The O‐methyl phosphoramidate (MeOPN) motif is a non‐stoichiometric modification of capsular polysaccharides (CPS) in ≈70 % of all Campylobacter jejuni strains. Infections by C. jejuni lead to food‐borne illnesses and the CPS they produce are key virulence factors. The MeOPN phosphorus atom in these CPS is stereogenic and is found as a single stereoisomer. However, to date, the absolute stereochemistry at this atom has been undefined. We report the synthesis of the three repeating units found in C. jejuni 81‐176 CPS; one of these possesses a MeOPN group. In the course of these studies we established that the stereochemistry of the phosphorus atom in this MeOPN group is R. These studies represent the first unequivocal proof of stereochemistry of this group in any C. jejuni CPS. The compounds produced are anticipated to be useful tools in investigations targeting the function and biosynthesis of this structurally‐interesting modification, which so far has only been identified in campylobacter.

中文翻译：

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空肠弯曲杆菌81-176菌株荚膜多糖重复单元的合成揭示了其O-甲基磷酸氨基磷酸酯基序的绝对构型

所述Ô甲基氨基磷酸酯（MeOPN）基序在所有的≈70％荚膜多糖（CPS）的一个非化学计量的修改空肠弯曲菌菌株。空肠弯曲杆菌的感染导致食源性疾病，它们产生的CPS是关键的毒力因子。这些CPS中的MeOPN磷原子是立体异构的，是单一的立体异构体。然而，迄今为止，该原子的绝对立体化学尚未确定。我们报告了空肠弯曲杆菌81-176 CPS中三个重复单元的合成；其中之一拥有MeOPN小组。在这些研究过程中，我们确定了该MeOPN基团中磷原子的立体化学是R。这些研究代表了空肠弯曲杆菌CPS中该组立体化学的第一个明确证据。预期所产生的化合物将是针对这种结构有趣的修饰的功能和生物合成进行研究的有用工具，到目前为止，这种修饰仅在弯曲杆菌中才能鉴定出来。