A methodology is described that can provide heparan sulfate oligosaccharides having a Δ4,5-double bond, which are needed as analytical standards and biomarkers for mucopolysaccharidoses. It is based on chemical oligosaccharide synthesis followed by modification of the C-4 hydroxyl of the terminal uronic acid moiety as methanesulfonate. This leaving group is stable under conditions used to remove temporary protecting groups, O-sulfation, and hydrogenolysis. Treatment with NaOH results in elimination of the methanesulfonate and formation of a Δ4,5-double bond.

中文翻译：

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用于生物标志物发现的 Δ-4,5 不饱和硫酸乙酰肝素寡糖的化学合成

描述了一种可以提供具有Δ4,5-双键的硫酸乙酰肝素寡糖的方法，其需要作为粘多糖病的分析标准品和生物标志物。它基于化学寡糖合成，然后将末端糖醛酸部分的 C-4 羟基修饰为甲磺酸盐。该离去基团在用于除去临时保护基团、O-硫酸化和氢解的条件下是稳定的。用 NaOH 处理导致消除甲磺酸盐并形成 Δ4,5-双键。