用不保护或少保护的糖基受体合成寡糖

Synthesis of Oligosaccharides with Unprotected or Lightly Protected Glycosyl Acceptors

用不保护或少保护的葡萄糖、甘露糖、鼠李糖作为糖基受体 ,经由糖原酸酯的中间体 ,能高区选和立体选地合成寡糖。α- ( 1→ 6) -连接的甘露寡糖、β- ( 1→ 6) -连接的葡萄寡糖、3,6-支化的甘露寡糖及葡萄寡糖用此方法能用很简单步骤合成 ,如具有重要生物活性的寡糖植保素激活剂葡萄六糖、具有抗肿瘤活性的香菇多糖的活性片段 ,以及一些具有重要生理功能的多糖的重复单元等。本文同时简述了用少保护的半乳糖和氨基葡萄糖为糖基受体合成寡糖的进展。

Regio- and stereoselective synthesis of oligosaccharides with unprotected or lightly protected gluco-, manno- and rhamnose as glycosyl acceptors was achieved via sugar orthoester formation-rearrangement. alpha-(1-->6)-Linked mannose oligosaccharides, beta-(1-->6)-linked glucose oligosaccahrides, and 3, 6-branched mannose and glucose oligosaccharides were conveniently synthesized with quite simplified procedures. Biologically important oligosaccharides such as phytoalexin elicitor glucohexaose, antitumor fragments of lentinan, and some repeating units of biologically important polysaccharides were prepared readily. Recent progress in regioselective synthesis of oligosaccharides with lightly protected glucosamine and galactose as acceptors was also outlined.