP多糖和糖缀合物疫苗的基础。9V血清型是目前市场上销售的结合疫苗的一部分，并含有醋酸盐修饰形式。为了更好地理解一般来说聚糖修饰的重要性，尤其是乙酰化的重要性，血清学和免疫学研究需要确定的寡糖抗原。在这里，我们展示了一种收敛的[2 + 3]合成策略，可制备9V的五糖重复单元（在甘露糖胺的C-6位带有和不带有乙酸酯基）。