Lipophosphoglycans (LPGs) are found on the surface of Leishmania, a protozoan parasite, and are immunologically important. Herein, disaccharide 1‐phosphate repeating units of LPGs were successfully synthesized on a solid support with high anomeric purity using a disaccharide α‐1‐phosphoramidite building block. To enhance solubility in the reaction solvent, hydroxy‐protecting groups in the form of para‐t‐butylbenzoyl were introduced to the building block. The saccharide chain was elongated via stable glycosyl boranophosphate linkages, followed by the conversion of inter‐sugar linkages to phosphodiester counterparts using an oxaziridine derivative. The addition of a silylating reagent post‐reaction with the oxaziridine derivative efficiently facilitated the conversion of boranophosohodiesters to phosphodiesters. This method enabled the α‐selective synthesis of up to 15 repeating units, marking the longest homogeneous repeating units of LPGs synthesized chemically. Given the chain length equivalence to native LPGs, the method developed herein holds promise for advancing anti‐Leishmanial pharmaceuticals and vaccines.

中文翻译：

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亚磷酰胺法α-选择性固相合成糖基磷酸重复结构


脂磷酸聚糖 (LPG) 存在于利什曼原虫（一种原生动物寄生虫）的表面，具有重要的免疫学意义。在此，使用二糖 α-1-亚磷酰胺结构单元，在具有高异头纯度的固体载体上成功合成了 LPG 的二糖 1-磷酸重复单元。为了提高在反应溶剂中的溶解度，对叔丁基苯甲酰形式的羟基保护基团被引入到结构单元中。糖链通过稳定的糖基硼磷酸酯键延长，然后使用氧氮丙啶衍生物将糖间键转化为磷酸二酯对应物。在与氧氮丙啶衍生物反应后添加甲硅烷基化试剂有效地促进了硼磷二酯向磷酸二酯的转化。该方法能够实现多达 15 个重复单元的 α 选择性合成，标志着化学合成的 LPG 的最长同质重复单元。鉴于链长与天然液化石油气相当，本文开发的方法有望推动抗利什曼原虫药物和疫苗的发展。